commit 956feb84cea01efe590aa37430b50be256776fb3
Author: Jake Koroman <jakekoroman@gmail.com>
Date: Fri, 9 Sep 2022 12:51:08 -0400
Ready. Set. Go!
Diffstat:
| A | .gitignore | | | 4 | ++++ |
| A | README.md | | | 20 | ++++++++++++++++++++ |
| A | ascii_gen.c | | | 237 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | build.sh | | | 5 | +++++ |
| A | libs/stb_image.h | | | 7897 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | libs/stb_image_resize.h | | | 2634 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
6 files changed, 10797 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,3 @@
+ag
+imgs/
+out.txt
+\ No newline at end of file
diff --git a/README.md b/README.md
@@ -0,0 +1,19 @@
+# Ascii Generator
+
+A simple application that will convert any image into ascii art.
+
+# Quick Start
+
+```console
+$ ./build.sh
+$ ./ag <image>
+```
+
+# Resources
+
+More info can be found with
+```console
+$ ./ag -h
+```
+
+[More Info](http://paulbourke.net/dataformats/asciiart/)
+\ No newline at end of file
diff --git a/ascii_gen.c b/ascii_gen.c
@@ -0,0 +1,237 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <getopt.h>
+#include <stdbool.h>
+
+#define STB_IMAGE_IMPLEMENTATION
+#include "libs/stb_image.h"
+
+#define STB_IMAGE_RESIZE_IMPLEMENTATION
+#include "libs/stb_image_resize.h"
+
+#define BUF_CAP 255
+
+#define internal static
+
+typedef uint8_t uint8;
+
+#define SET_LONG "$@B%8&WM#*oahkbdpqwmZO0QLCJUYXzcvunxrjft/\\|()1{}[]?-_+~<>i!lI;:,\"^`'. "
+#define SET_SIZE_LONG 70
+#define SET_SHORT "@%#*+=-:. "
+#define SET_SIZE_SHORT 10
+
+typedef enum {
+ SET_TYPE_SHORT,
+ SET_TYPE_LONG,
+ SET_TYPE_CUSTOM,
+} SetType;
+
+typedef struct {
+ char in_file[BUF_CAP];
+ char out_file[BUF_CAP];
+ char set[BUF_CAP];
+ SetType set_type; // defaults to short
+ int set_size;
+ int scale;
+ bool debug;
+} Options;
+
+internal inline int
+map(int x, int a, int b, int c, int d)
+{
+ return (x - a) * (d - c) / (b - a);
+}
+
+internal void
+print_docs(const char* fname)
+{
+ printf("Usage: %s img [-o file] [-s scale] [-S set] [-hltv]\n", fname);
+ printf(" -h: Shows help\n");
+ printf(" -o: Output to file, if no file is given it will output to stdout\n");
+ printf(" -s: The scale of the output image, defaults to 1\n");
+ printf(" -S: The character set that will be used to generate the output, defaults to the builtin 'short' character set\n");
+ printf(" -l: Uses the builtin 'long' character set for generating the output\n");
+ printf(" -t: Uses the builtin 'short' character set for generating the output\n");
+ printf(" -v: Shows debug info\n");
+}
+
+// Parses args with getopt and fills an Options struct of all the options passed
+// Resource: https://azrael.digipen.edu/~mmead/www/Courses/CS180/getopt.html
+internal void
+parse_args(int argc, char **argv, Options *options)
+{
+ int opt;
+ options->scale = 1;
+
+ while ((opt = getopt(argc, argv, ":o:hls:S:vc")) != -1)
+ {
+ switch (opt)
+ {
+ case 'o':
+ {
+ strncpy(options->out_file, optarg, BUF_CAP);
+ } break;
+
+ case 'h':
+ {
+ print_docs(argv[0]);
+ exit(0);
+ } break;
+
+ case 's':
+ {
+ options->scale = atoi(optarg);
+ if (options->scale == 0) {
+ fprintf(stderr, "Invalid scale %s\n", optarg);
+ exit(69);
+ }
+ } break;
+
+ case 'v':
+ {
+ options->debug = true;
+ } break;
+
+ case 'l':
+ {
+ options->set_type = SET_TYPE_LONG;
+ options->set_size = SET_SIZE_LONG;
+ strncpy(options->set, SET_LONG, BUF_CAP);
+ break;
+ } break;
+
+ case 't': // 't' for tiny I guess? wanted to keep 's' for scale
+ {
+ // Redundant because it will default to short but sometimes
+ // it's nice to request it even though its default.
+ options->set_type = SET_TYPE_SHORT;
+ break;
+ } break;
+
+ case 'S':
+ {
+ int size = strlen(optarg);
+ options->set_size = size > 255 ? BUF_CAP : size;
+ options->set_type = SET_TYPE_CUSTOM;
+ strncpy(options->set, optarg, BUF_CAP);
+ } break;
+
+ case '?':
+ {
+ printf("Unknown Option: %c\n", optopt);
+ exit(69);
+ } break;
+
+ case ':':
+ {
+ printf("Missing arg for %c\n", optopt);
+ exit(69);
+ } break;
+
+ default:
+ {
+ printf("Something broke\n");
+ break;
+ }
+ }
+ }
+
+ if (options->set_type == SET_TYPE_SHORT) {
+ options->set_size = SET_SIZE_SHORT;
+ strncpy(options->set, SET_SHORT, BUF_CAP);
+ }
+
+ if (optind < argc) {
+ strncpy(options->in_file, argv[optind], BUF_CAP);
+ }
+
+}
+
+int
+main(int argc, char **argv)
+{
+ if (argc < 2) {
+ printf("Basic Usage: %s img [-o file]\n", argv[0]);
+ exit(69);
+ }
+
+ Options options = {0};
+ parse_args(argc, argv, &options);
+
+ if (options.debug) {
+ printf("In File : %s\n", options.in_file);
+ printf("Out File : %s\n", options.out_file);
+ printf("Scale : %d\n", options.scale);
+ printf("Set size : %d\n", options.set_size);
+ printf("Set type : %d\n", options.set_type);
+ printf("Set : %s\n", options.set);
+ }
+
+ // TODO: Maybe bundle this stuff up? including the resized stuff?
+ int width, height;
+ int channels = 1;
+ uint8 *image_bytes = stbi_load(options.in_file, &width, &height, NULL, channels);
+
+ if (!image_bytes) {
+ fprintf(stderr, "Couldn't Open file %s\n", options.in_file);
+ exit(69);
+ }
+
+ int nw = width / options.scale;
+ int nh = height / options.scale;
+ bool resized = false;
+ uint8 *resized_bytes;
+
+ if (options.scale > 1) {
+ int stride = 0;
+ resized = true;
+ resized_bytes = malloc(sizeof(uint8) * (nw * nh));
+ if (!stbir_resize_uint8(image_bytes, width, height, stride,
+ resized_bytes, nw, nh, stride, channels)) // only resizes if the scale is greater than 1
+ {
+ printf("Couldn't Resize Image\n");
+ exit(69);
+ }
+ } else {
+ resized_bytes = image_bytes;
+ }
+
+ FILE *f;
+ if (strncmp(options.out_file, "", BUF_CAP)) {
+ f = fopen(options.out_file, "w");
+ } else {
+ f = stdout;
+ }
+
+ for (size_t i = 0;
+ i < nw * nh;
+ ++i)
+ {
+ int map_result = map(resized_bytes[i], 0, 255, 0, options.set_size - 1);
+ int idx = (options.set_size - 1) - map_result;
+
+ if (i % nw == 0) {
+ fprintf(f, "\n");
+ }
+
+ fprintf(f, "%c", options.set[idx]);
+ }
+
+ fprintf(f, "\n");
+
+ if (!(f == NULL || f == stdout)) {
+ fclose(f);
+ }
+
+ if (image_bytes) {
+ stbi_image_free(image_bytes);
+ }
+
+ if (resized_bytes && resized) {
+ stbi_image_free(resized_bytes);
+ }
+
+ return 0;
+}
diff --git a/build.sh b/build.sh
@@ -0,0 +1,5 @@
+CFLAGS='-Wall -std=c11 -pedantic -ggdb'
+LFLAGS='-lm'
+
+set -xe
+cc $CFLAGS -o ag ascii_gen.c $LFLAGS
diff --git a/libs/stb_image.h b/libs/stb_image.h
@@ -0,0 +1,7897 @@
+/* stb_image - v2.27 - public domain image loader - http://nothings.org/stb
+ no warranty implied; use at your own risk
+
+ Do this:
+ #define STB_IMAGE_IMPLEMENTATION
+ before you include this file in *one* C or C++ file to create the implementation.
+
+ // i.e. it should look like this:
+ #include ...
+ #include ...
+ #include ...
+ #define STB_IMAGE_IMPLEMENTATION
+ #include "stb_image.h"
+
+ You can #define STBI_ASSERT(x) before the #include to avoid using assert.h.
+ And #define STBI_MALLOC, STBI_REALLOC, and STBI_FREE to avoid using malloc,realloc,free
+
+
+ QUICK NOTES:
+ Primarily of interest to game developers and other people who can
+ avoid problematic images and only need the trivial interface
+
+ JPEG baseline & progressive (12 bpc/arithmetic not supported, same as stock IJG lib)
+ PNG 1/2/4/8/16-bit-per-channel
+
+ TGA (not sure what subset, if a subset)
+ BMP non-1bpp, non-RLE
+ PSD (composited view only, no extra channels, 8/16 bit-per-channel)
+
+ GIF (*comp always reports as 4-channel)
+ HDR (radiance rgbE format)
+ PIC (Softimage PIC)
+ PNM (PPM and PGM binary only)
+
+ Animated GIF still needs a proper API, but here's one way to do it:
+ http://gist.github.com/urraka/685d9a6340b26b830d49
+
+ - decode from memory or through FILE (define STBI_NO_STDIO to remove code)
+ - decode from arbitrary I/O callbacks
+ - SIMD acceleration on x86/x64 (SSE2) and ARM (NEON)
+
+ Full documentation under "DOCUMENTATION" below.
+
+
+LICENSE
+
+ See end of file for license information.
+
+RECENT REVISION HISTORY:
+
+ 2.27 (2021-07-11) document stbi_info better, 16-bit PNM support, bug fixes
+ 2.26 (2020-07-13) many minor fixes
+ 2.25 (2020-02-02) fix warnings
+ 2.24 (2020-02-02) fix warnings; thread-local failure_reason and flip_vertically
+ 2.23 (2019-08-11) fix clang static analysis warning
+ 2.22 (2019-03-04) gif fixes, fix warnings
+ 2.21 (2019-02-25) fix typo in comment
+ 2.20 (2019-02-07) support utf8 filenames in Windows; fix warnings and platform ifdefs
+ 2.19 (2018-02-11) fix warning
+ 2.18 (2018-01-30) fix warnings
+ 2.17 (2018-01-29) bugfix, 1-bit BMP, 16-bitness query, fix warnings
+ 2.16 (2017-07-23) all functions have 16-bit variants; optimizations; bugfixes
+ 2.15 (2017-03-18) fix png-1,2,4; all Imagenet JPGs; no runtime SSE detection on GCC
+ 2.14 (2017-03-03) remove deprecated STBI_JPEG_OLD; fixes for Imagenet JPGs
+ 2.13 (2016-12-04) experimental 16-bit API, only for PNG so far; fixes
+ 2.12 (2016-04-02) fix typo in 2.11 PSD fix that caused crashes
+ 2.11 (2016-04-02) 16-bit PNGS; enable SSE2 in non-gcc x64
+ RGB-format JPEG; remove white matting in PSD;
+ allocate large structures on the stack;
+ correct channel count for PNG & BMP
+ 2.10 (2016-01-22) avoid warning introduced in 2.09
+ 2.09 (2016-01-16) 16-bit TGA; comments in PNM files; STBI_REALLOC_SIZED
+
+ See end of file for full revision history.
+
+
+ ============================ Contributors =========================
+
+ Image formats Extensions, features
+ Sean Barrett (jpeg, png, bmp) Jetro Lauha (stbi_info)
+ Nicolas Schulz (hdr, psd) Martin "SpartanJ" Golini (stbi_info)
+ Jonathan Dummer (tga) James "moose2000" Brown (iPhone PNG)
+ Jean-Marc Lienher (gif) Ben "Disch" Wenger (io callbacks)
+ Tom Seddon (pic) Omar Cornut (1/2/4-bit PNG)
+ Thatcher Ulrich (psd) Nicolas Guillemot (vertical flip)
+ Ken Miller (pgm, ppm) Richard Mitton (16-bit PSD)
+ github:urraka (animated gif) Junggon Kim (PNM comments)
+ Christopher Forseth (animated gif) Daniel Gibson (16-bit TGA)
+ socks-the-fox (16-bit PNG)
+ Jeremy Sawicki (handle all ImageNet JPGs)
+ Optimizations & bugfixes Mikhail Morozov (1-bit BMP)
+ Fabian "ryg" Giesen Anael Seghezzi (is-16-bit query)
+ Arseny Kapoulkine Simon Breuss (16-bit PNM)
+ John-Mark Allen
+ Carmelo J Fdez-Aguera
+
+ Bug & warning fixes
+ Marc LeBlanc David Woo Guillaume George Martins Mozeiko
+ Christpher Lloyd Jerry Jansson Joseph Thomson Blazej Dariusz Roszkowski
+ Phil Jordan Dave Moore Roy Eltham
+ Hayaki Saito Nathan Reed Won Chun
+ Luke Graham Johan Duparc Nick Verigakis the Horde3D community
+ Thomas Ruf Ronny Chevalier github:rlyeh
+ Janez Zemva John Bartholomew Michal Cichon github:romigrou
+ Jonathan Blow Ken Hamada Tero Hanninen github:svdijk
+ Eugene Golushkov Laurent Gomila Cort Stratton github:snagar
+ Aruelien Pocheville Sergio Gonzalez Thibault Reuille github:Zelex
+ Cass Everitt Ryamond Barbiero github:grim210
+ Paul Du Bois Engin Manap Aldo Culquicondor github:sammyhw
+ Philipp Wiesemann Dale Weiler Oriol Ferrer Mesia github:phprus
+ Josh Tobin Matthew Gregan github:poppolopoppo
+ Julian Raschke Gregory Mullen Christian Floisand github:darealshinji
+ Baldur Karlsson Kevin Schmidt JR Smith github:Michaelangel007
+ Brad Weinberger Matvey Cherevko github:mosra
+ Luca Sas Alexander Veselov Zack Middleton [reserved]
+ Ryan C. Gordon [reserved] [reserved]
+ DO NOT ADD YOUR NAME HERE
+
+ Jacko Dirks
+
+ To add your name to the credits, pick a random blank space in the middle and fill it.
+ 80% of merge conflicts on stb PRs are due to people adding their name at the end
+ of the credits.
+*/
+
+#ifndef STBI_INCLUDE_STB_IMAGE_H
+#define STBI_INCLUDE_STB_IMAGE_H
+
+// DOCUMENTATION
+//
+// Limitations:
+// - no 12-bit-per-channel JPEG
+// - no JPEGs with arithmetic coding
+// - GIF always returns *comp=4
+//
+// Basic usage (see HDR discussion below for HDR usage):
+// int x,y,n;
+// unsigned char *data = stbi_load(filename, &x, &y, &n, 0);
+// // ... process data if not NULL ...
+// // ... x = width, y = height, n = # 8-bit components per pixel ...
+// // ... replace '0' with '1'..'4' to force that many components per pixel
+// // ... but 'n' will always be the number that it would have been if you said 0
+// stbi_image_free(data)
+//
+// Standard parameters:
+// int *x -- outputs image width in pixels
+// int *y -- outputs image height in pixels
+// int *channels_in_file -- outputs # of image components in image file
+// int desired_channels -- if non-zero, # of image components requested in result
+//
+// The return value from an image loader is an 'unsigned char *' which points
+// to the pixel data, or NULL on an allocation failure or if the image is
+// corrupt or invalid. The pixel data consists of *y scanlines of *x pixels,
+// with each pixel consisting of N interleaved 8-bit components; the first
+// pixel pointed to is top-left-most in the image. There is no padding between
+// image scanlines or between pixels, regardless of format. The number of
+// components N is 'desired_channels' if desired_channels is non-zero, or
+// *channels_in_file otherwise. If desired_channels is non-zero,
+// *channels_in_file has the number of components that _would_ have been
+// output otherwise. E.g. if you set desired_channels to 4, you will always
+// get RGBA output, but you can check *channels_in_file to see if it's trivially
+// opaque because e.g. there were only 3 channels in the source image.
+//
+// An output image with N components has the following components interleaved
+// in this order in each pixel:
+//
+// N=#comp components
+// 1 grey
+// 2 grey, alpha
+// 3 red, green, blue
+// 4 red, green, blue, alpha
+//
+// If image loading fails for any reason, the return value will be NULL,
+// and *x, *y, *channels_in_file will be unchanged. The function
+// stbi_failure_reason() can be queried for an extremely brief, end-user
+// unfriendly explanation of why the load failed. Define STBI_NO_FAILURE_STRINGS
+// to avoid compiling these strings at all, and STBI_FAILURE_USERMSG to get slightly
+// more user-friendly ones.
+//
+// Paletted PNG, BMP, GIF, and PIC images are automatically depalettized.
+//
+// To query the width, height and component count of an image without having to
+// decode the full file, you can use the stbi_info family of functions:
+//
+// int x,y,n,ok;
+// ok = stbi_info(filename, &x, &y, &n);
+// // returns ok=1 and sets x, y, n if image is a supported format,
+// // 0 otherwise.
+//
+// Note that stb_image pervasively uses ints in its public API for sizes,
+// including sizes of memory buffers. This is now part of the API and thus
+// hard to change without causing breakage. As a result, the various image
+// loaders all have certain limits on image size; these differ somewhat
+// by format but generally boil down to either just under 2GB or just under
+// 1GB. When the decoded image would be larger than this, stb_image decoding
+// will fail.
+//
+// Additionally, stb_image will reject image files that have any of their
+// dimensions set to a larger value than the configurable STBI_MAX_DIMENSIONS,
+// which defaults to 2**24 = 16777216 pixels. Due to the above memory limit,
+// the only way to have an image with such dimensions load correctly
+// is for it to have a rather extreme aspect ratio. Either way, the
+// assumption here is that such larger images are likely to be malformed
+// or malicious. If you do need to load an image with individual dimensions
+// larger than that, and it still fits in the overall size limit, you can
+// #define STBI_MAX_DIMENSIONS on your own to be something larger.
+//
+// ===========================================================================
+//
+// UNICODE:
+//
+// If compiling for Windows and you wish to use Unicode filenames, compile
+// with
+// #define STBI_WINDOWS_UTF8
+// and pass utf8-encoded filenames. Call stbi_convert_wchar_to_utf8 to convert
+// Windows wchar_t filenames to utf8.
+//
+// ===========================================================================
+//
+// Philosophy
+//
+// stb libraries are designed with the following priorities:
+//
+// 1. easy to use
+// 2. easy to maintain
+// 3. good performance
+//
+// Sometimes I let "good performance" creep up in priority over "easy to maintain",
+// and for best performance I may provide less-easy-to-use APIs that give higher
+// performance, in addition to the easy-to-use ones. Nevertheless, it's important
+// to keep in mind that from the standpoint of you, a client of this library,
+// all you care about is #1 and #3, and stb libraries DO NOT emphasize #3 above all.
+//
+// Some secondary priorities arise directly from the first two, some of which
+// provide more explicit reasons why performance can't be emphasized.
+//
+// - Portable ("ease of use")
+// - Small source code footprint ("easy to maintain")
+// - No dependencies ("ease of use")
+//
+// ===========================================================================
+//
+// I/O callbacks
+//
+// I/O callbacks allow you to read from arbitrary sources, like packaged
+// files or some other source. Data read from callbacks are processed
+// through a small internal buffer (currently 128 bytes) to try to reduce
+// overhead.
+//
+// The three functions you must define are "read" (reads some bytes of data),
+// "skip" (skips some bytes of data), "eof" (reports if the stream is at the end).
+//
+// ===========================================================================
+//
+// SIMD support
+//
+// The JPEG decoder will try to automatically use SIMD kernels on x86 when
+// supported by the compiler. For ARM Neon support, you must explicitly
+// request it.
+//
+// (The old do-it-yourself SIMD API is no longer supported in the current
+// code.)
+//
+// On x86, SSE2 will automatically be used when available based on a run-time
+// test; if not, the generic C versions are used as a fall-back. On ARM targets,
+// the typical path is to have separate builds for NEON and non-NEON devices
+// (at least this is true for iOS and Android). Therefore, the NEON support is
+// toggled by a build flag: define STBI_NEON to get NEON loops.
+//
+// If for some reason you do not want to use any of SIMD code, or if
+// you have issues compiling it, you can disable it entirely by
+// defining STBI_NO_SIMD.
+//
+// ===========================================================================
+//
+// HDR image support (disable by defining STBI_NO_HDR)
+//
+// stb_image supports loading HDR images in general, and currently the Radiance
+// .HDR file format specifically. You can still load any file through the existing
+// interface; if you attempt to load an HDR file, it will be automatically remapped
+// to LDR, assuming gamma 2.2 and an arbitrary scale factor defaulting to 1;
+// both of these constants can be reconfigured through this interface:
+//
+// stbi_hdr_to_ldr_gamma(2.2f);
+// stbi_hdr_to_ldr_scale(1.0f);
+//
+// (note, do not use _inverse_ constants; stbi_image will invert them
+// appropriately).
+//
+// Additionally, there is a new, parallel interface for loading files as
+// (linear) floats to preserve the full dynamic range:
+//
+// float *data = stbi_loadf(filename, &x, &y, &n, 0);
+//
+// If you load LDR images through this interface, those images will
+// be promoted to floating point values, run through the inverse of
+// constants corresponding to the above:
+//
+// stbi_ldr_to_hdr_scale(1.0f);
+// stbi_ldr_to_hdr_gamma(2.2f);
+//
+// Finally, given a filename (or an open file or memory block--see header
+// file for details) containing image data, you can query for the "most
+// appropriate" interface to use (that is, whether the image is HDR or
+// not), using:
+//
+// stbi_is_hdr(char *filename);
+//
+// ===========================================================================
+//
+// iPhone PNG support:
+//
+// We optionally support converting iPhone-formatted PNGs (which store
+// premultiplied BGRA) back to RGB, even though they're internally encoded
+// differently. To enable this conversion, call
+// stbi_convert_iphone_png_to_rgb(1).
+//
+// Call stbi_set_unpremultiply_on_load(1) as well to force a divide per
+// pixel to remove any premultiplied alpha *only* if the image file explicitly
+// says there's premultiplied data (currently only happens in iPhone images,
+// and only if iPhone convert-to-rgb processing is on).
+//
+// ===========================================================================
+//
+// ADDITIONAL CONFIGURATION
+//
+// - You can suppress implementation of any of the decoders to reduce
+// your code footprint by #defining one or more of the following
+// symbols before creating the implementation.
+//
+// STBI_NO_JPEG
+// STBI_NO_PNG
+// STBI_NO_BMP
+// STBI_NO_PSD
+// STBI_NO_TGA
+// STBI_NO_GIF
+// STBI_NO_HDR
+// STBI_NO_PIC
+// STBI_NO_PNM (.ppm and .pgm)
+//
+// - You can request *only* certain decoders and suppress all other ones
+// (this will be more forward-compatible, as addition of new decoders
+// doesn't require you to disable them explicitly):
+//
+// STBI_ONLY_JPEG
+// STBI_ONLY_PNG
+// STBI_ONLY_BMP
+// STBI_ONLY_PSD
+// STBI_ONLY_TGA
+// STBI_ONLY_GIF
+// STBI_ONLY_HDR
+// STBI_ONLY_PIC
+// STBI_ONLY_PNM (.ppm and .pgm)
+//
+// - If you use STBI_NO_PNG (or _ONLY_ without PNG), and you still
+// want the zlib decoder to be available, #define STBI_SUPPORT_ZLIB
+//
+// - If you define STBI_MAX_DIMENSIONS, stb_image will reject images greater
+// than that size (in either width or height) without further processing.
+// This is to let programs in the wild set an upper bound to prevent
+// denial-of-service attacks on untrusted data, as one could generate a
+// valid image of gigantic dimensions and force stb_image to allocate a
+// huge block of memory and spend disproportionate time decoding it. By
+// default this is set to (1 << 24), which is 16777216, but that's still
+// very big.
+
+#ifndef STBI_NO_STDIO
+#include <stdio.h>
+#endif // STBI_NO_STDIO
+
+#define STBI_VERSION 1
+
+enum
+{
+ STBI_default = 0, // only used for desired_channels
+
+ STBI_grey = 1,
+ STBI_grey_alpha = 2,
+ STBI_rgb = 3,
+ STBI_rgb_alpha = 4
+};
+
+#include <stdlib.h>
+typedef unsigned char stbi_uc;
+typedef unsigned short stbi_us;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef STBIDEF
+#ifdef STB_IMAGE_STATIC
+#define STBIDEF static
+#else
+#define STBIDEF extern
+#endif
+#endif
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// PRIMARY API - works on images of any type
+//
+
+//
+// load image by filename, open file, or memory buffer
+//
+
+typedef struct
+{
+ int (*read) (void *user,char *data,int size); // fill 'data' with 'size' bytes. return number of bytes actually read
+ void (*skip) (void *user,int n); // skip the next 'n' bytes, or 'unget' the last -n bytes if negative
+ int (*eof) (void *user); // returns nonzero if we are at end of file/data
+} stbi_io_callbacks;
+
+////////////////////////////////////
+//
+// 8-bits-per-channel interface
+//
+
+STBIDEF stbi_uc *stbi_load_from_memory (stbi_uc const *buffer, int len , int *x, int *y, int *channels_in_file, int desired_channels);
+STBIDEF stbi_uc *stbi_load_from_callbacks(stbi_io_callbacks const *clbk , void *user, int *x, int *y, int *channels_in_file, int desired_channels);
+
+#ifndef STBI_NO_STDIO
+STBIDEF stbi_uc *stbi_load (char const *filename, int *x, int *y, int *channels_in_file, int desired_channels);
+STBIDEF stbi_uc *stbi_load_from_file (FILE *f, int *x, int *y, int *channels_in_file, int desired_channels);
+// for stbi_load_from_file, file pointer is left pointing immediately after image
+#endif
+
+#ifndef STBI_NO_GIF
+STBIDEF stbi_uc *stbi_load_gif_from_memory(stbi_uc const *buffer, int len, int **delays, int *x, int *y, int *z, int *comp, int req_comp);
+#endif
+
+#ifdef STBI_WINDOWS_UTF8
+STBIDEF int stbi_convert_wchar_to_utf8(char *buffer, size_t bufferlen, const wchar_t* input);
+#endif
+
+////////////////////////////////////
+//
+// 16-bits-per-channel interface
+//
+
+STBIDEF stbi_us *stbi_load_16_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *channels_in_file, int desired_channels);
+STBIDEF stbi_us *stbi_load_16_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *channels_in_file, int desired_channels);
+
+#ifndef STBI_NO_STDIO
+STBIDEF stbi_us *stbi_load_16 (char const *filename, int *x, int *y, int *channels_in_file, int desired_channels);
+STBIDEF stbi_us *stbi_load_from_file_16(FILE *f, int *x, int *y, int *channels_in_file, int desired_channels);
+#endif
+
+////////////////////////////////////
+//
+// float-per-channel interface
+//
+#ifndef STBI_NO_LINEAR
+ STBIDEF float *stbi_loadf_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *channels_in_file, int desired_channels);
+ STBIDEF float *stbi_loadf_from_callbacks (stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *channels_in_file, int desired_channels);
+
+ #ifndef STBI_NO_STDIO
+ STBIDEF float *stbi_loadf (char const *filename, int *x, int *y, int *channels_in_file, int desired_channels);
+ STBIDEF float *stbi_loadf_from_file (FILE *f, int *x, int *y, int *channels_in_file, int desired_channels);
+ #endif
+#endif
+
+#ifndef STBI_NO_HDR
+ STBIDEF void stbi_hdr_to_ldr_gamma(float gamma);
+ STBIDEF void stbi_hdr_to_ldr_scale(float scale);
+#endif // STBI_NO_HDR
+
+#ifndef STBI_NO_LINEAR
+ STBIDEF void stbi_ldr_to_hdr_gamma(float gamma);
+ STBIDEF void stbi_ldr_to_hdr_scale(float scale);
+#endif // STBI_NO_LINEAR
+
+// stbi_is_hdr is always defined, but always returns false if STBI_NO_HDR
+STBIDEF int stbi_is_hdr_from_callbacks(stbi_io_callbacks const *clbk, void *user);
+STBIDEF int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len);
+#ifndef STBI_NO_STDIO
+STBIDEF int stbi_is_hdr (char const *filename);
+STBIDEF int stbi_is_hdr_from_file(FILE *f);
+#endif // STBI_NO_STDIO
+
+
+// get a VERY brief reason for failure
+// on most compilers (and ALL modern mainstream compilers) this is threadsafe
+STBIDEF const char *stbi_failure_reason (void);
+
+// free the loaded image -- this is just free()
+STBIDEF void stbi_image_free (void *retval_from_stbi_load);
+
+// get image dimensions & components without fully decoding
+STBIDEF int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp);
+STBIDEF int stbi_info_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp);
+STBIDEF int stbi_is_16_bit_from_memory(stbi_uc const *buffer, int len);
+STBIDEF int stbi_is_16_bit_from_callbacks(stbi_io_callbacks const *clbk, void *user);
+
+#ifndef STBI_NO_STDIO
+STBIDEF int stbi_info (char const *filename, int *x, int *y, int *comp);
+STBIDEF int stbi_info_from_file (FILE *f, int *x, int *y, int *comp);
+STBIDEF int stbi_is_16_bit (char const *filename);
+STBIDEF int stbi_is_16_bit_from_file(FILE *f);
+#endif
+
+
+
+// for image formats that explicitly notate that they have premultiplied alpha,
+// we just return the colors as stored in the file. set this flag to force
+// unpremultiplication. results are undefined if the unpremultiply overflow.
+STBIDEF void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply);
+
+// indicate whether we should process iphone images back to canonical format,
+// or just pass them through "as-is"
+STBIDEF void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert);
+
+// flip the image vertically, so the first pixel in the output array is the bottom left
+STBIDEF void stbi_set_flip_vertically_on_load(int flag_true_if_should_flip);
+
+// as above, but only applies to images loaded on the thread that calls the function
+// this function is only available if your compiler supports thread-local variables;
+// calling it will fail to link if your compiler doesn't
+STBIDEF void stbi_set_unpremultiply_on_load_thread(int flag_true_if_should_unpremultiply);
+STBIDEF void stbi_convert_iphone_png_to_rgb_thread(int flag_true_if_should_convert);
+STBIDEF void stbi_set_flip_vertically_on_load_thread(int flag_true_if_should_flip);
+
+// ZLIB client - used by PNG, available for other purposes
+
+STBIDEF char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen);
+STBIDEF char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header);
+STBIDEF char *stbi_zlib_decode_malloc(const char *buffer, int len, int *outlen);
+STBIDEF int stbi_zlib_decode_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
+
+STBIDEF char *stbi_zlib_decode_noheader_malloc(const char *buffer, int len, int *outlen);
+STBIDEF int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+//
+//
+//// end header file /////////////////////////////////////////////////////
+#endif // STBI_INCLUDE_STB_IMAGE_H
+
+#ifdef STB_IMAGE_IMPLEMENTATION
+
+#if defined(STBI_ONLY_JPEG) || defined(STBI_ONLY_PNG) || defined(STBI_ONLY_BMP) \
+ || defined(STBI_ONLY_TGA) || defined(STBI_ONLY_GIF) || defined(STBI_ONLY_PSD) \
+ || defined(STBI_ONLY_HDR) || defined(STBI_ONLY_PIC) || defined(STBI_ONLY_PNM) \
+ || defined(STBI_ONLY_ZLIB)
+ #ifndef STBI_ONLY_JPEG
+ #define STBI_NO_JPEG
+ #endif
+ #ifndef STBI_ONLY_PNG
+ #define STBI_NO_PNG
+ #endif
+ #ifndef STBI_ONLY_BMP
+ #define STBI_NO_BMP
+ #endif
+ #ifndef STBI_ONLY_PSD
+ #define STBI_NO_PSD
+ #endif
+ #ifndef STBI_ONLY_TGA
+ #define STBI_NO_TGA
+ #endif
+ #ifndef STBI_ONLY_GIF
+ #define STBI_NO_GIF
+ #endif
+ #ifndef STBI_ONLY_HDR
+ #define STBI_NO_HDR
+ #endif
+ #ifndef STBI_ONLY_PIC
+ #define STBI_NO_PIC
+ #endif
+ #ifndef STBI_ONLY_PNM
+ #define STBI_NO_PNM
+ #endif
+#endif
+
+#if defined(STBI_NO_PNG) && !defined(STBI_SUPPORT_ZLIB) && !defined(STBI_NO_ZLIB)
+#define STBI_NO_ZLIB
+#endif
+
+
+#include <stdarg.h>
+#include <stddef.h> // ptrdiff_t on osx
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+
+#if !defined(STBI_NO_LINEAR) || !defined(STBI_NO_HDR)
+#include <math.h> // ldexp, pow
+#endif
+
+#ifndef STBI_NO_STDIO
+#include <stdio.h>
+#endif
+
+#ifndef STBI_ASSERT
+#include <assert.h>
+#define STBI_ASSERT(x) assert(x)
+#endif
+
+#ifdef __cplusplus
+#define STBI_EXTERN extern "C"
+#else
+#define STBI_EXTERN extern
+#endif
+
+
+#ifndef _MSC_VER
+ #ifdef __cplusplus
+ #define stbi_inline inline
+ #else
+ #define stbi_inline
+ #endif
+#else
+ #define stbi_inline __forceinline
+#endif
+
+#ifndef STBI_NO_THREAD_LOCALS
+ #if defined(__cplusplus) && __cplusplus >= 201103L
+ #define STBI_THREAD_LOCAL thread_local
+ #elif defined(__GNUC__) && __GNUC__ < 5
+ #define STBI_THREAD_LOCAL __thread
+ #elif defined(_MSC_VER)
+ #define STBI_THREAD_LOCAL __declspec(thread)
+ #elif defined (__STDC_VERSION__) && __STDC_VERSION__ >= 201112L && !defined(__STDC_NO_THREADS__)
+ #define STBI_THREAD_LOCAL _Thread_local
+ #endif
+
+ #ifndef STBI_THREAD_LOCAL
+ #if defined(__GNUC__)
+ #define STBI_THREAD_LOCAL __thread
+ #endif
+ #endif
+#endif
+
+#ifdef _MSC_VER
+typedef unsigned short stbi__uint16;
+typedef signed short stbi__int16;
+typedef unsigned int stbi__uint32;
+typedef signed int stbi__int32;
+#else
+#include <stdint.h>
+typedef uint16_t stbi__uint16;
+typedef int16_t stbi__int16;
+typedef uint32_t stbi__uint32;
+typedef int32_t stbi__int32;
+#endif
+
+// should produce compiler error if size is wrong
+typedef unsigned char validate_uint32[sizeof(stbi__uint32)==4 ? 1 : -1];
+
+#ifdef _MSC_VER
+#define STBI_NOTUSED(v) (void)(v)
+#else
+#define STBI_NOTUSED(v) (void)sizeof(v)
+#endif
+
+#ifdef _MSC_VER
+#define STBI_HAS_LROTL
+#endif
+
+#ifdef STBI_HAS_LROTL
+ #define stbi_lrot(x,y) _lrotl(x,y)
+#else
+ #define stbi_lrot(x,y) (((x) << (y)) | ((x) >> (-(y) & 31)))
+#endif
+
+#if defined(STBI_MALLOC) && defined(STBI_FREE) && (defined(STBI_REALLOC) || defined(STBI_REALLOC_SIZED))
+// ok
+#elif !defined(STBI_MALLOC) && !defined(STBI_FREE) && !defined(STBI_REALLOC) && !defined(STBI_REALLOC_SIZED)
+// ok
+#else
+#error "Must define all or none of STBI_MALLOC, STBI_FREE, and STBI_REALLOC (or STBI_REALLOC_SIZED)."
+#endif
+
+#ifndef STBI_MALLOC
+#define STBI_MALLOC(sz) malloc(sz)
+#define STBI_REALLOC(p,newsz) realloc(p,newsz)
+#define STBI_FREE(p) free(p)
+#endif
+
+#ifndef STBI_REALLOC_SIZED
+#define STBI_REALLOC_SIZED(p,oldsz,newsz) STBI_REALLOC(p,newsz)
+#endif
+
+// x86/x64 detection
+#if defined(__x86_64__) || defined(_M_X64)
+#define STBI__X64_TARGET
+#elif defined(__i386) || defined(_M_IX86)
+#define STBI__X86_TARGET
+#endif
+
+#if defined(__GNUC__) && defined(STBI__X86_TARGET) && !defined(__SSE2__) && !defined(STBI_NO_SIMD)
+// gcc doesn't support sse2 intrinsics unless you compile with -msse2,
+// which in turn means it gets to use SSE2 everywhere. This is unfortunate,
+// but previous attempts to provide the SSE2 functions with runtime
+// detection caused numerous issues. The way architecture extensions are
+// exposed in GCC/Clang is, sadly, not really suited for one-file libs.
+// New behavior: if compiled with -msse2, we use SSE2 without any
+// detection; if not, we don't use it at all.
+#define STBI_NO_SIMD
+#endif
+
+#if defined(__MINGW32__) && defined(STBI__X86_TARGET) && !defined(STBI_MINGW_ENABLE_SSE2) && !defined(STBI_NO_SIMD)
+// Note that __MINGW32__ doesn't actually mean 32-bit, so we have to avoid STBI__X64_TARGET
+//
+// 32-bit MinGW wants ESP to be 16-byte aligned, but this is not in the
+// Windows ABI and VC++ as well as Windows DLLs don't maintain that invariant.
+// As a result, enabling SSE2 on 32-bit MinGW is dangerous when not
+// simultaneously enabling "-mstackrealign".
+//
+// See https://github.com/nothings/stb/issues/81 for more information.
+//
+// So default to no SSE2 on 32-bit MinGW. If you've read this far and added
+// -mstackrealign to your build settings, feel free to #define STBI_MINGW_ENABLE_SSE2.
+#define STBI_NO_SIMD
+#endif
+
+#if !defined(STBI_NO_SIMD) && (defined(STBI__X86_TARGET) || defined(STBI__X64_TARGET))
+#define STBI_SSE2
+#include <emmintrin.h>
+
+#ifdef _MSC_VER
+
+#if _MSC_VER >= 1400 // not VC6
+#include <intrin.h> // __cpuid
+static int stbi__cpuid3(void)
+{
+ int info[4];
+ __cpuid(info,1);
+ return info[3];
+}
+#else
+static int stbi__cpuid3(void)
+{
+ int res;
+ __asm {
+ mov eax,1
+ cpuid
+ mov res,edx
+ }
+ return res;
+}
+#endif
+
+#define STBI_SIMD_ALIGN(type, name) __declspec(align(16)) type name
+
+#if !defined(STBI_NO_JPEG) && defined(STBI_SSE2)
+static int stbi__sse2_available(void)
+{
+ int info3 = stbi__cpuid3();
+ return ((info3 >> 26) & 1) != 0;
+}
+#endif
+
+#else // assume GCC-style if not VC++
+#define STBI_SIMD_ALIGN(type, name) type name __attribute__((aligned(16)))
+
+#if !defined(STBI_NO_JPEG) && defined(STBI_SSE2)
+static int stbi__sse2_available(void)
+{
+ // If we're even attempting to compile this on GCC/Clang, that means
+ // -msse2 is on, which means the compiler is allowed to use SSE2
+ // instructions at will, and so are we.
+ return 1;
+}
+#endif
+
+#endif
+#endif
+
+// ARM NEON
+#if defined(STBI_NO_SIMD) && defined(STBI_NEON)
+#undef STBI_NEON
+#endif
+
+#ifdef STBI_NEON
+#include <arm_neon.h>
+#ifdef _MSC_VER
+#define STBI_SIMD_ALIGN(type, name) __declspec(align(16)) type name
+#else
+#define STBI_SIMD_ALIGN(type, name) type name __attribute__((aligned(16)))
+#endif
+#endif
+
+#ifndef STBI_SIMD_ALIGN
+#define STBI_SIMD_ALIGN(type, name) type name
+#endif
+
+#ifndef STBI_MAX_DIMENSIONS
+#define STBI_MAX_DIMENSIONS (1 << 24)
+#endif
+
+///////////////////////////////////////////////
+//
+// stbi__context struct and start_xxx functions
+
+// stbi__context structure is our basic context used by all images, so it
+// contains all the IO context, plus some basic image information
+typedef struct
+{
+ stbi__uint32 img_x, img_y;
+ int img_n, img_out_n;
+
+ stbi_io_callbacks io;
+ void *io_user_data;
+
+ int read_from_callbacks;
+ int buflen;
+ stbi_uc buffer_start[128];
+ int callback_already_read;
+
+ stbi_uc *img_buffer, *img_buffer_end;
+ stbi_uc *img_buffer_original, *img_buffer_original_end;
+} stbi__context;
+
+
+static void stbi__refill_buffer(stbi__context *s);
+
+// initialize a memory-decode context
+static void stbi__start_mem(stbi__context *s, stbi_uc const *buffer, int len)
+{
+ s->io.read = NULL;
+ s->read_from_callbacks = 0;
+ s->callback_already_read = 0;
+ s->img_buffer = s->img_buffer_original = (stbi_uc *) buffer;
+ s->img_buffer_end = s->img_buffer_original_end = (stbi_uc *) buffer+len;
+}
+
+// initialize a callback-based context
+static void stbi__start_callbacks(stbi__context *s, stbi_io_callbacks *c, void *user)
+{
+ s->io = *c;
+ s->io_user_data = user;
+ s->buflen = sizeof(s->buffer_start);
+ s->read_from_callbacks = 1;
+ s->callback_already_read = 0;
+ s->img_buffer = s->img_buffer_original = s->buffer_start;
+ stbi__refill_buffer(s);
+ s->img_buffer_original_end = s->img_buffer_end;
+}
+
+#ifndef STBI_NO_STDIO
+
+static int stbi__stdio_read(void *user, char *data, int size)
+{
+ return (int) fread(data,1,size,(FILE*) user);
+}
+
+static void stbi__stdio_skip(void *user, int n)
+{
+ int ch;
+ fseek((FILE*) user, n, SEEK_CUR);
+ ch = fgetc((FILE*) user); /* have to read a byte to reset feof()'s flag */
+ if (ch != EOF) {
+ ungetc(ch, (FILE *) user); /* push byte back onto stream if valid. */
+ }
+}
+
+static int stbi__stdio_eof(void *user)
+{
+ return feof((FILE*) user) || ferror((FILE *) user);
+}
+
+static stbi_io_callbacks stbi__stdio_callbacks =
+{
+ stbi__stdio_read,
+ stbi__stdio_skip,
+ stbi__stdio_eof,
+};
+
+static void stbi__start_file(stbi__context *s, FILE *f)
+{
+ stbi__start_callbacks(s, &stbi__stdio_callbacks, (void *) f);
+}
+
+//static void stop_file(stbi__context *s) { }
+
+#endif // !STBI_NO_STDIO
+
+static void stbi__rewind(stbi__context *s)
+{
+ // conceptually rewind SHOULD rewind to the beginning of the stream,
+ // but we just rewind to the beginning of the initial buffer, because
+ // we only use it after doing 'test', which only ever looks at at most 92 bytes
+ s->img_buffer = s->img_buffer_original;
+ s->img_buffer_end = s->img_buffer_original_end;
+}
+
+enum
+{
+ STBI_ORDER_RGB,
+ STBI_ORDER_BGR
+};
+
+typedef struct
+{
+ int bits_per_channel;
+ int num_channels;
+ int channel_order;
+} stbi__result_info;
+
+#ifndef STBI_NO_JPEG
+static int stbi__jpeg_test(stbi__context *s);
+static void *stbi__jpeg_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri);
+static int stbi__jpeg_info(stbi__context *s, int *x, int *y, int *comp);
+#endif
+
+#ifndef STBI_NO_PNG
+static int stbi__png_test(stbi__context *s);
+static void *stbi__png_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri);
+static int stbi__png_info(stbi__context *s, int *x, int *y, int *comp);
+static int stbi__png_is16(stbi__context *s);
+#endif
+
+#ifndef STBI_NO_BMP
+static int stbi__bmp_test(stbi__context *s);
+static void *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri);
+static int stbi__bmp_info(stbi__context *s, int *x, int *y, int *comp);
+#endif
+
+#ifndef STBI_NO_TGA
+static int stbi__tga_test(stbi__context *s);
+static void *stbi__tga_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri);
+static int stbi__tga_info(stbi__context *s, int *x, int *y, int *comp);
+#endif
+
+#ifndef STBI_NO_PSD
+static int stbi__psd_test(stbi__context *s);
+static void *stbi__psd_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri, int bpc);
+static int stbi__psd_info(stbi__context *s, int *x, int *y, int *comp);
+static int stbi__psd_is16(stbi__context *s);
+#endif
+
+#ifndef STBI_NO_HDR
+static int stbi__hdr_test(stbi__context *s);
+static float *stbi__hdr_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri);
+static int stbi__hdr_info(stbi__context *s, int *x, int *y, int *comp);
+#endif
+
+#ifndef STBI_NO_PIC
+static int stbi__pic_test(stbi__context *s);
+static void *stbi__pic_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri);
+static int stbi__pic_info(stbi__context *s, int *x, int *y, int *comp);
+#endif
+
+#ifndef STBI_NO_GIF
+static int stbi__gif_test(stbi__context *s);
+static void *stbi__gif_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri);
+static void *stbi__load_gif_main(stbi__context *s, int **delays, int *x, int *y, int *z, int *comp, int req_comp);
+static int stbi__gif_info(stbi__context *s, int *x, int *y, int *comp);
+#endif
+
+#ifndef STBI_NO_PNM
+static int stbi__pnm_test(stbi__context *s);
+static void *stbi__pnm_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri);
+static int stbi__pnm_info(stbi__context *s, int *x, int *y, int *comp);
+static int stbi__pnm_is16(stbi__context *s);
+#endif
+
+static
+#ifdef STBI_THREAD_LOCAL
+STBI_THREAD_LOCAL
+#endif
+const char *stbi__g_failure_reason;
+
+STBIDEF const char *stbi_failure_reason(void)
+{
+ return stbi__g_failure_reason;
+}
+
+#ifndef STBI_NO_FAILURE_STRINGS
+static int stbi__err(const char *str)
+{
+ stbi__g_failure_reason = str;
+ return 0;
+}
+#endif
+
+static void *stbi__malloc(size_t size)
+{
+ return STBI_MALLOC(size);
+}
+
+// stb_image uses ints pervasively, including for offset calculations.
+// therefore the largest decoded image size we can support with the
+// current code, even on 64-bit targets, is INT_MAX. this is not a
+// significant limitation for the intended use case.
+//
+// we do, however, need to make sure our size calculations don't
+// overflow. hence a few helper functions for size calculations that
+// multiply integers together, making sure that they're non-negative
+// and no overflow occurs.
+
+// return 1 if the sum is valid, 0 on overflow.
+// negative terms are considered invalid.
+static int stbi__addsizes_valid(int a, int b)
+{
+ if (b < 0) return 0;
+ // now 0 <= b <= INT_MAX, hence also
+ // 0 <= INT_MAX - b <= INTMAX.
+ // And "a + b <= INT_MAX" (which might overflow) is the
+ // same as a <= INT_MAX - b (no overflow)
+ return a <= INT_MAX - b;
+}
+
+// returns 1 if the product is valid, 0 on overflow.
+// negative factors are considered invalid.
+static int stbi__mul2sizes_valid(int a, int b)
+{
+ if (a < 0 || b < 0) return 0;
+ if (b == 0) return 1; // mul-by-0 is always safe
+ // portable way to check for no overflows in a*b
+ return a <= INT_MAX/b;
+}
+
+#if !defined(STBI_NO_JPEG) || !defined(STBI_NO_PNG) || !defined(STBI_NO_TGA) || !defined(STBI_NO_HDR)
+// returns 1 if "a*b + add" has no negative terms/factors and doesn't overflow
+static int stbi__mad2sizes_valid(int a, int b, int add)
+{
+ return stbi__mul2sizes_valid(a, b) && stbi__addsizes_valid(a*b, add);
+}
+#endif
+
+// returns 1 if "a*b*c + add" has no negative terms/factors and doesn't overflow
+static int stbi__mad3sizes_valid(int a, int b, int c, int add)
+{
+ return stbi__mul2sizes_valid(a, b) && stbi__mul2sizes_valid(a*b, c) &&
+ stbi__addsizes_valid(a*b*c, add);
+}
+
+// returns 1 if "a*b*c*d + add" has no negative terms/factors and doesn't overflow
+#if !defined(STBI_NO_LINEAR) || !defined(STBI_NO_HDR) || !defined(STBI_NO_PNM)
+static int stbi__mad4sizes_valid(int a, int b, int c, int d, int add)
+{
+ return stbi__mul2sizes_valid(a, b) && stbi__mul2sizes_valid(a*b, c) &&
+ stbi__mul2sizes_valid(a*b*c, d) && stbi__addsizes_valid(a*b*c*d, add);
+}
+#endif
+
+#if !defined(STBI_NO_JPEG) || !defined(STBI_NO_PNG) || !defined(STBI_NO_TGA) || !defined(STBI_NO_HDR)
+// mallocs with size overflow checking
+static void *stbi__malloc_mad2(int a, int b, int add)
+{
+ if (!stbi__mad2sizes_valid(a, b, add)) return NULL;
+ return stbi__malloc(a*b + add);
+}
+#endif
+
+static void *stbi__malloc_mad3(int a, int b, int c, int add)
+{
+ if (!stbi__mad3sizes_valid(a, b, c, add)) return NULL;
+ return stbi__malloc(a*b*c + add);
+}
+
+#if !defined(STBI_NO_LINEAR) || !defined(STBI_NO_HDR) || !defined(STBI_NO_PNM)
+static void *stbi__malloc_mad4(int a, int b, int c, int d, int add)
+{
+ if (!stbi__mad4sizes_valid(a, b, c, d, add)) return NULL;
+ return stbi__malloc(a*b*c*d + add);
+}
+#endif
+
+// stbi__err - error
+// stbi__errpf - error returning pointer to float
+// stbi__errpuc - error returning pointer to unsigned char
+
+#ifdef STBI_NO_FAILURE_STRINGS
+ #define stbi__err(x,y) 0
+#elif defined(STBI_FAILURE_USERMSG)
+ #define stbi__err(x,y) stbi__err(y)
+#else
+ #define stbi__err(x,y) stbi__err(x)
+#endif
+
+#define stbi__errpf(x,y) ((float *)(size_t) (stbi__err(x,y)?NULL:NULL))
+#define stbi__errpuc(x,y) ((unsigned char *)(size_t) (stbi__err(x,y)?NULL:NULL))
+
+STBIDEF void stbi_image_free(void *retval_from_stbi_load)
+{
+ STBI_FREE(retval_from_stbi_load);
+}
+
+#ifndef STBI_NO_LINEAR
+static float *stbi__ldr_to_hdr(stbi_uc *data, int x, int y, int comp);
+#endif
+
+#ifndef STBI_NO_HDR
+static stbi_uc *stbi__hdr_to_ldr(float *data, int x, int y, int comp);
+#endif
+
+static int stbi__vertically_flip_on_load_global = 0;
+
+STBIDEF void stbi_set_flip_vertically_on_load(int flag_true_if_should_flip)
+{
+ stbi__vertically_flip_on_load_global = flag_true_if_should_flip;
+}
+
+#ifndef STBI_THREAD_LOCAL
+#define stbi__vertically_flip_on_load stbi__vertically_flip_on_load_global
+#else
+static STBI_THREAD_LOCAL int stbi__vertically_flip_on_load_local, stbi__vertically_flip_on_load_set;
+
+STBIDEF void stbi_set_flip_vertically_on_load_thread(int flag_true_if_should_flip)
+{
+ stbi__vertically_flip_on_load_local = flag_true_if_should_flip;
+ stbi__vertically_flip_on_load_set = 1;
+}
+
+#define stbi__vertically_flip_on_load (stbi__vertically_flip_on_load_set \
+ ? stbi__vertically_flip_on_load_local \
+ : stbi__vertically_flip_on_load_global)
+#endif // STBI_THREAD_LOCAL
+
+static void *stbi__load_main(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri, int bpc)
+{
+ memset(ri, 0, sizeof(*ri)); // make sure it's initialized if we add new fields
+ ri->bits_per_channel = 8; // default is 8 so most paths don't have to be changed
+ ri->channel_order = STBI_ORDER_RGB; // all current input & output are this, but this is here so we can add BGR order
+ ri->num_channels = 0;
+
+ // test the formats with a very explicit header first (at least a FOURCC
+ // or distinctive magic number first)
+ #ifndef STBI_NO_PNG
+ if (stbi__png_test(s)) return stbi__png_load(s,x,y,comp,req_comp, ri);
+ #endif
+ #ifndef STBI_NO_BMP
+ if (stbi__bmp_test(s)) return stbi__bmp_load(s,x,y,comp,req_comp, ri);
+ #endif
+ #ifndef STBI_NO_GIF
+ if (stbi__gif_test(s)) return stbi__gif_load(s,x,y,comp,req_comp, ri);
+ #endif
+ #ifndef STBI_NO_PSD
+ if (stbi__psd_test(s)) return stbi__psd_load(s,x,y,comp,req_comp, ri, bpc);
+ #else
+ STBI_NOTUSED(bpc);
+ #endif
+ #ifndef STBI_NO_PIC
+ if (stbi__pic_test(s)) return stbi__pic_load(s,x,y,comp,req_comp, ri);
+ #endif
+
+ // then the formats that can end up attempting to load with just 1 or 2
+ // bytes matching expectations; these are prone to false positives, so
+ // try them later
+ #ifndef STBI_NO_JPEG
+ if (stbi__jpeg_test(s)) return stbi__jpeg_load(s,x,y,comp,req_comp, ri);
+ #endif
+ #ifndef STBI_NO_PNM
+ if (stbi__pnm_test(s)) return stbi__pnm_load(s,x,y,comp,req_comp, ri);
+ #endif
+
+ #ifndef STBI_NO_HDR
+ if (stbi__hdr_test(s)) {
+ float *hdr = stbi__hdr_load(s, x,y,comp,req_comp, ri);
+ return stbi__hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp);
+ }
+ #endif
+
+ #ifndef STBI_NO_TGA
+ // test tga last because it's a crappy test!
+ if (stbi__tga_test(s))
+ return stbi__tga_load(s,x,y,comp,req_comp, ri);
+ #endif
+
+ return stbi__errpuc("unknown image type", "Image not of any known type, or corrupt");
+}
+
+static stbi_uc *stbi__convert_16_to_8(stbi__uint16 *orig, int w, int h, int channels)
+{
+ int i;
+ int img_len = w * h * channels;
+ stbi_uc *reduced;
+
+ reduced = (stbi_uc *) stbi__malloc(img_len);
+ if (reduced == NULL) return stbi__errpuc("outofmem", "Out of memory");
+
+ for (i = 0; i < img_len; ++i)
+ reduced[i] = (stbi_uc)((orig[i] >> 8) & 0xFF); // top half of each byte is sufficient approx of 16->8 bit scaling
+
+ STBI_FREE(orig);
+ return reduced;
+}
+
+static stbi__uint16 *stbi__convert_8_to_16(stbi_uc *orig, int w, int h, int channels)
+{
+ int i;
+ int img_len = w * h * channels;
+ stbi__uint16 *enlarged;
+
+ enlarged = (stbi__uint16 *) stbi__malloc(img_len*2);
+ if (enlarged == NULL) return (stbi__uint16 *) stbi__errpuc("outofmem", "Out of memory");
+
+ for (i = 0; i < img_len; ++i)
+ enlarged[i] = (stbi__uint16)((orig[i] << 8) + orig[i]); // replicate to high and low byte, maps 0->0, 255->0xffff
+
+ STBI_FREE(orig);
+ return enlarged;
+}
+
+static void stbi__vertical_flip(void *image, int w, int h, int bytes_per_pixel)
+{
+ int row;
+ size_t bytes_per_row = (size_t)w * bytes_per_pixel;
+ stbi_uc temp[2048];
+ stbi_uc *bytes = (stbi_uc *)image;
+
+ for (row = 0; row < (h>>1); row++) {
+ stbi_uc *row0 = bytes + row*bytes_per_row;
+ stbi_uc *row1 = bytes + (h - row - 1)*bytes_per_row;
+ // swap row0 with row1
+ size_t bytes_left = bytes_per_row;
+ while (bytes_left) {
+ size_t bytes_copy = (bytes_left < sizeof(temp)) ? bytes_left : sizeof(temp);
+ memcpy(temp, row0, bytes_copy);
+ memcpy(row0, row1, bytes_copy);
+ memcpy(row1, temp, bytes_copy);
+ row0 += bytes_copy;
+ row1 += bytes_copy;
+ bytes_left -= bytes_copy;
+ }
+ }
+}
+
+#ifndef STBI_NO_GIF
+static void stbi__vertical_flip_slices(void *image, int w, int h, int z, int bytes_per_pixel)
+{
+ int slice;
+ int slice_size = w * h * bytes_per_pixel;
+
+ stbi_uc *bytes = (stbi_uc *)image;
+ for (slice = 0; slice < z; ++slice) {
+ stbi__vertical_flip(bytes, w, h, bytes_per_pixel);
+ bytes += slice_size;
+ }
+}
+#endif
+
+static unsigned char *stbi__load_and_postprocess_8bit(stbi__context *s, int *x, int *y, int *comp, int req_comp)
+{
+ stbi__result_info ri;
+ void *result = stbi__load_main(s, x, y, comp, req_comp, &ri, 8);
+
+ if (result == NULL)
+ return NULL;
+
+ // it is the responsibility of the loaders to make sure we get either 8 or 16 bit.
+ STBI_ASSERT(ri.bits_per_channel == 8 || ri.bits_per_channel == 16);
+
+ if (ri.bits_per_channel != 8) {
+ result = stbi__convert_16_to_8((stbi__uint16 *) result, *x, *y, req_comp == 0 ? *comp : req_comp);
+ ri.bits_per_channel = 8;
+ }
+
+ // @TODO: move stbi__convert_format to here
+
+ if (stbi__vertically_flip_on_load) {
+ int channels = req_comp ? req_comp : *comp;
+ stbi__vertical_flip(result, *x, *y, channels * sizeof(stbi_uc));
+ }
+
+ return (unsigned char *) result;
+}
+
+static stbi__uint16 *stbi__load_and_postprocess_16bit(stbi__context *s, int *x, int *y, int *comp, int req_comp)
+{
+ stbi__result_info ri;
+ void *result = stbi__load_main(s, x, y, comp, req_comp, &ri, 16);
+
+ if (result == NULL)
+ return NULL;
+
+ // it is the responsibility of the loaders to make sure we get either 8 or 16 bit.
+ STBI_ASSERT(ri.bits_per_channel == 8 || ri.bits_per_channel == 16);
+
+ if (ri.bits_per_channel != 16) {
+ result = stbi__convert_8_to_16((stbi_uc *) result, *x, *y, req_comp == 0 ? *comp : req_comp);
+ ri.bits_per_channel = 16;
+ }
+
+ // @TODO: move stbi__convert_format16 to here
+ // @TODO: special case RGB-to-Y (and RGBA-to-YA) for 8-bit-to-16-bit case to keep more precision
+
+ if (stbi__vertically_flip_on_load) {
+ int channels = req_comp ? req_comp : *comp;
+ stbi__vertical_flip(result, *x, *y, channels * sizeof(stbi__uint16));
+ }
+
+ return (stbi__uint16 *) result;
+}
+
+#if !defined(STBI_NO_HDR) && !defined(STBI_NO_LINEAR)
+static void stbi__float_postprocess(float *result, int *x, int *y, int *comp, int req_comp)
+{
+ if (stbi__vertically_flip_on_load && result != NULL) {
+ int channels = req_comp ? req_comp : *comp;
+ stbi__vertical_flip(result, *x, *y, channels * sizeof(float));
+ }
+}
+#endif
+
+#ifndef STBI_NO_STDIO
+
+#if defined(_WIN32) && defined(STBI_WINDOWS_UTF8)
+STBI_EXTERN __declspec(dllimport) int __stdcall MultiByteToWideChar(unsigned int cp, unsigned long flags, const char *str, int cbmb, wchar_t *widestr, int cchwide);
+STBI_EXTERN __declspec(dllimport) int __stdcall WideCharToMultiByte(unsigned int cp, unsigned long flags, const wchar_t *widestr, int cchwide, char *str, int cbmb, const char *defchar, int *used_default);
+#endif
+
+#if defined(_WIN32) && defined(STBI_WINDOWS_UTF8)
+STBIDEF int stbi_convert_wchar_to_utf8(char *buffer, size_t bufferlen, const wchar_t* input)
+{
+ return WideCharToMultiByte(65001 /* UTF8 */, 0, input, -1, buffer, (int) bufferlen, NULL, NULL);
+}
+#endif
+
+static FILE *stbi__fopen(char const *filename, char const *mode)
+{
+ FILE *f;
+#if defined(_WIN32) && defined(STBI_WINDOWS_UTF8)
+ wchar_t wMode[64];
+ wchar_t wFilename[1024];
+ if (0 == MultiByteToWideChar(65001 /* UTF8 */, 0, filename, -1, wFilename, sizeof(wFilename)/sizeof(*wFilename)))
+ return 0;
+
+ if (0 == MultiByteToWideChar(65001 /* UTF8 */, 0, mode, -1, wMode, sizeof(wMode)/sizeof(*wMode)))
+ return 0;
+
+#if defined(_MSC_VER) && _MSC_VER >= 1400
+ if (0 != _wfopen_s(&f, wFilename, wMode))
+ f = 0;
+#else
+ f = _wfopen(wFilename, wMode);
+#endif
+
+#elif defined(_MSC_VER) && _MSC_VER >= 1400
+ if (0 != fopen_s(&f, filename, mode))
+ f=0;
+#else
+ f = fopen(filename, mode);
+#endif
+ return f;
+}
+
+
+STBIDEF stbi_uc *stbi_load(char const *filename, int *x, int *y, int *comp, int req_comp)
+{
+ FILE *f = stbi__fopen(filename, "rb");
+ unsigned char *result;
+ if (!f) return stbi__errpuc("can't fopen", "Unable to open file");
+ result = stbi_load_from_file(f,x,y,comp,req_comp);
+ fclose(f);
+ return result;
+}
+
+STBIDEF stbi_uc *stbi_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
+{
+ unsigned char *result;
+ stbi__context s;
+ stbi__start_file(&s,f);
+ result = stbi__load_and_postprocess_8bit(&s,x,y,comp,req_comp);
+ if (result) {
+ // need to 'unget' all the characters in the IO buffer
+ fseek(f, - (int) (s.img_buffer_end - s.img_buffer), SEEK_CUR);
+ }
+ return result;
+}
+
+STBIDEF stbi__uint16 *stbi_load_from_file_16(FILE *f, int *x, int *y, int *comp, int req_comp)
+{
+ stbi__uint16 *result;
+ stbi__context s;
+ stbi__start_file(&s,f);
+ result = stbi__load_and_postprocess_16bit(&s,x,y,comp,req_comp);
+ if (result) {
+ // need to 'unget' all the characters in the IO buffer
+ fseek(f, - (int) (s.img_buffer_end - s.img_buffer), SEEK_CUR);
+ }
+ return result;
+}
+
+STBIDEF stbi_us *stbi_load_16(char const *filename, int *x, int *y, int *comp, int req_comp)
+{
+ FILE *f = stbi__fopen(filename, "rb");
+ stbi__uint16 *result;
+ if (!f) return (stbi_us *) stbi__errpuc("can't fopen", "Unable to open file");
+ result = stbi_load_from_file_16(f,x,y,comp,req_comp);
+ fclose(f);
+ return result;
+}
+
+
+#endif //!STBI_NO_STDIO
+
+STBIDEF stbi_us *stbi_load_16_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *channels_in_file, int desired_channels)
+{
+ stbi__context s;
+ stbi__start_mem(&s,buffer,len);
+ return stbi__load_and_postprocess_16bit(&s,x,y,channels_in_file,desired_channels);
+}
+
+STBIDEF stbi_us *stbi_load_16_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *channels_in_file, int desired_channels)
+{
+ stbi__context s;
+ stbi__start_callbacks(&s, (stbi_io_callbacks *)clbk, user);
+ return stbi__load_and_postprocess_16bit(&s,x,y,channels_in_file,desired_channels);
+}
+
+STBIDEF stbi_uc *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ stbi__context s;
+ stbi__start_mem(&s,buffer,len);
+ return stbi__load_and_postprocess_8bit(&s,x,y,comp,req_comp);
+}
+
+STBIDEF stbi_uc *stbi_load_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp, int req_comp)
+{
+ stbi__context s;
+ stbi__start_callbacks(&s, (stbi_io_callbacks *) clbk, user);
+ return stbi__load_and_postprocess_8bit(&s,x,y,comp,req_comp);
+}
+
+#ifndef STBI_NO_GIF
+STBIDEF stbi_uc *stbi_load_gif_from_memory(stbi_uc const *buffer, int len, int **delays, int *x, int *y, int *z, int *comp, int req_comp)
+{
+ unsigned char *result;
+ stbi__context s;
+ stbi__start_mem(&s,buffer,len);
+
+ result = (unsigned char*) stbi__load_gif_main(&s, delays, x, y, z, comp, req_comp);
+ if (stbi__vertically_flip_on_load) {
+ stbi__vertical_flip_slices( result, *x, *y, *z, *comp );
+ }
+
+ return result;
+}
+#endif
+
+#ifndef STBI_NO_LINEAR
+static float *stbi__loadf_main(stbi__context *s, int *x, int *y, int *comp, int req_comp)
+{
+ unsigned char *data;
+ #ifndef STBI_NO_HDR
+ if (stbi__hdr_test(s)) {
+ stbi__result_info ri;
+ float *hdr_data = stbi__hdr_load(s,x,y,comp,req_comp, &ri);
+ if (hdr_data)
+ stbi__float_postprocess(hdr_data,x,y,comp,req_comp);
+ return hdr_data;
+ }
+ #endif
+ data = stbi__load_and_postprocess_8bit(s, x, y, comp, req_comp);
+ if (data)
+ return stbi__ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp);
+ return stbi__errpf("unknown image type", "Image not of any known type, or corrupt");
+}
+
+STBIDEF float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ stbi__context s;
+ stbi__start_mem(&s,buffer,len);
+ return stbi__loadf_main(&s,x,y,comp,req_comp);
+}
+
+STBIDEF float *stbi_loadf_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp, int req_comp)
+{
+ stbi__context s;
+ stbi__start_callbacks(&s, (stbi_io_callbacks *) clbk, user);
+ return stbi__loadf_main(&s,x,y,comp,req_comp);
+}
+
+#ifndef STBI_NO_STDIO
+STBIDEF float *stbi_loadf(char const *filename, int *x, int *y, int *comp, int req_comp)
+{
+ float *result;
+ FILE *f = stbi__fopen(filename, "rb");
+ if (!f) return stbi__errpf("can't fopen", "Unable to open file");
+ result = stbi_loadf_from_file(f,x,y,comp,req_comp);
+ fclose(f);
+ return result;
+}
+
+STBIDEF float *stbi_loadf_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
+{
+ stbi__context s;
+ stbi__start_file(&s,f);
+ return stbi__loadf_main(&s,x,y,comp,req_comp);
+}
+#endif // !STBI_NO_STDIO
+
+#endif // !STBI_NO_LINEAR
+
+// these is-hdr-or-not is defined independent of whether STBI_NO_LINEAR is
+// defined, for API simplicity; if STBI_NO_LINEAR is defined, it always
+// reports false!
+
+STBIDEF int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len)
+{
+ #ifndef STBI_NO_HDR
+ stbi__context s;
+ stbi__start_mem(&s,buffer,len);
+ return stbi__hdr_test(&s);
+ #else
+ STBI_NOTUSED(buffer);
+ STBI_NOTUSED(len);
+ return 0;
+ #endif
+}
+
+#ifndef STBI_NO_STDIO
+STBIDEF int stbi_is_hdr (char const *filename)
+{
+ FILE *f = stbi__fopen(filename, "rb");
+ int result=0;
+ if (f) {
+ result = stbi_is_hdr_from_file(f);
+ fclose(f);
+ }
+ return result;
+}
+
+STBIDEF int stbi_is_hdr_from_file(FILE *f)
+{
+ #ifndef STBI_NO_HDR
+ long pos = ftell(f);
+ int res;
+ stbi__context s;
+ stbi__start_file(&s,f);
+ res = stbi__hdr_test(&s);
+ fseek(f, pos, SEEK_SET);
+ return res;
+ #else
+ STBI_NOTUSED(f);
+ return 0;
+ #endif
+}
+#endif // !STBI_NO_STDIO
+
+STBIDEF int stbi_is_hdr_from_callbacks(stbi_io_callbacks const *clbk, void *user)
+{
+ #ifndef STBI_NO_HDR
+ stbi__context s;
+ stbi__start_callbacks(&s, (stbi_io_callbacks *) clbk, user);
+ return stbi__hdr_test(&s);
+ #else
+ STBI_NOTUSED(clbk);
+ STBI_NOTUSED(user);
+ return 0;
+ #endif
+}
+
+#ifndef STBI_NO_LINEAR
+static float stbi__l2h_gamma=2.2f, stbi__l2h_scale=1.0f;
+
+STBIDEF void stbi_ldr_to_hdr_gamma(float gamma) { stbi__l2h_gamma = gamma; }
+STBIDEF void stbi_ldr_to_hdr_scale(float scale) { stbi__l2h_scale = scale; }
+#endif
+
+static float stbi__h2l_gamma_i=1.0f/2.2f, stbi__h2l_scale_i=1.0f;
+
+STBIDEF void stbi_hdr_to_ldr_gamma(float gamma) { stbi__h2l_gamma_i = 1/gamma; }
+STBIDEF void stbi_hdr_to_ldr_scale(float scale) { stbi__h2l_scale_i = 1/scale; }
+
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// Common code used by all image loaders
+//
+
+enum
+{
+ STBI__SCAN_load=0,
+ STBI__SCAN_type,
+ STBI__SCAN_header
+};
+
+static void stbi__refill_buffer(stbi__context *s)
+{
+ int n = (s->io.read)(s->io_user_data,(char*)s->buffer_start,s->buflen);
+ s->callback_already_read += (int) (s->img_buffer - s->img_buffer_original);
+ if (n == 0) {
+ // at end of file, treat same as if from memory, but need to handle case
+ // where s->img_buffer isn't pointing to safe memory, e.g. 0-byte file
+ s->read_from_callbacks = 0;
+ s->img_buffer = s->buffer_start;
+ s->img_buffer_end = s->buffer_start+1;
+ *s->img_buffer = 0;
+ } else {
+ s->img_buffer = s->buffer_start;
+ s->img_buffer_end = s->buffer_start + n;
+ }
+}
+
+stbi_inline static stbi_uc stbi__get8(stbi__context *s)
+{
+ if (s->img_buffer < s->img_buffer_end)
+ return *s->img_buffer++;
+ if (s->read_from_callbacks) {
+ stbi__refill_buffer(s);
+ return *s->img_buffer++;
+ }
+ return 0;
+}
+
+#if defined(STBI_NO_JPEG) && defined(STBI_NO_HDR) && defined(STBI_NO_PIC) && defined(STBI_NO_PNM)
+// nothing
+#else
+stbi_inline static int stbi__at_eof(stbi__context *s)
+{
+ if (s->io.read) {
+ if (!(s->io.eof)(s->io_user_data)) return 0;
+ // if feof() is true, check if buffer = end
+ // special case: we've only got the special 0 character at the end
+ if (s->read_from_callbacks == 0) return 1;
+ }
+
+ return s->img_buffer >= s->img_buffer_end;
+}
+#endif
+
+#if defined(STBI_NO_JPEG) && defined(STBI_NO_PNG) && defined(STBI_NO_BMP) && defined(STBI_NO_PSD) && defined(STBI_NO_TGA) && defined(STBI_NO_GIF) && defined(STBI_NO_PIC)
+// nothing
+#else
+static void stbi__skip(stbi__context *s, int n)
+{
+ if (n == 0) return; // already there!
+ if (n < 0) {
+ s->img_buffer = s->img_buffer_end;
+ return;
+ }
+ if (s->io.read) {
+ int blen = (int) (s->img_buffer_end - s->img_buffer);
+ if (blen < n) {
+ s->img_buffer = s->img_buffer_end;
+ (s->io.skip)(s->io_user_data, n - blen);
+ return;
+ }
+ }
+ s->img_buffer += n;
+}
+#endif
+
+#if defined(STBI_NO_PNG) && defined(STBI_NO_TGA) && defined(STBI_NO_HDR) && defined(STBI_NO_PNM)
+// nothing
+#else
+static int stbi__getn(stbi__context *s, stbi_uc *buffer, int n)
+{
+ if (s->io.read) {
+ int blen = (int) (s->img_buffer_end - s->img_buffer);
+ if (blen < n) {
+ int res, count;
+
+ memcpy(buffer, s->img_buffer, blen);
+
+ count = (s->io.read)(s->io_user_data, (char*) buffer + blen, n - blen);
+ res = (count == (n-blen));
+ s->img_buffer = s->img_buffer_end;
+ return res;
+ }
+ }
+
+ if (s->img_buffer+n <= s->img_buffer_end) {
+ memcpy(buffer, s->img_buffer, n);
+ s->img_buffer += n;
+ return 1;
+ } else
+ return 0;
+}
+#endif
+
+#if defined(STBI_NO_JPEG) && defined(STBI_NO_PNG) && defined(STBI_NO_PSD) && defined(STBI_NO_PIC)
+// nothing
+#else
+static int stbi__get16be(stbi__context *s)
+{
+ int z = stbi__get8(s);
+ return (z << 8) + stbi__get8(s);
+}
+#endif
+
+#if defined(STBI_NO_PNG) && defined(STBI_NO_PSD) && defined(STBI_NO_PIC)
+// nothing
+#else
+static stbi__uint32 stbi__get32be(stbi__context *s)
+{
+ stbi__uint32 z = stbi__get16be(s);
+ return (z << 16) + stbi__get16be(s);
+}
+#endif
+
+#if defined(STBI_NO_BMP) && defined(STBI_NO_TGA) && defined(STBI_NO_GIF)
+// nothing
+#else
+static int stbi__get16le(stbi__context *s)
+{
+ int z = stbi__get8(s);
+ return z + (stbi__get8(s) << 8);
+}
+#endif
+
+#ifndef STBI_NO_BMP
+static stbi__uint32 stbi__get32le(stbi__context *s)
+{
+ stbi__uint32 z = stbi__get16le(s);
+ z += (stbi__uint32)stbi__get16le(s) << 16;
+ return z;
+}
+#endif
+
+#define STBI__BYTECAST(x) ((stbi_uc) ((x) & 255)) // truncate int to byte without warnings
+
+#if defined(STBI_NO_JPEG) && defined(STBI_NO_PNG) && defined(STBI_NO_BMP) && defined(STBI_NO_PSD) && defined(STBI_NO_TGA) && defined(STBI_NO_GIF) && defined(STBI_NO_PIC) && defined(STBI_NO_PNM)
+// nothing
+#else
+//////////////////////////////////////////////////////////////////////////////
+//
+// generic converter from built-in img_n to req_comp
+// individual types do this automatically as much as possible (e.g. jpeg
+// does all cases internally since it needs to colorspace convert anyway,
+// and it never has alpha, so very few cases ). png can automatically
+// interleave an alpha=255 channel, but falls back to this for other cases
+//
+// assume data buffer is malloced, so malloc a new one and free that one
+// only failure mode is malloc failing
+
+static stbi_uc stbi__compute_y(int r, int g, int b)
+{
+ return (stbi_uc) (((r*77) + (g*150) + (29*b)) >> 8);
+}
+#endif
+
+#if defined(STBI_NO_PNG) && defined(STBI_NO_BMP) && defined(STBI_NO_PSD) && defined(STBI_NO_TGA) && defined(STBI_NO_GIF) && defined(STBI_NO_PIC) && defined(STBI_NO_PNM)
+// nothing
+#else
+static unsigned char *stbi__convert_format(unsigned char *data, int img_n, int req_comp, unsigned int x, unsigned int y)
+{
+ int i,j;
+ unsigned char *good;
+
+ if (req_comp == img_n) return data;
+ STBI_ASSERT(req_comp >= 1 && req_comp <= 4);
+
+ good = (unsigned char *) stbi__malloc_mad3(req_comp, x, y, 0);
+ if (good == NULL) {
+ STBI_FREE(data);
+ return stbi__errpuc("outofmem", "Out of memory");
+ }
+
+ for (j=0; j < (int) y; ++j) {
+ unsigned char *src = data + j * x * img_n ;
+ unsigned char *dest = good + j * x * req_comp;
+
+ #define STBI__COMBO(a,b) ((a)*8+(b))
+ #define STBI__CASE(a,b) case STBI__COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b)
+ // convert source image with img_n components to one with req_comp components;
+ // avoid switch per pixel, so use switch per scanline and massive macros
+ switch (STBI__COMBO(img_n, req_comp)) {
+ STBI__CASE(1,2) { dest[0]=src[0]; dest[1]=255; } break;
+ STBI__CASE(1,3) { dest[0]=dest[1]=dest[2]=src[0]; } break;
+ STBI__CASE(1,4) { dest[0]=dest[1]=dest[2]=src[0]; dest[3]=255; } break;
+ STBI__CASE(2,1) { dest[0]=src[0]; } break;
+ STBI__CASE(2,3) { dest[0]=dest[1]=dest[2]=src[0]; } break;
+ STBI__CASE(2,4) { dest[0]=dest[1]=dest[2]=src[0]; dest[3]=src[1]; } break;
+ STBI__CASE(3,4) { dest[0]=src[0];dest[1]=src[1];dest[2]=src[2];dest[3]=255; } break;
+ STBI__CASE(3,1) { dest[0]=stbi__compute_y(src[0],src[1],src[2]); } break;
+ STBI__CASE(3,2) { dest[0]=stbi__compute_y(src[0],src[1],src[2]); dest[1] = 255; } break;
+ STBI__CASE(4,1) { dest[0]=stbi__compute_y(src[0],src[1],src[2]); } break;
+ STBI__CASE(4,2) { dest[0]=stbi__compute_y(src[0],src[1],src[2]); dest[1] = src[3]; } break;
+ STBI__CASE(4,3) { dest[0]=src[0];dest[1]=src[1];dest[2]=src[2]; } break;
+ default: STBI_ASSERT(0); STBI_FREE(data); STBI_FREE(good); return stbi__errpuc("unsupported", "Unsupported format conversion");
+ }
+ #undef STBI__CASE
+ }
+
+ STBI_FREE(data);
+ return good;
+}
+#endif
+
+#if defined(STBI_NO_PNG) && defined(STBI_NO_PSD)
+// nothing
+#else
+static stbi__uint16 stbi__compute_y_16(int r, int g, int b)
+{
+ return (stbi__uint16) (((r*77) + (g*150) + (29*b)) >> 8);
+}
+#endif
+
+#if defined(STBI_NO_PNG) && defined(STBI_NO_PSD)
+// nothing
+#else
+static stbi__uint16 *stbi__convert_format16(stbi__uint16 *data, int img_n, int req_comp, unsigned int x, unsigned int y)
+{
+ int i,j;
+ stbi__uint16 *good;
+
+ if (req_comp == img_n) return data;
+ STBI_ASSERT(req_comp >= 1 && req_comp <= 4);
+
+ good = (stbi__uint16 *) stbi__malloc(req_comp * x * y * 2);
+ if (good == NULL) {
+ STBI_FREE(data);
+ return (stbi__uint16 *) stbi__errpuc("outofmem", "Out of memory");
+ }
+
+ for (j=0; j < (int) y; ++j) {
+ stbi__uint16 *src = data + j * x * img_n ;
+ stbi__uint16 *dest = good + j * x * req_comp;
+
+ #define STBI__COMBO(a,b) ((a)*8+(b))
+ #define STBI__CASE(a,b) case STBI__COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b)
+ // convert source image with img_n components to one with req_comp components;
+ // avoid switch per pixel, so use switch per scanline and massive macros
+ switch (STBI__COMBO(img_n, req_comp)) {
+ STBI__CASE(1,2) { dest[0]=src[0]; dest[1]=0xffff; } break;
+ STBI__CASE(1,3) { dest[0]=dest[1]=dest[2]=src[0]; } break;
+ STBI__CASE(1,4) { dest[0]=dest[1]=dest[2]=src[0]; dest[3]=0xffff; } break;
+ STBI__CASE(2,1) { dest[0]=src[0]; } break;
+ STBI__CASE(2,3) { dest[0]=dest[1]=dest[2]=src[0]; } break;
+ STBI__CASE(2,4) { dest[0]=dest[1]=dest[2]=src[0]; dest[3]=src[1]; } break;
+ STBI__CASE(3,4) { dest[0]=src[0];dest[1]=src[1];dest[2]=src[2];dest[3]=0xffff; } break;
+ STBI__CASE(3,1) { dest[0]=stbi__compute_y_16(src[0],src[1],src[2]); } break;
+ STBI__CASE(3,2) { dest[0]=stbi__compute_y_16(src[0],src[1],src[2]); dest[1] = 0xffff; } break;
+ STBI__CASE(4,1) { dest[0]=stbi__compute_y_16(src[0],src[1],src[2]); } break;
+ STBI__CASE(4,2) { dest[0]=stbi__compute_y_16(src[0],src[1],src[2]); dest[1] = src[3]; } break;
+ STBI__CASE(4,3) { dest[0]=src[0];dest[1]=src[1];dest[2]=src[2]; } break;
+ default: STBI_ASSERT(0); STBI_FREE(data); STBI_FREE(good); return (stbi__uint16*) stbi__errpuc("unsupported", "Unsupported format conversion");
+ }
+ #undef STBI__CASE
+ }
+
+ STBI_FREE(data);
+ return good;
+}
+#endif
+
+#ifndef STBI_NO_LINEAR
+static float *stbi__ldr_to_hdr(stbi_uc *data, int x, int y, int comp)
+{
+ int i,k,n;
+ float *output;
+ if (!data) return NULL;
+ output = (float *) stbi__malloc_mad4(x, y, comp, sizeof(float), 0);
+ if (output == NULL) { STBI_FREE(data); return stbi__errpf("outofmem", "Out of memory"); }
+ // compute number of non-alpha components
+ if (comp & 1) n = comp; else n = comp-1;
+ for (i=0; i < x*y; ++i) {
+ for (k=0; k < n; ++k) {
+ output[i*comp + k] = (float) (pow(data[i*comp+k]/255.0f, stbi__l2h_gamma) * stbi__l2h_scale);
+ }
+ }
+ if (n < comp) {
+ for (i=0; i < x*y; ++i) {
+ output[i*comp + n] = data[i*comp + n]/255.0f;
+ }
+ }
+ STBI_FREE(data);
+ return output;
+}
+#endif
+
+#ifndef STBI_NO_HDR
+#define stbi__float2int(x) ((int) (x))
+static stbi_uc *stbi__hdr_to_ldr(float *data, int x, int y, int comp)
+{
+ int i,k,n;
+ stbi_uc *output;
+ if (!data) return NULL;
+ output = (stbi_uc *) stbi__malloc_mad3(x, y, comp, 0);
+ if (output == NULL) { STBI_FREE(data); return stbi__errpuc("outofmem", "Out of memory"); }
+ // compute number of non-alpha components
+ if (comp & 1) n = comp; else n = comp-1;
+ for (i=0; i < x*y; ++i) {
+ for (k=0; k < n; ++k) {
+ float z = (float) pow(data[i*comp+k]*stbi__h2l_scale_i, stbi__h2l_gamma_i) * 255 + 0.5f;
+ if (z < 0) z = 0;
+ if (z > 255) z = 255;
+ output[i*comp + k] = (stbi_uc) stbi__float2int(z);
+ }
+ if (k < comp) {
+ float z = data[i*comp+k] * 255 + 0.5f;
+ if (z < 0) z = 0;
+ if (z > 255) z = 255;
+ output[i*comp + k] = (stbi_uc) stbi__float2int(z);
+ }
+ }
+ STBI_FREE(data);
+ return output;
+}
+#endif
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// "baseline" JPEG/JFIF decoder
+//
+// simple implementation
+// - doesn't support delayed output of y-dimension
+// - simple interface (only one output format: 8-bit interleaved RGB)
+// - doesn't try to recover corrupt jpegs
+// - doesn't allow partial loading, loading multiple at once
+// - still fast on x86 (copying globals into locals doesn't help x86)
+// - allocates lots of intermediate memory (full size of all components)
+// - non-interleaved case requires this anyway
+// - allows good upsampling (see next)
+// high-quality
+// - upsampled channels are bilinearly interpolated, even across blocks
+// - quality integer IDCT derived from IJG's 'slow'
+// performance
+// - fast huffman; reasonable integer IDCT
+// - some SIMD kernels for common paths on targets with SSE2/NEON
+// - uses a lot of intermediate memory, could cache poorly
+
+#ifndef STBI_NO_JPEG
+
+// huffman decoding acceleration
+#define FAST_BITS 9 // larger handles more cases; smaller stomps less cache
+
+typedef struct
+{
+ stbi_uc fast[1 << FAST_BITS];
+ // weirdly, repacking this into AoS is a 10% speed loss, instead of a win
+ stbi__uint16 code[256];
+ stbi_uc values[256];
+ stbi_uc size[257];
+ unsigned int maxcode[18];
+ int delta[17]; // old 'firstsymbol' - old 'firstcode'
+} stbi__huffman;
+
+typedef struct
+{
+ stbi__context *s;
+ stbi__huffman huff_dc[4];
+ stbi__huffman huff_ac[4];
+ stbi__uint16 dequant[4][64];
+ stbi__int16 fast_ac[4][1 << FAST_BITS];
+
+// sizes for components, interleaved MCUs
+ int img_h_max, img_v_max;
+ int img_mcu_x, img_mcu_y;
+ int img_mcu_w, img_mcu_h;
+
+// definition of jpeg image component
+ struct
+ {
+ int id;
+ int h,v;
+ int tq;
+ int hd,ha;
+ int dc_pred;
+
+ int x,y,w2,h2;
+ stbi_uc *data;
+ void *raw_data, *raw_coeff;
+ stbi_uc *linebuf;
+ short *coeff; // progressive only
+ int coeff_w, coeff_h; // number of 8x8 coefficient blocks
+ } img_comp[4];
+
+ stbi__uint32 code_buffer; // jpeg entropy-coded buffer
+ int code_bits; // number of valid bits
+ unsigned char marker; // marker seen while filling entropy buffer
+ int nomore; // flag if we saw a marker so must stop
+
+ int progressive;
+ int spec_start;
+ int spec_end;
+ int succ_high;
+ int succ_low;
+ int eob_run;
+ int jfif;
+ int app14_color_transform; // Adobe APP14 tag
+ int rgb;
+
+ int scan_n, order[4];
+ int restart_interval, todo;
+
+// kernels
+ void (*idct_block_kernel)(stbi_uc *out, int out_stride, short data[64]);
+ void (*YCbCr_to_RGB_kernel)(stbi_uc *out, const stbi_uc *y, const stbi_uc *pcb, const stbi_uc *pcr, int count, int step);
+ stbi_uc *(*resample_row_hv_2_kernel)(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs);
+} stbi__jpeg;
+
+static int stbi__build_huffman(stbi__huffman *h, int *count)
+{
+ int i,j,k=0;
+ unsigned int code;
+ // build size list for each symbol (from JPEG spec)
+ for (i=0; i < 16; ++i)
+ for (j=0; j < count[i]; ++j)
+ h->size[k++] = (stbi_uc) (i+1);
+ h->size[k] = 0;
+
+ // compute actual symbols (from jpeg spec)
+ code = 0;
+ k = 0;
+ for(j=1; j <= 16; ++j) {
+ // compute delta to add to code to compute symbol id
+ h->delta[j] = k - code;
+ if (h->size[k] == j) {
+ while (h->size[k] == j)
+ h->code[k++] = (stbi__uint16) (code++);
+ if (code-1 >= (1u << j)) return stbi__err("bad code lengths","Corrupt JPEG");
+ }
+ // compute largest code + 1 for this size, preshifted as needed later
+ h->maxcode[j] = code << (16-j);
+ code <<= 1;
+ }
+ h->maxcode[j] = 0xffffffff;
+
+ // build non-spec acceleration table; 255 is flag for not-accelerated
+ memset(h->fast, 255, 1 << FAST_BITS);
+ for (i=0; i < k; ++i) {
+ int s = h->size[i];
+ if (s <= FAST_BITS) {
+ int c = h->code[i] << (FAST_BITS-s);
+ int m = 1 << (FAST_BITS-s);
+ for (j=0; j < m; ++j) {
+ h->fast[c+j] = (stbi_uc) i;
+ }
+ }
+ }
+ return 1;
+}
+
+// build a table that decodes both magnitude and value of small ACs in
+// one go.
+static void stbi__build_fast_ac(stbi__int16 *fast_ac, stbi__huffman *h)
+{
+ int i;
+ for (i=0; i < (1 << FAST_BITS); ++i) {
+ stbi_uc fast = h->fast[i];
+ fast_ac[i] = 0;
+ if (fast < 255) {
+ int rs = h->values[fast];
+ int run = (rs >> 4) & 15;
+ int magbits = rs & 15;
+ int len = h->size[fast];
+
+ if (magbits && len + magbits <= FAST_BITS) {
+ // magnitude code followed by receive_extend code
+ int k = ((i << len) & ((1 << FAST_BITS) - 1)) >> (FAST_BITS - magbits);
+ int m = 1 << (magbits - 1);
+ if (k < m) k += (~0U << magbits) + 1;
+ // if the result is small enough, we can fit it in fast_ac table
+ if (k >= -128 && k <= 127)
+ fast_ac[i] = (stbi__int16) ((k * 256) + (run * 16) + (len + magbits));
+ }
+ }
+ }
+}
+
+static void stbi__grow_buffer_unsafe(stbi__jpeg *j)
+{
+ do {
+ unsigned int b = j->nomore ? 0 : stbi__get8(j->s);
+ if (b == 0xff) {
+ int c = stbi__get8(j->s);
+ while (c == 0xff) c = stbi__get8(j->s); // consume fill bytes
+ if (c != 0) {
+ j->marker = (unsigned char) c;
+ j->nomore = 1;
+ return;
+ }
+ }
+ j->code_buffer |= b << (24 - j->code_bits);
+ j->code_bits += 8;
+ } while (j->code_bits <= 24);
+}
+
+// (1 << n) - 1
+static const stbi__uint32 stbi__bmask[17]={0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535};
+
+// decode a jpeg huffman value from the bitstream
+stbi_inline static int stbi__jpeg_huff_decode(stbi__jpeg *j, stbi__huffman *h)
+{
+ unsigned int temp;
+ int c,k;
+
+ if (j->code_bits < 16) stbi__grow_buffer_unsafe(j);
+
+ // look at the top FAST_BITS and determine what symbol ID it is,
+ // if the code is <= FAST_BITS
+ c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS)-1);
+ k = h->fast[c];
+ if (k < 255) {
+ int s = h->size[k];
+ if (s > j->code_bits)
+ return -1;
+ j->code_buffer <<= s;
+ j->code_bits -= s;
+ return h->values[k];
+ }
+
+ // naive test is to shift the code_buffer down so k bits are
+ // valid, then test against maxcode. To speed this up, we've
+ // preshifted maxcode left so that it has (16-k) 0s at the
+ // end; in other words, regardless of the number of bits, it
+ // wants to be compared against something shifted to have 16;
+ // that way we don't need to shift inside the loop.
+ temp = j->code_buffer >> 16;
+ for (k=FAST_BITS+1 ; ; ++k)
+ if (temp < h->maxcode[k])
+ break;
+ if (k == 17) {
+ // error! code not found
+ j->code_bits -= 16;
+ return -1;
+ }
+
+ if (k > j->code_bits)
+ return -1;
+
+ // convert the huffman code to the symbol id
+ c = ((j->code_buffer >> (32 - k)) & stbi__bmask[k]) + h->delta[k];
+ STBI_ASSERT((((j->code_buffer) >> (32 - h->size[c])) & stbi__bmask[h->size[c]]) == h->code[c]);
+
+ // convert the id to a symbol
+ j->code_bits -= k;
+ j->code_buffer <<= k;
+ return h->values[c];
+}
+
+// bias[n] = (-1<<n) + 1
+static const int stbi__jbias[16] = {0,-1,-3,-7,-15,-31,-63,-127,-255,-511,-1023,-2047,-4095,-8191,-16383,-32767};
+
+// combined JPEG 'receive' and JPEG 'extend', since baseline
+// always extends everything it receives.
+stbi_inline static int stbi__extend_receive(stbi__jpeg *j, int n)
+{
+ unsigned int k;
+ int sgn;
+ if (j->code_bits < n) stbi__grow_buffer_unsafe(j);
+
+ sgn = j->code_buffer >> 31; // sign bit always in MSB; 0 if MSB clear (positive), 1 if MSB set (negative)
+ k = stbi_lrot(j->code_buffer, n);
+ j->code_buffer = k & ~stbi__bmask[n];
+ k &= stbi__bmask[n];
+ j->code_bits -= n;
+ return k + (stbi__jbias[n] & (sgn - 1));
+}
+
+// get some unsigned bits
+stbi_inline static int stbi__jpeg_get_bits(stbi__jpeg *j, int n)
+{
+ unsigned int k;
+ if (j->code_bits < n) stbi__grow_buffer_unsafe(j);
+ k = stbi_lrot(j->code_buffer, n);
+ j->code_buffer = k & ~stbi__bmask[n];
+ k &= stbi__bmask[n];
+ j->code_bits -= n;
+ return k;
+}
+
+stbi_inline static int stbi__jpeg_get_bit(stbi__jpeg *j)
+{
+ unsigned int k;
+ if (j->code_bits < 1) stbi__grow_buffer_unsafe(j);
+ k = j->code_buffer;
+ j->code_buffer <<= 1;
+ --j->code_bits;
+ return k & 0x80000000;
+}
+
+// given a value that's at position X in the zigzag stream,
+// where does it appear in the 8x8 matrix coded as row-major?
+static const stbi_uc stbi__jpeg_dezigzag[64+15] =
+{
+ 0, 1, 8, 16, 9, 2, 3, 10,
+ 17, 24, 32, 25, 18, 11, 4, 5,
+ 12, 19, 26, 33, 40, 48, 41, 34,
+ 27, 20, 13, 6, 7, 14, 21, 28,
+ 35, 42, 49, 56, 57, 50, 43, 36,
+ 29, 22, 15, 23, 30, 37, 44, 51,
+ 58, 59, 52, 45, 38, 31, 39, 46,
+ 53, 60, 61, 54, 47, 55, 62, 63,
+ // let corrupt input sample past end
+ 63, 63, 63, 63, 63, 63, 63, 63,
+ 63, 63, 63, 63, 63, 63, 63
+};
+
+// decode one 64-entry block--
+static int stbi__jpeg_decode_block(stbi__jpeg *j, short data[64], stbi__huffman *hdc, stbi__huffman *hac, stbi__int16 *fac, int b, stbi__uint16 *dequant)
+{
+ int diff,dc,k;
+ int t;
+
+ if (j->code_bits < 16) stbi__grow_buffer_unsafe(j);
+ t = stbi__jpeg_huff_decode(j, hdc);
+ if (t < 0 || t > 15) return stbi__err("bad huffman code","Corrupt JPEG");
+
+ // 0 all the ac values now so we can do it 32-bits at a time
+ memset(data,0,64*sizeof(data[0]));
+
+ diff = t ? stbi__extend_receive(j, t) : 0;
+ dc = j->img_comp[b].dc_pred + diff;
+ j->img_comp[b].dc_pred = dc;
+ data[0] = (short) (dc * dequant[0]);
+
+ // decode AC components, see JPEG spec
+ k = 1;
+ do {
+ unsigned int zig;
+ int c,r,s;
+ if (j->code_bits < 16) stbi__grow_buffer_unsafe(j);
+ c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS)-1);
+ r = fac[c];
+ if (r) { // fast-AC path
+ k += (r >> 4) & 15; // run
+ s = r & 15; // combined length
+ j->code_buffer <<= s;
+ j->code_bits -= s;
+ // decode into unzigzag'd location
+ zig = stbi__jpeg_dezigzag[k++];
+ data[zig] = (short) ((r >> 8) * dequant[zig]);
+ } else {
+ int rs = stbi__jpeg_huff_decode(j, hac);
+ if (rs < 0) return stbi__err("bad huffman code","Corrupt JPEG");
+ s = rs & 15;
+ r = rs >> 4;
+ if (s == 0) {
+ if (rs != 0xf0) break; // end block
+ k += 16;
+ } else {
+ k += r;
+ // decode into unzigzag'd location
+ zig = stbi__jpeg_dezigzag[k++];
+ data[zig] = (short) (stbi__extend_receive(j,s) * dequant[zig]);
+ }
+ }
+ } while (k < 64);
+ return 1;
+}
+
+static int stbi__jpeg_decode_block_prog_dc(stbi__jpeg *j, short data[64], stbi__huffman *hdc, int b)
+{
+ int diff,dc;
+ int t;
+ if (j->spec_end != 0) return stbi__err("can't merge dc and ac", "Corrupt JPEG");
+
+ if (j->code_bits < 16) stbi__grow_buffer_unsafe(j);
+
+ if (j->succ_high == 0) {
+ // first scan for DC coefficient, must be first
+ memset(data,0,64*sizeof(data[0])); // 0 all the ac values now
+ t = stbi__jpeg_huff_decode(j, hdc);
+ if (t < 0 || t > 15) return stbi__err("can't merge dc and ac", "Corrupt JPEG");
+ diff = t ? stbi__extend_receive(j, t) : 0;
+
+ dc = j->img_comp[b].dc_pred + diff;
+ j->img_comp[b].dc_pred = dc;
+ data[0] = (short) (dc * (1 << j->succ_low));
+ } else {
+ // refinement scan for DC coefficient
+ if (stbi__jpeg_get_bit(j))
+ data[0] += (short) (1 << j->succ_low);
+ }
+ return 1;
+}
+
+// @OPTIMIZE: store non-zigzagged during the decode passes,
+// and only de-zigzag when dequantizing
+static int stbi__jpeg_decode_block_prog_ac(stbi__jpeg *j, short data[64], stbi__huffman *hac, stbi__int16 *fac)
+{
+ int k;
+ if (j->spec_start == 0) return stbi__err("can't merge dc and ac", "Corrupt JPEG");
+
+ if (j->succ_high == 0) {
+ int shift = j->succ_low;
+
+ if (j->eob_run) {
+ --j->eob_run;
+ return 1;
+ }
+
+ k = j->spec_start;
+ do {
+ unsigned int zig;
+ int c,r,s;
+ if (j->code_bits < 16) stbi__grow_buffer_unsafe(j);
+ c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS)-1);
+ r = fac[c];
+ if (r) { // fast-AC path
+ k += (r >> 4) & 15; // run
+ s = r & 15; // combined length
+ j->code_buffer <<= s;
+ j->code_bits -= s;
+ zig = stbi__jpeg_dezigzag[k++];
+ data[zig] = (short) ((r >> 8) * (1 << shift));
+ } else {
+ int rs = stbi__jpeg_huff_decode(j, hac);
+ if (rs < 0) return stbi__err("bad huffman code","Corrupt JPEG");
+ s = rs & 15;
+ r = rs >> 4;
+ if (s == 0) {
+ if (r < 15) {
+ j->eob_run = (1 << r);
+ if (r)
+ j->eob_run += stbi__jpeg_get_bits(j, r);
+ --j->eob_run;
+ break;
+ }
+ k += 16;
+ } else {
+ k += r;
+ zig = stbi__jpeg_dezigzag[k++];
+ data[zig] = (short) (stbi__extend_receive(j,s) * (1 << shift));
+ }
+ }
+ } while (k <= j->spec_end);
+ } else {
+ // refinement scan for these AC coefficients
+
+ short bit = (short) (1 << j->succ_low);
+
+ if (j->eob_run) {
+ --j->eob_run;
+ for (k = j->spec_start; k <= j->spec_end; ++k) {
+ short *p = &data[stbi__jpeg_dezigzag[k]];
+ if (*p != 0)
+ if (stbi__jpeg_get_bit(j))
+ if ((*p & bit)==0) {
+ if (*p > 0)
+ *p += bit;
+ else
+ *p -= bit;
+ }
+ }
+ } else {
+ k = j->spec_start;
+ do {
+ int r,s;
+ int rs = stbi__jpeg_huff_decode(j, hac); // @OPTIMIZE see if we can use the fast path here, advance-by-r is so slow, eh
+ if (rs < 0) return stbi__err("bad huffman code","Corrupt JPEG");
+ s = rs & 15;
+ r = rs >> 4;
+ if (s == 0) {
+ if (r < 15) {
+ j->eob_run = (1 << r) - 1;
+ if (r)
+ j->eob_run += stbi__jpeg_get_bits(j, r);
+ r = 64; // force end of block
+ } else {
+ // r=15 s=0 should write 16 0s, so we just do
+ // a run of 15 0s and then write s (which is 0),
+ // so we don't have to do anything special here
+ }
+ } else {
+ if (s != 1) return stbi__err("bad huffman code", "Corrupt JPEG");
+ // sign bit
+ if (stbi__jpeg_get_bit(j))
+ s = bit;
+ else
+ s = -bit;
+ }
+
+ // advance by r
+ while (k <= j->spec_end) {
+ short *p = &data[stbi__jpeg_dezigzag[k++]];
+ if (*p != 0) {
+ if (stbi__jpeg_get_bit(j))
+ if ((*p & bit)==0) {
+ if (*p > 0)
+ *p += bit;
+ else
+ *p -= bit;
+ }
+ } else {
+ if (r == 0) {
+ *p = (short) s;
+ break;
+ }
+ --r;
+ }
+ }
+ } while (k <= j->spec_end);
+ }
+ }
+ return 1;
+}
+
+// take a -128..127 value and stbi__clamp it and convert to 0..255
+stbi_inline static stbi_uc stbi__clamp(int x)
+{
+ // trick to use a single test to catch both cases
+ if ((unsigned int) x > 255) {
+ if (x < 0) return 0;
+ if (x > 255) return 255;
+ }
+ return (stbi_uc) x;
+}
+
+#define stbi__f2f(x) ((int) (((x) * 4096 + 0.5)))
+#define stbi__fsh(x) ((x) * 4096)
+
+// derived from jidctint -- DCT_ISLOW
+#define STBI__IDCT_1D(s0,s1,s2,s3,s4,s5,s6,s7) \
+ int t0,t1,t2,t3,p1,p2,p3,p4,p5,x0,x1,x2,x3; \
+ p2 = s2; \
+ p3 = s6; \
+ p1 = (p2+p3) * stbi__f2f(0.5411961f); \
+ t2 = p1 + p3*stbi__f2f(-1.847759065f); \
+ t3 = p1 + p2*stbi__f2f( 0.765366865f); \
+ p2 = s0; \
+ p3 = s4; \
+ t0 = stbi__fsh(p2+p3); \
+ t1 = stbi__fsh(p2-p3); \
+ x0 = t0+t3; \
+ x3 = t0-t3; \
+ x1 = t1+t2; \
+ x2 = t1-t2; \
+ t0 = s7; \
+ t1 = s5; \
+ t2 = s3; \
+ t3 = s1; \
+ p3 = t0+t2; \
+ p4 = t1+t3; \
+ p1 = t0+t3; \
+ p2 = t1+t2; \
+ p5 = (p3+p4)*stbi__f2f( 1.175875602f); \
+ t0 = t0*stbi__f2f( 0.298631336f); \
+ t1 = t1*stbi__f2f( 2.053119869f); \
+ t2 = t2*stbi__f2f( 3.072711026f); \
+ t3 = t3*stbi__f2f( 1.501321110f); \
+ p1 = p5 + p1*stbi__f2f(-0.899976223f); \
+ p2 = p5 + p2*stbi__f2f(-2.562915447f); \
+ p3 = p3*stbi__f2f(-1.961570560f); \
+ p4 = p4*stbi__f2f(-0.390180644f); \
+ t3 += p1+p4; \
+ t2 += p2+p3; \
+ t1 += p2+p4; \
+ t0 += p1+p3;
+
+static void stbi__idct_block(stbi_uc *out, int out_stride, short data[64])
+{
+ int i,val[64],*v=val;
+ stbi_uc *o;
+ short *d = data;
+
+ // columns
+ for (i=0; i < 8; ++i,++d, ++v) {
+ // if all zeroes, shortcut -- this avoids dequantizing 0s and IDCTing
+ if (d[ 8]==0 && d[16]==0 && d[24]==0 && d[32]==0
+ && d[40]==0 && d[48]==0 && d[56]==0) {
+ // no shortcut 0 seconds
+ // (1|2|3|4|5|6|7)==0 0 seconds
+ // all separate -0.047 seconds
+ // 1 && 2|3 && 4|5 && 6|7: -0.047 seconds
+ int dcterm = d[0]*4;
+ v[0] = v[8] = v[16] = v[24] = v[32] = v[40] = v[48] = v[56] = dcterm;
+ } else {
+ STBI__IDCT_1D(d[ 0],d[ 8],d[16],d[24],d[32],d[40],d[48],d[56])
+ // constants scaled things up by 1<<12; let's bring them back
+ // down, but keep 2 extra bits of precision
+ x0 += 512; x1 += 512; x2 += 512; x3 += 512;
+ v[ 0] = (x0+t3) >> 10;
+ v[56] = (x0-t3) >> 10;
+ v[ 8] = (x1+t2) >> 10;
+ v[48] = (x1-t2) >> 10;
+ v[16] = (x2+t1) >> 10;
+ v[40] = (x2-t1) >> 10;
+ v[24] = (x3+t0) >> 10;
+ v[32] = (x3-t0) >> 10;
+ }
+ }
+
+ for (i=0, v=val, o=out; i < 8; ++i,v+=8,o+=out_stride) {
+ // no fast case since the first 1D IDCT spread components out
+ STBI__IDCT_1D(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7])
+ // constants scaled things up by 1<<12, plus we had 1<<2 from first
+ // loop, plus horizontal and vertical each scale by sqrt(8) so together
+ // we've got an extra 1<<3, so 1<<17 total we need to remove.
+ // so we want to round that, which means adding 0.5 * 1<<17,
+ // aka 65536. Also, we'll end up with -128 to 127 that we want
+ // to encode as 0..255 by adding 128, so we'll add that before the shift
+ x0 += 65536 + (128<<17);
+ x1 += 65536 + (128<<17);
+ x2 += 65536 + (128<<17);
+ x3 += 65536 + (128<<17);
+ // tried computing the shifts into temps, or'ing the temps to see
+ // if any were out of range, but that was slower
+ o[0] = stbi__clamp((x0+t3) >> 17);
+ o[7] = stbi__clamp((x0-t3) >> 17);
+ o[1] = stbi__clamp((x1+t2) >> 17);
+ o[6] = stbi__clamp((x1-t2) >> 17);
+ o[2] = stbi__clamp((x2+t1) >> 17);
+ o[5] = stbi__clamp((x2-t1) >> 17);
+ o[3] = stbi__clamp((x3+t0) >> 17);
+ o[4] = stbi__clamp((x3-t0) >> 17);
+ }
+}
+
+#ifdef STBI_SSE2
+// sse2 integer IDCT. not the fastest possible implementation but it
+// produces bit-identical results to the generic C version so it's
+// fully "transparent".
+static void stbi__idct_simd(stbi_uc *out, int out_stride, short data[64])
+{
+ // This is constructed to match our regular (generic) integer IDCT exactly.
+ __m128i row0, row1, row2, row3, row4, row5, row6, row7;
+ __m128i tmp;
+
+ // dot product constant: even elems=x, odd elems=y
+ #define dct_const(x,y) _mm_setr_epi16((x),(y),(x),(y),(x),(y),(x),(y))
+
+ // out(0) = c0[even]*x + c0[odd]*y (c0, x, y 16-bit, out 32-bit)
+ // out(1) = c1[even]*x + c1[odd]*y
+ #define dct_rot(out0,out1, x,y,c0,c1) \
+ __m128i c0##lo = _mm_unpacklo_epi16((x),(y)); \
+ __m128i c0##hi = _mm_unpackhi_epi16((x),(y)); \
+ __m128i out0##_l = _mm_madd_epi16(c0##lo, c0); \
+ __m128i out0##_h = _mm_madd_epi16(c0##hi, c0); \
+ __m128i out1##_l = _mm_madd_epi16(c0##lo, c1); \
+ __m128i out1##_h = _mm_madd_epi16(c0##hi, c1)
+
+ // out = in << 12 (in 16-bit, out 32-bit)
+ #define dct_widen(out, in) \
+ __m128i out##_l = _mm_srai_epi32(_mm_unpacklo_epi16(_mm_setzero_si128(), (in)), 4); \
+ __m128i out##_h = _mm_srai_epi32(_mm_unpackhi_epi16(_mm_setzero_si128(), (in)), 4)
+
+ // wide add
+ #define dct_wadd(out, a, b) \
+ __m128i out##_l = _mm_add_epi32(a##_l, b##_l); \
+ __m128i out##_h = _mm_add_epi32(a##_h, b##_h)
+
+ // wide sub
+ #define dct_wsub(out, a, b) \
+ __m128i out##_l = _mm_sub_epi32(a##_l, b##_l); \
+ __m128i out##_h = _mm_sub_epi32(a##_h, b##_h)
+
+ // butterfly a/b, add bias, then shift by "s" and pack
+ #define dct_bfly32o(out0, out1, a,b,bias,s) \
+ { \
+ __m128i abiased_l = _mm_add_epi32(a##_l, bias); \
+ __m128i abiased_h = _mm_add_epi32(a##_h, bias); \
+ dct_wadd(sum, abiased, b); \
+ dct_wsub(dif, abiased, b); \
+ out0 = _mm_packs_epi32(_mm_srai_epi32(sum_l, s), _mm_srai_epi32(sum_h, s)); \
+ out1 = _mm_packs_epi32(_mm_srai_epi32(dif_l, s), _mm_srai_epi32(dif_h, s)); \
+ }
+
+ // 8-bit interleave step (for transposes)
+ #define dct_interleave8(a, b) \
+ tmp = a; \
+ a = _mm_unpacklo_epi8(a, b); \
+ b = _mm_unpackhi_epi8(tmp, b)
+
+ // 16-bit interleave step (for transposes)
+ #define dct_interleave16(a, b) \
+ tmp = a; \
+ a = _mm_unpacklo_epi16(a, b); \
+ b = _mm_unpackhi_epi16(tmp, b)
+
+ #define dct_pass(bias,shift) \
+ { \
+ /* even part */ \
+ dct_rot(t2e,t3e, row2,row6, rot0_0,rot0_1); \
+ __m128i sum04 = _mm_add_epi16(row0, row4); \
+ __m128i dif04 = _mm_sub_epi16(row0, row4); \
+ dct_widen(t0e, sum04); \
+ dct_widen(t1e, dif04); \
+ dct_wadd(x0, t0e, t3e); \
+ dct_wsub(x3, t0e, t3e); \
+ dct_wadd(x1, t1e, t2e); \
+ dct_wsub(x2, t1e, t2e); \
+ /* odd part */ \
+ dct_rot(y0o,y2o, row7,row3, rot2_0,rot2_1); \
+ dct_rot(y1o,y3o, row5,row1, rot3_0,rot3_1); \
+ __m128i sum17 = _mm_add_epi16(row1, row7); \
+ __m128i sum35 = _mm_add_epi16(row3, row5); \
+ dct_rot(y4o,y5o, sum17,sum35, rot1_0,rot1_1); \
+ dct_wadd(x4, y0o, y4o); \
+ dct_wadd(x5, y1o, y5o); \
+ dct_wadd(x6, y2o, y5o); \
+ dct_wadd(x7, y3o, y4o); \
+ dct_bfly32o(row0,row7, x0,x7,bias,shift); \
+ dct_bfly32o(row1,row6, x1,x6,bias,shift); \
+ dct_bfly32o(row2,row5, x2,x5,bias,shift); \
+ dct_bfly32o(row3,row4, x3,x4,bias,shift); \
+ }
+
+ __m128i rot0_0 = dct_const(stbi__f2f(0.5411961f), stbi__f2f(0.5411961f) + stbi__f2f(-1.847759065f));
+ __m128i rot0_1 = dct_const(stbi__f2f(0.5411961f) + stbi__f2f( 0.765366865f), stbi__f2f(0.5411961f));
+ __m128i rot1_0 = dct_const(stbi__f2f(1.175875602f) + stbi__f2f(-0.899976223f), stbi__f2f(1.175875602f));
+ __m128i rot1_1 = dct_const(stbi__f2f(1.175875602f), stbi__f2f(1.175875602f) + stbi__f2f(-2.562915447f));
+ __m128i rot2_0 = dct_const(stbi__f2f(-1.961570560f) + stbi__f2f( 0.298631336f), stbi__f2f(-1.961570560f));
+ __m128i rot2_1 = dct_const(stbi__f2f(-1.961570560f), stbi__f2f(-1.961570560f) + stbi__f2f( 3.072711026f));
+ __m128i rot3_0 = dct_const(stbi__f2f(-0.390180644f) + stbi__f2f( 2.053119869f), stbi__f2f(-0.390180644f));
+ __m128i rot3_1 = dct_const(stbi__f2f(-0.390180644f), stbi__f2f(-0.390180644f) + stbi__f2f( 1.501321110f));
+
+ // rounding biases in column/row passes, see stbi__idct_block for explanation.
+ __m128i bias_0 = _mm_set1_epi32(512);
+ __m128i bias_1 = _mm_set1_epi32(65536 + (128<<17));
+
+ // load
+ row0 = _mm_load_si128((const __m128i *) (data + 0*8));
+ row1 = _mm_load_si128((const __m128i *) (data + 1*8));
+ row2 = _mm_load_si128((const __m128i *) (data + 2*8));
+ row3 = _mm_load_si128((const __m128i *) (data + 3*8));
+ row4 = _mm_load_si128((const __m128i *) (data + 4*8));
+ row5 = _mm_load_si128((const __m128i *) (data + 5*8));
+ row6 = _mm_load_si128((const __m128i *) (data + 6*8));
+ row7 = _mm_load_si128((const __m128i *) (data + 7*8));
+
+ // column pass
+ dct_pass(bias_0, 10);
+
+ {
+ // 16bit 8x8 transpose pass 1
+ dct_interleave16(row0, row4);
+ dct_interleave16(row1, row5);
+ dct_interleave16(row2, row6);
+ dct_interleave16(row3, row7);
+
+ // transpose pass 2
+ dct_interleave16(row0, row2);
+ dct_interleave16(row1, row3);
+ dct_interleave16(row4, row6);
+ dct_interleave16(row5, row7);
+
+ // transpose pass 3
+ dct_interleave16(row0, row1);
+ dct_interleave16(row2, row3);
+ dct_interleave16(row4, row5);
+ dct_interleave16(row6, row7);
+ }
+
+ // row pass
+ dct_pass(bias_1, 17);
+
+ {
+ // pack
+ __m128i p0 = _mm_packus_epi16(row0, row1); // a0a1a2a3...a7b0b1b2b3...b7
+ __m128i p1 = _mm_packus_epi16(row2, row3);
+ __m128i p2 = _mm_packus_epi16(row4, row5);
+ __m128i p3 = _mm_packus_epi16(row6, row7);
+
+ // 8bit 8x8 transpose pass 1
+ dct_interleave8(p0, p2); // a0e0a1e1...
+ dct_interleave8(p1, p3); // c0g0c1g1...
+
+ // transpose pass 2
+ dct_interleave8(p0, p1); // a0c0e0g0...
+ dct_interleave8(p2, p3); // b0d0f0h0...
+
+ // transpose pass 3
+ dct_interleave8(p0, p2); // a0b0c0d0...
+ dct_interleave8(p1, p3); // a4b4c4d4...
+
+ // store
+ _mm_storel_epi64((__m128i *) out, p0); out += out_stride;
+ _mm_storel_epi64((__m128i *) out, _mm_shuffle_epi32(p0, 0x4e)); out += out_stride;
+ _mm_storel_epi64((__m128i *) out, p2); out += out_stride;
+ _mm_storel_epi64((__m128i *) out, _mm_shuffle_epi32(p2, 0x4e)); out += out_stride;
+ _mm_storel_epi64((__m128i *) out, p1); out += out_stride;
+ _mm_storel_epi64((__m128i *) out, _mm_shuffle_epi32(p1, 0x4e)); out += out_stride;
+ _mm_storel_epi64((__m128i *) out, p3); out += out_stride;
+ _mm_storel_epi64((__m128i *) out, _mm_shuffle_epi32(p3, 0x4e));
+ }
+
+#undef dct_const
+#undef dct_rot
+#undef dct_widen
+#undef dct_wadd
+#undef dct_wsub
+#undef dct_bfly32o
+#undef dct_interleave8
+#undef dct_interleave16
+#undef dct_pass
+}
+
+#endif // STBI_SSE2
+
+#ifdef STBI_NEON
+
+// NEON integer IDCT. should produce bit-identical
+// results to the generic C version.
+static void stbi__idct_simd(stbi_uc *out, int out_stride, short data[64])
+{
+ int16x8_t row0, row1, row2, row3, row4, row5, row6, row7;
+
+ int16x4_t rot0_0 = vdup_n_s16(stbi__f2f(0.5411961f));
+ int16x4_t rot0_1 = vdup_n_s16(stbi__f2f(-1.847759065f));
+ int16x4_t rot0_2 = vdup_n_s16(stbi__f2f( 0.765366865f));
+ int16x4_t rot1_0 = vdup_n_s16(stbi__f2f( 1.175875602f));
+ int16x4_t rot1_1 = vdup_n_s16(stbi__f2f(-0.899976223f));
+ int16x4_t rot1_2 = vdup_n_s16(stbi__f2f(-2.562915447f));
+ int16x4_t rot2_0 = vdup_n_s16(stbi__f2f(-1.961570560f));
+ int16x4_t rot2_1 = vdup_n_s16(stbi__f2f(-0.390180644f));
+ int16x4_t rot3_0 = vdup_n_s16(stbi__f2f( 0.298631336f));
+ int16x4_t rot3_1 = vdup_n_s16(stbi__f2f( 2.053119869f));
+ int16x4_t rot3_2 = vdup_n_s16(stbi__f2f( 3.072711026f));
+ int16x4_t rot3_3 = vdup_n_s16(stbi__f2f( 1.501321110f));
+
+#define dct_long_mul(out, inq, coeff) \
+ int32x4_t out##_l = vmull_s16(vget_low_s16(inq), coeff); \
+ int32x4_t out##_h = vmull_s16(vget_high_s16(inq), coeff)
+
+#define dct_long_mac(out, acc, inq, coeff) \
+ int32x4_t out##_l = vmlal_s16(acc##_l, vget_low_s16(inq), coeff); \
+ int32x4_t out##_h = vmlal_s16(acc##_h, vget_high_s16(inq), coeff)
+
+#define dct_widen(out, inq) \
+ int32x4_t out##_l = vshll_n_s16(vget_low_s16(inq), 12); \
+ int32x4_t out##_h = vshll_n_s16(vget_high_s16(inq), 12)
+
+// wide add
+#define dct_wadd(out, a, b) \
+ int32x4_t out##_l = vaddq_s32(a##_l, b##_l); \
+ int32x4_t out##_h = vaddq_s32(a##_h, b##_h)
+
+// wide sub
+#define dct_wsub(out, a, b) \
+ int32x4_t out##_l = vsubq_s32(a##_l, b##_l); \
+ int32x4_t out##_h = vsubq_s32(a##_h, b##_h)
+
+// butterfly a/b, then shift using "shiftop" by "s" and pack
+#define dct_bfly32o(out0,out1, a,b,shiftop,s) \
+ { \
+ dct_wadd(sum, a, b); \
+ dct_wsub(dif, a, b); \
+ out0 = vcombine_s16(shiftop(sum_l, s), shiftop(sum_h, s)); \
+ out1 = vcombine_s16(shiftop(dif_l, s), shiftop(dif_h, s)); \
+ }
+
+#define dct_pass(shiftop, shift) \
+ { \
+ /* even part */ \
+ int16x8_t sum26 = vaddq_s16(row2, row6); \
+ dct_long_mul(p1e, sum26, rot0_0); \
+ dct_long_mac(t2e, p1e, row6, rot0_1); \
+ dct_long_mac(t3e, p1e, row2, rot0_2); \
+ int16x8_t sum04 = vaddq_s16(row0, row4); \
+ int16x8_t dif04 = vsubq_s16(row0, row4); \
+ dct_widen(t0e, sum04); \
+ dct_widen(t1e, dif04); \
+ dct_wadd(x0, t0e, t3e); \
+ dct_wsub(x3, t0e, t3e); \
+ dct_wadd(x1, t1e, t2e); \
+ dct_wsub(x2, t1e, t2e); \
+ /* odd part */ \
+ int16x8_t sum15 = vaddq_s16(row1, row5); \
+ int16x8_t sum17 = vaddq_s16(row1, row7); \
+ int16x8_t sum35 = vaddq_s16(row3, row5); \
+ int16x8_t sum37 = vaddq_s16(row3, row7); \
+ int16x8_t sumodd = vaddq_s16(sum17, sum35); \
+ dct_long_mul(p5o, sumodd, rot1_0); \
+ dct_long_mac(p1o, p5o, sum17, rot1_1); \
+ dct_long_mac(p2o, p5o, sum35, rot1_2); \
+ dct_long_mul(p3o, sum37, rot2_0); \
+ dct_long_mul(p4o, sum15, rot2_1); \
+ dct_wadd(sump13o, p1o, p3o); \
+ dct_wadd(sump24o, p2o, p4o); \
+ dct_wadd(sump23o, p2o, p3o); \
+ dct_wadd(sump14o, p1o, p4o); \
+ dct_long_mac(x4, sump13o, row7, rot3_0); \
+ dct_long_mac(x5, sump24o, row5, rot3_1); \
+ dct_long_mac(x6, sump23o, row3, rot3_2); \
+ dct_long_mac(x7, sump14o, row1, rot3_3); \
+ dct_bfly32o(row0,row7, x0,x7,shiftop,shift); \
+ dct_bfly32o(row1,row6, x1,x6,shiftop,shift); \
+ dct_bfly32o(row2,row5, x2,x5,shiftop,shift); \
+ dct_bfly32o(row3,row4, x3,x4,shiftop,shift); \
+ }
+
+ // load
+ row0 = vld1q_s16(data + 0*8);
+ row1 = vld1q_s16(data + 1*8);
+ row2 = vld1q_s16(data + 2*8);
+ row3 = vld1q_s16(data + 3*8);
+ row4 = vld1q_s16(data + 4*8);
+ row5 = vld1q_s16(data + 5*8);
+ row6 = vld1q_s16(data + 6*8);
+ row7 = vld1q_s16(data + 7*8);
+
+ // add DC bias
+ row0 = vaddq_s16(row0, vsetq_lane_s16(1024, vdupq_n_s16(0), 0));
+
+ // column pass
+ dct_pass(vrshrn_n_s32, 10);
+
+ // 16bit 8x8 transpose
+ {
+// these three map to a single VTRN.16, VTRN.32, and VSWP, respectively.
+// whether compilers actually get this is another story, sadly.
+#define dct_trn16(x, y) { int16x8x2_t t = vtrnq_s16(x, y); x = t.val[0]; y = t.val[1]; }
+#define dct_trn32(x, y) { int32x4x2_t t = vtrnq_s32(vreinterpretq_s32_s16(x), vreinterpretq_s32_s16(y)); x = vreinterpretq_s16_s32(t.val[0]); y = vreinterpretq_s16_s32(t.val[1]); }
+#define dct_trn64(x, y) { int16x8_t x0 = x; int16x8_t y0 = y; x = vcombine_s16(vget_low_s16(x0), vget_low_s16(y0)); y = vcombine_s16(vget_high_s16(x0), vget_high_s16(y0)); }
+
+ // pass 1
+ dct_trn16(row0, row1); // a0b0a2b2a4b4a6b6
+ dct_trn16(row2, row3);
+ dct_trn16(row4, row5);
+ dct_trn16(row6, row7);
+
+ // pass 2
+ dct_trn32(row0, row2); // a0b0c0d0a4b4c4d4
+ dct_trn32(row1, row3);
+ dct_trn32(row4, row6);
+ dct_trn32(row5, row7);
+
+ // pass 3
+ dct_trn64(row0, row4); // a0b0c0d0e0f0g0h0
+ dct_trn64(row1, row5);
+ dct_trn64(row2, row6);
+ dct_trn64(row3, row7);
+
+#undef dct_trn16
+#undef dct_trn32
+#undef dct_trn64
+ }
+
+ // row pass
+ // vrshrn_n_s32 only supports shifts up to 16, we need
+ // 17. so do a non-rounding shift of 16 first then follow
+ // up with a rounding shift by 1.
+ dct_pass(vshrn_n_s32, 16);
+
+ {
+ // pack and round
+ uint8x8_t p0 = vqrshrun_n_s16(row0, 1);
+ uint8x8_t p1 = vqrshrun_n_s16(row1, 1);
+ uint8x8_t p2 = vqrshrun_n_s16(row2, 1);
+ uint8x8_t p3 = vqrshrun_n_s16(row3, 1);
+ uint8x8_t p4 = vqrshrun_n_s16(row4, 1);
+ uint8x8_t p5 = vqrshrun_n_s16(row5, 1);
+ uint8x8_t p6 = vqrshrun_n_s16(row6, 1);
+ uint8x8_t p7 = vqrshrun_n_s16(row7, 1);
+
+ // again, these can translate into one instruction, but often don't.
+#define dct_trn8_8(x, y) { uint8x8x2_t t = vtrn_u8(x, y); x = t.val[0]; y = t.val[1]; }
+#define dct_trn8_16(x, y) { uint16x4x2_t t = vtrn_u16(vreinterpret_u16_u8(x), vreinterpret_u16_u8(y)); x = vreinterpret_u8_u16(t.val[0]); y = vreinterpret_u8_u16(t.val[1]); }
+#define dct_trn8_32(x, y) { uint32x2x2_t t = vtrn_u32(vreinterpret_u32_u8(x), vreinterpret_u32_u8(y)); x = vreinterpret_u8_u32(t.val[0]); y = vreinterpret_u8_u32(t.val[1]); }
+
+ // sadly can't use interleaved stores here since we only write
+ // 8 bytes to each scan line!
+
+ // 8x8 8-bit transpose pass 1
+ dct_trn8_8(p0, p1);
+ dct_trn8_8(p2, p3);
+ dct_trn8_8(p4, p5);
+ dct_trn8_8(p6, p7);
+
+ // pass 2
+ dct_trn8_16(p0, p2);
+ dct_trn8_16(p1, p3);
+ dct_trn8_16(p4, p6);
+ dct_trn8_16(p5, p7);
+
+ // pass 3
+ dct_trn8_32(p0, p4);
+ dct_trn8_32(p1, p5);
+ dct_trn8_32(p2, p6);
+ dct_trn8_32(p3, p7);
+
+ // store
+ vst1_u8(out, p0); out += out_stride;
+ vst1_u8(out, p1); out += out_stride;
+ vst1_u8(out, p2); out += out_stride;
+ vst1_u8(out, p3); out += out_stride;
+ vst1_u8(out, p4); out += out_stride;
+ vst1_u8(out, p5); out += out_stride;
+ vst1_u8(out, p6); out += out_stride;
+ vst1_u8(out, p7);
+
+#undef dct_trn8_8
+#undef dct_trn8_16
+#undef dct_trn8_32
+ }
+
+#undef dct_long_mul
+#undef dct_long_mac
+#undef dct_widen
+#undef dct_wadd
+#undef dct_wsub
+#undef dct_bfly32o
+#undef dct_pass
+}
+
+#endif // STBI_NEON
+
+#define STBI__MARKER_none 0xff
+// if there's a pending marker from the entropy stream, return that
+// otherwise, fetch from the stream and get a marker. if there's no
+// marker, return 0xff, which is never a valid marker value
+static stbi_uc stbi__get_marker(stbi__jpeg *j)
+{
+ stbi_uc x;
+ if (j->marker != STBI__MARKER_none) { x = j->marker; j->marker = STBI__MARKER_none; return x; }
+ x = stbi__get8(j->s);
+ if (x != 0xff) return STBI__MARKER_none;
+ while (x == 0xff)
+ x = stbi__get8(j->s); // consume repeated 0xff fill bytes
+ return x;
+}
+
+// in each scan, we'll have scan_n components, and the order
+// of the components is specified by order[]
+#define STBI__RESTART(x) ((x) >= 0xd0 && (x) <= 0xd7)
+
+// after a restart interval, stbi__jpeg_reset the entropy decoder and
+// the dc prediction
+static void stbi__jpeg_reset(stbi__jpeg *j)
+{
+ j->code_bits = 0;
+ j->code_buffer = 0;
+ j->nomore = 0;
+ j->img_comp[0].dc_pred = j->img_comp[1].dc_pred = j->img_comp[2].dc_pred = j->img_comp[3].dc_pred = 0;
+ j->marker = STBI__MARKER_none;
+ j->todo = j->restart_interval ? j->restart_interval : 0x7fffffff;
+ j->eob_run = 0;
+ // no more than 1<<31 MCUs if no restart_interal? that's plenty safe,
+ // since we don't even allow 1<<30 pixels
+}
+
+static int stbi__parse_entropy_coded_data(stbi__jpeg *z)
+{
+ stbi__jpeg_reset(z);
+ if (!z->progressive) {
+ if (z->scan_n == 1) {
+ int i,j;
+ STBI_SIMD_ALIGN(short, data[64]);
+ int n = z->order[0];
+ // non-interleaved data, we just need to process one block at a time,
+ // in trivial scanline order
+ // number of blocks to do just depends on how many actual "pixels" this
+ // component has, independent of interleaved MCU blocking and such
+ int w = (z->img_comp[n].x+7) >> 3;
+ int h = (z->img_comp[n].y+7) >> 3;
+ for (j=0; j < h; ++j) {
+ for (i=0; i < w; ++i) {
+ int ha = z->img_comp[n].ha;
+ if (!stbi__jpeg_decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+ha, z->fast_ac[ha], n, z->dequant[z->img_comp[n].tq])) return 0;
+ z->idct_block_kernel(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data);
+ // every data block is an MCU, so countdown the restart interval
+ if (--z->todo <= 0) {
+ if (z->code_bits < 24) stbi__grow_buffer_unsafe(z);
+ // if it's NOT a restart, then just bail, so we get corrupt data
+ // rather than no data
+ if (!STBI__RESTART(z->marker)) return 1;
+ stbi__jpeg_reset(z);
+ }
+ }
+ }
+ return 1;
+ } else { // interleaved
+ int i,j,k,x,y;
+ STBI_SIMD_ALIGN(short, data[64]);
+ for (j=0; j < z->img_mcu_y; ++j) {
+ for (i=0; i < z->img_mcu_x; ++i) {
+ // scan an interleaved mcu... process scan_n components in order
+ for (k=0; k < z->scan_n; ++k) {
+ int n = z->order[k];
+ // scan out an mcu's worth of this component; that's just determined
+ // by the basic H and V specified for the component
+ for (y=0; y < z->img_comp[n].v; ++y) {
+ for (x=0; x < z->img_comp[n].h; ++x) {
+ int x2 = (i*z->img_comp[n].h + x)*8;
+ int y2 = (j*z->img_comp[n].v + y)*8;
+ int ha = z->img_comp[n].ha;
+ if (!stbi__jpeg_decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+ha, z->fast_ac[ha], n, z->dequant[z->img_comp[n].tq])) return 0;
+ z->idct_block_kernel(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data);
+ }
+ }
+ }
+ // after all interleaved components, that's an interleaved MCU,
+ // so now count down the restart interval
+ if (--z->todo <= 0) {
+ if (z->code_bits < 24) stbi__grow_buffer_unsafe(z);
+ if (!STBI__RESTART(z->marker)) return 1;
+ stbi__jpeg_reset(z);
+ }
+ }
+ }
+ return 1;
+ }
+ } else {
+ if (z->scan_n == 1) {
+ int i,j;
+ int n = z->order[0];
+ // non-interleaved data, we just need to process one block at a time,
+ // in trivial scanline order
+ // number of blocks to do just depends on how many actual "pixels" this
+ // component has, independent of interleaved MCU blocking and such
+ int w = (z->img_comp[n].x+7) >> 3;
+ int h = (z->img_comp[n].y+7) >> 3;
+ for (j=0; j < h; ++j) {
+ for (i=0; i < w; ++i) {
+ short *data = z->img_comp[n].coeff + 64 * (i + j * z->img_comp[n].coeff_w);
+ if (z->spec_start == 0) {
+ if (!stbi__jpeg_decode_block_prog_dc(z, data, &z->huff_dc[z->img_comp[n].hd], n))
+ return 0;
+ } else {
+ int ha = z->img_comp[n].ha;
+ if (!stbi__jpeg_decode_block_prog_ac(z, data, &z->huff_ac[ha], z->fast_ac[ha]))
+ return 0;
+ }
+ // every data block is an MCU, so countdown the restart interval
+ if (--z->todo <= 0) {
+ if (z->code_bits < 24) stbi__grow_buffer_unsafe(z);
+ if (!STBI__RESTART(z->marker)) return 1;
+ stbi__jpeg_reset(z);
+ }
+ }
+ }
+ return 1;
+ } else { // interleaved
+ int i,j,k,x,y;
+ for (j=0; j < z->img_mcu_y; ++j) {
+ for (i=0; i < z->img_mcu_x; ++i) {
+ // scan an interleaved mcu... process scan_n components in order
+ for (k=0; k < z->scan_n; ++k) {
+ int n = z->order[k];
+ // scan out an mcu's worth of this component; that's just determined
+ // by the basic H and V specified for the component
+ for (y=0; y < z->img_comp[n].v; ++y) {
+ for (x=0; x < z->img_comp[n].h; ++x) {
+ int x2 = (i*z->img_comp[n].h + x);
+ int y2 = (j*z->img_comp[n].v + y);
+ short *data = z->img_comp[n].coeff + 64 * (x2 + y2 * z->img_comp[n].coeff_w);
+ if (!stbi__jpeg_decode_block_prog_dc(z, data, &z->huff_dc[z->img_comp[n].hd], n))
+ return 0;
+ }
+ }
+ }
+ // after all interleaved components, that's an interleaved MCU,
+ // so now count down the restart interval
+ if (--z->todo <= 0) {
+ if (z->code_bits < 24) stbi__grow_buffer_unsafe(z);
+ if (!STBI__RESTART(z->marker)) return 1;
+ stbi__jpeg_reset(z);
+ }
+ }
+ }
+ return 1;
+ }
+ }
+}
+
+static void stbi__jpeg_dequantize(short *data, stbi__uint16 *dequant)
+{
+ int i;
+ for (i=0; i < 64; ++i)
+ data[i] *= dequant[i];
+}
+
+static void stbi__jpeg_finish(stbi__jpeg *z)
+{
+ if (z->progressive) {
+ // dequantize and idct the data
+ int i,j,n;
+ for (n=0; n < z->s->img_n; ++n) {
+ int w = (z->img_comp[n].x+7) >> 3;
+ int h = (z->img_comp[n].y+7) >> 3;
+ for (j=0; j < h; ++j) {
+ for (i=0; i < w; ++i) {
+ short *data = z->img_comp[n].coeff + 64 * (i + j * z->img_comp[n].coeff_w);
+ stbi__jpeg_dequantize(data, z->dequant[z->img_comp[n].tq]);
+ z->idct_block_kernel(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data);
+ }
+ }
+ }
+ }
+}
+
+static int stbi__process_marker(stbi__jpeg *z, int m)
+{
+ int L;
+ switch (m) {
+ case STBI__MARKER_none: // no marker found
+ return stbi__err("expected marker","Corrupt JPEG");
+
+ case 0xDD: // DRI - specify restart interval
+ if (stbi__get16be(z->s) != 4) return stbi__err("bad DRI len","Corrupt JPEG");
+ z->restart_interval = stbi__get16be(z->s);
+ return 1;
+
+ case 0xDB: // DQT - define quantization table
+ L = stbi__get16be(z->s)-2;
+ while (L > 0) {
+ int q = stbi__get8(z->s);
+ int p = q >> 4, sixteen = (p != 0);
+ int t = q & 15,i;
+ if (p != 0 && p != 1) return stbi__err("bad DQT type","Corrupt JPEG");
+ if (t > 3) return stbi__err("bad DQT table","Corrupt JPEG");
+
+ for (i=0; i < 64; ++i)
+ z->dequant[t][stbi__jpeg_dezigzag[i]] = (stbi__uint16)(sixteen ? stbi__get16be(z->s) : stbi__get8(z->s));
+ L -= (sixteen ? 129 : 65);
+ }
+ return L==0;
+
+ case 0xC4: // DHT - define huffman table
+ L = stbi__get16be(z->s)-2;
+ while (L > 0) {
+ stbi_uc *v;
+ int sizes[16],i,n=0;
+ int q = stbi__get8(z->s);
+ int tc = q >> 4;
+ int th = q & 15;
+ if (tc > 1 || th > 3) return stbi__err("bad DHT header","Corrupt JPEG");
+ for (i=0; i < 16; ++i) {
+ sizes[i] = stbi__get8(z->s);
+ n += sizes[i];
+ }
+ L -= 17;
+ if (tc == 0) {
+ if (!stbi__build_huffman(z->huff_dc+th, sizes)) return 0;
+ v = z->huff_dc[th].values;
+ } else {
+ if (!stbi__build_huffman(z->huff_ac+th, sizes)) return 0;
+ v = z->huff_ac[th].values;
+ }
+ for (i=0; i < n; ++i)
+ v[i] = stbi__get8(z->s);
+ if (tc != 0)
+ stbi__build_fast_ac(z->fast_ac[th], z->huff_ac + th);
+ L -= n;
+ }
+ return L==0;
+ }
+
+ // check for comment block or APP blocks
+ if ((m >= 0xE0 && m <= 0xEF) || m == 0xFE) {
+ L = stbi__get16be(z->s);
+ if (L < 2) {
+ if (m == 0xFE)
+ return stbi__err("bad COM len","Corrupt JPEG");
+ else
+ return stbi__err("bad APP len","Corrupt JPEG");
+ }
+ L -= 2;
+
+ if (m == 0xE0 && L >= 5) { // JFIF APP0 segment
+ static const unsigned char tag[5] = {'J','F','I','F','\0'};
+ int ok = 1;
+ int i;
+ for (i=0; i < 5; ++i)
+ if (stbi__get8(z->s) != tag[i])
+ ok = 0;
+ L -= 5;
+ if (ok)
+ z->jfif = 1;
+ } else if (m == 0xEE && L >= 12) { // Adobe APP14 segment
+ static const unsigned char tag[6] = {'A','d','o','b','e','\0'};
+ int ok = 1;
+ int i;
+ for (i=0; i < 6; ++i)
+ if (stbi__get8(z->s) != tag[i])
+ ok = 0;
+ L -= 6;
+ if (ok) {
+ stbi__get8(z->s); // version
+ stbi__get16be(z->s); // flags0
+ stbi__get16be(z->s); // flags1
+ z->app14_color_transform = stbi__get8(z->s); // color transform
+ L -= 6;
+ }
+ }
+
+ stbi__skip(z->s, L);
+ return 1;
+ }
+
+ return stbi__err("unknown marker","Corrupt JPEG");
+}
+
+// after we see SOS
+static int stbi__process_scan_header(stbi__jpeg *z)
+{
+ int i;
+ int Ls = stbi__get16be(z->s);
+ z->scan_n = stbi__get8(z->s);
+ if (z->scan_n < 1 || z->scan_n > 4 || z->scan_n > (int) z->s->img_n) return stbi__err("bad SOS component count","Corrupt JPEG");
+ if (Ls != 6+2*z->scan_n) return stbi__err("bad SOS len","Corrupt JPEG");
+ for (i=0; i < z->scan_n; ++i) {
+ int id = stbi__get8(z->s), which;
+ int q = stbi__get8(z->s);
+ for (which = 0; which < z->s->img_n; ++which)
+ if (z->img_comp[which].id == id)
+ break;
+ if (which == z->s->img_n) return 0; // no match
+ z->img_comp[which].hd = q >> 4; if (z->img_comp[which].hd > 3) return stbi__err("bad DC huff","Corrupt JPEG");
+ z->img_comp[which].ha = q & 15; if (z->img_comp[which].ha > 3) return stbi__err("bad AC huff","Corrupt JPEG");
+ z->order[i] = which;
+ }
+
+ {
+ int aa;
+ z->spec_start = stbi__get8(z->s);
+ z->spec_end = stbi__get8(z->s); // should be 63, but might be 0
+ aa = stbi__get8(z->s);
+ z->succ_high = (aa >> 4);
+ z->succ_low = (aa & 15);
+ if (z->progressive) {
+ if (z->spec_start > 63 || z->spec_end > 63 || z->spec_start > z->spec_end || z->succ_high > 13 || z->succ_low > 13)
+ return stbi__err("bad SOS", "Corrupt JPEG");
+ } else {
+ if (z->spec_start != 0) return stbi__err("bad SOS","Corrupt JPEG");
+ if (z->succ_high != 0 || z->succ_low != 0) return stbi__err("bad SOS","Corrupt JPEG");
+ z->spec_end = 63;
+ }
+ }
+
+ return 1;
+}
+
+static int stbi__free_jpeg_components(stbi__jpeg *z, int ncomp, int why)
+{
+ int i;
+ for (i=0; i < ncomp; ++i) {
+ if (z->img_comp[i].raw_data) {
+ STBI_FREE(z->img_comp[i].raw_data);
+ z->img_comp[i].raw_data = NULL;
+ z->img_comp[i].data = NULL;
+ }
+ if (z->img_comp[i].raw_coeff) {
+ STBI_FREE(z->img_comp[i].raw_coeff);
+ z->img_comp[i].raw_coeff = 0;
+ z->img_comp[i].coeff = 0;
+ }
+ if (z->img_comp[i].linebuf) {
+ STBI_FREE(z->img_comp[i].linebuf);
+ z->img_comp[i].linebuf = NULL;
+ }
+ }
+ return why;
+}
+
+static int stbi__process_frame_header(stbi__jpeg *z, int scan)
+{
+ stbi__context *s = z->s;
+ int Lf,p,i,q, h_max=1,v_max=1,c;
+ Lf = stbi__get16be(s); if (Lf < 11) return stbi__err("bad SOF len","Corrupt JPEG"); // JPEG
+ p = stbi__get8(s); if (p != 8) return stbi__err("only 8-bit","JPEG format not supported: 8-bit only"); // JPEG baseline
+ s->img_y = stbi__get16be(s); if (s->img_y == 0) return stbi__err("no header height", "JPEG format not supported: delayed height"); // Legal, but we don't handle it--but neither does IJG
+ s->img_x = stbi__get16be(s); if (s->img_x == 0) return stbi__err("0 width","Corrupt JPEG"); // JPEG requires
+ if (s->img_y > STBI_MAX_DIMENSIONS) return stbi__err("too large","Very large image (corrupt?)");
+ if (s->img_x > STBI_MAX_DIMENSIONS) return stbi__err("too large","Very large image (corrupt?)");
+ c = stbi__get8(s);
+ if (c != 3 && c != 1 && c != 4) return stbi__err("bad component count","Corrupt JPEG");
+ s->img_n = c;
+ for (i=0; i < c; ++i) {
+ z->img_comp[i].data = NULL;
+ z->img_comp[i].linebuf = NULL;
+ }
+
+ if (Lf != 8+3*s->img_n) return stbi__err("bad SOF len","Corrupt JPEG");
+
+ z->rgb = 0;
+ for (i=0; i < s->img_n; ++i) {
+ static const unsigned char rgb[3] = { 'R', 'G', 'B' };
+ z->img_comp[i].id = stbi__get8(s);
+ if (s->img_n == 3 && z->img_comp[i].id == rgb[i])
+ ++z->rgb;
+ q = stbi__get8(s);
+ z->img_comp[i].h = (q >> 4); if (!z->img_comp[i].h || z->img_comp[i].h > 4) return stbi__err("bad H","Corrupt JPEG");
+ z->img_comp[i].v = q & 15; if (!z->img_comp[i].v || z->img_comp[i].v > 4) return stbi__err("bad V","Corrupt JPEG");
+ z->img_comp[i].tq = stbi__get8(s); if (z->img_comp[i].tq > 3) return stbi__err("bad TQ","Corrupt JPEG");
+ }
+
+ if (scan != STBI__SCAN_load) return 1;
+
+ if (!stbi__mad3sizes_valid(s->img_x, s->img_y, s->img_n, 0)) return stbi__err("too large", "Image too large to decode");
+
+ for (i=0; i < s->img_n; ++i) {
+ if (z->img_comp[i].h > h_max) h_max = z->img_comp[i].h;
+ if (z->img_comp[i].v > v_max) v_max = z->img_comp[i].v;
+ }
+
+ // check that plane subsampling factors are integer ratios; our resamplers can't deal with fractional ratios
+ // and I've never seen a non-corrupted JPEG file actually use them
+ for (i=0; i < s->img_n; ++i) {
+ if (h_max % z->img_comp[i].h != 0) return stbi__err("bad H","Corrupt JPEG");
+ if (v_max % z->img_comp[i].v != 0) return stbi__err("bad V","Corrupt JPEG");
+ }
+
+ // compute interleaved mcu info
+ z->img_h_max = h_max;
+ z->img_v_max = v_max;
+ z->img_mcu_w = h_max * 8;
+ z->img_mcu_h = v_max * 8;
+ // these sizes can't be more than 17 bits
+ z->img_mcu_x = (s->img_x + z->img_mcu_w-1) / z->img_mcu_w;
+ z->img_mcu_y = (s->img_y + z->img_mcu_h-1) / z->img_mcu_h;
+
+ for (i=0; i < s->img_n; ++i) {
+ // number of effective pixels (e.g. for non-interleaved MCU)
+ z->img_comp[i].x = (s->img_x * z->img_comp[i].h + h_max-1) / h_max;
+ z->img_comp[i].y = (s->img_y * z->img_comp[i].v + v_max-1) / v_max;
+ // to simplify generation, we'll allocate enough memory to decode
+ // the bogus oversized data from using interleaved MCUs and their
+ // big blocks (e.g. a 16x16 iMCU on an image of width 33); we won't
+ // discard the extra data until colorspace conversion
+ //
+ // img_mcu_x, img_mcu_y: <=17 bits; comp[i].h and .v are <=4 (checked earlier)
+ // so these muls can't overflow with 32-bit ints (which we require)
+ z->img_comp[i].w2 = z->img_mcu_x * z->img_comp[i].h * 8;
+ z->img_comp[i].h2 = z->img_mcu_y * z->img_comp[i].v * 8;
+ z->img_comp[i].coeff = 0;
+ z->img_comp[i].raw_coeff = 0;
+ z->img_comp[i].linebuf = NULL;
+ z->img_comp[i].raw_data = stbi__malloc_mad2(z->img_comp[i].w2, z->img_comp[i].h2, 15);
+ if (z->img_comp[i].raw_data == NULL)
+ return stbi__free_jpeg_components(z, i+1, stbi__err("outofmem", "Out of memory"));
+ // align blocks for idct using mmx/sse
+ z->img_comp[i].data = (stbi_uc*) (((size_t) z->img_comp[i].raw_data + 15) & ~15);
+ if (z->progressive) {
+ // w2, h2 are multiples of 8 (see above)
+ z->img_comp[i].coeff_w = z->img_comp[i].w2 / 8;
+ z->img_comp[i].coeff_h = z->img_comp[i].h2 / 8;
+ z->img_comp[i].raw_coeff = stbi__malloc_mad3(z->img_comp[i].w2, z->img_comp[i].h2, sizeof(short), 15);
+ if (z->img_comp[i].raw_coeff == NULL)
+ return stbi__free_jpeg_components(z, i+1, stbi__err("outofmem", "Out of memory"));
+ z->img_comp[i].coeff = (short*) (((size_t) z->img_comp[i].raw_coeff + 15) & ~15);
+ }
+ }
+
+ return 1;
+}
+
+// use comparisons since in some cases we handle more than one case (e.g. SOF)
+#define stbi__DNL(x) ((x) == 0xdc)
+#define stbi__SOI(x) ((x) == 0xd8)
+#define stbi__EOI(x) ((x) == 0xd9)
+#define stbi__SOF(x) ((x) == 0xc0 || (x) == 0xc1 || (x) == 0xc2)
+#define stbi__SOS(x) ((x) == 0xda)
+
+#define stbi__SOF_progressive(x) ((x) == 0xc2)
+
+static int stbi__decode_jpeg_header(stbi__jpeg *z, int scan)
+{
+ int m;
+ z->jfif = 0;
+ z->app14_color_transform = -1; // valid values are 0,1,2
+ z->marker = STBI__MARKER_none; // initialize cached marker to empty
+ m = stbi__get_marker(z);
+ if (!stbi__SOI(m)) return stbi__err("no SOI","Corrupt JPEG");
+ if (scan == STBI__SCAN_type) return 1;
+ m = stbi__get_marker(z);
+ while (!stbi__SOF(m)) {
+ if (!stbi__process_marker(z,m)) return 0;
+ m = stbi__get_marker(z);
+ while (m == STBI__MARKER_none) {
+ // some files have extra padding after their blocks, so ok, we'll scan
+ if (stbi__at_eof(z->s)) return stbi__err("no SOF", "Corrupt JPEG");
+ m = stbi__get_marker(z);
+ }
+ }
+ z->progressive = stbi__SOF_progressive(m);
+ if (!stbi__process_frame_header(z, scan)) return 0;
+ return 1;
+}
+
+// decode image to YCbCr format
+static int stbi__decode_jpeg_image(stbi__jpeg *j)
+{
+ int m;
+ for (m = 0; m < 4; m++) {
+ j->img_comp[m].raw_data = NULL;
+ j->img_comp[m].raw_coeff = NULL;
+ }
+ j->restart_interval = 0;
+ if (!stbi__decode_jpeg_header(j, STBI__SCAN_load)) return 0;
+ m = stbi__get_marker(j);
+ while (!stbi__EOI(m)) {
+ if (stbi__SOS(m)) {
+ if (!stbi__process_scan_header(j)) return 0;
+ if (!stbi__parse_entropy_coded_data(j)) return 0;
+ if (j->marker == STBI__MARKER_none ) {
+ // handle 0s at the end of image data from IP Kamera 9060
+ while (!stbi__at_eof(j->s)) {
+ int x = stbi__get8(j->s);
+ if (x == 255) {
+ j->marker = stbi__get8(j->s);
+ break;
+ }
+ }
+ // if we reach eof without hitting a marker, stbi__get_marker() below will fail and we'll eventually return 0
+ }
+ } else if (stbi__DNL(m)) {
+ int Ld = stbi__get16be(j->s);
+ stbi__uint32 NL = stbi__get16be(j->s);
+ if (Ld != 4) return stbi__err("bad DNL len", "Corrupt JPEG");
+ if (NL != j->s->img_y) return stbi__err("bad DNL height", "Corrupt JPEG");
+ } else {
+ if (!stbi__process_marker(j, m)) return 0;
+ }
+ m = stbi__get_marker(j);
+ }
+ if (j->progressive)
+ stbi__jpeg_finish(j);
+ return 1;
+}
+
+// static jfif-centered resampling (across block boundaries)
+
+typedef stbi_uc *(*resample_row_func)(stbi_uc *out, stbi_uc *in0, stbi_uc *in1,
+ int w, int hs);
+
+#define stbi__div4(x) ((stbi_uc) ((x) >> 2))
+
+static stbi_uc *resample_row_1(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs)
+{
+ STBI_NOTUSED(out);
+ STBI_NOTUSED(in_far);
+ STBI_NOTUSED(w);
+ STBI_NOTUSED(hs);
+ return in_near;
+}
+
+static stbi_uc* stbi__resample_row_v_2(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs)
+{
+ // need to generate two samples vertically for every one in input
+ int i;
+ STBI_NOTUSED(hs);
+ for (i=0; i < w; ++i)
+ out[i] = stbi__div4(3*in_near[i] + in_far[i] + 2);
+ return out;
+}
+
+static stbi_uc* stbi__resample_row_h_2(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs)
+{
+ // need to generate two samples horizontally for every one in input
+ int i;
+ stbi_uc *input = in_near;
+
+ if (w == 1) {
+ // if only one sample, can't do any interpolation
+ out[0] = out[1] = input[0];
+ return out;
+ }
+
+ out[0] = input[0];
+ out[1] = stbi__div4(input[0]*3 + input[1] + 2);
+ for (i=1; i < w-1; ++i) {
+ int n = 3*input[i]+2;
+ out[i*2+0] = stbi__div4(n+input[i-1]);
+ out[i*2+1] = stbi__div4(n+input[i+1]);
+ }
+ out[i*2+0] = stbi__div4(input[w-2]*3 + input[w-1] + 2);
+ out[i*2+1] = input[w-1];
+
+ STBI_NOTUSED(in_far);
+ STBI_NOTUSED(hs);
+
+ return out;
+}
+
+#define stbi__div16(x) ((stbi_uc) ((x) >> 4))
+
+static stbi_uc *stbi__resample_row_hv_2(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs)
+{
+ // need to generate 2x2 samples for every one in input
+ int i,t0,t1;
+ if (w == 1) {
+ out[0] = out[1] = stbi__div4(3*in_near[0] + in_far[0] + 2);
+ return out;
+ }
+
+ t1 = 3*in_near[0] + in_far[0];
+ out[0] = stbi__div4(t1+2);
+ for (i=1; i < w; ++i) {
+ t0 = t1;
+ t1 = 3*in_near[i]+in_far[i];
+ out[i*2-1] = stbi__div16(3*t0 + t1 + 8);
+ out[i*2 ] = stbi__div16(3*t1 + t0 + 8);
+ }
+ out[w*2-1] = stbi__div4(t1+2);
+
+ STBI_NOTUSED(hs);
+
+ return out;
+}
+
+#if defined(STBI_SSE2) || defined(STBI_NEON)
+static stbi_uc *stbi__resample_row_hv_2_simd(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs)
+{
+ // need to generate 2x2 samples for every one in input
+ int i=0,t0,t1;
+
+ if (w == 1) {
+ out[0] = out[1] = stbi__div4(3*in_near[0] + in_far[0] + 2);
+ return out;
+ }
+
+ t1 = 3*in_near[0] + in_far[0];
+ // process groups of 8 pixels for as long as we can.
+ // note we can't handle the last pixel in a row in this loop
+ // because we need to handle the filter boundary conditions.
+ for (; i < ((w-1) & ~7); i += 8) {
+#if defined(STBI_SSE2)
+ // load and perform the vertical filtering pass
+ // this uses 3*x + y = 4*x + (y - x)
+ __m128i zero = _mm_setzero_si128();
+ __m128i farb = _mm_loadl_epi64((__m128i *) (in_far + i));
+ __m128i nearb = _mm_loadl_epi64((__m128i *) (in_near + i));
+ __m128i farw = _mm_unpacklo_epi8(farb, zero);
+ __m128i nearw = _mm_unpacklo_epi8(nearb, zero);
+ __m128i diff = _mm_sub_epi16(farw, nearw);
+ __m128i nears = _mm_slli_epi16(nearw, 2);
+ __m128i curr = _mm_add_epi16(nears, diff); // current row
+
+ // horizontal filter works the same based on shifted vers of current
+ // row. "prev" is current row shifted right by 1 pixel; we need to
+ // insert the previous pixel value (from t1).
+ // "next" is current row shifted left by 1 pixel, with first pixel
+ // of next block of 8 pixels added in.
+ __m128i prv0 = _mm_slli_si128(curr, 2);
+ __m128i nxt0 = _mm_srli_si128(curr, 2);
+ __m128i prev = _mm_insert_epi16(prv0, t1, 0);
+ __m128i next = _mm_insert_epi16(nxt0, 3*in_near[i+8] + in_far[i+8], 7);
+
+ // horizontal filter, polyphase implementation since it's convenient:
+ // even pixels = 3*cur + prev = cur*4 + (prev - cur)
+ // odd pixels = 3*cur + next = cur*4 + (next - cur)
+ // note the shared term.
+ __m128i bias = _mm_set1_epi16(8);
+ __m128i curs = _mm_slli_epi16(curr, 2);
+ __m128i prvd = _mm_sub_epi16(prev, curr);
+ __m128i nxtd = _mm_sub_epi16(next, curr);
+ __m128i curb = _mm_add_epi16(curs, bias);
+ __m128i even = _mm_add_epi16(prvd, curb);
+ __m128i odd = _mm_add_epi16(nxtd, curb);
+
+ // interleave even and odd pixels, then undo scaling.
+ __m128i int0 = _mm_unpacklo_epi16(even, odd);
+ __m128i int1 = _mm_unpackhi_epi16(even, odd);
+ __m128i de0 = _mm_srli_epi16(int0, 4);
+ __m128i de1 = _mm_srli_epi16(int1, 4);
+
+ // pack and write output
+ __m128i outv = _mm_packus_epi16(de0, de1);
+ _mm_storeu_si128((__m128i *) (out + i*2), outv);
+#elif defined(STBI_NEON)
+ // load and perform the vertical filtering pass
+ // this uses 3*x + y = 4*x + (y - x)
+ uint8x8_t farb = vld1_u8(in_far + i);
+ uint8x8_t nearb = vld1_u8(in_near + i);
+ int16x8_t diff = vreinterpretq_s16_u16(vsubl_u8(farb, nearb));
+ int16x8_t nears = vreinterpretq_s16_u16(vshll_n_u8(nearb, 2));
+ int16x8_t curr = vaddq_s16(nears, diff); // current row
+
+ // horizontal filter works the same based on shifted vers of current
+ // row. "prev" is current row shifted right by 1 pixel; we need to
+ // insert the previous pixel value (from t1).
+ // "next" is current row shifted left by 1 pixel, with first pixel
+ // of next block of 8 pixels added in.
+ int16x8_t prv0 = vextq_s16(curr, curr, 7);
+ int16x8_t nxt0 = vextq_s16(curr, curr, 1);
+ int16x8_t prev = vsetq_lane_s16(t1, prv0, 0);
+ int16x8_t next = vsetq_lane_s16(3*in_near[i+8] + in_far[i+8], nxt0, 7);
+
+ // horizontal filter, polyphase implementation since it's convenient:
+ // even pixels = 3*cur + prev = cur*4 + (prev - cur)
+ // odd pixels = 3*cur + next = cur*4 + (next - cur)
+ // note the shared term.
+ int16x8_t curs = vshlq_n_s16(curr, 2);
+ int16x8_t prvd = vsubq_s16(prev, curr);
+ int16x8_t nxtd = vsubq_s16(next, curr);
+ int16x8_t even = vaddq_s16(curs, prvd);
+ int16x8_t odd = vaddq_s16(curs, nxtd);
+
+ // undo scaling and round, then store with even/odd phases interleaved
+ uint8x8x2_t o;
+ o.val[0] = vqrshrun_n_s16(even, 4);
+ o.val[1] = vqrshrun_n_s16(odd, 4);
+ vst2_u8(out + i*2, o);
+#endif
+
+ // "previous" value for next iter
+ t1 = 3*in_near[i+7] + in_far[i+7];
+ }
+
+ t0 = t1;
+ t1 = 3*in_near[i] + in_far[i];
+ out[i*2] = stbi__div16(3*t1 + t0 + 8);
+
+ for (++i; i < w; ++i) {
+ t0 = t1;
+ t1 = 3*in_near[i]+in_far[i];
+ out[i*2-1] = stbi__div16(3*t0 + t1 + 8);
+ out[i*2 ] = stbi__div16(3*t1 + t0 + 8);
+ }
+ out[w*2-1] = stbi__div4(t1+2);
+
+ STBI_NOTUSED(hs);
+
+ return out;
+}
+#endif
+
+static stbi_uc *stbi__resample_row_generic(stbi_uc *out, stbi_uc *in_near, stbi_uc *in_far, int w, int hs)
+{
+ // resample with nearest-neighbor
+ int i,j;
+ STBI_NOTUSED(in_far);
+ for (i=0; i < w; ++i)
+ for (j=0; j < hs; ++j)
+ out[i*hs+j] = in_near[i];
+ return out;
+}
+
+// this is a reduced-precision calculation of YCbCr-to-RGB introduced
+// to make sure the code produces the same results in both SIMD and scalar
+#define stbi__float2fixed(x) (((int) ((x) * 4096.0f + 0.5f)) << 8)
+static void stbi__YCbCr_to_RGB_row(stbi_uc *out, const stbi_uc *y, const stbi_uc *pcb, const stbi_uc *pcr, int count, int step)
+{
+ int i;
+ for (i=0; i < count; ++i) {
+ int y_fixed = (y[i] << 20) + (1<<19); // rounding
+ int r,g,b;
+ int cr = pcr[i] - 128;
+ int cb = pcb[i] - 128;
+ r = y_fixed + cr* stbi__float2fixed(1.40200f);
+ g = y_fixed + (cr*-stbi__float2fixed(0.71414f)) + ((cb*-stbi__float2fixed(0.34414f)) & 0xffff0000);
+ b = y_fixed + cb* stbi__float2fixed(1.77200f);
+ r >>= 20;
+ g >>= 20;
+ b >>= 20;
+ if ((unsigned) r > 255) { if (r < 0) r = 0; else r = 255; }
+ if ((unsigned) g > 255) { if (g < 0) g = 0; else g = 255; }
+ if ((unsigned) b > 255) { if (b < 0) b = 0; else b = 255; }
+ out[0] = (stbi_uc)r;
+ out[1] = (stbi_uc)g;
+ out[2] = (stbi_uc)b;
+ out[3] = 255;
+ out += step;
+ }
+}
+
+#if defined(STBI_SSE2) || defined(STBI_NEON)
+static void stbi__YCbCr_to_RGB_simd(stbi_uc *out, stbi_uc const *y, stbi_uc const *pcb, stbi_uc const *pcr, int count, int step)
+{
+ int i = 0;
+
+#ifdef STBI_SSE2
+ // step == 3 is pretty ugly on the final interleave, and i'm not convinced
+ // it's useful in practice (you wouldn't use it for textures, for example).
+ // so just accelerate step == 4 case.
+ if (step == 4) {
+ // this is a fairly straightforward implementation and not super-optimized.
+ __m128i signflip = _mm_set1_epi8(-0x80);
+ __m128i cr_const0 = _mm_set1_epi16( (short) ( 1.40200f*4096.0f+0.5f));
+ __m128i cr_const1 = _mm_set1_epi16( - (short) ( 0.71414f*4096.0f+0.5f));
+ __m128i cb_const0 = _mm_set1_epi16( - (short) ( 0.34414f*4096.0f+0.5f));
+ __m128i cb_const1 = _mm_set1_epi16( (short) ( 1.77200f*4096.0f+0.5f));
+ __m128i y_bias = _mm_set1_epi8((char) (unsigned char) 128);
+ __m128i xw = _mm_set1_epi16(255); // alpha channel
+
+ for (; i+7 < count; i += 8) {
+ // load
+ __m128i y_bytes = _mm_loadl_epi64((__m128i *) (y+i));
+ __m128i cr_bytes = _mm_loadl_epi64((__m128i *) (pcr+i));
+ __m128i cb_bytes = _mm_loadl_epi64((__m128i *) (pcb+i));
+ __m128i cr_biased = _mm_xor_si128(cr_bytes, signflip); // -128
+ __m128i cb_biased = _mm_xor_si128(cb_bytes, signflip); // -128
+
+ // unpack to short (and left-shift cr, cb by 8)
+ __m128i yw = _mm_unpacklo_epi8(y_bias, y_bytes);
+ __m128i crw = _mm_unpacklo_epi8(_mm_setzero_si128(), cr_biased);
+ __m128i cbw = _mm_unpacklo_epi8(_mm_setzero_si128(), cb_biased);
+
+ // color transform
+ __m128i yws = _mm_srli_epi16(yw, 4);
+ __m128i cr0 = _mm_mulhi_epi16(cr_const0, crw);
+ __m128i cb0 = _mm_mulhi_epi16(cb_const0, cbw);
+ __m128i cb1 = _mm_mulhi_epi16(cbw, cb_const1);
+ __m128i cr1 = _mm_mulhi_epi16(crw, cr_const1);
+ __m128i rws = _mm_add_epi16(cr0, yws);
+ __m128i gwt = _mm_add_epi16(cb0, yws);
+ __m128i bws = _mm_add_epi16(yws, cb1);
+ __m128i gws = _mm_add_epi16(gwt, cr1);
+
+ // descale
+ __m128i rw = _mm_srai_epi16(rws, 4);
+ __m128i bw = _mm_srai_epi16(bws, 4);
+ __m128i gw = _mm_srai_epi16(gws, 4);
+
+ // back to byte, set up for transpose
+ __m128i brb = _mm_packus_epi16(rw, bw);
+ __m128i gxb = _mm_packus_epi16(gw, xw);
+
+ // transpose to interleave channels
+ __m128i t0 = _mm_unpacklo_epi8(brb, gxb);
+ __m128i t1 = _mm_unpackhi_epi8(brb, gxb);
+ __m128i o0 = _mm_unpacklo_epi16(t0, t1);
+ __m128i o1 = _mm_unpackhi_epi16(t0, t1);
+
+ // store
+ _mm_storeu_si128((__m128i *) (out + 0), o0);
+ _mm_storeu_si128((__m128i *) (out + 16), o1);
+ out += 32;
+ }
+ }
+#endif
+
+#ifdef STBI_NEON
+ // in this version, step=3 support would be easy to add. but is there demand?
+ if (step == 4) {
+ // this is a fairly straightforward implementation and not super-optimized.
+ uint8x8_t signflip = vdup_n_u8(0x80);
+ int16x8_t cr_const0 = vdupq_n_s16( (short) ( 1.40200f*4096.0f+0.5f));
+ int16x8_t cr_const1 = vdupq_n_s16( - (short) ( 0.71414f*4096.0f+0.5f));
+ int16x8_t cb_const0 = vdupq_n_s16( - (short) ( 0.34414f*4096.0f+0.5f));
+ int16x8_t cb_const1 = vdupq_n_s16( (short) ( 1.77200f*4096.0f+0.5f));
+
+ for (; i+7 < count; i += 8) {
+ // load
+ uint8x8_t y_bytes = vld1_u8(y + i);
+ uint8x8_t cr_bytes = vld1_u8(pcr + i);
+ uint8x8_t cb_bytes = vld1_u8(pcb + i);
+ int8x8_t cr_biased = vreinterpret_s8_u8(vsub_u8(cr_bytes, signflip));
+ int8x8_t cb_biased = vreinterpret_s8_u8(vsub_u8(cb_bytes, signflip));
+
+ // expand to s16
+ int16x8_t yws = vreinterpretq_s16_u16(vshll_n_u8(y_bytes, 4));
+ int16x8_t crw = vshll_n_s8(cr_biased, 7);
+ int16x8_t cbw = vshll_n_s8(cb_biased, 7);
+
+ // color transform
+ int16x8_t cr0 = vqdmulhq_s16(crw, cr_const0);
+ int16x8_t cb0 = vqdmulhq_s16(cbw, cb_const0);
+ int16x8_t cr1 = vqdmulhq_s16(crw, cr_const1);
+ int16x8_t cb1 = vqdmulhq_s16(cbw, cb_const1);
+ int16x8_t rws = vaddq_s16(yws, cr0);
+ int16x8_t gws = vaddq_s16(vaddq_s16(yws, cb0), cr1);
+ int16x8_t bws = vaddq_s16(yws, cb1);
+
+ // undo scaling, round, convert to byte
+ uint8x8x4_t o;
+ o.val[0] = vqrshrun_n_s16(rws, 4);
+ o.val[1] = vqrshrun_n_s16(gws, 4);
+ o.val[2] = vqrshrun_n_s16(bws, 4);
+ o.val[3] = vdup_n_u8(255);
+
+ // store, interleaving r/g/b/a
+ vst4_u8(out, o);
+ out += 8*4;
+ }
+ }
+#endif
+
+ for (; i < count; ++i) {
+ int y_fixed = (y[i] << 20) + (1<<19); // rounding
+ int r,g,b;
+ int cr = pcr[i] - 128;
+ int cb = pcb[i] - 128;
+ r = y_fixed + cr* stbi__float2fixed(1.40200f);
+ g = y_fixed + cr*-stbi__float2fixed(0.71414f) + ((cb*-stbi__float2fixed(0.34414f)) & 0xffff0000);
+ b = y_fixed + cb* stbi__float2fixed(1.77200f);
+ r >>= 20;
+ g >>= 20;
+ b >>= 20;
+ if ((unsigned) r > 255) { if (r < 0) r = 0; else r = 255; }
+ if ((unsigned) g > 255) { if (g < 0) g = 0; else g = 255; }
+ if ((unsigned) b > 255) { if (b < 0) b = 0; else b = 255; }
+ out[0] = (stbi_uc)r;
+ out[1] = (stbi_uc)g;
+ out[2] = (stbi_uc)b;
+ out[3] = 255;
+ out += step;
+ }
+}
+#endif
+
+// set up the kernels
+static void stbi__setup_jpeg(stbi__jpeg *j)
+{
+ j->idct_block_kernel = stbi__idct_block;
+ j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_row;
+ j->resample_row_hv_2_kernel = stbi__resample_row_hv_2;
+
+#ifdef STBI_SSE2
+ if (stbi__sse2_available()) {
+ j->idct_block_kernel = stbi__idct_simd;
+ j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_simd;
+ j->resample_row_hv_2_kernel = stbi__resample_row_hv_2_simd;
+ }
+#endif
+
+#ifdef STBI_NEON
+ j->idct_block_kernel = stbi__idct_simd;
+ j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_simd;
+ j->resample_row_hv_2_kernel = stbi__resample_row_hv_2_simd;
+#endif
+}
+
+// clean up the temporary component buffers
+static void stbi__cleanup_jpeg(stbi__jpeg *j)
+{
+ stbi__free_jpeg_components(j, j->s->img_n, 0);
+}
+
+typedef struct
+{
+ resample_row_func resample;
+ stbi_uc *line0,*line1;
+ int hs,vs; // expansion factor in each axis
+ int w_lores; // horizontal pixels pre-expansion
+ int ystep; // how far through vertical expansion we are
+ int ypos; // which pre-expansion row we're on
+} stbi__resample;
+
+// fast 0..255 * 0..255 => 0..255 rounded multiplication
+static stbi_uc stbi__blinn_8x8(stbi_uc x, stbi_uc y)
+{
+ unsigned int t = x*y + 128;
+ return (stbi_uc) ((t + (t >>8)) >> 8);
+}
+
+static stbi_uc *load_jpeg_image(stbi__jpeg *z, int *out_x, int *out_y, int *comp, int req_comp)
+{
+ int n, decode_n, is_rgb;
+ z->s->img_n = 0; // make stbi__cleanup_jpeg safe
+
+ // validate req_comp
+ if (req_comp < 0 || req_comp > 4) return stbi__errpuc("bad req_comp", "Internal error");
+
+ // load a jpeg image from whichever source, but leave in YCbCr format
+ if (!stbi__decode_jpeg_image(z)) { stbi__cleanup_jpeg(z); return NULL; }
+
+ // determine actual number of components to generate
+ n = req_comp ? req_comp : z->s->img_n >= 3 ? 3 : 1;
+
+ is_rgb = z->s->img_n == 3 && (z->rgb == 3 || (z->app14_color_transform == 0 && !z->jfif));
+
+ if (z->s->img_n == 3 && n < 3 && !is_rgb)
+ decode_n = 1;
+ else
+ decode_n = z->s->img_n;
+
+ // nothing to do if no components requested; check this now to avoid
+ // accessing uninitialized coutput[0] later
+ if (decode_n <= 0) { stbi__cleanup_jpeg(z); return NULL; }
+
+ // resample and color-convert
+ {
+ int k;
+ unsigned int i,j;
+ stbi_uc *output;
+ stbi_uc *coutput[4] = { NULL, NULL, NULL, NULL };
+
+ stbi__resample res_comp[4];
+
+ for (k=0; k < decode_n; ++k) {
+ stbi__resample *r = &res_comp[k];
+
+ // allocate line buffer big enough for upsampling off the edges
+ // with upsample factor of 4
+ z->img_comp[k].linebuf = (stbi_uc *) stbi__malloc(z->s->img_x + 3);
+ if (!z->img_comp[k].linebuf) { stbi__cleanup_jpeg(z); return stbi__errpuc("outofmem", "Out of memory"); }
+
+ r->hs = z->img_h_max / z->img_comp[k].h;
+ r->vs = z->img_v_max / z->img_comp[k].v;
+ r->ystep = r->vs >> 1;
+ r->w_lores = (z->s->img_x + r->hs-1) / r->hs;
+ r->ypos = 0;
+ r->line0 = r->line1 = z->img_comp[k].data;
+
+ if (r->hs == 1 && r->vs == 1) r->resample = resample_row_1;
+ else if (r->hs == 1 && r->vs == 2) r->resample = stbi__resample_row_v_2;
+ else if (r->hs == 2 && r->vs == 1) r->resample = stbi__resample_row_h_2;
+ else if (r->hs == 2 && r->vs == 2) r->resample = z->resample_row_hv_2_kernel;
+ else r->resample = stbi__resample_row_generic;
+ }
+
+ // can't error after this so, this is safe
+ output = (stbi_uc *) stbi__malloc_mad3(n, z->s->img_x, z->s->img_y, 1);
+ if (!output) { stbi__cleanup_jpeg(z); return stbi__errpuc("outofmem", "Out of memory"); }
+
+ // now go ahead and resample
+ for (j=0; j < z->s->img_y; ++j) {
+ stbi_uc *out = output + n * z->s->img_x * j;
+ for (k=0; k < decode_n; ++k) {
+ stbi__resample *r = &res_comp[k];
+ int y_bot = r->ystep >= (r->vs >> 1);
+ coutput[k] = r->resample(z->img_comp[k].linebuf,
+ y_bot ? r->line1 : r->line0,
+ y_bot ? r->line0 : r->line1,
+ r->w_lores, r->hs);
+ if (++r->ystep >= r->vs) {
+ r->ystep = 0;
+ r->line0 = r->line1;
+ if (++r->ypos < z->img_comp[k].y)
+ r->line1 += z->img_comp[k].w2;
+ }
+ }
+ if (n >= 3) {
+ stbi_uc *y = coutput[0];
+ if (z->s->img_n == 3) {
+ if (is_rgb) {
+ for (i=0; i < z->s->img_x; ++i) {
+ out[0] = y[i];
+ out[1] = coutput[1][i];
+ out[2] = coutput[2][i];
+ out[3] = 255;
+ out += n;
+ }
+ } else {
+ z->YCbCr_to_RGB_kernel(out, y, coutput[1], coutput[2], z->s->img_x, n);
+ }
+ } else if (z->s->img_n == 4) {
+ if (z->app14_color_transform == 0) { // CMYK
+ for (i=0; i < z->s->img_x; ++i) {
+ stbi_uc m = coutput[3][i];
+ out[0] = stbi__blinn_8x8(coutput[0][i], m);
+ out[1] = stbi__blinn_8x8(coutput[1][i], m);
+ out[2] = stbi__blinn_8x8(coutput[2][i], m);
+ out[3] = 255;
+ out += n;
+ }
+ } else if (z->app14_color_transform == 2) { // YCCK
+ z->YCbCr_to_RGB_kernel(out, y, coutput[1], coutput[2], z->s->img_x, n);
+ for (i=0; i < z->s->img_x; ++i) {
+ stbi_uc m = coutput[3][i];
+ out[0] = stbi__blinn_8x8(255 - out[0], m);
+ out[1] = stbi__blinn_8x8(255 - out[1], m);
+ out[2] = stbi__blinn_8x8(255 - out[2], m);
+ out += n;
+ }
+ } else { // YCbCr + alpha? Ignore the fourth channel for now
+ z->YCbCr_to_RGB_kernel(out, y, coutput[1], coutput[2], z->s->img_x, n);
+ }
+ } else
+ for (i=0; i < z->s->img_x; ++i) {
+ out[0] = out[1] = out[2] = y[i];
+ out[3] = 255; // not used if n==3
+ out += n;
+ }
+ } else {
+ if (is_rgb) {
+ if (n == 1)
+ for (i=0; i < z->s->img_x; ++i)
+ *out++ = stbi__compute_y(coutput[0][i], coutput[1][i], coutput[2][i]);
+ else {
+ for (i=0; i < z->s->img_x; ++i, out += 2) {
+ out[0] = stbi__compute_y(coutput[0][i], coutput[1][i], coutput[2][i]);
+ out[1] = 255;
+ }
+ }
+ } else if (z->s->img_n == 4 && z->app14_color_transform == 0) {
+ for (i=0; i < z->s->img_x; ++i) {
+ stbi_uc m = coutput[3][i];
+ stbi_uc r = stbi__blinn_8x8(coutput[0][i], m);
+ stbi_uc g = stbi__blinn_8x8(coutput[1][i], m);
+ stbi_uc b = stbi__blinn_8x8(coutput[2][i], m);
+ out[0] = stbi__compute_y(r, g, b);
+ out[1] = 255;
+ out += n;
+ }
+ } else if (z->s->img_n == 4 && z->app14_color_transform == 2) {
+ for (i=0; i < z->s->img_x; ++i) {
+ out[0] = stbi__blinn_8x8(255 - coutput[0][i], coutput[3][i]);
+ out[1] = 255;
+ out += n;
+ }
+ } else {
+ stbi_uc *y = coutput[0];
+ if (n == 1)
+ for (i=0; i < z->s->img_x; ++i) out[i] = y[i];
+ else
+ for (i=0; i < z->s->img_x; ++i) { *out++ = y[i]; *out++ = 255; }
+ }
+ }
+ }
+ stbi__cleanup_jpeg(z);
+ *out_x = z->s->img_x;
+ *out_y = z->s->img_y;
+ if (comp) *comp = z->s->img_n >= 3 ? 3 : 1; // report original components, not output
+ return output;
+ }
+}
+
+static void *stbi__jpeg_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri)
+{
+ unsigned char* result;
+ stbi__jpeg* j = (stbi__jpeg*) stbi__malloc(sizeof(stbi__jpeg));
+ if (!j) return stbi__errpuc("outofmem", "Out of memory");
+ STBI_NOTUSED(ri);
+ j->s = s;
+ stbi__setup_jpeg(j);
+ result = load_jpeg_image(j, x,y,comp,req_comp);
+ STBI_FREE(j);
+ return result;
+}
+
+static int stbi__jpeg_test(stbi__context *s)
+{
+ int r;
+ stbi__jpeg* j = (stbi__jpeg*)stbi__malloc(sizeof(stbi__jpeg));
+ if (!j) return stbi__err("outofmem", "Out of memory");
+ j->s = s;
+ stbi__setup_jpeg(j);
+ r = stbi__decode_jpeg_header(j, STBI__SCAN_type);
+ stbi__rewind(s);
+ STBI_FREE(j);
+ return r;
+}
+
+static int stbi__jpeg_info_raw(stbi__jpeg *j, int *x, int *y, int *comp)
+{
+ if (!stbi__decode_jpeg_header(j, STBI__SCAN_header)) {
+ stbi__rewind( j->s );
+ return 0;
+ }
+ if (x) *x = j->s->img_x;
+ if (y) *y = j->s->img_y;
+ if (comp) *comp = j->s->img_n >= 3 ? 3 : 1;
+ return 1;
+}
+
+static int stbi__jpeg_info(stbi__context *s, int *x, int *y, int *comp)
+{
+ int result;
+ stbi__jpeg* j = (stbi__jpeg*) (stbi__malloc(sizeof(stbi__jpeg)));
+ if (!j) return stbi__err("outofmem", "Out of memory");
+ j->s = s;
+ result = stbi__jpeg_info_raw(j, x, y, comp);
+ STBI_FREE(j);
+ return result;
+}
+#endif
+
+// public domain zlib decode v0.2 Sean Barrett 2006-11-18
+// simple implementation
+// - all input must be provided in an upfront buffer
+// - all output is written to a single output buffer (can malloc/realloc)
+// performance
+// - fast huffman
+
+#ifndef STBI_NO_ZLIB
+
+// fast-way is faster to check than jpeg huffman, but slow way is slower
+#define STBI__ZFAST_BITS 9 // accelerate all cases in default tables
+#define STBI__ZFAST_MASK ((1 << STBI__ZFAST_BITS) - 1)
+#define STBI__ZNSYMS 288 // number of symbols in literal/length alphabet
+
+// zlib-style huffman encoding
+// (jpegs packs from left, zlib from right, so can't share code)
+typedef struct
+{
+ stbi__uint16 fast[1 << STBI__ZFAST_BITS];
+ stbi__uint16 firstcode[16];
+ int maxcode[17];
+ stbi__uint16 firstsymbol[16];
+ stbi_uc size[STBI__ZNSYMS];
+ stbi__uint16 value[STBI__ZNSYMS];
+} stbi__zhuffman;
+
+stbi_inline static int stbi__bitreverse16(int n)
+{
+ n = ((n & 0xAAAA) >> 1) | ((n & 0x5555) << 1);
+ n = ((n & 0xCCCC) >> 2) | ((n & 0x3333) << 2);
+ n = ((n & 0xF0F0) >> 4) | ((n & 0x0F0F) << 4);
+ n = ((n & 0xFF00) >> 8) | ((n & 0x00FF) << 8);
+ return n;
+}
+
+stbi_inline static int stbi__bit_reverse(int v, int bits)
+{
+ STBI_ASSERT(bits <= 16);
+ // to bit reverse n bits, reverse 16 and shift
+ // e.g. 11 bits, bit reverse and shift away 5
+ return stbi__bitreverse16(v) >> (16-bits);
+}
+
+static int stbi__zbuild_huffman(stbi__zhuffman *z, const stbi_uc *sizelist, int num)
+{
+ int i,k=0;
+ int code, next_code[16], sizes[17];
+
+ // DEFLATE spec for generating codes
+ memset(sizes, 0, sizeof(sizes));
+ memset(z->fast, 0, sizeof(z->fast));
+ for (i=0; i < num; ++i)
+ ++sizes[sizelist[i]];
+ sizes[0] = 0;
+ for (i=1; i < 16; ++i)
+ if (sizes[i] > (1 << i))
+ return stbi__err("bad sizes", "Corrupt PNG");
+ code = 0;
+ for (i=1; i < 16; ++i) {
+ next_code[i] = code;
+ z->firstcode[i] = (stbi__uint16) code;
+ z->firstsymbol[i] = (stbi__uint16) k;
+ code = (code + sizes[i]);
+ if (sizes[i])
+ if (code-1 >= (1 << i)) return stbi__err("bad codelengths","Corrupt PNG");
+ z->maxcode[i] = code << (16-i); // preshift for inner loop
+ code <<= 1;
+ k += sizes[i];
+ }
+ z->maxcode[16] = 0x10000; // sentinel
+ for (i=0; i < num; ++i) {
+ int s = sizelist[i];
+ if (s) {
+ int c = next_code[s] - z->firstcode[s] + z->firstsymbol[s];
+ stbi__uint16 fastv = (stbi__uint16) ((s << 9) | i);
+ z->size [c] = (stbi_uc ) s;
+ z->value[c] = (stbi__uint16) i;
+ if (s <= STBI__ZFAST_BITS) {
+ int j = stbi__bit_reverse(next_code[s],s);
+ while (j < (1 << STBI__ZFAST_BITS)) {
+ z->fast[j] = fastv;
+ j += (1 << s);
+ }
+ }
+ ++next_code[s];
+ }
+ }
+ return 1;
+}
+
+// zlib-from-memory implementation for PNG reading
+// because PNG allows splitting the zlib stream arbitrarily,
+// and it's annoying structurally to have PNG call ZLIB call PNG,
+// we require PNG read all the IDATs and combine them into a single
+// memory buffer
+
+typedef struct
+{
+ stbi_uc *zbuffer, *zbuffer_end;
+ int num_bits;
+ stbi__uint32 code_buffer;
+
+ char *zout;
+ char *zout_start;
+ char *zout_end;
+ int z_expandable;
+
+ stbi__zhuffman z_length, z_distance;
+} stbi__zbuf;
+
+stbi_inline static int stbi__zeof(stbi__zbuf *z)
+{
+ return (z->zbuffer >= z->zbuffer_end);
+}
+
+stbi_inline static stbi_uc stbi__zget8(stbi__zbuf *z)
+{
+ return stbi__zeof(z) ? 0 : *z->zbuffer++;
+}
+
+static void stbi__fill_bits(stbi__zbuf *z)
+{
+ do {
+ if (z->code_buffer >= (1U << z->num_bits)) {
+ z->zbuffer = z->zbuffer_end; /* treat this as EOF so we fail. */
+ return;
+ }
+ z->code_buffer |= (unsigned int) stbi__zget8(z) << z->num_bits;
+ z->num_bits += 8;
+ } while (z->num_bits <= 24);
+}
+
+stbi_inline static unsigned int stbi__zreceive(stbi__zbuf *z, int n)
+{
+ unsigned int k;
+ if (z->num_bits < n) stbi__fill_bits(z);
+ k = z->code_buffer & ((1 << n) - 1);
+ z->code_buffer >>= n;
+ z->num_bits -= n;
+ return k;
+}
+
+static int stbi__zhuffman_decode_slowpath(stbi__zbuf *a, stbi__zhuffman *z)
+{
+ int b,s,k;
+ // not resolved by fast table, so compute it the slow way
+ // use jpeg approach, which requires MSbits at top
+ k = stbi__bit_reverse(a->code_buffer, 16);
+ for (s=STBI__ZFAST_BITS+1; ; ++s)
+ if (k < z->maxcode[s])
+ break;
+ if (s >= 16) return -1; // invalid code!
+ // code size is s, so:
+ b = (k >> (16-s)) - z->firstcode[s] + z->firstsymbol[s];
+ if (b >= STBI__ZNSYMS) return -1; // some data was corrupt somewhere!
+ if (z->size[b] != s) return -1; // was originally an assert, but report failure instead.
+ a->code_buffer >>= s;
+ a->num_bits -= s;
+ return z->value[b];
+}
+
+stbi_inline static int stbi__zhuffman_decode(stbi__zbuf *a, stbi__zhuffman *z)
+{
+ int b,s;
+ if (a->num_bits < 16) {
+ if (stbi__zeof(a)) {
+ return -1; /* report error for unexpected end of data. */
+ }
+ stbi__fill_bits(a);
+ }
+ b = z->fast[a->code_buffer & STBI__ZFAST_MASK];
+ if (b) {
+ s = b >> 9;
+ a->code_buffer >>= s;
+ a->num_bits -= s;
+ return b & 511;
+ }
+ return stbi__zhuffman_decode_slowpath(a, z);
+}
+
+static int stbi__zexpand(stbi__zbuf *z, char *zout, int n) // need to make room for n bytes
+{
+ char *q;
+ unsigned int cur, limit, old_limit;
+ z->zout = zout;
+ if (!z->z_expandable) return stbi__err("output buffer limit","Corrupt PNG");
+ cur = (unsigned int) (z->zout - z->zout_start);
+ limit = old_limit = (unsigned) (z->zout_end - z->zout_start);
+ if (UINT_MAX - cur < (unsigned) n) return stbi__err("outofmem", "Out of memory");
+ while (cur + n > limit) {
+ if(limit > UINT_MAX / 2) return stbi__err("outofmem", "Out of memory");
+ limit *= 2;
+ }
+ q = (char *) STBI_REALLOC_SIZED(z->zout_start, old_limit, limit);
+ STBI_NOTUSED(old_limit);
+ if (q == NULL) return stbi__err("outofmem", "Out of memory");
+ z->zout_start = q;
+ z->zout = q + cur;
+ z->zout_end = q + limit;
+ return 1;
+}
+
+static const int stbi__zlength_base[31] = {
+ 3,4,5,6,7,8,9,10,11,13,
+ 15,17,19,23,27,31,35,43,51,59,
+ 67,83,99,115,131,163,195,227,258,0,0 };
+
+static const int stbi__zlength_extra[31]=
+{ 0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0,0,0 };
+
+static const int stbi__zdist_base[32] = { 1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,
+257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577,0,0};
+
+static const int stbi__zdist_extra[32] =
+{ 0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};
+
+static int stbi__parse_huffman_block(stbi__zbuf *a)
+{
+ char *zout = a->zout;
+ for(;;) {
+ int z = stbi__zhuffman_decode(a, &a->z_length);
+ if (z < 256) {
+ if (z < 0) return stbi__err("bad huffman code","Corrupt PNG"); // error in huffman codes
+ if (zout >= a->zout_end) {
+ if (!stbi__zexpand(a, zout, 1)) return 0;
+ zout = a->zout;
+ }
+ *zout++ = (char) z;
+ } else {
+ stbi_uc *p;
+ int len,dist;
+ if (z == 256) {
+ a->zout = zout;
+ return 1;
+ }
+ z -= 257;
+ len = stbi__zlength_base[z];
+ if (stbi__zlength_extra[z]) len += stbi__zreceive(a, stbi__zlength_extra[z]);
+ z = stbi__zhuffman_decode(a, &a->z_distance);
+ if (z < 0) return stbi__err("bad huffman code","Corrupt PNG");
+ dist = stbi__zdist_base[z];
+ if (stbi__zdist_extra[z]) dist += stbi__zreceive(a, stbi__zdist_extra[z]);
+ if (zout - a->zout_start < dist) return stbi__err("bad dist","Corrupt PNG");
+ if (zout + len > a->zout_end) {
+ if (!stbi__zexpand(a, zout, len)) return 0;
+ zout = a->zout;
+ }
+ p = (stbi_uc *) (zout - dist);
+ if (dist == 1) { // run of one byte; common in images.
+ stbi_uc v = *p;
+ if (len) { do *zout++ = v; while (--len); }
+ } else {
+ if (len) { do *zout++ = *p++; while (--len); }
+ }
+ }
+ }
+}
+
+static int stbi__compute_huffman_codes(stbi__zbuf *a)
+{
+ static const stbi_uc length_dezigzag[19] = { 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 };
+ stbi__zhuffman z_codelength;
+ stbi_uc lencodes[286+32+137];//padding for maximum single op
+ stbi_uc codelength_sizes[19];
+ int i,n;
+
+ int hlit = stbi__zreceive(a,5) + 257;
+ int hdist = stbi__zreceive(a,5) + 1;
+ int hclen = stbi__zreceive(a,4) + 4;
+ int ntot = hlit + hdist;
+
+ memset(codelength_sizes, 0, sizeof(codelength_sizes));
+ for (i=0; i < hclen; ++i) {
+ int s = stbi__zreceive(a,3);
+ codelength_sizes[length_dezigzag[i]] = (stbi_uc) s;
+ }
+ if (!stbi__zbuild_huffman(&z_codelength, codelength_sizes, 19)) return 0;
+
+ n = 0;
+ while (n < ntot) {
+ int c = stbi__zhuffman_decode(a, &z_codelength);
+ if (c < 0 || c >= 19) return stbi__err("bad codelengths", "Corrupt PNG");
+ if (c < 16)
+ lencodes[n++] = (stbi_uc) c;
+ else {
+ stbi_uc fill = 0;
+ if (c == 16) {
+ c = stbi__zreceive(a,2)+3;
+ if (n == 0) return stbi__err("bad codelengths", "Corrupt PNG");
+ fill = lencodes[n-1];
+ } else if (c == 17) {
+ c = stbi__zreceive(a,3)+3;
+ } else if (c == 18) {
+ c = stbi__zreceive(a,7)+11;
+ } else {
+ return stbi__err("bad codelengths", "Corrupt PNG");
+ }
+ if (ntot - n < c) return stbi__err("bad codelengths", "Corrupt PNG");
+ memset(lencodes+n, fill, c);
+ n += c;
+ }
+ }
+ if (n != ntot) return stbi__err("bad codelengths","Corrupt PNG");
+ if (!stbi__zbuild_huffman(&a->z_length, lencodes, hlit)) return 0;
+ if (!stbi__zbuild_huffman(&a->z_distance, lencodes+hlit, hdist)) return 0;
+ return 1;
+}
+
+static int stbi__parse_uncompressed_block(stbi__zbuf *a)
+{
+ stbi_uc header[4];
+ int len,nlen,k;
+ if (a->num_bits & 7)
+ stbi__zreceive(a, a->num_bits & 7); // discard
+ // drain the bit-packed data into header
+ k = 0;
+ while (a->num_bits > 0) {
+ header[k++] = (stbi_uc) (a->code_buffer & 255); // suppress MSVC run-time check
+ a->code_buffer >>= 8;
+ a->num_bits -= 8;
+ }
+ if (a->num_bits < 0) return stbi__err("zlib corrupt","Corrupt PNG");
+ // now fill header the normal way
+ while (k < 4)
+ header[k++] = stbi__zget8(a);
+ len = header[1] * 256 + header[0];
+ nlen = header[3] * 256 + header[2];
+ if (nlen != (len ^ 0xffff)) return stbi__err("zlib corrupt","Corrupt PNG");
+ if (a->zbuffer + len > a->zbuffer_end) return stbi__err("read past buffer","Corrupt PNG");
+ if (a->zout + len > a->zout_end)
+ if (!stbi__zexpand(a, a->zout, len)) return 0;
+ memcpy(a->zout, a->zbuffer, len);
+ a->zbuffer += len;
+ a->zout += len;
+ return 1;
+}
+
+static int stbi__parse_zlib_header(stbi__zbuf *a)
+{
+ int cmf = stbi__zget8(a);
+ int cm = cmf & 15;
+ /* int cinfo = cmf >> 4; */
+ int flg = stbi__zget8(a);
+ if (stbi__zeof(a)) return stbi__err("bad zlib header","Corrupt PNG"); // zlib spec
+ if ((cmf*256+flg) % 31 != 0) return stbi__err("bad zlib header","Corrupt PNG"); // zlib spec
+ if (flg & 32) return stbi__err("no preset dict","Corrupt PNG"); // preset dictionary not allowed in png
+ if (cm != 8) return stbi__err("bad compression","Corrupt PNG"); // DEFLATE required for png
+ // window = 1 << (8 + cinfo)... but who cares, we fully buffer output
+ return 1;
+}
+
+static const stbi_uc stbi__zdefault_length[STBI__ZNSYMS] =
+{
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
+ 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
+ 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, 7,7,7,7,7,7,7,7,8,8,8,8,8,8,8,8
+};
+static const stbi_uc stbi__zdefault_distance[32] =
+{
+ 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5
+};
+/*
+Init algorithm:
+{
+ int i; // use <= to match clearly with spec
+ for (i=0; i <= 143; ++i) stbi__zdefault_length[i] = 8;
+ for ( ; i <= 255; ++i) stbi__zdefault_length[i] = 9;
+ for ( ; i <= 279; ++i) stbi__zdefault_length[i] = 7;
+ for ( ; i <= 287; ++i) stbi__zdefault_length[i] = 8;
+
+ for (i=0; i <= 31; ++i) stbi__zdefault_distance[i] = 5;
+}
+*/
+
+static int stbi__parse_zlib(stbi__zbuf *a, int parse_header)
+{
+ int final, type;
+ if (parse_header)
+ if (!stbi__parse_zlib_header(a)) return 0;
+ a->num_bits = 0;
+ a->code_buffer = 0;
+ do {
+ final = stbi__zreceive(a,1);
+ type = stbi__zreceive(a,2);
+ if (type == 0) {
+ if (!stbi__parse_uncompressed_block(a)) return 0;
+ } else if (type == 3) {
+ return 0;
+ } else {
+ if (type == 1) {
+ // use fixed code lengths
+ if (!stbi__zbuild_huffman(&a->z_length , stbi__zdefault_length , STBI__ZNSYMS)) return 0;
+ if (!stbi__zbuild_huffman(&a->z_distance, stbi__zdefault_distance, 32)) return 0;
+ } else {
+ if (!stbi__compute_huffman_codes(a)) return 0;
+ }
+ if (!stbi__parse_huffman_block(a)) return 0;
+ }
+ } while (!final);
+ return 1;
+}
+
+static int stbi__do_zlib(stbi__zbuf *a, char *obuf, int olen, int exp, int parse_header)
+{
+ a->zout_start = obuf;
+ a->zout = obuf;
+ a->zout_end = obuf + olen;
+ a->z_expandable = exp;
+
+ return stbi__parse_zlib(a, parse_header);
+}
+
+STBIDEF char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen)
+{
+ stbi__zbuf a;
+ char *p = (char *) stbi__malloc(initial_size);
+ if (p == NULL) return NULL;
+ a.zbuffer = (stbi_uc *) buffer;
+ a.zbuffer_end = (stbi_uc *) buffer + len;
+ if (stbi__do_zlib(&a, p, initial_size, 1, 1)) {
+ if (outlen) *outlen = (int) (a.zout - a.zout_start);
+ return a.zout_start;
+ } else {
+ STBI_FREE(a.zout_start);
+ return NULL;
+ }
+}
+
+STBIDEF char *stbi_zlib_decode_malloc(char const *buffer, int len, int *outlen)
+{
+ return stbi_zlib_decode_malloc_guesssize(buffer, len, 16384, outlen);
+}
+
+STBIDEF char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header)
+{
+ stbi__zbuf a;
+ char *p = (char *) stbi__malloc(initial_size);
+ if (p == NULL) return NULL;
+ a.zbuffer = (stbi_uc *) buffer;
+ a.zbuffer_end = (stbi_uc *) buffer + len;
+ if (stbi__do_zlib(&a, p, initial_size, 1, parse_header)) {
+ if (outlen) *outlen = (int) (a.zout - a.zout_start);
+ return a.zout_start;
+ } else {
+ STBI_FREE(a.zout_start);
+ return NULL;
+ }
+}
+
+STBIDEF int stbi_zlib_decode_buffer(char *obuffer, int olen, char const *ibuffer, int ilen)
+{
+ stbi__zbuf a;
+ a.zbuffer = (stbi_uc *) ibuffer;
+ a.zbuffer_end = (stbi_uc *) ibuffer + ilen;
+ if (stbi__do_zlib(&a, obuffer, olen, 0, 1))
+ return (int) (a.zout - a.zout_start);
+ else
+ return -1;
+}
+
+STBIDEF char *stbi_zlib_decode_noheader_malloc(char const *buffer, int len, int *outlen)
+{
+ stbi__zbuf a;
+ char *p = (char *) stbi__malloc(16384);
+ if (p == NULL) return NULL;
+ a.zbuffer = (stbi_uc *) buffer;
+ a.zbuffer_end = (stbi_uc *) buffer+len;
+ if (stbi__do_zlib(&a, p, 16384, 1, 0)) {
+ if (outlen) *outlen = (int) (a.zout - a.zout_start);
+ return a.zout_start;
+ } else {
+ STBI_FREE(a.zout_start);
+ return NULL;
+ }
+}
+
+STBIDEF int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen)
+{
+ stbi__zbuf a;
+ a.zbuffer = (stbi_uc *) ibuffer;
+ a.zbuffer_end = (stbi_uc *) ibuffer + ilen;
+ if (stbi__do_zlib(&a, obuffer, olen, 0, 0))
+ return (int) (a.zout - a.zout_start);
+ else
+ return -1;
+}
+#endif
+
+// public domain "baseline" PNG decoder v0.10 Sean Barrett 2006-11-18
+// simple implementation
+// - only 8-bit samples
+// - no CRC checking
+// - allocates lots of intermediate memory
+// - avoids problem of streaming data between subsystems
+// - avoids explicit window management
+// performance
+// - uses stb_zlib, a PD zlib implementation with fast huffman decoding
+
+#ifndef STBI_NO_PNG
+typedef struct
+{
+ stbi__uint32 length;
+ stbi__uint32 type;
+} stbi__pngchunk;
+
+static stbi__pngchunk stbi__get_chunk_header(stbi__context *s)
+{
+ stbi__pngchunk c;
+ c.length = stbi__get32be(s);
+ c.type = stbi__get32be(s);
+ return c;
+}
+
+static int stbi__check_png_header(stbi__context *s)
+{
+ static const stbi_uc png_sig[8] = { 137,80,78,71,13,10,26,10 };
+ int i;
+ for (i=0; i < 8; ++i)
+ if (stbi__get8(s) != png_sig[i]) return stbi__err("bad png sig","Not a PNG");
+ return 1;
+}
+
+typedef struct
+{
+ stbi__context *s;
+ stbi_uc *idata, *expanded, *out;
+ int depth;
+} stbi__png;
+
+
+enum {
+ STBI__F_none=0,
+ STBI__F_sub=1,
+ STBI__F_up=2,
+ STBI__F_avg=3,
+ STBI__F_paeth=4,
+ // synthetic filters used for first scanline to avoid needing a dummy row of 0s
+ STBI__F_avg_first,
+ STBI__F_paeth_first
+};
+
+static stbi_uc first_row_filter[5] =
+{
+ STBI__F_none,
+ STBI__F_sub,
+ STBI__F_none,
+ STBI__F_avg_first,
+ STBI__F_paeth_first
+};
+
+static int stbi__paeth(int a, int b, int c)
+{
+ int p = a + b - c;
+ int pa = abs(p-a);
+ int pb = abs(p-b);
+ int pc = abs(p-c);
+ if (pa <= pb && pa <= pc) return a;
+ if (pb <= pc) return b;
+ return c;
+}
+
+static const stbi_uc stbi__depth_scale_table[9] = { 0, 0xff, 0x55, 0, 0x11, 0,0,0, 0x01 };
+
+// create the png data from post-deflated data
+static int stbi__create_png_image_raw(stbi__png *a, stbi_uc *raw, stbi__uint32 raw_len, int out_n, stbi__uint32 x, stbi__uint32 y, int depth, int color)
+{
+ int bytes = (depth == 16? 2 : 1);
+ stbi__context *s = a->s;
+ stbi__uint32 i,j,stride = x*out_n*bytes;
+ stbi__uint32 img_len, img_width_bytes;
+ int k;
+ int img_n = s->img_n; // copy it into a local for later
+
+ int output_bytes = out_n*bytes;
+ int filter_bytes = img_n*bytes;
+ int width = x;
+
+ STBI_ASSERT(out_n == s->img_n || out_n == s->img_n+1);
+ a->out = (stbi_uc *) stbi__malloc_mad3(x, y, output_bytes, 0); // extra bytes to write off the end into
+ if (!a->out) return stbi__err("outofmem", "Out of memory");
+
+ if (!stbi__mad3sizes_valid(img_n, x, depth, 7)) return stbi__err("too large", "Corrupt PNG");
+ img_width_bytes = (((img_n * x * depth) + 7) >> 3);
+ img_len = (img_width_bytes + 1) * y;
+
+ // we used to check for exact match between raw_len and img_len on non-interlaced PNGs,
+ // but issue #276 reported a PNG in the wild that had extra data at the end (all zeros),
+ // so just check for raw_len < img_len always.
+ if (raw_len < img_len) return stbi__err("not enough pixels","Corrupt PNG");
+
+ for (j=0; j < y; ++j) {
+ stbi_uc *cur = a->out + stride*j;
+ stbi_uc *prior;
+ int filter = *raw++;
+
+ if (filter > 4)
+ return stbi__err("invalid filter","Corrupt PNG");
+
+ if (depth < 8) {
+ if (img_width_bytes > x) return stbi__err("invalid width","Corrupt PNG");
+ cur += x*out_n - img_width_bytes; // store output to the rightmost img_len bytes, so we can decode in place
+ filter_bytes = 1;
+ width = img_width_bytes;
+ }
+ prior = cur - stride; // bugfix: need to compute this after 'cur +=' computation above
+
+ // if first row, use special filter that doesn't sample previous row
+ if (j == 0) filter = first_row_filter[filter];
+
+ // handle first byte explicitly
+ for (k=0; k < filter_bytes; ++k) {
+ switch (filter) {
+ case STBI__F_none : cur[k] = raw[k]; break;
+ case STBI__F_sub : cur[k] = raw[k]; break;
+ case STBI__F_up : cur[k] = STBI__BYTECAST(raw[k] + prior[k]); break;
+ case STBI__F_avg : cur[k] = STBI__BYTECAST(raw[k] + (prior[k]>>1)); break;
+ case STBI__F_paeth : cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(0,prior[k],0)); break;
+ case STBI__F_avg_first : cur[k] = raw[k]; break;
+ case STBI__F_paeth_first: cur[k] = raw[k]; break;
+ }
+ }
+
+ if (depth == 8) {
+ if (img_n != out_n)
+ cur[img_n] = 255; // first pixel
+ raw += img_n;
+ cur += out_n;
+ prior += out_n;
+ } else if (depth == 16) {
+ if (img_n != out_n) {
+ cur[filter_bytes] = 255; // first pixel top byte
+ cur[filter_bytes+1] = 255; // first pixel bottom byte
+ }
+ raw += filter_bytes;
+ cur += output_bytes;
+ prior += output_bytes;
+ } else {
+ raw += 1;
+ cur += 1;
+ prior += 1;
+ }
+
+ // this is a little gross, so that we don't switch per-pixel or per-component
+ if (depth < 8 || img_n == out_n) {
+ int nk = (width - 1)*filter_bytes;
+ #define STBI__CASE(f) \
+ case f: \
+ for (k=0; k < nk; ++k)
+ switch (filter) {
+ // "none" filter turns into a memcpy here; make that explicit.
+ case STBI__F_none: memcpy(cur, raw, nk); break;
+ STBI__CASE(STBI__F_sub) { cur[k] = STBI__BYTECAST(raw[k] + cur[k-filter_bytes]); } break;
+ STBI__CASE(STBI__F_up) { cur[k] = STBI__BYTECAST(raw[k] + prior[k]); } break;
+ STBI__CASE(STBI__F_avg) { cur[k] = STBI__BYTECAST(raw[k] + ((prior[k] + cur[k-filter_bytes])>>1)); } break;
+ STBI__CASE(STBI__F_paeth) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k-filter_bytes],prior[k],prior[k-filter_bytes])); } break;
+ STBI__CASE(STBI__F_avg_first) { cur[k] = STBI__BYTECAST(raw[k] + (cur[k-filter_bytes] >> 1)); } break;
+ STBI__CASE(STBI__F_paeth_first) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k-filter_bytes],0,0)); } break;
+ }
+ #undef STBI__CASE
+ raw += nk;
+ } else {
+ STBI_ASSERT(img_n+1 == out_n);
+ #define STBI__CASE(f) \
+ case f: \
+ for (i=x-1; i >= 1; --i, cur[filter_bytes]=255,raw+=filter_bytes,cur+=output_bytes,prior+=output_bytes) \
+ for (k=0; k < filter_bytes; ++k)
+ switch (filter) {
+ STBI__CASE(STBI__F_none) { cur[k] = raw[k]; } break;
+ STBI__CASE(STBI__F_sub) { cur[k] = STBI__BYTECAST(raw[k] + cur[k- output_bytes]); } break;
+ STBI__CASE(STBI__F_up) { cur[k] = STBI__BYTECAST(raw[k] + prior[k]); } break;
+ STBI__CASE(STBI__F_avg) { cur[k] = STBI__BYTECAST(raw[k] + ((prior[k] + cur[k- output_bytes])>>1)); } break;
+ STBI__CASE(STBI__F_paeth) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k- output_bytes],prior[k],prior[k- output_bytes])); } break;
+ STBI__CASE(STBI__F_avg_first) { cur[k] = STBI__BYTECAST(raw[k] + (cur[k- output_bytes] >> 1)); } break;
+ STBI__CASE(STBI__F_paeth_first) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k- output_bytes],0,0)); } break;
+ }
+ #undef STBI__CASE
+
+ // the loop above sets the high byte of the pixels' alpha, but for
+ // 16 bit png files we also need the low byte set. we'll do that here.
+ if (depth == 16) {
+ cur = a->out + stride*j; // start at the beginning of the row again
+ for (i=0; i < x; ++i,cur+=output_bytes) {
+ cur[filter_bytes+1] = 255;
+ }
+ }
+ }
+ }
+
+ // we make a separate pass to expand bits to pixels; for performance,
+ // this could run two scanlines behind the above code, so it won't
+ // intefere with filtering but will still be in the cache.
+ if (depth < 8) {
+ for (j=0; j < y; ++j) {
+ stbi_uc *cur = a->out + stride*j;
+ stbi_uc *in = a->out + stride*j + x*out_n - img_width_bytes;
+ // unpack 1/2/4-bit into a 8-bit buffer. allows us to keep the common 8-bit path optimal at minimal cost for 1/2/4-bit
+ // png guarante byte alignment, if width is not multiple of 8/4/2 we'll decode dummy trailing data that will be skipped in the later loop
+ stbi_uc scale = (color == 0) ? stbi__depth_scale_table[depth] : 1; // scale grayscale values to 0..255 range
+
+ // note that the final byte might overshoot and write more data than desired.
+ // we can allocate enough data that this never writes out of memory, but it
+ // could also overwrite the next scanline. can it overwrite non-empty data
+ // on the next scanline? yes, consider 1-pixel-wide scanlines with 1-bit-per-pixel.
+ // so we need to explicitly clamp the final ones
+
+ if (depth == 4) {
+ for (k=x*img_n; k >= 2; k-=2, ++in) {
+ *cur++ = scale * ((*in >> 4) );
+ *cur++ = scale * ((*in ) & 0x0f);
+ }
+ if (k > 0) *cur++ = scale * ((*in >> 4) );
+ } else if (depth == 2) {
+ for (k=x*img_n; k >= 4; k-=4, ++in) {
+ *cur++ = scale * ((*in >> 6) );
+ *cur++ = scale * ((*in >> 4) & 0x03);
+ *cur++ = scale * ((*in >> 2) & 0x03);
+ *cur++ = scale * ((*in ) & 0x03);
+ }
+ if (k > 0) *cur++ = scale * ((*in >> 6) );
+ if (k > 1) *cur++ = scale * ((*in >> 4) & 0x03);
+ if (k > 2) *cur++ = scale * ((*in >> 2) & 0x03);
+ } else if (depth == 1) {
+ for (k=x*img_n; k >= 8; k-=8, ++in) {
+ *cur++ = scale * ((*in >> 7) );
+ *cur++ = scale * ((*in >> 6) & 0x01);
+ *cur++ = scale * ((*in >> 5) & 0x01);
+ *cur++ = scale * ((*in >> 4) & 0x01);
+ *cur++ = scale * ((*in >> 3) & 0x01);
+ *cur++ = scale * ((*in >> 2) & 0x01);
+ *cur++ = scale * ((*in >> 1) & 0x01);
+ *cur++ = scale * ((*in ) & 0x01);
+ }
+ if (k > 0) *cur++ = scale * ((*in >> 7) );
+ if (k > 1) *cur++ = scale * ((*in >> 6) & 0x01);
+ if (k > 2) *cur++ = scale * ((*in >> 5) & 0x01);
+ if (k > 3) *cur++ = scale * ((*in >> 4) & 0x01);
+ if (k > 4) *cur++ = scale * ((*in >> 3) & 0x01);
+ if (k > 5) *cur++ = scale * ((*in >> 2) & 0x01);
+ if (k > 6) *cur++ = scale * ((*in >> 1) & 0x01);
+ }
+ if (img_n != out_n) {
+ int q;
+ // insert alpha = 255
+ cur = a->out + stride*j;
+ if (img_n == 1) {
+ for (q=x-1; q >= 0; --q) {
+ cur[q*2+1] = 255;
+ cur[q*2+0] = cur[q];
+ }
+ } else {
+ STBI_ASSERT(img_n == 3);
+ for (q=x-1; q >= 0; --q) {
+ cur[q*4+3] = 255;
+ cur[q*4+2] = cur[q*3+2];
+ cur[q*4+1] = cur[q*3+1];
+ cur[q*4+0] = cur[q*3+0];
+ }
+ }
+ }
+ }
+ } else if (depth == 16) {
+ // force the image data from big-endian to platform-native.
+ // this is done in a separate pass due to the decoding relying
+ // on the data being untouched, but could probably be done
+ // per-line during decode if care is taken.
+ stbi_uc *cur = a->out;
+ stbi__uint16 *cur16 = (stbi__uint16*)cur;
+
+ for(i=0; i < x*y*out_n; ++i,cur16++,cur+=2) {
+ *cur16 = (cur[0] << 8) | cur[1];
+ }
+ }
+
+ return 1;
+}
+
+static int stbi__create_png_image(stbi__png *a, stbi_uc *image_data, stbi__uint32 image_data_len, int out_n, int depth, int color, int interlaced)
+{
+ int bytes = (depth == 16 ? 2 : 1);
+ int out_bytes = out_n * bytes;
+ stbi_uc *final;
+ int p;
+ if (!interlaced)
+ return stbi__create_png_image_raw(a, image_data, image_data_len, out_n, a->s->img_x, a->s->img_y, depth, color);
+
+ // de-interlacing
+ final = (stbi_uc *) stbi__malloc_mad3(a->s->img_x, a->s->img_y, out_bytes, 0);
+ if (!final) return stbi__err("outofmem", "Out of memory");
+ for (p=0; p < 7; ++p) {
+ int xorig[] = { 0,4,0,2,0,1,0 };
+ int yorig[] = { 0,0,4,0,2,0,1 };
+ int xspc[] = { 8,8,4,4,2,2,1 };
+ int yspc[] = { 8,8,8,4,4,2,2 };
+ int i,j,x,y;
+ // pass1_x[4] = 0, pass1_x[5] = 1, pass1_x[12] = 1
+ x = (a->s->img_x - xorig[p] + xspc[p]-1) / xspc[p];
+ y = (a->s->img_y - yorig[p] + yspc[p]-1) / yspc[p];
+ if (x && y) {
+ stbi__uint32 img_len = ((((a->s->img_n * x * depth) + 7) >> 3) + 1) * y;
+ if (!stbi__create_png_image_raw(a, image_data, image_data_len, out_n, x, y, depth, color)) {
+ STBI_FREE(final);
+ return 0;
+ }
+ for (j=0; j < y; ++j) {
+ for (i=0; i < x; ++i) {
+ int out_y = j*yspc[p]+yorig[p];
+ int out_x = i*xspc[p]+xorig[p];
+ memcpy(final + out_y*a->s->img_x*out_bytes + out_x*out_bytes,
+ a->out + (j*x+i)*out_bytes, out_bytes);
+ }
+ }
+ STBI_FREE(a->out);
+ image_data += img_len;
+ image_data_len -= img_len;
+ }
+ }
+ a->out = final;
+
+ return 1;
+}
+
+static int stbi__compute_transparency(stbi__png *z, stbi_uc tc[3], int out_n)
+{
+ stbi__context *s = z->s;
+ stbi__uint32 i, pixel_count = s->img_x * s->img_y;
+ stbi_uc *p = z->out;
+
+ // compute color-based transparency, assuming we've
+ // already got 255 as the alpha value in the output
+ STBI_ASSERT(out_n == 2 || out_n == 4);
+
+ if (out_n == 2) {
+ for (i=0; i < pixel_count; ++i) {
+ p[1] = (p[0] == tc[0] ? 0 : 255);
+ p += 2;
+ }
+ } else {
+ for (i=0; i < pixel_count; ++i) {
+ if (p[0] == tc[0] && p[1] == tc[1] && p[2] == tc[2])
+ p[3] = 0;
+ p += 4;
+ }
+ }
+ return 1;
+}
+
+static int stbi__compute_transparency16(stbi__png *z, stbi__uint16 tc[3], int out_n)
+{
+ stbi__context *s = z->s;
+ stbi__uint32 i, pixel_count = s->img_x * s->img_y;
+ stbi__uint16 *p = (stbi__uint16*) z->out;
+
+ // compute color-based transparency, assuming we've
+ // already got 65535 as the alpha value in the output
+ STBI_ASSERT(out_n == 2 || out_n == 4);
+
+ if (out_n == 2) {
+ for (i = 0; i < pixel_count; ++i) {
+ p[1] = (p[0] == tc[0] ? 0 : 65535);
+ p += 2;
+ }
+ } else {
+ for (i = 0; i < pixel_count; ++i) {
+ if (p[0] == tc[0] && p[1] == tc[1] && p[2] == tc[2])
+ p[3] = 0;
+ p += 4;
+ }
+ }
+ return 1;
+}
+
+static int stbi__expand_png_palette(stbi__png *a, stbi_uc *palette, int len, int pal_img_n)
+{
+ stbi__uint32 i, pixel_count = a->s->img_x * a->s->img_y;
+ stbi_uc *p, *temp_out, *orig = a->out;
+
+ p = (stbi_uc *) stbi__malloc_mad2(pixel_count, pal_img_n, 0);
+ if (p == NULL) return stbi__err("outofmem", "Out of memory");
+
+ // between here and free(out) below, exitting would leak
+ temp_out = p;
+
+ if (pal_img_n == 3) {
+ for (i=0; i < pixel_count; ++i) {
+ int n = orig[i]*4;
+ p[0] = palette[n ];
+ p[1] = palette[n+1];
+ p[2] = palette[n+2];
+ p += 3;
+ }
+ } else {
+ for (i=0; i < pixel_count; ++i) {
+ int n = orig[i]*4;
+ p[0] = palette[n ];
+ p[1] = palette[n+1];
+ p[2] = palette[n+2];
+ p[3] = palette[n+3];
+ p += 4;
+ }
+ }
+ STBI_FREE(a->out);
+ a->out = temp_out;
+
+ STBI_NOTUSED(len);
+
+ return 1;
+}
+
+static int stbi__unpremultiply_on_load_global = 0;
+static int stbi__de_iphone_flag_global = 0;
+
+STBIDEF void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply)
+{
+ stbi__unpremultiply_on_load_global = flag_true_if_should_unpremultiply;
+}
+
+STBIDEF void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert)
+{
+ stbi__de_iphone_flag_global = flag_true_if_should_convert;
+}
+
+#ifndef STBI_THREAD_LOCAL
+#define stbi__unpremultiply_on_load stbi__unpremultiply_on_load_global
+#define stbi__de_iphone_flag stbi__de_iphone_flag_global
+#else
+static STBI_THREAD_LOCAL int stbi__unpremultiply_on_load_local, stbi__unpremultiply_on_load_set;
+static STBI_THREAD_LOCAL int stbi__de_iphone_flag_local, stbi__de_iphone_flag_set;
+
+STBIDEF void stbi__unpremultiply_on_load_thread(int flag_true_if_should_unpremultiply)
+{
+ stbi__unpremultiply_on_load_local = flag_true_if_should_unpremultiply;
+ stbi__unpremultiply_on_load_set = 1;
+}
+
+STBIDEF void stbi_convert_iphone_png_to_rgb_thread(int flag_true_if_should_convert)
+{
+ stbi__de_iphone_flag_local = flag_true_if_should_convert;
+ stbi__de_iphone_flag_set = 1;
+}
+
+#define stbi__unpremultiply_on_load (stbi__unpremultiply_on_load_set \
+ ? stbi__unpremultiply_on_load_local \
+ : stbi__unpremultiply_on_load_global)
+#define stbi__de_iphone_flag (stbi__de_iphone_flag_set \
+ ? stbi__de_iphone_flag_local \
+ : stbi__de_iphone_flag_global)
+#endif // STBI_THREAD_LOCAL
+
+static void stbi__de_iphone(stbi__png *z)
+{
+ stbi__context *s = z->s;
+ stbi__uint32 i, pixel_count = s->img_x * s->img_y;
+ stbi_uc *p = z->out;
+
+ if (s->img_out_n == 3) { // convert bgr to rgb
+ for (i=0; i < pixel_count; ++i) {
+ stbi_uc t = p[0];
+ p[0] = p[2];
+ p[2] = t;
+ p += 3;
+ }
+ } else {
+ STBI_ASSERT(s->img_out_n == 4);
+ if (stbi__unpremultiply_on_load) {
+ // convert bgr to rgb and unpremultiply
+ for (i=0; i < pixel_count; ++i) {
+ stbi_uc a = p[3];
+ stbi_uc t = p[0];
+ if (a) {
+ stbi_uc half = a / 2;
+ p[0] = (p[2] * 255 + half) / a;
+ p[1] = (p[1] * 255 + half) / a;
+ p[2] = ( t * 255 + half) / a;
+ } else {
+ p[0] = p[2];
+ p[2] = t;
+ }
+ p += 4;
+ }
+ } else {
+ // convert bgr to rgb
+ for (i=0; i < pixel_count; ++i) {
+ stbi_uc t = p[0];
+ p[0] = p[2];
+ p[2] = t;
+ p += 4;
+ }
+ }
+ }
+}
+
+#define STBI__PNG_TYPE(a,b,c,d) (((unsigned) (a) << 24) + ((unsigned) (b) << 16) + ((unsigned) (c) << 8) + (unsigned) (d))
+
+static int stbi__parse_png_file(stbi__png *z, int scan, int req_comp)
+{
+ stbi_uc palette[1024], pal_img_n=0;
+ stbi_uc has_trans=0, tc[3]={0};
+ stbi__uint16 tc16[3];
+ stbi__uint32 ioff=0, idata_limit=0, i, pal_len=0;
+ int first=1,k,interlace=0, color=0, is_iphone=0;
+ stbi__context *s = z->s;
+
+ z->expanded = NULL;
+ z->idata = NULL;
+ z->out = NULL;
+
+ if (!stbi__check_png_header(s)) return 0;
+
+ if (scan == STBI__SCAN_type) return 1;
+
+ for (;;) {
+ stbi__pngchunk c = stbi__get_chunk_header(s);
+ switch (c.type) {
+ case STBI__PNG_TYPE('C','g','B','I'):
+ is_iphone = 1;
+ stbi__skip(s, c.length);
+ break;
+ case STBI__PNG_TYPE('I','H','D','R'): {
+ int comp,filter;
+ if (!first) return stbi__err("multiple IHDR","Corrupt PNG");
+ first = 0;
+ if (c.length != 13) return stbi__err("bad IHDR len","Corrupt PNG");
+ s->img_x = stbi__get32be(s);
+ s->img_y = stbi__get32be(s);
+ if (s->img_y > STBI_MAX_DIMENSIONS) return stbi__err("too large","Very large image (corrupt?)");
+ if (s->img_x > STBI_MAX_DIMENSIONS) return stbi__err("too large","Very large image (corrupt?)");
+ z->depth = stbi__get8(s); if (z->depth != 1 && z->depth != 2 && z->depth != 4 && z->depth != 8 && z->depth != 16) return stbi__err("1/2/4/8/16-bit only","PNG not supported: 1/2/4/8/16-bit only");
+ color = stbi__get8(s); if (color > 6) return stbi__err("bad ctype","Corrupt PNG");
+ if (color == 3 && z->depth == 16) return stbi__err("bad ctype","Corrupt PNG");
+ if (color == 3) pal_img_n = 3; else if (color & 1) return stbi__err("bad ctype","Corrupt PNG");
+ comp = stbi__get8(s); if (comp) return stbi__err("bad comp method","Corrupt PNG");
+ filter= stbi__get8(s); if (filter) return stbi__err("bad filter method","Corrupt PNG");
+ interlace = stbi__get8(s); if (interlace>1) return stbi__err("bad interlace method","Corrupt PNG");
+ if (!s->img_x || !s->img_y) return stbi__err("0-pixel image","Corrupt PNG");
+ if (!pal_img_n) {
+ s->img_n = (color & 2 ? 3 : 1) + (color & 4 ? 1 : 0);
+ if ((1 << 30) / s->img_x / s->img_n < s->img_y) return stbi__err("too large", "Image too large to decode");
+ if (scan == STBI__SCAN_header) return 1;
+ } else {
+ // if paletted, then pal_n is our final components, and
+ // img_n is # components to decompress/filter.
+ s->img_n = 1;
+ if ((1 << 30) / s->img_x / 4 < s->img_y) return stbi__err("too large","Corrupt PNG");
+ // if SCAN_header, have to scan to see if we have a tRNS
+ }
+ break;
+ }
+
+ case STBI__PNG_TYPE('P','L','T','E'): {
+ if (first) return stbi__err("first not IHDR", "Corrupt PNG");
+ if (c.length > 256*3) return stbi__err("invalid PLTE","Corrupt PNG");
+ pal_len = c.length / 3;
+ if (pal_len * 3 != c.length) return stbi__err("invalid PLTE","Corrupt PNG");
+ for (i=0; i < pal_len; ++i) {
+ palette[i*4+0] = stbi__get8(s);
+ palette[i*4+1] = stbi__get8(s);
+ palette[i*4+2] = stbi__get8(s);
+ palette[i*4+3] = 255;
+ }
+ break;
+ }
+
+ case STBI__PNG_TYPE('t','R','N','S'): {
+ if (first) return stbi__err("first not IHDR", "Corrupt PNG");
+ if (z->idata) return stbi__err("tRNS after IDAT","Corrupt PNG");
+ if (pal_img_n) {
+ if (scan == STBI__SCAN_header) { s->img_n = 4; return 1; }
+ if (pal_len == 0) return stbi__err("tRNS before PLTE","Corrupt PNG");
+ if (c.length > pal_len) return stbi__err("bad tRNS len","Corrupt PNG");
+ pal_img_n = 4;
+ for (i=0; i < c.length; ++i)
+ palette[i*4+3] = stbi__get8(s);
+ } else {
+ if (!(s->img_n & 1)) return stbi__err("tRNS with alpha","Corrupt PNG");
+ if (c.length != (stbi__uint32) s->img_n*2) return stbi__err("bad tRNS len","Corrupt PNG");
+ has_trans = 1;
+ if (z->depth == 16) {
+ for (k = 0; k < s->img_n; ++k) tc16[k] = (stbi__uint16)stbi__get16be(s); // copy the values as-is
+ } else {
+ for (k = 0; k < s->img_n; ++k) tc[k] = (stbi_uc)(stbi__get16be(s) & 255) * stbi__depth_scale_table[z->depth]; // non 8-bit images will be larger
+ }
+ }
+ break;
+ }
+
+ case STBI__PNG_TYPE('I','D','A','T'): {
+ if (first) return stbi__err("first not IHDR", "Corrupt PNG");
+ if (pal_img_n && !pal_len) return stbi__err("no PLTE","Corrupt PNG");
+ if (scan == STBI__SCAN_header) { s->img_n = pal_img_n; return 1; }
+ if ((int)(ioff + c.length) < (int)ioff) return 0;
+ if (ioff + c.length > idata_limit) {
+ stbi__uint32 idata_limit_old = idata_limit;
+ stbi_uc *p;
+ if (idata_limit == 0) idata_limit = c.length > 4096 ? c.length : 4096;
+ while (ioff + c.length > idata_limit)
+ idata_limit *= 2;
+ STBI_NOTUSED(idata_limit_old);
+ p = (stbi_uc *) STBI_REALLOC_SIZED(z->idata, idata_limit_old, idata_limit); if (p == NULL) return stbi__err("outofmem", "Out of memory");
+ z->idata = p;
+ }
+ if (!stbi__getn(s, z->idata+ioff,c.length)) return stbi__err("outofdata","Corrupt PNG");
+ ioff += c.length;
+ break;
+ }
+
+ case STBI__PNG_TYPE('I','E','N','D'): {
+ stbi__uint32 raw_len, bpl;
+ if (first) return stbi__err("first not IHDR", "Corrupt PNG");
+ if (scan != STBI__SCAN_load) return 1;
+ if (z->idata == NULL) return stbi__err("no IDAT","Corrupt PNG");
+ // initial guess for decoded data size to avoid unnecessary reallocs
+ bpl = (s->img_x * z->depth + 7) / 8; // bytes per line, per component
+ raw_len = bpl * s->img_y * s->img_n /* pixels */ + s->img_y /* filter mode per row */;
+ z->expanded = (stbi_uc *) stbi_zlib_decode_malloc_guesssize_headerflag((char *) z->idata, ioff, raw_len, (int *) &raw_len, !is_iphone);
+ if (z->expanded == NULL) return 0; // zlib should set error
+ STBI_FREE(z->idata); z->idata = NULL;
+ if ((req_comp == s->img_n+1 && req_comp != 3 && !pal_img_n) || has_trans)
+ s->img_out_n = s->img_n+1;
+ else
+ s->img_out_n = s->img_n;
+ if (!stbi__create_png_image(z, z->expanded, raw_len, s->img_out_n, z->depth, color, interlace)) return 0;
+ if (has_trans) {
+ if (z->depth == 16) {
+ if (!stbi__compute_transparency16(z, tc16, s->img_out_n)) return 0;
+ } else {
+ if (!stbi__compute_transparency(z, tc, s->img_out_n)) return 0;
+ }
+ }
+ if (is_iphone && stbi__de_iphone_flag && s->img_out_n > 2)
+ stbi__de_iphone(z);
+ if (pal_img_n) {
+ // pal_img_n == 3 or 4
+ s->img_n = pal_img_n; // record the actual colors we had
+ s->img_out_n = pal_img_n;
+ if (req_comp >= 3) s->img_out_n = req_comp;
+ if (!stbi__expand_png_palette(z, palette, pal_len, s->img_out_n))
+ return 0;
+ } else if (has_trans) {
+ // non-paletted image with tRNS -> source image has (constant) alpha
+ ++s->img_n;
+ }
+ STBI_FREE(z->expanded); z->expanded = NULL;
+ // end of PNG chunk, read and skip CRC
+ stbi__get32be(s);
+ return 1;
+ }
+
+ default:
+ // if critical, fail
+ if (first) return stbi__err("first not IHDR", "Corrupt PNG");
+ if ((c.type & (1 << 29)) == 0) {
+ #ifndef STBI_NO_FAILURE_STRINGS
+ // not threadsafe
+ static char invalid_chunk[] = "XXXX PNG chunk not known";
+ invalid_chunk[0] = STBI__BYTECAST(c.type >> 24);
+ invalid_chunk[1] = STBI__BYTECAST(c.type >> 16);
+ invalid_chunk[2] = STBI__BYTECAST(c.type >> 8);
+ invalid_chunk[3] = STBI__BYTECAST(c.type >> 0);
+ #endif
+ return stbi__err(invalid_chunk, "PNG not supported: unknown PNG chunk type");
+ }
+ stbi__skip(s, c.length);
+ break;
+ }
+ // end of PNG chunk, read and skip CRC
+ stbi__get32be(s);
+ }
+}
+
+static void *stbi__do_png(stbi__png *p, int *x, int *y, int *n, int req_comp, stbi__result_info *ri)
+{
+ void *result=NULL;
+ if (req_comp < 0 || req_comp > 4) return stbi__errpuc("bad req_comp", "Internal error");
+ if (stbi__parse_png_file(p, STBI__SCAN_load, req_comp)) {
+ if (p->depth <= 8)
+ ri->bits_per_channel = 8;
+ else if (p->depth == 16)
+ ri->bits_per_channel = 16;
+ else
+ return stbi__errpuc("bad bits_per_channel", "PNG not supported: unsupported color depth");
+ result = p->out;
+ p->out = NULL;
+ if (req_comp && req_comp != p->s->img_out_n) {
+ if (ri->bits_per_channel == 8)
+ result = stbi__convert_format((unsigned char *) result, p->s->img_out_n, req_comp, p->s->img_x, p->s->img_y);
+ else
+ result = stbi__convert_format16((stbi__uint16 *) result, p->s->img_out_n, req_comp, p->s->img_x, p->s->img_y);
+ p->s->img_out_n = req_comp;
+ if (result == NULL) return result;
+ }
+ *x = p->s->img_x;
+ *y = p->s->img_y;
+ if (n) *n = p->s->img_n;
+ }
+ STBI_FREE(p->out); p->out = NULL;
+ STBI_FREE(p->expanded); p->expanded = NULL;
+ STBI_FREE(p->idata); p->idata = NULL;
+
+ return result;
+}
+
+static void *stbi__png_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri)
+{
+ stbi__png p;
+ p.s = s;
+ return stbi__do_png(&p, x,y,comp,req_comp, ri);
+}
+
+static int stbi__png_test(stbi__context *s)
+{
+ int r;
+ r = stbi__check_png_header(s);
+ stbi__rewind(s);
+ return r;
+}
+
+static int stbi__png_info_raw(stbi__png *p, int *x, int *y, int *comp)
+{
+ if (!stbi__parse_png_file(p, STBI__SCAN_header, 0)) {
+ stbi__rewind( p->s );
+ return 0;
+ }
+ if (x) *x = p->s->img_x;
+ if (y) *y = p->s->img_y;
+ if (comp) *comp = p->s->img_n;
+ return 1;
+}
+
+static int stbi__png_info(stbi__context *s, int *x, int *y, int *comp)
+{
+ stbi__png p;
+ p.s = s;
+ return stbi__png_info_raw(&p, x, y, comp);
+}
+
+static int stbi__png_is16(stbi__context *s)
+{
+ stbi__png p;
+ p.s = s;
+ if (!stbi__png_info_raw(&p, NULL, NULL, NULL))
+ return 0;
+ if (p.depth != 16) {
+ stbi__rewind(p.s);
+ return 0;
+ }
+ return 1;
+}
+#endif
+
+// Microsoft/Windows BMP image
+
+#ifndef STBI_NO_BMP
+static int stbi__bmp_test_raw(stbi__context *s)
+{
+ int r;
+ int sz;
+ if (stbi__get8(s) != 'B') return 0;
+ if (stbi__get8(s) != 'M') return 0;
+ stbi__get32le(s); // discard filesize
+ stbi__get16le(s); // discard reserved
+ stbi__get16le(s); // discard reserved
+ stbi__get32le(s); // discard data offset
+ sz = stbi__get32le(s);
+ r = (sz == 12 || sz == 40 || sz == 56 || sz == 108 || sz == 124);
+ return r;
+}
+
+static int stbi__bmp_test(stbi__context *s)
+{
+ int r = stbi__bmp_test_raw(s);
+ stbi__rewind(s);
+ return r;
+}
+
+
+// returns 0..31 for the highest set bit
+static int stbi__high_bit(unsigned int z)
+{
+ int n=0;
+ if (z == 0) return -1;
+ if (z >= 0x10000) { n += 16; z >>= 16; }
+ if (z >= 0x00100) { n += 8; z >>= 8; }
+ if (z >= 0x00010) { n += 4; z >>= 4; }
+ if (z >= 0x00004) { n += 2; z >>= 2; }
+ if (z >= 0x00002) { n += 1;/* >>= 1;*/ }
+ return n;
+}
+
+static int stbi__bitcount(unsigned int a)
+{
+ a = (a & 0x55555555) + ((a >> 1) & 0x55555555); // max 2
+ a = (a & 0x33333333) + ((a >> 2) & 0x33333333); // max 4
+ a = (a + (a >> 4)) & 0x0f0f0f0f; // max 8 per 4, now 8 bits
+ a = (a + (a >> 8)); // max 16 per 8 bits
+ a = (a + (a >> 16)); // max 32 per 8 bits
+ return a & 0xff;
+}
+
+// extract an arbitrarily-aligned N-bit value (N=bits)
+// from v, and then make it 8-bits long and fractionally
+// extend it to full full range.
+static int stbi__shiftsigned(unsigned int v, int shift, int bits)
+{
+ static unsigned int mul_table[9] = {
+ 0,
+ 0xff/*0b11111111*/, 0x55/*0b01010101*/, 0x49/*0b01001001*/, 0x11/*0b00010001*/,
+ 0x21/*0b00100001*/, 0x41/*0b01000001*/, 0x81/*0b10000001*/, 0x01/*0b00000001*/,
+ };
+ static unsigned int shift_table[9] = {
+ 0, 0,0,1,0,2,4,6,0,
+ };
+ if (shift < 0)
+ v <<= -shift;
+ else
+ v >>= shift;
+ STBI_ASSERT(v < 256);
+ v >>= (8-bits);
+ STBI_ASSERT(bits >= 0 && bits <= 8);
+ return (int) ((unsigned) v * mul_table[bits]) >> shift_table[bits];
+}
+
+typedef struct
+{
+ int bpp, offset, hsz;
+ unsigned int mr,mg,mb,ma, all_a;
+ int extra_read;
+} stbi__bmp_data;
+
+static int stbi__bmp_set_mask_defaults(stbi__bmp_data *info, int compress)
+{
+ // BI_BITFIELDS specifies masks explicitly, don't override
+ if (compress == 3)
+ return 1;
+
+ if (compress == 0) {
+ if (info->bpp == 16) {
+ info->mr = 31u << 10;
+ info->mg = 31u << 5;
+ info->mb = 31u << 0;
+ } else if (info->bpp == 32) {
+ info->mr = 0xffu << 16;
+ info->mg = 0xffu << 8;
+ info->mb = 0xffu << 0;
+ info->ma = 0xffu << 24;
+ info->all_a = 0; // if all_a is 0 at end, then we loaded alpha channel but it was all 0
+ } else {
+ // otherwise, use defaults, which is all-0
+ info->mr = info->mg = info->mb = info->ma = 0;
+ }
+ return 1;
+ }
+ return 0; // error
+}
+
+static void *stbi__bmp_parse_header(stbi__context *s, stbi__bmp_data *info)
+{
+ int hsz;
+ if (stbi__get8(s) != 'B' || stbi__get8(s) != 'M') return stbi__errpuc("not BMP", "Corrupt BMP");
+ stbi__get32le(s); // discard filesize
+ stbi__get16le(s); // discard reserved
+ stbi__get16le(s); // discard reserved
+ info->offset = stbi__get32le(s);
+ info->hsz = hsz = stbi__get32le(s);
+ info->mr = info->mg = info->mb = info->ma = 0;
+ info->extra_read = 14;
+
+ if (info->offset < 0) return stbi__errpuc("bad BMP", "bad BMP");
+
+ if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108 && hsz != 124) return stbi__errpuc("unknown BMP", "BMP type not supported: unknown");
+ if (hsz == 12) {
+ s->img_x = stbi__get16le(s);
+ s->img_y = stbi__get16le(s);
+ } else {
+ s->img_x = stbi__get32le(s);
+ s->img_y = stbi__get32le(s);
+ }
+ if (stbi__get16le(s) != 1) return stbi__errpuc("bad BMP", "bad BMP");
+ info->bpp = stbi__get16le(s);
+ if (hsz != 12) {
+ int compress = stbi__get32le(s);
+ if (compress == 1 || compress == 2) return stbi__errpuc("BMP RLE", "BMP type not supported: RLE");
+ if (compress >= 4) return stbi__errpuc("BMP JPEG/PNG", "BMP type not supported: unsupported compression"); // this includes PNG/JPEG modes
+ if (compress == 3 && info->bpp != 16 && info->bpp != 32) return stbi__errpuc("bad BMP", "bad BMP"); // bitfields requires 16 or 32 bits/pixel
+ stbi__get32le(s); // discard sizeof
+ stbi__get32le(s); // discard hres
+ stbi__get32le(s); // discard vres
+ stbi__get32le(s); // discard colorsused
+ stbi__get32le(s); // discard max important
+ if (hsz == 40 || hsz == 56) {
+ if (hsz == 56) {
+ stbi__get32le(s);
+ stbi__get32le(s);
+ stbi__get32le(s);
+ stbi__get32le(s);
+ }
+ if (info->bpp == 16 || info->bpp == 32) {
+ if (compress == 0) {
+ stbi__bmp_set_mask_defaults(info, compress);
+ } else if (compress == 3) {
+ info->mr = stbi__get32le(s);
+ info->mg = stbi__get32le(s);
+ info->mb = stbi__get32le(s);
+ info->extra_read += 12;
+ // not documented, but generated by photoshop and handled by mspaint
+ if (info->mr == info->mg && info->mg == info->mb) {
+ // ?!?!?
+ return stbi__errpuc("bad BMP", "bad BMP");
+ }
+ } else
+ return stbi__errpuc("bad BMP", "bad BMP");
+ }
+ } else {
+ // V4/V5 header
+ int i;
+ if (hsz != 108 && hsz != 124)
+ return stbi__errpuc("bad BMP", "bad BMP");
+ info->mr = stbi__get32le(s);
+ info->mg = stbi__get32le(s);
+ info->mb = stbi__get32le(s);
+ info->ma = stbi__get32le(s);
+ if (compress != 3) // override mr/mg/mb unless in BI_BITFIELDS mode, as per docs
+ stbi__bmp_set_mask_defaults(info, compress);
+ stbi__get32le(s); // discard color space
+ for (i=0; i < 12; ++i)
+ stbi__get32le(s); // discard color space parameters
+ if (hsz == 124) {
+ stbi__get32le(s); // discard rendering intent
+ stbi__get32le(s); // discard offset of profile data
+ stbi__get32le(s); // discard size of profile data
+ stbi__get32le(s); // discard reserved
+ }
+ }
+ }
+ return (void *) 1;
+}
+
+
+static void *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri)
+{
+ stbi_uc *out;
+ unsigned int mr=0,mg=0,mb=0,ma=0, all_a;
+ stbi_uc pal[256][4];
+ int psize=0,i,j,width;
+ int flip_vertically, pad, target;
+ stbi__bmp_data info;
+ STBI_NOTUSED(ri);
+
+ info.all_a = 255;
+ if (stbi__bmp_parse_header(s, &info) == NULL)
+ return NULL; // error code already set
+
+ flip_vertically = ((int) s->img_y) > 0;
+ s->img_y = abs((int) s->img_y);
+
+ if (s->img_y > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large","Very large image (corrupt?)");
+ if (s->img_x > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large","Very large image (corrupt?)");
+
+ mr = info.mr;
+ mg = info.mg;
+ mb = info.mb;
+ ma = info.ma;
+ all_a = info.all_a;
+
+ if (info.hsz == 12) {
+ if (info.bpp < 24)
+ psize = (info.offset - info.extra_read - 24) / 3;
+ } else {
+ if (info.bpp < 16)
+ psize = (info.offset - info.extra_read - info.hsz) >> 2;
+ }
+ if (psize == 0) {
+ if (info.offset != s->callback_already_read + (s->img_buffer - s->img_buffer_original)) {
+ return stbi__errpuc("bad offset", "Corrupt BMP");
+ }
+ }
+
+ if (info.bpp == 24 && ma == 0xff000000)
+ s->img_n = 3;
+ else
+ s->img_n = ma ? 4 : 3;
+ if (req_comp && req_comp >= 3) // we can directly decode 3 or 4
+ target = req_comp;
+ else
+ target = s->img_n; // if they want monochrome, we'll post-convert
+
+ // sanity-check size
+ if (!stbi__mad3sizes_valid(target, s->img_x, s->img_y, 0))
+ return stbi__errpuc("too large", "Corrupt BMP");
+
+ out = (stbi_uc *) stbi__malloc_mad3(target, s->img_x, s->img_y, 0);
+ if (!out) return stbi__errpuc("outofmem", "Out of memory");
+ if (info.bpp < 16) {
+ int z=0;
+ if (psize == 0 || psize > 256) { STBI_FREE(out); return stbi__errpuc("invalid", "Corrupt BMP"); }
+ for (i=0; i < psize; ++i) {
+ pal[i][2] = stbi__get8(s);
+ pal[i][1] = stbi__get8(s);
+ pal[i][0] = stbi__get8(s);
+ if (info.hsz != 12) stbi__get8(s);
+ pal[i][3] = 255;
+ }
+ stbi__skip(s, info.offset - info.extra_read - info.hsz - psize * (info.hsz == 12 ? 3 : 4));
+ if (info.bpp == 1) width = (s->img_x + 7) >> 3;
+ else if (info.bpp == 4) width = (s->img_x + 1) >> 1;
+ else if (info.bpp == 8) width = s->img_x;
+ else { STBI_FREE(out); return stbi__errpuc("bad bpp", "Corrupt BMP"); }
+ pad = (-width)&3;
+ if (info.bpp == 1) {
+ for (j=0; j < (int) s->img_y; ++j) {
+ int bit_offset = 7, v = stbi__get8(s);
+ for (i=0; i < (int) s->img_x; ++i) {
+ int color = (v>>bit_offset)&0x1;
+ out[z++] = pal[color][0];
+ out[z++] = pal[color][1];
+ out[z++] = pal[color][2];
+ if (target == 4) out[z++] = 255;
+ if (i+1 == (int) s->img_x) break;
+ if((--bit_offset) < 0) {
+ bit_offset = 7;
+ v = stbi__get8(s);
+ }
+ }
+ stbi__skip(s, pad);
+ }
+ } else {
+ for (j=0; j < (int) s->img_y; ++j) {
+ for (i=0; i < (int) s->img_x; i += 2) {
+ int v=stbi__get8(s),v2=0;
+ if (info.bpp == 4) {
+ v2 = v & 15;
+ v >>= 4;
+ }
+ out[z++] = pal[v][0];
+ out[z++] = pal[v][1];
+ out[z++] = pal[v][2];
+ if (target == 4) out[z++] = 255;
+ if (i+1 == (int) s->img_x) break;
+ v = (info.bpp == 8) ? stbi__get8(s) : v2;
+ out[z++] = pal[v][0];
+ out[z++] = pal[v][1];
+ out[z++] = pal[v][2];
+ if (target == 4) out[z++] = 255;
+ }
+ stbi__skip(s, pad);
+ }
+ }
+ } else {
+ int rshift=0,gshift=0,bshift=0,ashift=0,rcount=0,gcount=0,bcount=0,acount=0;
+ int z = 0;
+ int easy=0;
+ stbi__skip(s, info.offset - info.extra_read - info.hsz);
+ if (info.bpp == 24) width = 3 * s->img_x;
+ else if (info.bpp == 16) width = 2*s->img_x;
+ else /* bpp = 32 and pad = 0 */ width=0;
+ pad = (-width) & 3;
+ if (info.bpp == 24) {
+ easy = 1;
+ } else if (info.bpp == 32) {
+ if (mb == 0xff && mg == 0xff00 && mr == 0x00ff0000 && ma == 0xff000000)
+ easy = 2;
+ }
+ if (!easy) {
+ if (!mr || !mg || !mb) { STBI_FREE(out); return stbi__errpuc("bad masks", "Corrupt BMP"); }
+ // right shift amt to put high bit in position #7
+ rshift = stbi__high_bit(mr)-7; rcount = stbi__bitcount(mr);
+ gshift = stbi__high_bit(mg)-7; gcount = stbi__bitcount(mg);
+ bshift = stbi__high_bit(mb)-7; bcount = stbi__bitcount(mb);
+ ashift = stbi__high_bit(ma)-7; acount = stbi__bitcount(ma);
+ if (rcount > 8 || gcount > 8 || bcount > 8 || acount > 8) { STBI_FREE(out); return stbi__errpuc("bad masks", "Corrupt BMP"); }
+ }
+ for (j=0; j < (int) s->img_y; ++j) {
+ if (easy) {
+ for (i=0; i < (int) s->img_x; ++i) {
+ unsigned char a;
+ out[z+2] = stbi__get8(s);
+ out[z+1] = stbi__get8(s);
+ out[z+0] = stbi__get8(s);
+ z += 3;
+ a = (easy == 2 ? stbi__get8(s) : 255);
+ all_a |= a;
+ if (target == 4) out[z++] = a;
+ }
+ } else {
+ int bpp = info.bpp;
+ for (i=0; i < (int) s->img_x; ++i) {
+ stbi__uint32 v = (bpp == 16 ? (stbi__uint32) stbi__get16le(s) : stbi__get32le(s));
+ unsigned int a;
+ out[z++] = STBI__BYTECAST(stbi__shiftsigned(v & mr, rshift, rcount));
+ out[z++] = STBI__BYTECAST(stbi__shiftsigned(v & mg, gshift, gcount));
+ out[z++] = STBI__BYTECAST(stbi__shiftsigned(v & mb, bshift, bcount));
+ a = (ma ? stbi__shiftsigned(v & ma, ashift, acount) : 255);
+ all_a |= a;
+ if (target == 4) out[z++] = STBI__BYTECAST(a);
+ }
+ }
+ stbi__skip(s, pad);
+ }
+ }
+
+ // if alpha channel is all 0s, replace with all 255s
+ if (target == 4 && all_a == 0)
+ for (i=4*s->img_x*s->img_y-1; i >= 0; i -= 4)
+ out[i] = 255;
+
+ if (flip_vertically) {
+ stbi_uc t;
+ for (j=0; j < (int) s->img_y>>1; ++j) {
+ stbi_uc *p1 = out + j *s->img_x*target;
+ stbi_uc *p2 = out + (s->img_y-1-j)*s->img_x*target;
+ for (i=0; i < (int) s->img_x*target; ++i) {
+ t = p1[i]; p1[i] = p2[i]; p2[i] = t;
+ }
+ }
+ }
+
+ if (req_comp && req_comp != target) {
+ out = stbi__convert_format(out, target, req_comp, s->img_x, s->img_y);
+ if (out == NULL) return out; // stbi__convert_format frees input on failure
+ }
+
+ *x = s->img_x;
+ *y = s->img_y;
+ if (comp) *comp = s->img_n;
+ return out;
+}
+#endif
+
+// Targa Truevision - TGA
+// by Jonathan Dummer
+#ifndef STBI_NO_TGA
+// returns STBI_rgb or whatever, 0 on error
+static int stbi__tga_get_comp(int bits_per_pixel, int is_grey, int* is_rgb16)
+{
+ // only RGB or RGBA (incl. 16bit) or grey allowed
+ if (is_rgb16) *is_rgb16 = 0;
+ switch(bits_per_pixel) {
+ case 8: return STBI_grey;
+ case 16: if(is_grey) return STBI_grey_alpha;
+ // fallthrough
+ case 15: if(is_rgb16) *is_rgb16 = 1;
+ return STBI_rgb;
+ case 24: // fallthrough
+ case 32: return bits_per_pixel/8;
+ default: return 0;
+ }
+}
+
+static int stbi__tga_info(stbi__context *s, int *x, int *y, int *comp)
+{
+ int tga_w, tga_h, tga_comp, tga_image_type, tga_bits_per_pixel, tga_colormap_bpp;
+ int sz, tga_colormap_type;
+ stbi__get8(s); // discard Offset
+ tga_colormap_type = stbi__get8(s); // colormap type
+ if( tga_colormap_type > 1 ) {
+ stbi__rewind(s);
+ return 0; // only RGB or indexed allowed
+ }
+ tga_image_type = stbi__get8(s); // image type
+ if ( tga_colormap_type == 1 ) { // colormapped (paletted) image
+ if (tga_image_type != 1 && tga_image_type != 9) {
+ stbi__rewind(s);
+ return 0;
+ }
+ stbi__skip(s,4); // skip index of first colormap entry and number of entries
+ sz = stbi__get8(s); // check bits per palette color entry
+ if ( (sz != 8) && (sz != 15) && (sz != 16) && (sz != 24) && (sz != 32) ) {
+ stbi__rewind(s);
+ return 0;
+ }
+ stbi__skip(s,4); // skip image x and y origin
+ tga_colormap_bpp = sz;
+ } else { // "normal" image w/o colormap - only RGB or grey allowed, +/- RLE
+ if ( (tga_image_type != 2) && (tga_image_type != 3) && (tga_image_type != 10) && (tga_image_type != 11) ) {
+ stbi__rewind(s);
+ return 0; // only RGB or grey allowed, +/- RLE
+ }
+ stbi__skip(s,9); // skip colormap specification and image x/y origin
+ tga_colormap_bpp = 0;
+ }
+ tga_w = stbi__get16le(s);
+ if( tga_w < 1 ) {
+ stbi__rewind(s);
+ return 0; // test width
+ }
+ tga_h = stbi__get16le(s);
+ if( tga_h < 1 ) {
+ stbi__rewind(s);
+ return 0; // test height
+ }
+ tga_bits_per_pixel = stbi__get8(s); // bits per pixel
+ stbi__get8(s); // ignore alpha bits
+ if (tga_colormap_bpp != 0) {
+ if((tga_bits_per_pixel != 8) && (tga_bits_per_pixel != 16)) {
+ // when using a colormap, tga_bits_per_pixel is the size of the indexes
+ // I don't think anything but 8 or 16bit indexes makes sense
+ stbi__rewind(s);
+ return 0;
+ }
+ tga_comp = stbi__tga_get_comp(tga_colormap_bpp, 0, NULL);
+ } else {
+ tga_comp = stbi__tga_get_comp(tga_bits_per_pixel, (tga_image_type == 3) || (tga_image_type == 11), NULL);
+ }
+ if(!tga_comp) {
+ stbi__rewind(s);
+ return 0;
+ }
+ if (x) *x = tga_w;
+ if (y) *y = tga_h;
+ if (comp) *comp = tga_comp;
+ return 1; // seems to have passed everything
+}
+
+static int stbi__tga_test(stbi__context *s)
+{
+ int res = 0;
+ int sz, tga_color_type;
+ stbi__get8(s); // discard Offset
+ tga_color_type = stbi__get8(s); // color type
+ if ( tga_color_type > 1 ) goto errorEnd; // only RGB or indexed allowed
+ sz = stbi__get8(s); // image type
+ if ( tga_color_type == 1 ) { // colormapped (paletted) image
+ if (sz != 1 && sz != 9) goto errorEnd; // colortype 1 demands image type 1 or 9
+ stbi__skip(s,4); // skip index of first colormap entry and number of entries
+ sz = stbi__get8(s); // check bits per palette color entry
+ if ( (sz != 8) && (sz != 15) && (sz != 16) && (sz != 24) && (sz != 32) ) goto errorEnd;
+ stbi__skip(s,4); // skip image x and y origin
+ } else { // "normal" image w/o colormap
+ if ( (sz != 2) && (sz != 3) && (sz != 10) && (sz != 11) ) goto errorEnd; // only RGB or grey allowed, +/- RLE
+ stbi__skip(s,9); // skip colormap specification and image x/y origin
+ }
+ if ( stbi__get16le(s) < 1 ) goto errorEnd; // test width
+ if ( stbi__get16le(s) < 1 ) goto errorEnd; // test height
+ sz = stbi__get8(s); // bits per pixel
+ if ( (tga_color_type == 1) && (sz != 8) && (sz != 16) ) goto errorEnd; // for colormapped images, bpp is size of an index
+ if ( (sz != 8) && (sz != 15) && (sz != 16) && (sz != 24) && (sz != 32) ) goto errorEnd;
+
+ res = 1; // if we got this far, everything's good and we can return 1 instead of 0
+
+errorEnd:
+ stbi__rewind(s);
+ return res;
+}
+
+// read 16bit value and convert to 24bit RGB
+static void stbi__tga_read_rgb16(stbi__context *s, stbi_uc* out)
+{
+ stbi__uint16 px = (stbi__uint16)stbi__get16le(s);
+ stbi__uint16 fiveBitMask = 31;
+ // we have 3 channels with 5bits each
+ int r = (px >> 10) & fiveBitMask;
+ int g = (px >> 5) & fiveBitMask;
+ int b = px & fiveBitMask;
+ // Note that this saves the data in RGB(A) order, so it doesn't need to be swapped later
+ out[0] = (stbi_uc)((r * 255)/31);
+ out[1] = (stbi_uc)((g * 255)/31);
+ out[2] = (stbi_uc)((b * 255)/31);
+
+ // some people claim that the most significant bit might be used for alpha
+ // (possibly if an alpha-bit is set in the "image descriptor byte")
+ // but that only made 16bit test images completely translucent..
+ // so let's treat all 15 and 16bit TGAs as RGB with no alpha.
+}
+
+static void *stbi__tga_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri)
+{
+ // read in the TGA header stuff
+ int tga_offset = stbi__get8(s);
+ int tga_indexed = stbi__get8(s);
+ int tga_image_type = stbi__get8(s);
+ int tga_is_RLE = 0;
+ int tga_palette_start = stbi__get16le(s);
+ int tga_palette_len = stbi__get16le(s);
+ int tga_palette_bits = stbi__get8(s);
+ int tga_x_origin = stbi__get16le(s);
+ int tga_y_origin = stbi__get16le(s);
+ int tga_width = stbi__get16le(s);
+ int tga_height = stbi__get16le(s);
+ int tga_bits_per_pixel = stbi__get8(s);
+ int tga_comp, tga_rgb16=0;
+ int tga_inverted = stbi__get8(s);
+ // int tga_alpha_bits = tga_inverted & 15; // the 4 lowest bits - unused (useless?)
+ // image data
+ unsigned char *tga_data;
+ unsigned char *tga_palette = NULL;
+ int i, j;
+ unsigned char raw_data[4] = {0};
+ int RLE_count = 0;
+ int RLE_repeating = 0;
+ int read_next_pixel = 1;
+ STBI_NOTUSED(ri);
+ STBI_NOTUSED(tga_x_origin); // @TODO
+ STBI_NOTUSED(tga_y_origin); // @TODO
+
+ if (tga_height > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large","Very large image (corrupt?)");
+ if (tga_width > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large","Very large image (corrupt?)");
+
+ // do a tiny bit of precessing
+ if ( tga_image_type >= 8 )
+ {
+ tga_image_type -= 8;
+ tga_is_RLE = 1;
+ }
+ tga_inverted = 1 - ((tga_inverted >> 5) & 1);
+
+ // If I'm paletted, then I'll use the number of bits from the palette
+ if ( tga_indexed ) tga_comp = stbi__tga_get_comp(tga_palette_bits, 0, &tga_rgb16);
+ else tga_comp = stbi__tga_get_comp(tga_bits_per_pixel, (tga_image_type == 3), &tga_rgb16);
+
+ if(!tga_comp) // shouldn't really happen, stbi__tga_test() should have ensured basic consistency
+ return stbi__errpuc("bad format", "Can't find out TGA pixelformat");
+
+ // tga info
+ *x = tga_width;
+ *y = tga_height;
+ if (comp) *comp = tga_comp;
+
+ if (!stbi__mad3sizes_valid(tga_width, tga_height, tga_comp, 0))
+ return stbi__errpuc("too large", "Corrupt TGA");
+
+ tga_data = (unsigned char*)stbi__malloc_mad3(tga_width, tga_height, tga_comp, 0);
+ if (!tga_data) return stbi__errpuc("outofmem", "Out of memory");
+
+ // skip to the data's starting position (offset usually = 0)
+ stbi__skip(s, tga_offset );
+
+ if ( !tga_indexed && !tga_is_RLE && !tga_rgb16 ) {
+ for (i=0; i < tga_height; ++i) {
+ int row = tga_inverted ? tga_height -i - 1 : i;
+ stbi_uc *tga_row = tga_data + row*tga_width*tga_comp;
+ stbi__getn(s, tga_row, tga_width * tga_comp);
+ }
+ } else {
+ // do I need to load a palette?
+ if ( tga_indexed)
+ {
+ if (tga_palette_len == 0) { /* you have to have at least one entry! */
+ STBI_FREE(tga_data);
+ return stbi__errpuc("bad palette", "Corrupt TGA");
+ }
+
+ // any data to skip? (offset usually = 0)
+ stbi__skip(s, tga_palette_start );
+ // load the palette
+ tga_palette = (unsigned char*)stbi__malloc_mad2(tga_palette_len, tga_comp, 0);
+ if (!tga_palette) {
+ STBI_FREE(tga_data);
+ return stbi__errpuc("outofmem", "Out of memory");
+ }
+ if (tga_rgb16) {
+ stbi_uc *pal_entry = tga_palette;
+ STBI_ASSERT(tga_comp == STBI_rgb);
+ for (i=0; i < tga_palette_len; ++i) {
+ stbi__tga_read_rgb16(s, pal_entry);
+ pal_entry += tga_comp;
+ }
+ } else if (!stbi__getn(s, tga_palette, tga_palette_len * tga_comp)) {
+ STBI_FREE(tga_data);
+ STBI_FREE(tga_palette);
+ return stbi__errpuc("bad palette", "Corrupt TGA");
+ }
+ }
+ // load the data
+ for (i=0; i < tga_width * tga_height; ++i)
+ {
+ // if I'm in RLE mode, do I need to get a RLE stbi__pngchunk?
+ if ( tga_is_RLE )
+ {
+ if ( RLE_count == 0 )
+ {
+ // yep, get the next byte as a RLE command
+ int RLE_cmd = stbi__get8(s);
+ RLE_count = 1 + (RLE_cmd & 127);
+ RLE_repeating = RLE_cmd >> 7;
+ read_next_pixel = 1;
+ } else if ( !RLE_repeating )
+ {
+ read_next_pixel = 1;
+ }
+ } else
+ {
+ read_next_pixel = 1;
+ }
+ // OK, if I need to read a pixel, do it now
+ if ( read_next_pixel )
+ {
+ // load however much data we did have
+ if ( tga_indexed )
+ {
+ // read in index, then perform the lookup
+ int pal_idx = (tga_bits_per_pixel == 8) ? stbi__get8(s) : stbi__get16le(s);
+ if ( pal_idx >= tga_palette_len ) {
+ // invalid index
+ pal_idx = 0;
+ }
+ pal_idx *= tga_comp;
+ for (j = 0; j < tga_comp; ++j) {
+ raw_data[j] = tga_palette[pal_idx+j];
+ }
+ } else if(tga_rgb16) {
+ STBI_ASSERT(tga_comp == STBI_rgb);
+ stbi__tga_read_rgb16(s, raw_data);
+ } else {
+ // read in the data raw
+ for (j = 0; j < tga_comp; ++j) {
+ raw_data[j] = stbi__get8(s);
+ }
+ }
+ // clear the reading flag for the next pixel
+ read_next_pixel = 0;
+ } // end of reading a pixel
+
+ // copy data
+ for (j = 0; j < tga_comp; ++j)
+ tga_data[i*tga_comp+j] = raw_data[j];
+
+ // in case we're in RLE mode, keep counting down
+ --RLE_count;
+ }
+ // do I need to invert the image?
+ if ( tga_inverted )
+ {
+ for (j = 0; j*2 < tga_height; ++j)
+ {
+ int index1 = j * tga_width * tga_comp;
+ int index2 = (tga_height - 1 - j) * tga_width * tga_comp;
+ for (i = tga_width * tga_comp; i > 0; --i)
+ {
+ unsigned char temp = tga_data[index1];
+ tga_data[index1] = tga_data[index2];
+ tga_data[index2] = temp;
+ ++index1;
+ ++index2;
+ }
+ }
+ }
+ // clear my palette, if I had one
+ if ( tga_palette != NULL )
+ {
+ STBI_FREE( tga_palette );
+ }
+ }
+
+ // swap RGB - if the source data was RGB16, it already is in the right order
+ if (tga_comp >= 3 && !tga_rgb16)
+ {
+ unsigned char* tga_pixel = tga_data;
+ for (i=0; i < tga_width * tga_height; ++i)
+ {
+ unsigned char temp = tga_pixel[0];
+ tga_pixel[0] = tga_pixel[2];
+ tga_pixel[2] = temp;
+ tga_pixel += tga_comp;
+ }
+ }
+
+ // convert to target component count
+ if (req_comp && req_comp != tga_comp)
+ tga_data = stbi__convert_format(tga_data, tga_comp, req_comp, tga_width, tga_height);
+
+ // the things I do to get rid of an error message, and yet keep
+ // Microsoft's C compilers happy... [8^(
+ tga_palette_start = tga_palette_len = tga_palette_bits =
+ tga_x_origin = tga_y_origin = 0;
+ STBI_NOTUSED(tga_palette_start);
+ // OK, done
+ return tga_data;
+}
+#endif
+
+// *************************************************************************************************
+// Photoshop PSD loader -- PD by Thatcher Ulrich, integration by Nicolas Schulz, tweaked by STB
+
+#ifndef STBI_NO_PSD
+static int stbi__psd_test(stbi__context *s)
+{
+ int r = (stbi__get32be(s) == 0x38425053);
+ stbi__rewind(s);
+ return r;
+}
+
+static int stbi__psd_decode_rle(stbi__context *s, stbi_uc *p, int pixelCount)
+{
+ int count, nleft, len;
+
+ count = 0;
+ while ((nleft = pixelCount - count) > 0) {
+ len = stbi__get8(s);
+ if (len == 128) {
+ // No-op.
+ } else if (len < 128) {
+ // Copy next len+1 bytes literally.
+ len++;
+ if (len > nleft) return 0; // corrupt data
+ count += len;
+ while (len) {
+ *p = stbi__get8(s);
+ p += 4;
+ len--;
+ }
+ } else if (len > 128) {
+ stbi_uc val;
+ // Next -len+1 bytes in the dest are replicated from next source byte.
+ // (Interpret len as a negative 8-bit int.)
+ len = 257 - len;
+ if (len > nleft) return 0; // corrupt data
+ val = stbi__get8(s);
+ count += len;
+ while (len) {
+ *p = val;
+ p += 4;
+ len--;
+ }
+ }
+ }
+
+ return 1;
+}
+
+static void *stbi__psd_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri, int bpc)
+{
+ int pixelCount;
+ int channelCount, compression;
+ int channel, i;
+ int bitdepth;
+ int w,h;
+ stbi_uc *out;
+ STBI_NOTUSED(ri);
+
+ // Check identifier
+ if (stbi__get32be(s) != 0x38425053) // "8BPS"
+ return stbi__errpuc("not PSD", "Corrupt PSD image");
+
+ // Check file type version.
+ if (stbi__get16be(s) != 1)
+ return stbi__errpuc("wrong version", "Unsupported version of PSD image");
+
+ // Skip 6 reserved bytes.
+ stbi__skip(s, 6 );
+
+ // Read the number of channels (R, G, B, A, etc).
+ channelCount = stbi__get16be(s);
+ if (channelCount < 0 || channelCount > 16)
+ return stbi__errpuc("wrong channel count", "Unsupported number of channels in PSD image");
+
+ // Read the rows and columns of the image.
+ h = stbi__get32be(s);
+ w = stbi__get32be(s);
+
+ if (h > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large","Very large image (corrupt?)");
+ if (w > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large","Very large image (corrupt?)");
+
+ // Make sure the depth is 8 bits.
+ bitdepth = stbi__get16be(s);
+ if (bitdepth != 8 && bitdepth != 16)
+ return stbi__errpuc("unsupported bit depth", "PSD bit depth is not 8 or 16 bit");
+
+ // Make sure the color mode is RGB.
+ // Valid options are:
+ // 0: Bitmap
+ // 1: Grayscale
+ // 2: Indexed color
+ // 3: RGB color
+ // 4: CMYK color
+ // 7: Multichannel
+ // 8: Duotone
+ // 9: Lab color
+ if (stbi__get16be(s) != 3)
+ return stbi__errpuc("wrong color format", "PSD is not in RGB color format");
+
+ // Skip the Mode Data. (It's the palette for indexed color; other info for other modes.)
+ stbi__skip(s,stbi__get32be(s) );
+
+ // Skip the image resources. (resolution, pen tool paths, etc)
+ stbi__skip(s, stbi__get32be(s) );
+
+ // Skip the reserved data.
+ stbi__skip(s, stbi__get32be(s) );
+
+ // Find out if the data is compressed.
+ // Known values:
+ // 0: no compression
+ // 1: RLE compressed
+ compression = stbi__get16be(s);
+ if (compression > 1)
+ return stbi__errpuc("bad compression", "PSD has an unknown compression format");
+
+ // Check size
+ if (!stbi__mad3sizes_valid(4, w, h, 0))
+ return stbi__errpuc("too large", "Corrupt PSD");
+
+ // Create the destination image.
+
+ if (!compression && bitdepth == 16 && bpc == 16) {
+ out = (stbi_uc *) stbi__malloc_mad3(8, w, h, 0);
+ ri->bits_per_channel = 16;
+ } else
+ out = (stbi_uc *) stbi__malloc(4 * w*h);
+
+ if (!out) return stbi__errpuc("outofmem", "Out of memory");
+ pixelCount = w*h;
+
+ // Initialize the data to zero.
+ //memset( out, 0, pixelCount * 4 );
+
+ // Finally, the image data.
+ if (compression) {
+ // RLE as used by .PSD and .TIFF
+ // Loop until you get the number of unpacked bytes you are expecting:
+ // Read the next source byte into n.
+ // If n is between 0 and 127 inclusive, copy the next n+1 bytes literally.
+ // Else if n is between -127 and -1 inclusive, copy the next byte -n+1 times.
+ // Else if n is 128, noop.
+ // Endloop
+
+ // The RLE-compressed data is preceded by a 2-byte data count for each row in the data,
+ // which we're going to just skip.
+ stbi__skip(s, h * channelCount * 2 );
+
+ // Read the RLE data by channel.
+ for (channel = 0; channel < 4; channel++) {
+ stbi_uc *p;
+
+ p = out+channel;
+ if (channel >= channelCount) {
+ // Fill this channel with default data.
+ for (i = 0; i < pixelCount; i++, p += 4)
+ *p = (channel == 3 ? 255 : 0);
+ } else {
+ // Read the RLE data.
+ if (!stbi__psd_decode_rle(s, p, pixelCount)) {
+ STBI_FREE(out);
+ return stbi__errpuc("corrupt", "bad RLE data");
+ }
+ }
+ }
+
+ } else {
+ // We're at the raw image data. It's each channel in order (Red, Green, Blue, Alpha, ...)
+ // where each channel consists of an 8-bit (or 16-bit) value for each pixel in the image.
+
+ // Read the data by channel.
+ for (channel = 0; channel < 4; channel++) {
+ if (channel >= channelCount) {
+ // Fill this channel with default data.
+ if (bitdepth == 16 && bpc == 16) {
+ stbi__uint16 *q = ((stbi__uint16 *) out) + channel;
+ stbi__uint16 val = channel == 3 ? 65535 : 0;
+ for (i = 0; i < pixelCount; i++, q += 4)
+ *q = val;
+ } else {
+ stbi_uc *p = out+channel;
+ stbi_uc val = channel == 3 ? 255 : 0;
+ for (i = 0; i < pixelCount; i++, p += 4)
+ *p = val;
+ }
+ } else {
+ if (ri->bits_per_channel == 16) { // output bpc
+ stbi__uint16 *q = ((stbi__uint16 *) out) + channel;
+ for (i = 0; i < pixelCount; i++, q += 4)
+ *q = (stbi__uint16) stbi__get16be(s);
+ } else {
+ stbi_uc *p = out+channel;
+ if (bitdepth == 16) { // input bpc
+ for (i = 0; i < pixelCount; i++, p += 4)
+ *p = (stbi_uc) (stbi__get16be(s) >> 8);
+ } else {
+ for (i = 0; i < pixelCount; i++, p += 4)
+ *p = stbi__get8(s);
+ }
+ }
+ }
+ }
+ }
+
+ // remove weird white matte from PSD
+ if (channelCount >= 4) {
+ if (ri->bits_per_channel == 16) {
+ for (i=0; i < w*h; ++i) {
+ stbi__uint16 *pixel = (stbi__uint16 *) out + 4*i;
+ if (pixel[3] != 0 && pixel[3] != 65535) {
+ float a = pixel[3] / 65535.0f;
+ float ra = 1.0f / a;
+ float inv_a = 65535.0f * (1 - ra);
+ pixel[0] = (stbi__uint16) (pixel[0]*ra + inv_a);
+ pixel[1] = (stbi__uint16) (pixel[1]*ra + inv_a);
+ pixel[2] = (stbi__uint16) (pixel[2]*ra + inv_a);
+ }
+ }
+ } else {
+ for (i=0; i < w*h; ++i) {
+ unsigned char *pixel = out + 4*i;
+ if (pixel[3] != 0 && pixel[3] != 255) {
+ float a = pixel[3] / 255.0f;
+ float ra = 1.0f / a;
+ float inv_a = 255.0f * (1 - ra);
+ pixel[0] = (unsigned char) (pixel[0]*ra + inv_a);
+ pixel[1] = (unsigned char) (pixel[1]*ra + inv_a);
+ pixel[2] = (unsigned char) (pixel[2]*ra + inv_a);
+ }
+ }
+ }
+ }
+
+ // convert to desired output format
+ if (req_comp && req_comp != 4) {
+ if (ri->bits_per_channel == 16)
+ out = (stbi_uc *) stbi__convert_format16((stbi__uint16 *) out, 4, req_comp, w, h);
+ else
+ out = stbi__convert_format(out, 4, req_comp, w, h);
+ if (out == NULL) return out; // stbi__convert_format frees input on failure
+ }
+
+ if (comp) *comp = 4;
+ *y = h;
+ *x = w;
+
+ return out;
+}
+#endif
+
+// *************************************************************************************************
+// Softimage PIC loader
+// by Tom Seddon
+//
+// See http://softimage.wiki.softimage.com/index.php/INFO:_PIC_file_format
+// See http://ozviz.wasp.uwa.edu.au/~pbourke/dataformats/softimagepic/
+
+#ifndef STBI_NO_PIC
+static int stbi__pic_is4(stbi__context *s,const char *str)
+{
+ int i;
+ for (i=0; i<4; ++i)
+ if (stbi__get8(s) != (stbi_uc)str[i])
+ return 0;
+
+ return 1;
+}
+
+static int stbi__pic_test_core(stbi__context *s)
+{
+ int i;
+
+ if (!stbi__pic_is4(s,"\x53\x80\xF6\x34"))
+ return 0;
+
+ for(i=0;i<84;++i)
+ stbi__get8(s);
+
+ if (!stbi__pic_is4(s,"PICT"))
+ return 0;
+
+ return 1;
+}
+
+typedef struct
+{
+ stbi_uc size,type,channel;
+} stbi__pic_packet;
+
+static stbi_uc *stbi__readval(stbi__context *s, int channel, stbi_uc *dest)
+{
+ int mask=0x80, i;
+
+ for (i=0; i<4; ++i, mask>>=1) {
+ if (channel & mask) {
+ if (stbi__at_eof(s)) return stbi__errpuc("bad file","PIC file too short");
+ dest[i]=stbi__get8(s);
+ }
+ }
+
+ return dest;
+}
+
+static void stbi__copyval(int channel,stbi_uc *dest,const stbi_uc *src)
+{
+ int mask=0x80,i;
+
+ for (i=0;i<4; ++i, mask>>=1)
+ if (channel&mask)
+ dest[i]=src[i];
+}
+
+static stbi_uc *stbi__pic_load_core(stbi__context *s,int width,int height,int *comp, stbi_uc *result)
+{
+ int act_comp=0,num_packets=0,y,chained;
+ stbi__pic_packet packets[10];
+
+ // this will (should...) cater for even some bizarre stuff like having data
+ // for the same channel in multiple packets.
+ do {
+ stbi__pic_packet *packet;
+
+ if (num_packets==sizeof(packets)/sizeof(packets[0]))
+ return stbi__errpuc("bad format","too many packets");
+
+ packet = &packets[num_packets++];
+
+ chained = stbi__get8(s);
+ packet->size = stbi__get8(s);
+ packet->type = stbi__get8(s);
+ packet->channel = stbi__get8(s);
+
+ act_comp |= packet->channel;
+
+ if (stbi__at_eof(s)) return stbi__errpuc("bad file","file too short (reading packets)");
+ if (packet->size != 8) return stbi__errpuc("bad format","packet isn't 8bpp");
+ } while (chained);
+
+ *comp = (act_comp & 0x10 ? 4 : 3); // has alpha channel?
+
+ for(y=0; y<height; ++y) {
+ int packet_idx;
+
+ for(packet_idx=0; packet_idx < num_packets; ++packet_idx) {
+ stbi__pic_packet *packet = &packets[packet_idx];
+ stbi_uc *dest = result+y*width*4;
+
+ switch (packet->type) {
+ default:
+ return stbi__errpuc("bad format","packet has bad compression type");
+
+ case 0: {//uncompressed
+ int x;
+
+ for(x=0;x<width;++x, dest+=4)
+ if (!stbi__readval(s,packet->channel,dest))
+ return 0;
+ break;
+ }
+
+ case 1://Pure RLE
+ {
+ int left=width, i;
+
+ while (left>0) {
+ stbi_uc count,value[4];
+
+ count=stbi__get8(s);
+ if (stbi__at_eof(s)) return stbi__errpuc("bad file","file too short (pure read count)");
+
+ if (count > left)
+ count = (stbi_uc) left;
+
+ if (!stbi__readval(s,packet->channel,value)) return 0;
+
+ for(i=0; i<count; ++i,dest+=4)
+ stbi__copyval(packet->channel,dest,value);
+ left -= count;
+ }
+ }
+ break;
+
+ case 2: {//Mixed RLE
+ int left=width;
+ while (left>0) {
+ int count = stbi__get8(s), i;
+ if (stbi__at_eof(s)) return stbi__errpuc("bad file","file too short (mixed read count)");
+
+ if (count >= 128) { // Repeated
+ stbi_uc value[4];
+
+ if (count==128)
+ count = stbi__get16be(s);
+ else
+ count -= 127;
+ if (count > left)
+ return stbi__errpuc("bad file","scanline overrun");
+
+ if (!stbi__readval(s,packet->channel,value))
+ return 0;
+
+ for(i=0;i<count;++i, dest += 4)
+ stbi__copyval(packet->channel,dest,value);
+ } else { // Raw
+ ++count;
+ if (count>left) return stbi__errpuc("bad file","scanline overrun");
+
+ for(i=0;i<count;++i, dest+=4)
+ if (!stbi__readval(s,packet->channel,dest))
+ return 0;
+ }
+ left-=count;
+ }
+ break;
+ }
+ }
+ }
+ }
+
+ return result;
+}
+
+static void *stbi__pic_load(stbi__context *s,int *px,int *py,int *comp,int req_comp, stbi__result_info *ri)
+{
+ stbi_uc *result;
+ int i, x,y, internal_comp;
+ STBI_NOTUSED(ri);
+
+ if (!comp) comp = &internal_comp;
+
+ for (i=0; i<92; ++i)
+ stbi__get8(s);
+
+ x = stbi__get16be(s);
+ y = stbi__get16be(s);
+
+ if (y > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large","Very large image (corrupt?)");
+ if (x > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large","Very large image (corrupt?)");
+
+ if (stbi__at_eof(s)) return stbi__errpuc("bad file","file too short (pic header)");
+ if (!stbi__mad3sizes_valid(x, y, 4, 0)) return stbi__errpuc("too large", "PIC image too large to decode");
+
+ stbi__get32be(s); //skip `ratio'
+ stbi__get16be(s); //skip `fields'
+ stbi__get16be(s); //skip `pad'
+
+ // intermediate buffer is RGBA
+ result = (stbi_uc *) stbi__malloc_mad3(x, y, 4, 0);
+ if (!result) return stbi__errpuc("outofmem", "Out of memory");
+ memset(result, 0xff, x*y*4);
+
+ if (!stbi__pic_load_core(s,x,y,comp, result)) {
+ STBI_FREE(result);
+ result=0;
+ }
+ *px = x;
+ *py = y;
+ if (req_comp == 0) req_comp = *comp;
+ result=stbi__convert_format(result,4,req_comp,x,y);
+
+ return result;
+}
+
+static int stbi__pic_test(stbi__context *s)
+{
+ int r = stbi__pic_test_core(s);
+ stbi__rewind(s);
+ return r;
+}
+#endif
+
+// *************************************************************************************************
+// GIF loader -- public domain by Jean-Marc Lienher -- simplified/shrunk by stb
+
+#ifndef STBI_NO_GIF
+typedef struct
+{
+ stbi__int16 prefix;
+ stbi_uc first;
+ stbi_uc suffix;
+} stbi__gif_lzw;
+
+typedef struct
+{
+ int w,h;
+ stbi_uc *out; // output buffer (always 4 components)
+ stbi_uc *background; // The current "background" as far as a gif is concerned
+ stbi_uc *history;
+ int flags, bgindex, ratio, transparent, eflags;
+ stbi_uc pal[256][4];
+ stbi_uc lpal[256][4];
+ stbi__gif_lzw codes[8192];
+ stbi_uc *color_table;
+ int parse, step;
+ int lflags;
+ int start_x, start_y;
+ int max_x, max_y;
+ int cur_x, cur_y;
+ int line_size;
+ int delay;
+} stbi__gif;
+
+static int stbi__gif_test_raw(stbi__context *s)
+{
+ int sz;
+ if (stbi__get8(s) != 'G' || stbi__get8(s) != 'I' || stbi__get8(s) != 'F' || stbi__get8(s) != '8') return 0;
+ sz = stbi__get8(s);
+ if (sz != '9' && sz != '7') return 0;
+ if (stbi__get8(s) != 'a') return 0;
+ return 1;
+}
+
+static int stbi__gif_test(stbi__context *s)
+{
+ int r = stbi__gif_test_raw(s);
+ stbi__rewind(s);
+ return r;
+}
+
+static void stbi__gif_parse_colortable(stbi__context *s, stbi_uc pal[256][4], int num_entries, int transp)
+{
+ int i;
+ for (i=0; i < num_entries; ++i) {
+ pal[i][2] = stbi__get8(s);
+ pal[i][1] = stbi__get8(s);
+ pal[i][0] = stbi__get8(s);
+ pal[i][3] = transp == i ? 0 : 255;
+ }
+}
+
+static int stbi__gif_header(stbi__context *s, stbi__gif *g, int *comp, int is_info)
+{
+ stbi_uc version;
+ if (stbi__get8(s) != 'G' || stbi__get8(s) != 'I' || stbi__get8(s) != 'F' || stbi__get8(s) != '8')
+ return stbi__err("not GIF", "Corrupt GIF");
+
+ version = stbi__get8(s);
+ if (version != '7' && version != '9') return stbi__err("not GIF", "Corrupt GIF");
+ if (stbi__get8(s) != 'a') return stbi__err("not GIF", "Corrupt GIF");
+
+ stbi__g_failure_reason = "";
+ g->w = stbi__get16le(s);
+ g->h = stbi__get16le(s);
+ g->flags = stbi__get8(s);
+ g->bgindex = stbi__get8(s);
+ g->ratio = stbi__get8(s);
+ g->transparent = -1;
+
+ if (g->w > STBI_MAX_DIMENSIONS) return stbi__err("too large","Very large image (corrupt?)");
+ if (g->h > STBI_MAX_DIMENSIONS) return stbi__err("too large","Very large image (corrupt?)");
+
+ if (comp != 0) *comp = 4; // can't actually tell whether it's 3 or 4 until we parse the comments
+
+ if (is_info) return 1;
+
+ if (g->flags & 0x80)
+ stbi__gif_parse_colortable(s,g->pal, 2 << (g->flags & 7), -1);
+
+ return 1;
+}
+
+static int stbi__gif_info_raw(stbi__context *s, int *x, int *y, int *comp)
+{
+ stbi__gif* g = (stbi__gif*) stbi__malloc(sizeof(stbi__gif));
+ if (!g) return stbi__err("outofmem", "Out of memory");
+ if (!stbi__gif_header(s, g, comp, 1)) {
+ STBI_FREE(g);
+ stbi__rewind( s );
+ return 0;
+ }
+ if (x) *x = g->w;
+ if (y) *y = g->h;
+ STBI_FREE(g);
+ return 1;
+}
+
+static void stbi__out_gif_code(stbi__gif *g, stbi__uint16 code)
+{
+ stbi_uc *p, *c;
+ int idx;
+
+ // recurse to decode the prefixes, since the linked-list is backwards,
+ // and working backwards through an interleaved image would be nasty
+ if (g->codes[code].prefix >= 0)
+ stbi__out_gif_code(g, g->codes[code].prefix);
+
+ if (g->cur_y >= g->max_y) return;
+
+ idx = g->cur_x + g->cur_y;
+ p = &g->out[idx];
+ g->history[idx / 4] = 1;
+
+ c = &g->color_table[g->codes[code].suffix * 4];
+ if (c[3] > 128) { // don't render transparent pixels;
+ p[0] = c[2];
+ p[1] = c[1];
+ p[2] = c[0];
+ p[3] = c[3];
+ }
+ g->cur_x += 4;
+
+ if (g->cur_x >= g->max_x) {
+ g->cur_x = g->start_x;
+ g->cur_y += g->step;
+
+ while (g->cur_y >= g->max_y && g->parse > 0) {
+ g->step = (1 << g->parse) * g->line_size;
+ g->cur_y = g->start_y + (g->step >> 1);
+ --g->parse;
+ }
+ }
+}
+
+static stbi_uc *stbi__process_gif_raster(stbi__context *s, stbi__gif *g)
+{
+ stbi_uc lzw_cs;
+ stbi__int32 len, init_code;
+ stbi__uint32 first;
+ stbi__int32 codesize, codemask, avail, oldcode, bits, valid_bits, clear;
+ stbi__gif_lzw *p;
+
+ lzw_cs = stbi__get8(s);
+ if (lzw_cs > 12) return NULL;
+ clear = 1 << lzw_cs;
+ first = 1;
+ codesize = lzw_cs + 1;
+ codemask = (1 << codesize) - 1;
+ bits = 0;
+ valid_bits = 0;
+ for (init_code = 0; init_code < clear; init_code++) {
+ g->codes[init_code].prefix = -1;
+ g->codes[init_code].first = (stbi_uc) init_code;
+ g->codes[init_code].suffix = (stbi_uc) init_code;
+ }
+
+ // support no starting clear code
+ avail = clear+2;
+ oldcode = -1;
+
+ len = 0;
+ for(;;) {
+ if (valid_bits < codesize) {
+ if (len == 0) {
+ len = stbi__get8(s); // start new block
+ if (len == 0)
+ return g->out;
+ }
+ --len;
+ bits |= (stbi__int32) stbi__get8(s) << valid_bits;
+ valid_bits += 8;
+ } else {
+ stbi__int32 code = bits & codemask;
+ bits >>= codesize;
+ valid_bits -= codesize;
+ // @OPTIMIZE: is there some way we can accelerate the non-clear path?
+ if (code == clear) { // clear code
+ codesize = lzw_cs + 1;
+ codemask = (1 << codesize) - 1;
+ avail = clear + 2;
+ oldcode = -1;
+ first = 0;
+ } else if (code == clear + 1) { // end of stream code
+ stbi__skip(s, len);
+ while ((len = stbi__get8(s)) > 0)
+ stbi__skip(s,len);
+ return g->out;
+ } else if (code <= avail) {
+ if (first) {
+ return stbi__errpuc("no clear code", "Corrupt GIF");
+ }
+
+ if (oldcode >= 0) {
+ p = &g->codes[avail++];
+ if (avail > 8192) {
+ return stbi__errpuc("too many codes", "Corrupt GIF");
+ }
+
+ p->prefix = (stbi__int16) oldcode;
+ p->first = g->codes[oldcode].first;
+ p->suffix = (code == avail) ? p->first : g->codes[code].first;
+ } else if (code == avail)
+ return stbi__errpuc("illegal code in raster", "Corrupt GIF");
+
+ stbi__out_gif_code(g, (stbi__uint16) code);
+
+ if ((avail & codemask) == 0 && avail <= 0x0FFF) {
+ codesize++;
+ codemask = (1 << codesize) - 1;
+ }
+
+ oldcode = code;
+ } else {
+ return stbi__errpuc("illegal code in raster", "Corrupt GIF");
+ }
+ }
+ }
+}
+
+// this function is designed to support animated gifs, although stb_image doesn't support it
+// two back is the image from two frames ago, used for a very specific disposal format
+static stbi_uc *stbi__gif_load_next(stbi__context *s, stbi__gif *g, int *comp, int req_comp, stbi_uc *two_back)
+{
+ int dispose;
+ int first_frame;
+ int pi;
+ int pcount;
+ STBI_NOTUSED(req_comp);
+
+ // on first frame, any non-written pixels get the background colour (non-transparent)
+ first_frame = 0;
+ if (g->out == 0) {
+ if (!stbi__gif_header(s, g, comp,0)) return 0; // stbi__g_failure_reason set by stbi__gif_header
+ if (!stbi__mad3sizes_valid(4, g->w, g->h, 0))
+ return stbi__errpuc("too large", "GIF image is too large");
+ pcount = g->w * g->h;
+ g->out = (stbi_uc *) stbi__malloc(4 * pcount);
+ g->background = (stbi_uc *) stbi__malloc(4 * pcount);
+ g->history = (stbi_uc *) stbi__malloc(pcount);
+ if (!g->out || !g->background || !g->history)
+ return stbi__errpuc("outofmem", "Out of memory");
+
+ // image is treated as "transparent" at the start - ie, nothing overwrites the current background;
+ // background colour is only used for pixels that are not rendered first frame, after that "background"
+ // color refers to the color that was there the previous frame.
+ memset(g->out, 0x00, 4 * pcount);
+ memset(g->background, 0x00, 4 * pcount); // state of the background (starts transparent)
+ memset(g->history, 0x00, pcount); // pixels that were affected previous frame
+ first_frame = 1;
+ } else {
+ // second frame - how do we dispose of the previous one?
+ dispose = (g->eflags & 0x1C) >> 2;
+ pcount = g->w * g->h;
+
+ if ((dispose == 3) && (two_back == 0)) {
+ dispose = 2; // if I don't have an image to revert back to, default to the old background
+ }
+
+ if (dispose == 3) { // use previous graphic
+ for (pi = 0; pi < pcount; ++pi) {
+ if (g->history[pi]) {
+ memcpy( &g->out[pi * 4], &two_back[pi * 4], 4 );
+ }
+ }
+ } else if (dispose == 2) {
+ // restore what was changed last frame to background before that frame;
+ for (pi = 0; pi < pcount; ++pi) {
+ if (g->history[pi]) {
+ memcpy( &g->out[pi * 4], &g->background[pi * 4], 4 );
+ }
+ }
+ } else {
+ // This is a non-disposal case eithe way, so just
+ // leave the pixels as is, and they will become the new background
+ // 1: do not dispose
+ // 0: not specified.
+ }
+
+ // background is what out is after the undoing of the previou frame;
+ memcpy( g->background, g->out, 4 * g->w * g->h );
+ }
+
+ // clear my history;
+ memset( g->history, 0x00, g->w * g->h ); // pixels that were affected previous frame
+
+ for (;;) {
+ int tag = stbi__get8(s);
+ switch (tag) {
+ case 0x2C: /* Image Descriptor */
+ {
+ stbi__int32 x, y, w, h;
+ stbi_uc *o;
+
+ x = stbi__get16le(s);
+ y = stbi__get16le(s);
+ w = stbi__get16le(s);
+ h = stbi__get16le(s);
+ if (((x + w) > (g->w)) || ((y + h) > (g->h)))
+ return stbi__errpuc("bad Image Descriptor", "Corrupt GIF");
+
+ g->line_size = g->w * 4;
+ g->start_x = x * 4;
+ g->start_y = y * g->line_size;
+ g->max_x = g->start_x + w * 4;
+ g->max_y = g->start_y + h * g->line_size;
+ g->cur_x = g->start_x;
+ g->cur_y = g->start_y;
+
+ // if the width of the specified rectangle is 0, that means
+ // we may not see *any* pixels or the image is malformed;
+ // to make sure this is caught, move the current y down to
+ // max_y (which is what out_gif_code checks).
+ if (w == 0)
+ g->cur_y = g->max_y;
+
+ g->lflags = stbi__get8(s);
+
+ if (g->lflags & 0x40) {
+ g->step = 8 * g->line_size; // first interlaced spacing
+ g->parse = 3;
+ } else {
+ g->step = g->line_size;
+ g->parse = 0;
+ }
+
+ if (g->lflags & 0x80) {
+ stbi__gif_parse_colortable(s,g->lpal, 2 << (g->lflags & 7), g->eflags & 0x01 ? g->transparent : -1);
+ g->color_table = (stbi_uc *) g->lpal;
+ } else if (g->flags & 0x80) {
+ g->color_table = (stbi_uc *) g->pal;
+ } else
+ return stbi__errpuc("missing color table", "Corrupt GIF");
+
+ o = stbi__process_gif_raster(s, g);
+ if (!o) return NULL;
+
+ // if this was the first frame,
+ pcount = g->w * g->h;
+ if (first_frame && (g->bgindex > 0)) {
+ // if first frame, any pixel not drawn to gets the background color
+ for (pi = 0; pi < pcount; ++pi) {
+ if (g->history[pi] == 0) {
+ g->pal[g->bgindex][3] = 255; // just in case it was made transparent, undo that; It will be reset next frame if need be;
+ memcpy( &g->out[pi * 4], &g->pal[g->bgindex], 4 );
+ }
+ }
+ }
+
+ return o;
+ }
+
+ case 0x21: // Comment Extension.
+ {
+ int len;
+ int ext = stbi__get8(s);
+ if (ext == 0xF9) { // Graphic Control Extension.
+ len = stbi__get8(s);
+ if (len == 4) {
+ g->eflags = stbi__get8(s);
+ g->delay = 10 * stbi__get16le(s); // delay - 1/100th of a second, saving as 1/1000ths.
+
+ // unset old transparent
+ if (g->transparent >= 0) {
+ g->pal[g->transparent][3] = 255;
+ }
+ if (g->eflags & 0x01) {
+ g->transparent = stbi__get8(s);
+ if (g->transparent >= 0) {
+ g->pal[g->transparent][3] = 0;
+ }
+ } else {
+ // don't need transparent
+ stbi__skip(s, 1);
+ g->transparent = -1;
+ }
+ } else {
+ stbi__skip(s, len);
+ break;
+ }
+ }
+ while ((len = stbi__get8(s)) != 0) {
+ stbi__skip(s, len);
+ }
+ break;
+ }
+
+ case 0x3B: // gif stream termination code
+ return (stbi_uc *) s; // using '1' causes warning on some compilers
+
+ default:
+ return stbi__errpuc("unknown code", "Corrupt GIF");
+ }
+ }
+}
+
+static void *stbi__load_gif_main_outofmem(stbi__gif *g, stbi_uc *out, int **delays)
+{
+ STBI_FREE(g->out);
+ STBI_FREE(g->history);
+ STBI_FREE(g->background);
+
+ if (out) STBI_FREE(out);
+ if (delays && *delays) STBI_FREE(*delays);
+ return stbi__errpuc("outofmem", "Out of memory");
+}
+
+static void *stbi__load_gif_main(stbi__context *s, int **delays, int *x, int *y, int *z, int *comp, int req_comp)
+{
+ if (stbi__gif_test(s)) {
+ int layers = 0;
+ stbi_uc *u = 0;
+ stbi_uc *out = 0;
+ stbi_uc *two_back = 0;
+ stbi__gif g;
+ int stride;
+ int out_size = 0;
+ int delays_size = 0;
+
+ STBI_NOTUSED(out_size);
+ STBI_NOTUSED(delays_size);
+
+ memset(&g, 0, sizeof(g));
+ if (delays) {
+ *delays = 0;
+ }
+
+ do {
+ u = stbi__gif_load_next(s, &g, comp, req_comp, two_back);
+ if (u == (stbi_uc *) s) u = 0; // end of animated gif marker
+
+ if (u) {
+ *x = g.w;
+ *y = g.h;
+ ++layers;
+ stride = g.w * g.h * 4;
+
+ if (out) {
+ void *tmp = (stbi_uc*) STBI_REALLOC_SIZED( out, out_size, layers * stride );
+ if (!tmp)
+ return stbi__load_gif_main_outofmem(&g, out, delays);
+ else {
+ out = (stbi_uc*) tmp;
+ out_size = layers * stride;
+ }
+
+ if (delays) {
+ int *new_delays = (int*) STBI_REALLOC_SIZED( *delays, delays_size, sizeof(int) * layers );
+ if (!new_delays)
+ return stbi__load_gif_main_outofmem(&g, out, delays);
+ *delays = new_delays;
+ delays_size = layers * sizeof(int);
+ }
+ } else {
+ out = (stbi_uc*)stbi__malloc( layers * stride );
+ if (!out)
+ return stbi__load_gif_main_outofmem(&g, out, delays);
+ out_size = layers * stride;
+ if (delays) {
+ *delays = (int*) stbi__malloc( layers * sizeof(int) );
+ if (!*delays)
+ return stbi__load_gif_main_outofmem(&g, out, delays);
+ delays_size = layers * sizeof(int);
+ }
+ }
+ memcpy( out + ((layers - 1) * stride), u, stride );
+ if (layers >= 2) {
+ two_back = out - 2 * stride;
+ }
+
+ if (delays) {
+ (*delays)[layers - 1U] = g.delay;
+ }
+ }
+ } while (u != 0);
+
+ // free temp buffer;
+ STBI_FREE(g.out);
+ STBI_FREE(g.history);
+ STBI_FREE(g.background);
+
+ // do the final conversion after loading everything;
+ if (req_comp && req_comp != 4)
+ out = stbi__convert_format(out, 4, req_comp, layers * g.w, g.h);
+
+ *z = layers;
+ return out;
+ } else {
+ return stbi__errpuc("not GIF", "Image was not as a gif type.");
+ }
+}
+
+static void *stbi__gif_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri)
+{
+ stbi_uc *u = 0;
+ stbi__gif g;
+ memset(&g, 0, sizeof(g));
+ STBI_NOTUSED(ri);
+
+ u = stbi__gif_load_next(s, &g, comp, req_comp, 0);
+ if (u == (stbi_uc *) s) u = 0; // end of animated gif marker
+ if (u) {
+ *x = g.w;
+ *y = g.h;
+
+ // moved conversion to after successful load so that the same
+ // can be done for multiple frames.
+ if (req_comp && req_comp != 4)
+ u = stbi__convert_format(u, 4, req_comp, g.w, g.h);
+ } else if (g.out) {
+ // if there was an error and we allocated an image buffer, free it!
+ STBI_FREE(g.out);
+ }
+
+ // free buffers needed for multiple frame loading;
+ STBI_FREE(g.history);
+ STBI_FREE(g.background);
+
+ return u;
+}
+
+static int stbi__gif_info(stbi__context *s, int *x, int *y, int *comp)
+{
+ return stbi__gif_info_raw(s,x,y,comp);
+}
+#endif
+
+// *************************************************************************************************
+// Radiance RGBE HDR loader
+// originally by Nicolas Schulz
+#ifndef STBI_NO_HDR
+static int stbi__hdr_test_core(stbi__context *s, const char *signature)
+{
+ int i;
+ for (i=0; signature[i]; ++i)
+ if (stbi__get8(s) != signature[i])
+ return 0;
+ stbi__rewind(s);
+ return 1;
+}
+
+static int stbi__hdr_test(stbi__context* s)
+{
+ int r = stbi__hdr_test_core(s, "#?RADIANCE\n");
+ stbi__rewind(s);
+ if(!r) {
+ r = stbi__hdr_test_core(s, "#?RGBE\n");
+ stbi__rewind(s);
+ }
+ return r;
+}
+
+#define STBI__HDR_BUFLEN 1024
+static char *stbi__hdr_gettoken(stbi__context *z, char *buffer)
+{
+ int len=0;
+ char c = '\0';
+
+ c = (char) stbi__get8(z);
+
+ while (!stbi__at_eof(z) && c != '\n') {
+ buffer[len++] = c;
+ if (len == STBI__HDR_BUFLEN-1) {
+ // flush to end of line
+ while (!stbi__at_eof(z) && stbi__get8(z) != '\n')
+ ;
+ break;
+ }
+ c = (char) stbi__get8(z);
+ }
+
+ buffer[len] = 0;
+ return buffer;
+}
+
+static void stbi__hdr_convert(float *output, stbi_uc *input, int req_comp)
+{
+ if ( input[3] != 0 ) {
+ float f1;
+ // Exponent
+ f1 = (float) ldexp(1.0f, input[3] - (int)(128 + 8));
+ if (req_comp <= 2)
+ output[0] = (input[0] + input[1] + input[2]) * f1 / 3;
+ else {
+ output[0] = input[0] * f1;
+ output[1] = input[1] * f1;
+ output[2] = input[2] * f1;
+ }
+ if (req_comp == 2) output[1] = 1;
+ if (req_comp == 4) output[3] = 1;
+ } else {
+ switch (req_comp) {
+ case 4: output[3] = 1; /* fallthrough */
+ case 3: output[0] = output[1] = output[2] = 0;
+ break;
+ case 2: output[1] = 1; /* fallthrough */
+ case 1: output[0] = 0;
+ break;
+ }
+ }
+}
+
+static float *stbi__hdr_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri)
+{
+ char buffer[STBI__HDR_BUFLEN];
+ char *token;
+ int valid = 0;
+ int width, height;
+ stbi_uc *scanline;
+ float *hdr_data;
+ int len;
+ unsigned char count, value;
+ int i, j, k, c1,c2, z;
+ const char *headerToken;
+ STBI_NOTUSED(ri);
+
+ // Check identifier
+ headerToken = stbi__hdr_gettoken(s,buffer);
+ if (strcmp(headerToken, "#?RADIANCE") != 0 && strcmp(headerToken, "#?RGBE") != 0)
+ return stbi__errpf("not HDR", "Corrupt HDR image");
+
+ // Parse header
+ for(;;) {
+ token = stbi__hdr_gettoken(s,buffer);
+ if (token[0] == 0) break;
+ if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1;
+ }
+
+ if (!valid) return stbi__errpf("unsupported format", "Unsupported HDR format");
+
+ // Parse width and height
+ // can't use sscanf() if we're not using stdio!
+ token = stbi__hdr_gettoken(s,buffer);
+ if (strncmp(token, "-Y ", 3)) return stbi__errpf("unsupported data layout", "Unsupported HDR format");
+ token += 3;
+ height = (int) strtol(token, &token, 10);
+ while (*token == ' ') ++token;
+ if (strncmp(token, "+X ", 3)) return stbi__errpf("unsupported data layout", "Unsupported HDR format");
+ token += 3;
+ width = (int) strtol(token, NULL, 10);
+
+ if (height > STBI_MAX_DIMENSIONS) return stbi__errpf("too large","Very large image (corrupt?)");
+ if (width > STBI_MAX_DIMENSIONS) return stbi__errpf("too large","Very large image (corrupt?)");
+
+ *x = width;
+ *y = height;
+
+ if (comp) *comp = 3;
+ if (req_comp == 0) req_comp = 3;
+
+ if (!stbi__mad4sizes_valid(width, height, req_comp, sizeof(float), 0))
+ return stbi__errpf("too large", "HDR image is too large");
+
+ // Read data
+ hdr_data = (float *) stbi__malloc_mad4(width, height, req_comp, sizeof(float), 0);
+ if (!hdr_data)
+ return stbi__errpf("outofmem", "Out of memory");
+
+ // Load image data
+ // image data is stored as some number of sca
+ if ( width < 8 || width >= 32768) {
+ // Read flat data
+ for (j=0; j < height; ++j) {
+ for (i=0; i < width; ++i) {
+ stbi_uc rgbe[4];
+ main_decode_loop:
+ stbi__getn(s, rgbe, 4);
+ stbi__hdr_convert(hdr_data + j * width * req_comp + i * req_comp, rgbe, req_comp);
+ }
+ }
+ } else {
+ // Read RLE-encoded data
+ scanline = NULL;
+
+ for (j = 0; j < height; ++j) {
+ c1 = stbi__get8(s);
+ c2 = stbi__get8(s);
+ len = stbi__get8(s);
+ if (c1 != 2 || c2 != 2 || (len & 0x80)) {
+ // not run-length encoded, so we have to actually use THIS data as a decoded
+ // pixel (note this can't be a valid pixel--one of RGB must be >= 128)
+ stbi_uc rgbe[4];
+ rgbe[0] = (stbi_uc) c1;
+ rgbe[1] = (stbi_uc) c2;
+ rgbe[2] = (stbi_uc) len;
+ rgbe[3] = (stbi_uc) stbi__get8(s);
+ stbi__hdr_convert(hdr_data, rgbe, req_comp);
+ i = 1;
+ j = 0;
+ STBI_FREE(scanline);
+ goto main_decode_loop; // yes, this makes no sense
+ }
+ len <<= 8;
+ len |= stbi__get8(s);
+ if (len != width) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("invalid decoded scanline length", "corrupt HDR"); }
+ if (scanline == NULL) {
+ scanline = (stbi_uc *) stbi__malloc_mad2(width, 4, 0);
+ if (!scanline) {
+ STBI_FREE(hdr_data);
+ return stbi__errpf("outofmem", "Out of memory");
+ }
+ }
+
+ for (k = 0; k < 4; ++k) {
+ int nleft;
+ i = 0;
+ while ((nleft = width - i) > 0) {
+ count = stbi__get8(s);
+ if (count > 128) {
+ // Run
+ value = stbi__get8(s);
+ count -= 128;
+ if (count > nleft) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("corrupt", "bad RLE data in HDR"); }
+ for (z = 0; z < count; ++z)
+ scanline[i++ * 4 + k] = value;
+ } else {
+ // Dump
+ if (count > nleft) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("corrupt", "bad RLE data in HDR"); }
+ for (z = 0; z < count; ++z)
+ scanline[i++ * 4 + k] = stbi__get8(s);
+ }
+ }
+ }
+ for (i=0; i < width; ++i)
+ stbi__hdr_convert(hdr_data+(j*width + i)*req_comp, scanline + i*4, req_comp);
+ }
+ if (scanline)
+ STBI_FREE(scanline);
+ }
+
+ return hdr_data;
+}
+
+static int stbi__hdr_info(stbi__context *s, int *x, int *y, int *comp)
+{
+ char buffer[STBI__HDR_BUFLEN];
+ char *token;
+ int valid = 0;
+ int dummy;
+
+ if (!x) x = &dummy;
+ if (!y) y = &dummy;
+ if (!comp) comp = &dummy;
+
+ if (stbi__hdr_test(s) == 0) {
+ stbi__rewind( s );
+ return 0;
+ }
+
+ for(;;) {
+ token = stbi__hdr_gettoken(s,buffer);
+ if (token[0] == 0) break;
+ if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1;
+ }
+
+ if (!valid) {
+ stbi__rewind( s );
+ return 0;
+ }
+ token = stbi__hdr_gettoken(s,buffer);
+ if (strncmp(token, "-Y ", 3)) {
+ stbi__rewind( s );
+ return 0;
+ }
+ token += 3;
+ *y = (int) strtol(token, &token, 10);
+ while (*token == ' ') ++token;
+ if (strncmp(token, "+X ", 3)) {
+ stbi__rewind( s );
+ return 0;
+ }
+ token += 3;
+ *x = (int) strtol(token, NULL, 10);
+ *comp = 3;
+ return 1;
+}
+#endif // STBI_NO_HDR
+
+#ifndef STBI_NO_BMP
+static int stbi__bmp_info(stbi__context *s, int *x, int *y, int *comp)
+{
+ void *p;
+ stbi__bmp_data info;
+
+ info.all_a = 255;
+ p = stbi__bmp_parse_header(s, &info);
+ if (p == NULL) {
+ stbi__rewind( s );
+ return 0;
+ }
+ if (x) *x = s->img_x;
+ if (y) *y = s->img_y;
+ if (comp) {
+ if (info.bpp == 24 && info.ma == 0xff000000)
+ *comp = 3;
+ else
+ *comp = info.ma ? 4 : 3;
+ }
+ return 1;
+}
+#endif
+
+#ifndef STBI_NO_PSD
+static int stbi__psd_info(stbi__context *s, int *x, int *y, int *comp)
+{
+ int channelCount, dummy, depth;
+ if (!x) x = &dummy;
+ if (!y) y = &dummy;
+ if (!comp) comp = &dummy;
+ if (stbi__get32be(s) != 0x38425053) {
+ stbi__rewind( s );
+ return 0;
+ }
+ if (stbi__get16be(s) != 1) {
+ stbi__rewind( s );
+ return 0;
+ }
+ stbi__skip(s, 6);
+ channelCount = stbi__get16be(s);
+ if (channelCount < 0 || channelCount > 16) {
+ stbi__rewind( s );
+ return 0;
+ }
+ *y = stbi__get32be(s);
+ *x = stbi__get32be(s);
+ depth = stbi__get16be(s);
+ if (depth != 8 && depth != 16) {
+ stbi__rewind( s );
+ return 0;
+ }
+ if (stbi__get16be(s) != 3) {
+ stbi__rewind( s );
+ return 0;
+ }
+ *comp = 4;
+ return 1;
+}
+
+static int stbi__psd_is16(stbi__context *s)
+{
+ int channelCount, depth;
+ if (stbi__get32be(s) != 0x38425053) {
+ stbi__rewind( s );
+ return 0;
+ }
+ if (stbi__get16be(s) != 1) {
+ stbi__rewind( s );
+ return 0;
+ }
+ stbi__skip(s, 6);
+ channelCount = stbi__get16be(s);
+ if (channelCount < 0 || channelCount > 16) {
+ stbi__rewind( s );
+ return 0;
+ }
+ STBI_NOTUSED(stbi__get32be(s));
+ STBI_NOTUSED(stbi__get32be(s));
+ depth = stbi__get16be(s);
+ if (depth != 16) {
+ stbi__rewind( s );
+ return 0;
+ }
+ return 1;
+}
+#endif
+
+#ifndef STBI_NO_PIC
+static int stbi__pic_info(stbi__context *s, int *x, int *y, int *comp)
+{
+ int act_comp=0,num_packets=0,chained,dummy;
+ stbi__pic_packet packets[10];
+
+ if (!x) x = &dummy;
+ if (!y) y = &dummy;
+ if (!comp) comp = &dummy;
+
+ if (!stbi__pic_is4(s,"\x53\x80\xF6\x34")) {
+ stbi__rewind(s);
+ return 0;
+ }
+
+ stbi__skip(s, 88);
+
+ *x = stbi__get16be(s);
+ *y = stbi__get16be(s);
+ if (stbi__at_eof(s)) {
+ stbi__rewind( s);
+ return 0;
+ }
+ if ( (*x) != 0 && (1 << 28) / (*x) < (*y)) {
+ stbi__rewind( s );
+ return 0;
+ }
+
+ stbi__skip(s, 8);
+
+ do {
+ stbi__pic_packet *packet;
+
+ if (num_packets==sizeof(packets)/sizeof(packets[0]))
+ return 0;
+
+ packet = &packets[num_packets++];
+ chained = stbi__get8(s);
+ packet->size = stbi__get8(s);
+ packet->type = stbi__get8(s);
+ packet->channel = stbi__get8(s);
+ act_comp |= packet->channel;
+
+ if (stbi__at_eof(s)) {
+ stbi__rewind( s );
+ return 0;
+ }
+ if (packet->size != 8) {
+ stbi__rewind( s );
+ return 0;
+ }
+ } while (chained);
+
+ *comp = (act_comp & 0x10 ? 4 : 3);
+
+ return 1;
+}
+#endif
+
+// *************************************************************************************************
+// Portable Gray Map and Portable Pixel Map loader
+// by Ken Miller
+//
+// PGM: http://netpbm.sourceforge.net/doc/pgm.html
+// PPM: http://netpbm.sourceforge.net/doc/ppm.html
+//
+// Known limitations:
+// Does not support comments in the header section
+// Does not support ASCII image data (formats P2 and P3)
+
+#ifndef STBI_NO_PNM
+
+static int stbi__pnm_test(stbi__context *s)
+{
+ char p, t;
+ p = (char) stbi__get8(s);
+ t = (char) stbi__get8(s);
+ if (p != 'P' || (t != '5' && t != '6')) {
+ stbi__rewind( s );
+ return 0;
+ }
+ return 1;
+}
+
+static void *stbi__pnm_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri)
+{
+ stbi_uc *out;
+ STBI_NOTUSED(ri);
+
+ ri->bits_per_channel = stbi__pnm_info(s, (int *)&s->img_x, (int *)&s->img_y, (int *)&s->img_n);
+ if (ri->bits_per_channel == 0)
+ return 0;
+
+ if (s->img_y > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large","Very large image (corrupt?)");
+ if (s->img_x > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large","Very large image (corrupt?)");
+
+ *x = s->img_x;
+ *y = s->img_y;
+ if (comp) *comp = s->img_n;
+
+ if (!stbi__mad4sizes_valid(s->img_n, s->img_x, s->img_y, ri->bits_per_channel / 8, 0))
+ return stbi__errpuc("too large", "PNM too large");
+
+ out = (stbi_uc *) stbi__malloc_mad4(s->img_n, s->img_x, s->img_y, ri->bits_per_channel / 8, 0);
+ if (!out) return stbi__errpuc("outofmem", "Out of memory");
+ stbi__getn(s, out, s->img_n * s->img_x * s->img_y * (ri->bits_per_channel / 8));
+
+ if (req_comp && req_comp != s->img_n) {
+ out = stbi__convert_format(out, s->img_n, req_comp, s->img_x, s->img_y);
+ if (out == NULL) return out; // stbi__convert_format frees input on failure
+ }
+ return out;
+}
+
+static int stbi__pnm_isspace(char c)
+{
+ return c == ' ' || c == '\t' || c == '\n' || c == '\v' || c == '\f' || c == '\r';
+}
+
+static void stbi__pnm_skip_whitespace(stbi__context *s, char *c)
+{
+ for (;;) {
+ while (!stbi__at_eof(s) && stbi__pnm_isspace(*c))
+ *c = (char) stbi__get8(s);
+
+ if (stbi__at_eof(s) || *c != '#')
+ break;
+
+ while (!stbi__at_eof(s) && *c != '\n' && *c != '\r' )
+ *c = (char) stbi__get8(s);
+ }
+}
+
+static int stbi__pnm_isdigit(char c)
+{
+ return c >= '0' && c <= '9';
+}
+
+static int stbi__pnm_getinteger(stbi__context *s, char *c)
+{
+ int value = 0;
+
+ while (!stbi__at_eof(s) && stbi__pnm_isdigit(*c)) {
+ value = value*10 + (*c - '0');
+ *c = (char) stbi__get8(s);
+ }
+
+ return value;
+}
+
+static int stbi__pnm_info(stbi__context *s, int *x, int *y, int *comp)
+{
+ int maxv, dummy;
+ char c, p, t;
+
+ if (!x) x = &dummy;
+ if (!y) y = &dummy;
+ if (!comp) comp = &dummy;
+
+ stbi__rewind(s);
+
+ // Get identifier
+ p = (char) stbi__get8(s);
+ t = (char) stbi__get8(s);
+ if (p != 'P' || (t != '5' && t != '6')) {
+ stbi__rewind(s);
+ return 0;
+ }
+
+ *comp = (t == '6') ? 3 : 1; // '5' is 1-component .pgm; '6' is 3-component .ppm
+
+ c = (char) stbi__get8(s);
+ stbi__pnm_skip_whitespace(s, &c);
+
+ *x = stbi__pnm_getinteger(s, &c); // read width
+ stbi__pnm_skip_whitespace(s, &c);
+
+ *y = stbi__pnm_getinteger(s, &c); // read height
+ stbi__pnm_skip_whitespace(s, &c);
+
+ maxv = stbi__pnm_getinteger(s, &c); // read max value
+ if (maxv > 65535)
+ return stbi__err("max value > 65535", "PPM image supports only 8-bit and 16-bit images");
+ else if (maxv > 255)
+ return 16;
+ else
+ return 8;
+}
+
+static int stbi__pnm_is16(stbi__context *s)
+{
+ if (stbi__pnm_info(s, NULL, NULL, NULL) == 16)
+ return 1;
+ return 0;
+}
+#endif
+
+static int stbi__info_main(stbi__context *s, int *x, int *y, int *comp)
+{
+ #ifndef STBI_NO_JPEG
+ if (stbi__jpeg_info(s, x, y, comp)) return 1;
+ #endif
+
+ #ifndef STBI_NO_PNG
+ if (stbi__png_info(s, x, y, comp)) return 1;
+ #endif
+
+ #ifndef STBI_NO_GIF
+ if (stbi__gif_info(s, x, y, comp)) return 1;
+ #endif
+
+ #ifndef STBI_NO_BMP
+ if (stbi__bmp_info(s, x, y, comp)) return 1;
+ #endif
+
+ #ifndef STBI_NO_PSD
+ if (stbi__psd_info(s, x, y, comp)) return 1;
+ #endif
+
+ #ifndef STBI_NO_PIC
+ if (stbi__pic_info(s, x, y, comp)) return 1;
+ #endif
+
+ #ifndef STBI_NO_PNM
+ if (stbi__pnm_info(s, x, y, comp)) return 1;
+ #endif
+
+ #ifndef STBI_NO_HDR
+ if (stbi__hdr_info(s, x, y, comp)) return 1;
+ #endif
+
+ // test tga last because it's a crappy test!
+ #ifndef STBI_NO_TGA
+ if (stbi__tga_info(s, x, y, comp))
+ return 1;
+ #endif
+ return stbi__err("unknown image type", "Image not of any known type, or corrupt");
+}
+
+static int stbi__is_16_main(stbi__context *s)
+{
+ #ifndef STBI_NO_PNG
+ if (stbi__png_is16(s)) return 1;
+ #endif
+
+ #ifndef STBI_NO_PSD
+ if (stbi__psd_is16(s)) return 1;
+ #endif
+
+ #ifndef STBI_NO_PNM
+ if (stbi__pnm_is16(s)) return 1;
+ #endif
+ return 0;
+}
+
+#ifndef STBI_NO_STDIO
+STBIDEF int stbi_info(char const *filename, int *x, int *y, int *comp)
+{
+ FILE *f = stbi__fopen(filename, "rb");
+ int result;
+ if (!f) return stbi__err("can't fopen", "Unable to open file");
+ result = stbi_info_from_file(f, x, y, comp);
+ fclose(f);
+ return result;
+}
+
+STBIDEF int stbi_info_from_file(FILE *f, int *x, int *y, int *comp)
+{
+ int r;
+ stbi__context s;
+ long pos = ftell(f);
+ stbi__start_file(&s, f);
+ r = stbi__info_main(&s,x,y,comp);
+ fseek(f,pos,SEEK_SET);
+ return r;
+}
+
+STBIDEF int stbi_is_16_bit(char const *filename)
+{
+ FILE *f = stbi__fopen(filename, "rb");
+ int result;
+ if (!f) return stbi__err("can't fopen", "Unable to open file");
+ result = stbi_is_16_bit_from_file(f);
+ fclose(f);
+ return result;
+}
+
+STBIDEF int stbi_is_16_bit_from_file(FILE *f)
+{
+ int r;
+ stbi__context s;
+ long pos = ftell(f);
+ stbi__start_file(&s, f);
+ r = stbi__is_16_main(&s);
+ fseek(f,pos,SEEK_SET);
+ return r;
+}
+#endif // !STBI_NO_STDIO
+
+STBIDEF int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp)
+{
+ stbi__context s;
+ stbi__start_mem(&s,buffer,len);
+ return stbi__info_main(&s,x,y,comp);
+}
+
+STBIDEF int stbi_info_from_callbacks(stbi_io_callbacks const *c, void *user, int *x, int *y, int *comp)
+{
+ stbi__context s;
+ stbi__start_callbacks(&s, (stbi_io_callbacks *) c, user);
+ return stbi__info_main(&s,x,y,comp);
+}
+
+STBIDEF int stbi_is_16_bit_from_memory(stbi_uc const *buffer, int len)
+{
+ stbi__context s;
+ stbi__start_mem(&s,buffer,len);
+ return stbi__is_16_main(&s);
+}
+
+STBIDEF int stbi_is_16_bit_from_callbacks(stbi_io_callbacks const *c, void *user)
+{
+ stbi__context s;
+ stbi__start_callbacks(&s, (stbi_io_callbacks *) c, user);
+ return stbi__is_16_main(&s);
+}
+
+#endif // STB_IMAGE_IMPLEMENTATION
+
+/*
+ revision history:
+ 2.20 (2019-02-07) support utf8 filenames in Windows; fix warnings and platform ifdefs
+ 2.19 (2018-02-11) fix warning
+ 2.18 (2018-01-30) fix warnings
+ 2.17 (2018-01-29) change sbti__shiftsigned to avoid clang -O2 bug
+ 1-bit BMP
+ *_is_16_bit api
+ avoid warnings
+ 2.16 (2017-07-23) all functions have 16-bit variants;
+ STBI_NO_STDIO works again;
+ compilation fixes;
+ fix rounding in unpremultiply;
+ optimize vertical flip;
+ disable raw_len validation;
+ documentation fixes
+ 2.15 (2017-03-18) fix png-1,2,4 bug; now all Imagenet JPGs decode;
+ warning fixes; disable run-time SSE detection on gcc;
+ uniform handling of optional "return" values;
+ thread-safe initialization of zlib tables
+ 2.14 (2017-03-03) remove deprecated STBI_JPEG_OLD; fixes for Imagenet JPGs
+ 2.13 (2016-11-29) add 16-bit API, only supported for PNG right now
+ 2.12 (2016-04-02) fix typo in 2.11 PSD fix that caused crashes
+ 2.11 (2016-04-02) allocate large structures on the stack
+ remove white matting for transparent PSD
+ fix reported channel count for PNG & BMP
+ re-enable SSE2 in non-gcc 64-bit
+ support RGB-formatted JPEG
+ read 16-bit PNGs (only as 8-bit)
+ 2.10 (2016-01-22) avoid warning introduced in 2.09 by STBI_REALLOC_SIZED
+ 2.09 (2016-01-16) allow comments in PNM files
+ 16-bit-per-pixel TGA (not bit-per-component)
+ info() for TGA could break due to .hdr handling
+ info() for BMP to shares code instead of sloppy parse
+ can use STBI_REALLOC_SIZED if allocator doesn't support realloc
+ code cleanup
+ 2.08 (2015-09-13) fix to 2.07 cleanup, reading RGB PSD as RGBA
+ 2.07 (2015-09-13) fix compiler warnings
+ partial animated GIF support
+ limited 16-bpc PSD support
+ #ifdef unused functions
+ bug with < 92 byte PIC,PNM,HDR,TGA
+ 2.06 (2015-04-19) fix bug where PSD returns wrong '*comp' value
+ 2.05 (2015-04-19) fix bug in progressive JPEG handling, fix warning
+ 2.04 (2015-04-15) try to re-enable SIMD on MinGW 64-bit
+ 2.03 (2015-04-12) extra corruption checking (mmozeiko)
+ stbi_set_flip_vertically_on_load (nguillemot)
+ fix NEON support; fix mingw support
+ 2.02 (2015-01-19) fix incorrect assert, fix warning
+ 2.01 (2015-01-17) fix various warnings; suppress SIMD on gcc 32-bit without -msse2
+ 2.00b (2014-12-25) fix STBI_MALLOC in progressive JPEG
+ 2.00 (2014-12-25) optimize JPG, including x86 SSE2 & NEON SIMD (ryg)
+ progressive JPEG (stb)
+ PGM/PPM support (Ken Miller)
+ STBI_MALLOC,STBI_REALLOC,STBI_FREE
+ GIF bugfix -- seemingly never worked
+ STBI_NO_*, STBI_ONLY_*
+ 1.48 (2014-12-14) fix incorrectly-named assert()
+ 1.47 (2014-12-14) 1/2/4-bit PNG support, both direct and paletted (Omar Cornut & stb)
+ optimize PNG (ryg)
+ fix bug in interlaced PNG with user-specified channel count (stb)
+ 1.46 (2014-08-26)
+ fix broken tRNS chunk (colorkey-style transparency) in non-paletted PNG
+ 1.45 (2014-08-16)
+ fix MSVC-ARM internal compiler error by wrapping malloc
+ 1.44 (2014-08-07)
+ various warning fixes from Ronny Chevalier
+ 1.43 (2014-07-15)
+ fix MSVC-only compiler problem in code changed in 1.42
+ 1.42 (2014-07-09)
+ don't define _CRT_SECURE_NO_WARNINGS (affects user code)
+ fixes to stbi__cleanup_jpeg path
+ added STBI_ASSERT to avoid requiring assert.h
+ 1.41 (2014-06-25)
+ fix search&replace from 1.36 that messed up comments/error messages
+ 1.40 (2014-06-22)
+ fix gcc struct-initialization warning
+ 1.39 (2014-06-15)
+ fix to TGA optimization when req_comp != number of components in TGA;
+ fix to GIF loading because BMP wasn't rewinding (whoops, no GIFs in my test suite)
+ add support for BMP version 5 (more ignored fields)
+ 1.38 (2014-06-06)
+ suppress MSVC warnings on integer casts truncating values
+ fix accidental rename of 'skip' field of I/O
+ 1.37 (2014-06-04)
+ remove duplicate typedef
+ 1.36 (2014-06-03)
+ convert to header file single-file library
+ if de-iphone isn't set, load iphone images color-swapped instead of returning NULL
+ 1.35 (2014-05-27)
+ various warnings
+ fix broken STBI_SIMD path
+ fix bug where stbi_load_from_file no longer left file pointer in correct place
+ fix broken non-easy path for 32-bit BMP (possibly never used)
+ TGA optimization by Arseny Kapoulkine
+ 1.34 (unknown)
+ use STBI_NOTUSED in stbi__resample_row_generic(), fix one more leak in tga failure case
+ 1.33 (2011-07-14)
+ make stbi_is_hdr work in STBI_NO_HDR (as specified), minor compiler-friendly improvements
+ 1.32 (2011-07-13)
+ support for "info" function for all supported filetypes (SpartanJ)
+ 1.31 (2011-06-20)
+ a few more leak fixes, bug in PNG handling (SpartanJ)
+ 1.30 (2011-06-11)
+ added ability to load files via callbacks to accomidate custom input streams (Ben Wenger)
+ removed deprecated format-specific test/load functions
+ removed support for installable file formats (stbi_loader) -- would have been broken for IO callbacks anyway
+ error cases in bmp and tga give messages and don't leak (Raymond Barbiero, grisha)
+ fix inefficiency in decoding 32-bit BMP (David Woo)
+ 1.29 (2010-08-16)
+ various warning fixes from Aurelien Pocheville
+ 1.28 (2010-08-01)
+ fix bug in GIF palette transparency (SpartanJ)
+ 1.27 (2010-08-01)
+ cast-to-stbi_uc to fix warnings
+ 1.26 (2010-07-24)
+ fix bug in file buffering for PNG reported by SpartanJ
+ 1.25 (2010-07-17)
+ refix trans_data warning (Won Chun)
+ 1.24 (2010-07-12)
+ perf improvements reading from files on platforms with lock-heavy fgetc()
+ minor perf improvements for jpeg
+ deprecated type-specific functions so we'll get feedback if they're needed
+ attempt to fix trans_data warning (Won Chun)
+ 1.23 fixed bug in iPhone support
+ 1.22 (2010-07-10)
+ removed image *writing* support
+ stbi_info support from Jetro Lauha
+ GIF support from Jean-Marc Lienher
+ iPhone PNG-extensions from James Brown
+ warning-fixes from Nicolas Schulz and Janez Zemva (i.stbi__err. Janez (U+017D)emva)
+ 1.21 fix use of 'stbi_uc' in header (reported by jon blow)
+ 1.20 added support for Softimage PIC, by Tom Seddon
+ 1.19 bug in interlaced PNG corruption check (found by ryg)
+ 1.18 (2008-08-02)
+ fix a threading bug (local mutable static)
+ 1.17 support interlaced PNG
+ 1.16 major bugfix - stbi__convert_format converted one too many pixels
+ 1.15 initialize some fields for thread safety
+ 1.14 fix threadsafe conversion bug
+ header-file-only version (#define STBI_HEADER_FILE_ONLY before including)
+ 1.13 threadsafe
+ 1.12 const qualifiers in the API
+ 1.11 Support installable IDCT, colorspace conversion routines
+ 1.10 Fixes for 64-bit (don't use "unsigned long")
+ optimized upsampling by Fabian "ryg" Giesen
+ 1.09 Fix format-conversion for PSD code (bad global variables!)
+ 1.08 Thatcher Ulrich's PSD code integrated by Nicolas Schulz
+ 1.07 attempt to fix C++ warning/errors again
+ 1.06 attempt to fix C++ warning/errors again
+ 1.05 fix TGA loading to return correct *comp and use good luminance calc
+ 1.04 default float alpha is 1, not 255; use 'void *' for stbi_image_free
+ 1.03 bugfixes to STBI_NO_STDIO, STBI_NO_HDR
+ 1.02 support for (subset of) HDR files, float interface for preferred access to them
+ 1.01 fix bug: possible bug in handling right-side up bmps... not sure
+ fix bug: the stbi__bmp_load() and stbi__tga_load() functions didn't work at all
+ 1.00 interface to zlib that skips zlib header
+ 0.99 correct handling of alpha in palette
+ 0.98 TGA loader by lonesock; dynamically add loaders (untested)
+ 0.97 jpeg errors on too large a file; also catch another malloc failure
+ 0.96 fix detection of invalid v value - particleman@mollyrocket forum
+ 0.95 during header scan, seek to markers in case of padding
+ 0.94 STBI_NO_STDIO to disable stdio usage; rename all #defines the same
+ 0.93 handle jpegtran output; verbose errors
+ 0.92 read 4,8,16,24,32-bit BMP files of several formats
+ 0.91 output 24-bit Windows 3.0 BMP files
+ 0.90 fix a few more warnings; bump version number to approach 1.0
+ 0.61 bugfixes due to Marc LeBlanc, Christopher Lloyd
+ 0.60 fix compiling as c++
+ 0.59 fix warnings: merge Dave Moore's -Wall fixes
+ 0.58 fix bug: zlib uncompressed mode len/nlen was wrong endian
+ 0.57 fix bug: jpg last huffman symbol before marker was >9 bits but less than 16 available
+ 0.56 fix bug: zlib uncompressed mode len vs. nlen
+ 0.55 fix bug: restart_interval not initialized to 0
+ 0.54 allow NULL for 'int *comp'
+ 0.53 fix bug in png 3->4; speedup png decoding
+ 0.52 png handles req_comp=3,4 directly; minor cleanup; jpeg comments
+ 0.51 obey req_comp requests, 1-component jpegs return as 1-component,
+ on 'test' only check type, not whether we support this variant
+ 0.50 (2006-11-19)
+ first released version
+*/
+
+
+/*
+------------------------------------------------------------------------------
+This software is available under 2 licenses -- choose whichever you prefer.
+------------------------------------------------------------------------------
+ALTERNATIVE A - MIT License
+Copyright (c) 2017 Sean Barrett
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+------------------------------------------------------------------------------
+ALTERNATIVE B - Public Domain (www.unlicense.org)
+This is free and unencumbered software released into the public domain.
+Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
+software, either in source code form or as a compiled binary, for any purpose,
+commercial or non-commercial, and by any means.
+In jurisdictions that recognize copyright laws, the author or authors of this
+software dedicate any and all copyright interest in the software to the public
+domain. We make this dedication for the benefit of the public at large and to
+the detriment of our heirs and successors. We intend this dedication to be an
+overt act of relinquishment in perpetuity of all present and future rights to
+this software under copyright law.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+------------------------------------------------------------------------------
+*/
diff --git a/libs/stb_image_resize.h b/libs/stb_image_resize.h
@@ -0,0 +1,2634 @@
+/* stb_image_resize - v0.97 - public domain image resizing
+ by Jorge L Rodriguez (@VinoBS) - 2014
+ http://github.com/nothings/stb
+
+ Written with emphasis on usability, portability, and efficiency. (No
+ SIMD or threads, so it be easily outperformed by libs that use those.)
+ Only scaling and translation is supported, no rotations or shears.
+ Easy API downsamples w/Mitchell filter, upsamples w/cubic interpolation.
+
+ COMPILING & LINKING
+ In one C/C++ file that #includes this file, do this:
+ #define STB_IMAGE_RESIZE_IMPLEMENTATION
+ before the #include. That will create the implementation in that file.
+
+ QUICKSTART
+ stbir_resize_uint8( input_pixels , in_w , in_h , 0,
+ output_pixels, out_w, out_h, 0, num_channels)
+ stbir_resize_float(...)
+ stbir_resize_uint8_srgb( input_pixels , in_w , in_h , 0,
+ output_pixels, out_w, out_h, 0,
+ num_channels , alpha_chan , 0)
+ stbir_resize_uint8_srgb_edgemode(
+ input_pixels , in_w , in_h , 0,
+ output_pixels, out_w, out_h, 0,
+ num_channels , alpha_chan , 0, STBIR_EDGE_CLAMP)
+ // WRAP/REFLECT/ZERO
+
+ FULL API
+ See the "header file" section of the source for API documentation.
+
+ ADDITIONAL DOCUMENTATION
+
+ SRGB & FLOATING POINT REPRESENTATION
+ The sRGB functions presume IEEE floating point. If you do not have
+ IEEE floating point, define STBIR_NON_IEEE_FLOAT. This will use
+ a slower implementation.
+
+ MEMORY ALLOCATION
+ The resize functions here perform a single memory allocation using
+ malloc. To control the memory allocation, before the #include that
+ triggers the implementation, do:
+
+ #define STBIR_MALLOC(size,context) ...
+ #define STBIR_FREE(ptr,context) ...
+
+ Each resize function makes exactly one call to malloc/free, so to use
+ temp memory, store the temp memory in the context and return that.
+
+ ASSERT
+ Define STBIR_ASSERT(boolval) to override assert() and not use assert.h
+
+ OPTIMIZATION
+ Define STBIR_SATURATE_INT to compute clamp values in-range using
+ integer operations instead of float operations. This may be faster
+ on some platforms.
+
+ DEFAULT FILTERS
+ For functions which don't provide explicit control over what filters
+ to use, you can change the compile-time defaults with
+
+ #define STBIR_DEFAULT_FILTER_UPSAMPLE STBIR_FILTER_something
+ #define STBIR_DEFAULT_FILTER_DOWNSAMPLE STBIR_FILTER_something
+
+ See stbir_filter in the header-file section for the list of filters.
+
+ NEW FILTERS
+ A number of 1D filter kernels are used. For a list of
+ supported filters see the stbir_filter enum. To add a new filter,
+ write a filter function and add it to stbir__filter_info_table.
+
+ PROGRESS
+ For interactive use with slow resize operations, you can install
+ a progress-report callback:
+
+ #define STBIR_PROGRESS_REPORT(val) some_func(val)
+
+ The parameter val is a float which goes from 0 to 1 as progress is made.
+
+ For example:
+
+ static void my_progress_report(float progress);
+ #define STBIR_PROGRESS_REPORT(val) my_progress_report(val)
+
+ #define STB_IMAGE_RESIZE_IMPLEMENTATION
+ #include "stb_image_resize.h"
+
+ static void my_progress_report(float progress)
+ {
+ printf("Progress: %f%%\n", progress*100);
+ }
+
+ MAX CHANNELS
+ If your image has more than 64 channels, define STBIR_MAX_CHANNELS
+ to the max you'll have.
+
+ ALPHA CHANNEL
+ Most of the resizing functions provide the ability to control how
+ the alpha channel of an image is processed. The important things
+ to know about this:
+
+ 1. The best mathematically-behaved version of alpha to use is
+ called "premultiplied alpha", in which the other color channels
+ have had the alpha value multiplied in. If you use premultiplied
+ alpha, linear filtering (such as image resampling done by this
+ library, or performed in texture units on GPUs) does the "right
+ thing". While premultiplied alpha is standard in the movie CGI
+ industry, it is still uncommon in the videogame/real-time world.
+
+ If you linearly filter non-premultiplied alpha, strange effects
+ occur. (For example, the 50/50 average of 99% transparent bright green
+ and 1% transparent black produces 50% transparent dark green when
+ non-premultiplied, whereas premultiplied it produces 50%
+ transparent near-black. The former introduces green energy
+ that doesn't exist in the source image.)
+
+ 2. Artists should not edit premultiplied-alpha images; artists
+ want non-premultiplied alpha images. Thus, art tools generally output
+ non-premultiplied alpha images.
+
+ 3. You will get best results in most cases by converting images
+ to premultiplied alpha before processing them mathematically.
+
+ 4. If you pass the flag STBIR_FLAG_ALPHA_PREMULTIPLIED, the
+ resizer does not do anything special for the alpha channel;
+ it is resampled identically to other channels. This produces
+ the correct results for premultiplied-alpha images, but produces
+ less-than-ideal results for non-premultiplied-alpha images.
+
+ 5. If you do not pass the flag STBIR_FLAG_ALPHA_PREMULTIPLIED,
+ then the resizer weights the contribution of input pixels
+ based on their alpha values, or, equivalently, it multiplies
+ the alpha value into the color channels, resamples, then divides
+ by the resultant alpha value. Input pixels which have alpha=0 do
+ not contribute at all to output pixels unless _all_ of the input
+ pixels affecting that output pixel have alpha=0, in which case
+ the result for that pixel is the same as it would be without
+ STBIR_FLAG_ALPHA_PREMULTIPLIED. However, this is only true for
+ input images in integer formats. For input images in float format,
+ input pixels with alpha=0 have no effect, and output pixels
+ which have alpha=0 will be 0 in all channels. (For float images,
+ you can manually achieve the same result by adding a tiny epsilon
+ value to the alpha channel of every image, and then subtracting
+ or clamping it at the end.)
+
+ 6. You can suppress the behavior described in #5 and make
+ all-0-alpha pixels have 0 in all channels by #defining
+ STBIR_NO_ALPHA_EPSILON.
+
+ 7. You can separately control whether the alpha channel is
+ interpreted as linear or affected by the colorspace. By default
+ it is linear; you almost never want to apply the colorspace.
+ (For example, graphics hardware does not apply sRGB conversion
+ to the alpha channel.)
+
+ CONTRIBUTORS
+ Jorge L Rodriguez: Implementation
+ Sean Barrett: API design, optimizations
+ Aras Pranckevicius: bugfix
+ Nathan Reed: warning fixes
+
+ REVISIONS
+ 0.97 (2020-02-02) fixed warning
+ 0.96 (2019-03-04) fixed warnings
+ 0.95 (2017-07-23) fixed warnings
+ 0.94 (2017-03-18) fixed warnings
+ 0.93 (2017-03-03) fixed bug with certain combinations of heights
+ 0.92 (2017-01-02) fix integer overflow on large (>2GB) images
+ 0.91 (2016-04-02) fix warnings; fix handling of subpixel regions
+ 0.90 (2014-09-17) first released version
+
+ LICENSE
+ See end of file for license information.
+
+ TODO
+ Don't decode all of the image data when only processing a partial tile
+ Don't use full-width decode buffers when only processing a partial tile
+ When processing wide images, break processing into tiles so data fits in L1 cache
+ Installable filters?
+ Resize that respects alpha test coverage
+ (Reference code: FloatImage::alphaTestCoverage and FloatImage::scaleAlphaToCoverage:
+ https://code.google.com/p/nvidia-texture-tools/source/browse/trunk/src/nvimage/FloatImage.cpp )
+*/
+
+#ifndef STBIR_INCLUDE_STB_IMAGE_RESIZE_H
+#define STBIR_INCLUDE_STB_IMAGE_RESIZE_H
+
+#ifdef _MSC_VER
+typedef unsigned char stbir_uint8;
+typedef unsigned short stbir_uint16;
+typedef unsigned int stbir_uint32;
+#else
+#include <stdint.h>
+typedef uint8_t stbir_uint8;
+typedef uint16_t stbir_uint16;
+typedef uint32_t stbir_uint32;
+#endif
+
+#ifndef STBIRDEF
+#ifdef STB_IMAGE_RESIZE_STATIC
+#define STBIRDEF static
+#else
+#ifdef __cplusplus
+#define STBIRDEF extern "C"
+#else
+#define STBIRDEF extern
+#endif
+#endif
+#endif
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// Easy-to-use API:
+//
+// * "input pixels" points to an array of image data with 'num_channels' channels (e.g. RGB=3, RGBA=4)
+// * input_w is input image width (x-axis), input_h is input image height (y-axis)
+// * stride is the offset between successive rows of image data in memory, in bytes. you can
+// specify 0 to mean packed continuously in memory
+// * alpha channel is treated identically to other channels.
+// * colorspace is linear or sRGB as specified by function name
+// * returned result is 1 for success or 0 in case of an error.
+// #define STBIR_ASSERT() to trigger an assert on parameter validation errors.
+// * Memory required grows approximately linearly with input and output size, but with
+// discontinuities at input_w == output_w and input_h == output_h.
+// * These functions use a "default" resampling filter defined at compile time. To change the filter,
+// you can change the compile-time defaults by #defining STBIR_DEFAULT_FILTER_UPSAMPLE
+// and STBIR_DEFAULT_FILTER_DOWNSAMPLE, or you can use the medium-complexity API.
+
+STBIRDEF int stbir_resize_uint8( const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels);
+
+STBIRDEF int stbir_resize_float( const float *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ float *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels);
+
+
+// The following functions interpret image data as gamma-corrected sRGB.
+// Specify STBIR_ALPHA_CHANNEL_NONE if you have no alpha channel,
+// or otherwise provide the index of the alpha channel. Flags value
+// of 0 will probably do the right thing if you're not sure what
+// the flags mean.
+
+#define STBIR_ALPHA_CHANNEL_NONE -1
+
+// Set this flag if your texture has premultiplied alpha. Otherwise, stbir will
+// use alpha-weighted resampling (effectively premultiplying, resampling,
+// then unpremultiplying).
+#define STBIR_FLAG_ALPHA_PREMULTIPLIED (1 << 0)
+// The specified alpha channel should be handled as gamma-corrected value even
+// when doing sRGB operations.
+#define STBIR_FLAG_ALPHA_USES_COLORSPACE (1 << 1)
+
+STBIRDEF int stbir_resize_uint8_srgb(const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels, int alpha_channel, int flags);
+
+
+typedef enum
+{
+ STBIR_EDGE_CLAMP = 1,
+ STBIR_EDGE_REFLECT = 2,
+ STBIR_EDGE_WRAP = 3,
+ STBIR_EDGE_ZERO = 4,
+} stbir_edge;
+
+// This function adds the ability to specify how requests to sample off the edge of the image are handled.
+STBIRDEF int stbir_resize_uint8_srgb_edgemode(const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_wrap_mode);
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// Medium-complexity API
+//
+// This extends the easy-to-use API as follows:
+//
+// * Alpha-channel can be processed separately
+// * If alpha_channel is not STBIR_ALPHA_CHANNEL_NONE
+// * Alpha channel will not be gamma corrected (unless flags&STBIR_FLAG_GAMMA_CORRECT)
+// * Filters will be weighted by alpha channel (unless flags&STBIR_FLAG_ALPHA_PREMULTIPLIED)
+// * Filter can be selected explicitly
+// * uint16 image type
+// * sRGB colorspace available for all types
+// * context parameter for passing to STBIR_MALLOC
+
+typedef enum
+{
+ STBIR_FILTER_DEFAULT = 0, // use same filter type that easy-to-use API chooses
+ STBIR_FILTER_BOX = 1, // A trapezoid w/1-pixel wide ramps, same result as box for integer scale ratios
+ STBIR_FILTER_TRIANGLE = 2, // On upsampling, produces same results as bilinear texture filtering
+ STBIR_FILTER_CUBICBSPLINE = 3, // The cubic b-spline (aka Mitchell-Netrevalli with B=1,C=0), gaussian-esque
+ STBIR_FILTER_CATMULLROM = 4, // An interpolating cubic spline
+ STBIR_FILTER_MITCHELL = 5, // Mitchell-Netrevalli filter with B=1/3, C=1/3
+} stbir_filter;
+
+typedef enum
+{
+ STBIR_COLORSPACE_LINEAR,
+ STBIR_COLORSPACE_SRGB,
+
+ STBIR_MAX_COLORSPACES,
+} stbir_colorspace;
+
+// The following functions are all identical except for the type of the image data
+
+STBIRDEF int stbir_resize_uint8_generic( const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space,
+ void *alloc_context);
+
+STBIRDEF int stbir_resize_uint16_generic(const stbir_uint16 *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ stbir_uint16 *output_pixels , int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space,
+ void *alloc_context);
+
+STBIRDEF int stbir_resize_float_generic( const float *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ float *output_pixels , int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space,
+ void *alloc_context);
+
+
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// Full-complexity API
+//
+// This extends the medium API as follows:
+//
+// * uint32 image type
+// * not typesafe
+// * separate filter types for each axis
+// * separate edge modes for each axis
+// * can specify scale explicitly for subpixel correctness
+// * can specify image source tile using texture coordinates
+
+typedef enum
+{
+ STBIR_TYPE_UINT8 ,
+ STBIR_TYPE_UINT16,
+ STBIR_TYPE_UINT32,
+ STBIR_TYPE_FLOAT ,
+
+ STBIR_MAX_TYPES
+} stbir_datatype;
+
+STBIRDEF int stbir_resize( const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ void *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ stbir_datatype datatype,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical,
+ stbir_filter filter_horizontal, stbir_filter filter_vertical,
+ stbir_colorspace space, void *alloc_context);
+
+STBIRDEF int stbir_resize_subpixel(const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ void *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ stbir_datatype datatype,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical,
+ stbir_filter filter_horizontal, stbir_filter filter_vertical,
+ stbir_colorspace space, void *alloc_context,
+ float x_scale, float y_scale,
+ float x_offset, float y_offset);
+
+STBIRDEF int stbir_resize_region( const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ void *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ stbir_datatype datatype,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical,
+ stbir_filter filter_horizontal, stbir_filter filter_vertical,
+ stbir_colorspace space, void *alloc_context,
+ float s0, float t0, float s1, float t1);
+// (s0, t0) & (s1, t1) are the top-left and bottom right corner (uv addressing style: [0, 1]x[0, 1]) of a region of the input image to use.
+
+//
+//
+//// end header file /////////////////////////////////////////////////////
+#endif // STBIR_INCLUDE_STB_IMAGE_RESIZE_H
+
+
+
+
+
+#ifdef STB_IMAGE_RESIZE_IMPLEMENTATION
+
+#ifndef STBIR_ASSERT
+#include <assert.h>
+#define STBIR_ASSERT(x) assert(x)
+#endif
+
+// For memset
+#include <string.h>
+
+#include <math.h>
+
+#ifndef STBIR_MALLOC
+#include <stdlib.h>
+// use comma operator to evaluate c, to avoid "unused parameter" warnings
+#define STBIR_MALLOC(size,c) ((void)(c), malloc(size))
+#define STBIR_FREE(ptr,c) ((void)(c), free(ptr))
+#endif
+
+#ifndef _MSC_VER
+#ifdef __cplusplus
+#define stbir__inline inline
+#else
+#define stbir__inline
+#endif
+#else
+#define stbir__inline __forceinline
+#endif
+
+
+// should produce compiler error if size is wrong
+typedef unsigned char stbir__validate_uint32[sizeof(stbir_uint32) == 4 ? 1 : -1];
+
+#ifdef _MSC_VER
+#define STBIR__NOTUSED(v) (void)(v)
+#else
+#define STBIR__NOTUSED(v) (void)sizeof(v)
+#endif
+
+#define STBIR__ARRAY_SIZE(a) (sizeof((a))/sizeof((a)[0]))
+
+#ifndef STBIR_DEFAULT_FILTER_UPSAMPLE
+#define STBIR_DEFAULT_FILTER_UPSAMPLE STBIR_FILTER_CATMULLROM
+#endif
+
+#ifndef STBIR_DEFAULT_FILTER_DOWNSAMPLE
+#define STBIR_DEFAULT_FILTER_DOWNSAMPLE STBIR_FILTER_MITCHELL
+#endif
+
+#ifndef STBIR_PROGRESS_REPORT
+#define STBIR_PROGRESS_REPORT(float_0_to_1)
+#endif
+
+#ifndef STBIR_MAX_CHANNELS
+#define STBIR_MAX_CHANNELS 64
+#endif
+
+#if STBIR_MAX_CHANNELS > 65536
+#error "Too many channels; STBIR_MAX_CHANNELS must be no more than 65536."
+// because we store the indices in 16-bit variables
+#endif
+
+// This value is added to alpha just before premultiplication to avoid
+// zeroing out color values. It is equivalent to 2^-80. If you don't want
+// that behavior (it may interfere if you have floating point images with
+// very small alpha values) then you can define STBIR_NO_ALPHA_EPSILON to
+// disable it.
+#ifndef STBIR_ALPHA_EPSILON
+#define STBIR_ALPHA_EPSILON ((float)1 / (1 << 20) / (1 << 20) / (1 << 20) / (1 << 20))
+#endif
+
+
+
+#ifdef _MSC_VER
+#define STBIR__UNUSED_PARAM(v) (void)(v)
+#else
+#define STBIR__UNUSED_PARAM(v) (void)sizeof(v)
+#endif
+
+// must match stbir_datatype
+static unsigned char stbir__type_size[] = {
+ 1, // STBIR_TYPE_UINT8
+ 2, // STBIR_TYPE_UINT16
+ 4, // STBIR_TYPE_UINT32
+ 4, // STBIR_TYPE_FLOAT
+};
+
+// Kernel function centered at 0
+typedef float (stbir__kernel_fn)(float x, float scale);
+typedef float (stbir__support_fn)(float scale);
+
+typedef struct
+{
+ stbir__kernel_fn* kernel;
+ stbir__support_fn* support;
+} stbir__filter_info;
+
+// When upsampling, the contributors are which source pixels contribute.
+// When downsampling, the contributors are which destination pixels are contributed to.
+typedef struct
+{
+ int n0; // First contributing pixel
+ int n1; // Last contributing pixel
+} stbir__contributors;
+
+typedef struct
+{
+ const void* input_data;
+ int input_w;
+ int input_h;
+ int input_stride_bytes;
+
+ void* output_data;
+ int output_w;
+ int output_h;
+ int output_stride_bytes;
+
+ float s0, t0, s1, t1;
+
+ float horizontal_shift; // Units: output pixels
+ float vertical_shift; // Units: output pixels
+ float horizontal_scale;
+ float vertical_scale;
+
+ int channels;
+ int alpha_channel;
+ stbir_uint32 flags;
+ stbir_datatype type;
+ stbir_filter horizontal_filter;
+ stbir_filter vertical_filter;
+ stbir_edge edge_horizontal;
+ stbir_edge edge_vertical;
+ stbir_colorspace colorspace;
+
+ stbir__contributors* horizontal_contributors;
+ float* horizontal_coefficients;
+
+ stbir__contributors* vertical_contributors;
+ float* vertical_coefficients;
+
+ int decode_buffer_pixels;
+ float* decode_buffer;
+
+ float* horizontal_buffer;
+
+ // cache these because ceil/floor are inexplicably showing up in profile
+ int horizontal_coefficient_width;
+ int vertical_coefficient_width;
+ int horizontal_filter_pixel_width;
+ int vertical_filter_pixel_width;
+ int horizontal_filter_pixel_margin;
+ int vertical_filter_pixel_margin;
+ int horizontal_num_contributors;
+ int vertical_num_contributors;
+
+ int ring_buffer_length_bytes; // The length of an individual entry in the ring buffer. The total number of ring buffers is stbir__get_filter_pixel_width(filter)
+ int ring_buffer_num_entries; // Total number of entries in the ring buffer.
+ int ring_buffer_first_scanline;
+ int ring_buffer_last_scanline;
+ int ring_buffer_begin_index; // first_scanline is at this index in the ring buffer
+ float* ring_buffer;
+
+ float* encode_buffer; // A temporary buffer to store floats so we don't lose precision while we do multiply-adds.
+
+ int horizontal_contributors_size;
+ int horizontal_coefficients_size;
+ int vertical_contributors_size;
+ int vertical_coefficients_size;
+ int decode_buffer_size;
+ int horizontal_buffer_size;
+ int ring_buffer_size;
+ int encode_buffer_size;
+} stbir__info;
+
+
+static const float stbir__max_uint8_as_float = 255.0f;
+static const float stbir__max_uint16_as_float = 65535.0f;
+static const double stbir__max_uint32_as_float = 4294967295.0;
+
+
+static stbir__inline int stbir__min(int a, int b)
+{
+ return a < b ? a : b;
+}
+
+static stbir__inline float stbir__saturate(float x)
+{
+ if (x < 0)
+ return 0;
+
+ if (x > 1)
+ return 1;
+
+ return x;
+}
+
+#ifdef STBIR_SATURATE_INT
+static stbir__inline stbir_uint8 stbir__saturate8(int x)
+{
+ if ((unsigned int) x <= 255)
+ return x;
+
+ if (x < 0)
+ return 0;
+
+ return 255;
+}
+
+static stbir__inline stbir_uint16 stbir__saturate16(int x)
+{
+ if ((unsigned int) x <= 65535)
+ return x;
+
+ if (x < 0)
+ return 0;
+
+ return 65535;
+}
+#endif
+
+static float stbir__srgb_uchar_to_linear_float[256] = {
+ 0.000000f, 0.000304f, 0.000607f, 0.000911f, 0.001214f, 0.001518f, 0.001821f, 0.002125f, 0.002428f, 0.002732f, 0.003035f,
+ 0.003347f, 0.003677f, 0.004025f, 0.004391f, 0.004777f, 0.005182f, 0.005605f, 0.006049f, 0.006512f, 0.006995f, 0.007499f,
+ 0.008023f, 0.008568f, 0.009134f, 0.009721f, 0.010330f, 0.010960f, 0.011612f, 0.012286f, 0.012983f, 0.013702f, 0.014444f,
+ 0.015209f, 0.015996f, 0.016807f, 0.017642f, 0.018500f, 0.019382f, 0.020289f, 0.021219f, 0.022174f, 0.023153f, 0.024158f,
+ 0.025187f, 0.026241f, 0.027321f, 0.028426f, 0.029557f, 0.030713f, 0.031896f, 0.033105f, 0.034340f, 0.035601f, 0.036889f,
+ 0.038204f, 0.039546f, 0.040915f, 0.042311f, 0.043735f, 0.045186f, 0.046665f, 0.048172f, 0.049707f, 0.051269f, 0.052861f,
+ 0.054480f, 0.056128f, 0.057805f, 0.059511f, 0.061246f, 0.063010f, 0.064803f, 0.066626f, 0.068478f, 0.070360f, 0.072272f,
+ 0.074214f, 0.076185f, 0.078187f, 0.080220f, 0.082283f, 0.084376f, 0.086500f, 0.088656f, 0.090842f, 0.093059f, 0.095307f,
+ 0.097587f, 0.099899f, 0.102242f, 0.104616f, 0.107023f, 0.109462f, 0.111932f, 0.114435f, 0.116971f, 0.119538f, 0.122139f,
+ 0.124772f, 0.127438f, 0.130136f, 0.132868f, 0.135633f, 0.138432f, 0.141263f, 0.144128f, 0.147027f, 0.149960f, 0.152926f,
+ 0.155926f, 0.158961f, 0.162029f, 0.165132f, 0.168269f, 0.171441f, 0.174647f, 0.177888f, 0.181164f, 0.184475f, 0.187821f,
+ 0.191202f, 0.194618f, 0.198069f, 0.201556f, 0.205079f, 0.208637f, 0.212231f, 0.215861f, 0.219526f, 0.223228f, 0.226966f,
+ 0.230740f, 0.234551f, 0.238398f, 0.242281f, 0.246201f, 0.250158f, 0.254152f, 0.258183f, 0.262251f, 0.266356f, 0.270498f,
+ 0.274677f, 0.278894f, 0.283149f, 0.287441f, 0.291771f, 0.296138f, 0.300544f, 0.304987f, 0.309469f, 0.313989f, 0.318547f,
+ 0.323143f, 0.327778f, 0.332452f, 0.337164f, 0.341914f, 0.346704f, 0.351533f, 0.356400f, 0.361307f, 0.366253f, 0.371238f,
+ 0.376262f, 0.381326f, 0.386430f, 0.391573f, 0.396755f, 0.401978f, 0.407240f, 0.412543f, 0.417885f, 0.423268f, 0.428691f,
+ 0.434154f, 0.439657f, 0.445201f, 0.450786f, 0.456411f, 0.462077f, 0.467784f, 0.473532f, 0.479320f, 0.485150f, 0.491021f,
+ 0.496933f, 0.502887f, 0.508881f, 0.514918f, 0.520996f, 0.527115f, 0.533276f, 0.539480f, 0.545725f, 0.552011f, 0.558340f,
+ 0.564712f, 0.571125f, 0.577581f, 0.584078f, 0.590619f, 0.597202f, 0.603827f, 0.610496f, 0.617207f, 0.623960f, 0.630757f,
+ 0.637597f, 0.644480f, 0.651406f, 0.658375f, 0.665387f, 0.672443f, 0.679543f, 0.686685f, 0.693872f, 0.701102f, 0.708376f,
+ 0.715694f, 0.723055f, 0.730461f, 0.737911f, 0.745404f, 0.752942f, 0.760525f, 0.768151f, 0.775822f, 0.783538f, 0.791298f,
+ 0.799103f, 0.806952f, 0.814847f, 0.822786f, 0.830770f, 0.838799f, 0.846873f, 0.854993f, 0.863157f, 0.871367f, 0.879622f,
+ 0.887923f, 0.896269f, 0.904661f, 0.913099f, 0.921582f, 0.930111f, 0.938686f, 0.947307f, 0.955974f, 0.964686f, 0.973445f,
+ 0.982251f, 0.991102f, 1.0f
+};
+
+static float stbir__srgb_to_linear(float f)
+{
+ if (f <= 0.04045f)
+ return f / 12.92f;
+ else
+ return (float)pow((f + 0.055f) / 1.055f, 2.4f);
+}
+
+static float stbir__linear_to_srgb(float f)
+{
+ if (f <= 0.0031308f)
+ return f * 12.92f;
+ else
+ return 1.055f * (float)pow(f, 1 / 2.4f) - 0.055f;
+}
+
+#ifndef STBIR_NON_IEEE_FLOAT
+// From https://gist.github.com/rygorous/2203834
+
+typedef union
+{
+ stbir_uint32 u;
+ float f;
+} stbir__FP32;
+
+static const stbir_uint32 fp32_to_srgb8_tab4[104] = {
+ 0x0073000d, 0x007a000d, 0x0080000d, 0x0087000d, 0x008d000d, 0x0094000d, 0x009a000d, 0x00a1000d,
+ 0x00a7001a, 0x00b4001a, 0x00c1001a, 0x00ce001a, 0x00da001a, 0x00e7001a, 0x00f4001a, 0x0101001a,
+ 0x010e0033, 0x01280033, 0x01410033, 0x015b0033, 0x01750033, 0x018f0033, 0x01a80033, 0x01c20033,
+ 0x01dc0067, 0x020f0067, 0x02430067, 0x02760067, 0x02aa0067, 0x02dd0067, 0x03110067, 0x03440067,
+ 0x037800ce, 0x03df00ce, 0x044600ce, 0x04ad00ce, 0x051400ce, 0x057b00c5, 0x05dd00bc, 0x063b00b5,
+ 0x06970158, 0x07420142, 0x07e30130, 0x087b0120, 0x090b0112, 0x09940106, 0x0a1700fc, 0x0a9500f2,
+ 0x0b0f01cb, 0x0bf401ae, 0x0ccb0195, 0x0d950180, 0x0e56016e, 0x0f0d015e, 0x0fbc0150, 0x10630143,
+ 0x11070264, 0x1238023e, 0x1357021d, 0x14660201, 0x156601e9, 0x165a01d3, 0x174401c0, 0x182401af,
+ 0x18fe0331, 0x1a9602fe, 0x1c1502d2, 0x1d7e02ad, 0x1ed4028d, 0x201a0270, 0x21520256, 0x227d0240,
+ 0x239f0443, 0x25c003fe, 0x27bf03c4, 0x29a10392, 0x2b6a0367, 0x2d1d0341, 0x2ebe031f, 0x304d0300,
+ 0x31d105b0, 0x34a80555, 0x37520507, 0x39d504c5, 0x3c37048b, 0x3e7c0458, 0x40a8042a, 0x42bd0401,
+ 0x44c20798, 0x488e071e, 0x4c1c06b6, 0x4f76065d, 0x52a50610, 0x55ac05cc, 0x5892058f, 0x5b590559,
+ 0x5e0c0a23, 0x631c0980, 0x67db08f6, 0x6c55087f, 0x70940818, 0x74a007bd, 0x787d076c, 0x7c330723,
+};
+
+static stbir_uint8 stbir__linear_to_srgb_uchar(float in)
+{
+ static const stbir__FP32 almostone = { 0x3f7fffff }; // 1-eps
+ static const stbir__FP32 minval = { (127-13) << 23 };
+ stbir_uint32 tab,bias,scale,t;
+ stbir__FP32 f;
+
+ // Clamp to [2^(-13), 1-eps]; these two values map to 0 and 1, respectively.
+ // The tests are carefully written so that NaNs map to 0, same as in the reference
+ // implementation.
+ if (!(in > minval.f)) // written this way to catch NaNs
+ in = minval.f;
+ if (in > almostone.f)
+ in = almostone.f;
+
+ // Do the table lookup and unpack bias, scale
+ f.f = in;
+ tab = fp32_to_srgb8_tab4[(f.u - minval.u) >> 20];
+ bias = (tab >> 16) << 9;
+ scale = tab & 0xffff;
+
+ // Grab next-highest mantissa bits and perform linear interpolation
+ t = (f.u >> 12) & 0xff;
+ return (unsigned char) ((bias + scale*t) >> 16);
+}
+
+#else
+// sRGB transition values, scaled by 1<<28
+static int stbir__srgb_offset_to_linear_scaled[256] =
+{
+ 0, 40738, 122216, 203693, 285170, 366648, 448125, 529603,
+ 611080, 692557, 774035, 855852, 942009, 1033024, 1128971, 1229926,
+ 1335959, 1447142, 1563542, 1685229, 1812268, 1944725, 2082664, 2226148,
+ 2375238, 2529996, 2690481, 2856753, 3028870, 3206888, 3390865, 3580856,
+ 3776916, 3979100, 4187460, 4402049, 4622919, 4850123, 5083710, 5323731,
+ 5570236, 5823273, 6082892, 6349140, 6622065, 6901714, 7188133, 7481369,
+ 7781466, 8088471, 8402427, 8723380, 9051372, 9386448, 9728650, 10078021,
+ 10434603, 10798439, 11169569, 11548036, 11933879, 12327139, 12727857, 13136073,
+ 13551826, 13975156, 14406100, 14844697, 15290987, 15745007, 16206795, 16676389,
+ 17153826, 17639142, 18132374, 18633560, 19142734, 19659934, 20185196, 20718552,
+ 21260042, 21809696, 22367554, 22933648, 23508010, 24090680, 24681686, 25281066,
+ 25888850, 26505076, 27129772, 27762974, 28404716, 29055026, 29713942, 30381490,
+ 31057708, 31742624, 32436272, 33138682, 33849884, 34569912, 35298800, 36036568,
+ 36783260, 37538896, 38303512, 39077136, 39859796, 40651528, 41452360, 42262316,
+ 43081432, 43909732, 44747252, 45594016, 46450052, 47315392, 48190064, 49074096,
+ 49967516, 50870356, 51782636, 52704392, 53635648, 54576432, 55526772, 56486700,
+ 57456236, 58435408, 59424248, 60422780, 61431036, 62449032, 63476804, 64514376,
+ 65561776, 66619028, 67686160, 68763192, 69850160, 70947088, 72053992, 73170912,
+ 74297864, 75434880, 76581976, 77739184, 78906536, 80084040, 81271736, 82469648,
+ 83677792, 84896192, 86124888, 87363888, 88613232, 89872928, 91143016, 92423512,
+ 93714432, 95015816, 96327688, 97650056, 98982952, 100326408, 101680440, 103045072,
+ 104420320, 105806224, 107202800, 108610064, 110028048, 111456776, 112896264, 114346544,
+ 115807632, 117279552, 118762328, 120255976, 121760536, 123276016, 124802440, 126339832,
+ 127888216, 129447616, 131018048, 132599544, 134192112, 135795792, 137410592, 139036528,
+ 140673648, 142321952, 143981456, 145652208, 147334208, 149027488, 150732064, 152447968,
+ 154175200, 155913792, 157663776, 159425168, 161197984, 162982240, 164777968, 166585184,
+ 168403904, 170234160, 172075968, 173929344, 175794320, 177670896, 179559120, 181458992,
+ 183370528, 185293776, 187228736, 189175424, 191133888, 193104112, 195086128, 197079968,
+ 199085648, 201103184, 203132592, 205173888, 207227120, 209292272, 211369392, 213458480,
+ 215559568, 217672656, 219797792, 221934976, 224084240, 226245600, 228419056, 230604656,
+ 232802400, 235012320, 237234432, 239468736, 241715280, 243974080, 246245120, 248528464,
+ 250824112, 253132064, 255452368, 257785040, 260130080, 262487520, 264857376, 267239664,
+};
+
+static stbir_uint8 stbir__linear_to_srgb_uchar(float f)
+{
+ int x = (int) (f * (1 << 28)); // has headroom so you don't need to clamp
+ int v = 0;
+ int i;
+
+ // Refine the guess with a short binary search.
+ i = v + 128; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i;
+ i = v + 64; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i;
+ i = v + 32; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i;
+ i = v + 16; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i;
+ i = v + 8; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i;
+ i = v + 4; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i;
+ i = v + 2; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i;
+ i = v + 1; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i;
+
+ return (stbir_uint8) v;
+}
+#endif
+
+static float stbir__filter_trapezoid(float x, float scale)
+{
+ float halfscale = scale / 2;
+ float t = 0.5f + halfscale;
+ STBIR_ASSERT(scale <= 1);
+
+ x = (float)fabs(x);
+
+ if (x >= t)
+ return 0;
+ else
+ {
+ float r = 0.5f - halfscale;
+ if (x <= r)
+ return 1;
+ else
+ return (t - x) / scale;
+ }
+}
+
+static float stbir__support_trapezoid(float scale)
+{
+ STBIR_ASSERT(scale <= 1);
+ return 0.5f + scale / 2;
+}
+
+static float stbir__filter_triangle(float x, float s)
+{
+ STBIR__UNUSED_PARAM(s);
+
+ x = (float)fabs(x);
+
+ if (x <= 1.0f)
+ return 1 - x;
+ else
+ return 0;
+}
+
+static float stbir__filter_cubic(float x, float s)
+{
+ STBIR__UNUSED_PARAM(s);
+
+ x = (float)fabs(x);
+
+ if (x < 1.0f)
+ return (4 + x*x*(3*x - 6))/6;
+ else if (x < 2.0f)
+ return (8 + x*(-12 + x*(6 - x)))/6;
+
+ return (0.0f);
+}
+
+static float stbir__filter_catmullrom(float x, float s)
+{
+ STBIR__UNUSED_PARAM(s);
+
+ x = (float)fabs(x);
+
+ if (x < 1.0f)
+ return 1 - x*x*(2.5f - 1.5f*x);
+ else if (x < 2.0f)
+ return 2 - x*(4 + x*(0.5f*x - 2.5f));
+
+ return (0.0f);
+}
+
+static float stbir__filter_mitchell(float x, float s)
+{
+ STBIR__UNUSED_PARAM(s);
+
+ x = (float)fabs(x);
+
+ if (x < 1.0f)
+ return (16 + x*x*(21 * x - 36))/18;
+ else if (x < 2.0f)
+ return (32 + x*(-60 + x*(36 - 7*x)))/18;
+
+ return (0.0f);
+}
+
+static float stbir__support_zero(float s)
+{
+ STBIR__UNUSED_PARAM(s);
+ return 0;
+}
+
+static float stbir__support_one(float s)
+{
+ STBIR__UNUSED_PARAM(s);
+ return 1;
+}
+
+static float stbir__support_two(float s)
+{
+ STBIR__UNUSED_PARAM(s);
+ return 2;
+}
+
+static stbir__filter_info stbir__filter_info_table[] = {
+ { NULL, stbir__support_zero },
+ { stbir__filter_trapezoid, stbir__support_trapezoid },
+ { stbir__filter_triangle, stbir__support_one },
+ { stbir__filter_cubic, stbir__support_two },
+ { stbir__filter_catmullrom, stbir__support_two },
+ { stbir__filter_mitchell, stbir__support_two },
+};
+
+stbir__inline static int stbir__use_upsampling(float ratio)
+{
+ return ratio > 1;
+}
+
+stbir__inline static int stbir__use_width_upsampling(stbir__info* stbir_info)
+{
+ return stbir__use_upsampling(stbir_info->horizontal_scale);
+}
+
+stbir__inline static int stbir__use_height_upsampling(stbir__info* stbir_info)
+{
+ return stbir__use_upsampling(stbir_info->vertical_scale);
+}
+
+// This is the maximum number of input samples that can affect an output sample
+// with the given filter
+static int stbir__get_filter_pixel_width(stbir_filter filter, float scale)
+{
+ STBIR_ASSERT(filter != 0);
+ STBIR_ASSERT(filter < STBIR__ARRAY_SIZE(stbir__filter_info_table));
+
+ if (stbir__use_upsampling(scale))
+ return (int)ceil(stbir__filter_info_table[filter].support(1/scale) * 2);
+ else
+ return (int)ceil(stbir__filter_info_table[filter].support(scale) * 2 / scale);
+}
+
+// This is how much to expand buffers to account for filters seeking outside
+// the image boundaries.
+static int stbir__get_filter_pixel_margin(stbir_filter filter, float scale)
+{
+ return stbir__get_filter_pixel_width(filter, scale) / 2;
+}
+
+static int stbir__get_coefficient_width(stbir_filter filter, float scale)
+{
+ if (stbir__use_upsampling(scale))
+ return (int)ceil(stbir__filter_info_table[filter].support(1 / scale) * 2);
+ else
+ return (int)ceil(stbir__filter_info_table[filter].support(scale) * 2);
+}
+
+static int stbir__get_contributors(float scale, stbir_filter filter, int input_size, int output_size)
+{
+ if (stbir__use_upsampling(scale))
+ return output_size;
+ else
+ return (input_size + stbir__get_filter_pixel_margin(filter, scale) * 2);
+}
+
+static int stbir__get_total_horizontal_coefficients(stbir__info* info)
+{
+ return info->horizontal_num_contributors
+ * stbir__get_coefficient_width (info->horizontal_filter, info->horizontal_scale);
+}
+
+static int stbir__get_total_vertical_coefficients(stbir__info* info)
+{
+ return info->vertical_num_contributors
+ * stbir__get_coefficient_width (info->vertical_filter, info->vertical_scale);
+}
+
+static stbir__contributors* stbir__get_contributor(stbir__contributors* contributors, int n)
+{
+ return &contributors[n];
+}
+
+// For perf reasons this code is duplicated in stbir__resample_horizontal_upsample/downsample,
+// if you change it here change it there too.
+static float* stbir__get_coefficient(float* coefficients, stbir_filter filter, float scale, int n, int c)
+{
+ int width = stbir__get_coefficient_width(filter, scale);
+ return &coefficients[width*n + c];
+}
+
+static int stbir__edge_wrap_slow(stbir_edge edge, int n, int max)
+{
+ switch (edge)
+ {
+ case STBIR_EDGE_ZERO:
+ return 0; // we'll decode the wrong pixel here, and then overwrite with 0s later
+
+ case STBIR_EDGE_CLAMP:
+ if (n < 0)
+ return 0;
+
+ if (n >= max)
+ return max - 1;
+
+ return n; // NOTREACHED
+
+ case STBIR_EDGE_REFLECT:
+ {
+ if (n < 0)
+ {
+ if (n < max)
+ return -n;
+ else
+ return max - 1;
+ }
+
+ if (n >= max)
+ {
+ int max2 = max * 2;
+ if (n >= max2)
+ return 0;
+ else
+ return max2 - n - 1;
+ }
+
+ return n; // NOTREACHED
+ }
+
+ case STBIR_EDGE_WRAP:
+ if (n >= 0)
+ return (n % max);
+ else
+ {
+ int m = (-n) % max;
+
+ if (m != 0)
+ m = max - m;
+
+ return (m);
+ }
+ // NOTREACHED
+
+ default:
+ STBIR_ASSERT(!"Unimplemented edge type");
+ return 0;
+ }
+}
+
+stbir__inline static int stbir__edge_wrap(stbir_edge edge, int n, int max)
+{
+ // avoid per-pixel switch
+ if (n >= 0 && n < max)
+ return n;
+ return stbir__edge_wrap_slow(edge, n, max);
+}
+
+// What input pixels contribute to this output pixel?
+static void stbir__calculate_sample_range_upsample(int n, float out_filter_radius, float scale_ratio, float out_shift, int* in_first_pixel, int* in_last_pixel, float* in_center_of_out)
+{
+ float out_pixel_center = (float)n + 0.5f;
+ float out_pixel_influence_lowerbound = out_pixel_center - out_filter_radius;
+ float out_pixel_influence_upperbound = out_pixel_center + out_filter_radius;
+
+ float in_pixel_influence_lowerbound = (out_pixel_influence_lowerbound + out_shift) / scale_ratio;
+ float in_pixel_influence_upperbound = (out_pixel_influence_upperbound + out_shift) / scale_ratio;
+
+ *in_center_of_out = (out_pixel_center + out_shift) / scale_ratio;
+ *in_first_pixel = (int)(floor(in_pixel_influence_lowerbound + 0.5));
+ *in_last_pixel = (int)(floor(in_pixel_influence_upperbound - 0.5));
+}
+
+// What output pixels does this input pixel contribute to?
+static void stbir__calculate_sample_range_downsample(int n, float in_pixels_radius, float scale_ratio, float out_shift, int* out_first_pixel, int* out_last_pixel, float* out_center_of_in)
+{
+ float in_pixel_center = (float)n + 0.5f;
+ float in_pixel_influence_lowerbound = in_pixel_center - in_pixels_radius;
+ float in_pixel_influence_upperbound = in_pixel_center + in_pixels_radius;
+
+ float out_pixel_influence_lowerbound = in_pixel_influence_lowerbound * scale_ratio - out_shift;
+ float out_pixel_influence_upperbound = in_pixel_influence_upperbound * scale_ratio - out_shift;
+
+ *out_center_of_in = in_pixel_center * scale_ratio - out_shift;
+ *out_first_pixel = (int)(floor(out_pixel_influence_lowerbound + 0.5));
+ *out_last_pixel = (int)(floor(out_pixel_influence_upperbound - 0.5));
+}
+
+static void stbir__calculate_coefficients_upsample(stbir_filter filter, float scale, int in_first_pixel, int in_last_pixel, float in_center_of_out, stbir__contributors* contributor, float* coefficient_group)
+{
+ int i;
+ float total_filter = 0;
+ float filter_scale;
+
+ STBIR_ASSERT(in_last_pixel - in_first_pixel <= (int)ceil(stbir__filter_info_table[filter].support(1/scale) * 2)); // Taken directly from stbir__get_coefficient_width() which we can't call because we don't know if we're horizontal or vertical.
+
+ contributor->n0 = in_first_pixel;
+ contributor->n1 = in_last_pixel;
+
+ STBIR_ASSERT(contributor->n1 >= contributor->n0);
+
+ for (i = 0; i <= in_last_pixel - in_first_pixel; i++)
+ {
+ float in_pixel_center = (float)(i + in_first_pixel) + 0.5f;
+ coefficient_group[i] = stbir__filter_info_table[filter].kernel(in_center_of_out - in_pixel_center, 1 / scale);
+
+ // If the coefficient is zero, skip it. (Don't do the <0 check here, we want the influence of those outside pixels.)
+ if (i == 0 && !coefficient_group[i])
+ {
+ contributor->n0 = ++in_first_pixel;
+ i--;
+ continue;
+ }
+
+ total_filter += coefficient_group[i];
+ }
+
+ // NOTE(fg): Not actually true in general, nor is there any reason to expect it should be.
+ // It would be true in exact math but is at best approximately true in floating-point math,
+ // and it would not make sense to try and put actual bounds on this here because it depends
+ // on the image aspect ratio which can get pretty extreme.
+ //STBIR_ASSERT(stbir__filter_info_table[filter].kernel((float)(in_last_pixel + 1) + 0.5f - in_center_of_out, 1/scale) == 0);
+
+ STBIR_ASSERT(total_filter > 0.9);
+ STBIR_ASSERT(total_filter < 1.1f); // Make sure it's not way off.
+
+ // Make sure the sum of all coefficients is 1.
+ filter_scale = 1 / total_filter;
+
+ for (i = 0; i <= in_last_pixel - in_first_pixel; i++)
+ coefficient_group[i] *= filter_scale;
+
+ for (i = in_last_pixel - in_first_pixel; i >= 0; i--)
+ {
+ if (coefficient_group[i])
+ break;
+
+ // This line has no weight. We can skip it.
+ contributor->n1 = contributor->n0 + i - 1;
+ }
+}
+
+static void stbir__calculate_coefficients_downsample(stbir_filter filter, float scale_ratio, int out_first_pixel, int out_last_pixel, float out_center_of_in, stbir__contributors* contributor, float* coefficient_group)
+{
+ int i;
+
+ STBIR_ASSERT(out_last_pixel - out_first_pixel <= (int)ceil(stbir__filter_info_table[filter].support(scale_ratio) * 2)); // Taken directly from stbir__get_coefficient_width() which we can't call because we don't know if we're horizontal or vertical.
+
+ contributor->n0 = out_first_pixel;
+ contributor->n1 = out_last_pixel;
+
+ STBIR_ASSERT(contributor->n1 >= contributor->n0);
+
+ for (i = 0; i <= out_last_pixel - out_first_pixel; i++)
+ {
+ float out_pixel_center = (float)(i + out_first_pixel) + 0.5f;
+ float x = out_pixel_center - out_center_of_in;
+ coefficient_group[i] = stbir__filter_info_table[filter].kernel(x, scale_ratio) * scale_ratio;
+ }
+
+ // NOTE(fg): Not actually true in general, nor is there any reason to expect it should be.
+ // It would be true in exact math but is at best approximately true in floating-point math,
+ // and it would not make sense to try and put actual bounds on this here because it depends
+ // on the image aspect ratio which can get pretty extreme.
+ //STBIR_ASSERT(stbir__filter_info_table[filter].kernel((float)(out_last_pixel + 1) + 0.5f - out_center_of_in, scale_ratio) == 0);
+
+ for (i = out_last_pixel - out_first_pixel; i >= 0; i--)
+ {
+ if (coefficient_group[i])
+ break;
+
+ // This line has no weight. We can skip it.
+ contributor->n1 = contributor->n0 + i - 1;
+ }
+}
+
+static void stbir__normalize_downsample_coefficients(stbir__contributors* contributors, float* coefficients, stbir_filter filter, float scale_ratio, int input_size, int output_size)
+{
+ int num_contributors = stbir__get_contributors(scale_ratio, filter, input_size, output_size);
+ int num_coefficients = stbir__get_coefficient_width(filter, scale_ratio);
+ int i, j;
+ int skip;
+
+ for (i = 0; i < output_size; i++)
+ {
+ float scale;
+ float total = 0;
+
+ for (j = 0; j < num_contributors; j++)
+ {
+ if (i >= contributors[j].n0 && i <= contributors[j].n1)
+ {
+ float coefficient = *stbir__get_coefficient(coefficients, filter, scale_ratio, j, i - contributors[j].n0);
+ total += coefficient;
+ }
+ else if (i < contributors[j].n0)
+ break;
+ }
+
+ STBIR_ASSERT(total > 0.9f);
+ STBIR_ASSERT(total < 1.1f);
+
+ scale = 1 / total;
+
+ for (j = 0; j < num_contributors; j++)
+ {
+ if (i >= contributors[j].n0 && i <= contributors[j].n1)
+ *stbir__get_coefficient(coefficients, filter, scale_ratio, j, i - contributors[j].n0) *= scale;
+ else if (i < contributors[j].n0)
+ break;
+ }
+ }
+
+ // Optimize: Skip zero coefficients and contributions outside of image bounds.
+ // Do this after normalizing because normalization depends on the n0/n1 values.
+ for (j = 0; j < num_contributors; j++)
+ {
+ int range, max, width;
+
+ skip = 0;
+ while (*stbir__get_coefficient(coefficients, filter, scale_ratio, j, skip) == 0)
+ skip++;
+
+ contributors[j].n0 += skip;
+
+ while (contributors[j].n0 < 0)
+ {
+ contributors[j].n0++;
+ skip++;
+ }
+
+ range = contributors[j].n1 - contributors[j].n0 + 1;
+ max = stbir__min(num_coefficients, range);
+
+ width = stbir__get_coefficient_width(filter, scale_ratio);
+ for (i = 0; i < max; i++)
+ {
+ if (i + skip >= width)
+ break;
+
+ *stbir__get_coefficient(coefficients, filter, scale_ratio, j, i) = *stbir__get_coefficient(coefficients, filter, scale_ratio, j, i + skip);
+ }
+
+ continue;
+ }
+
+ // Using min to avoid writing into invalid pixels.
+ for (i = 0; i < num_contributors; i++)
+ contributors[i].n1 = stbir__min(contributors[i].n1, output_size - 1);
+}
+
+// Each scan line uses the same kernel values so we should calculate the kernel
+// values once and then we can use them for every scan line.
+static void stbir__calculate_filters(stbir__contributors* contributors, float* coefficients, stbir_filter filter, float scale_ratio, float shift, int input_size, int output_size)
+{
+ int n;
+ int total_contributors = stbir__get_contributors(scale_ratio, filter, input_size, output_size);
+
+ if (stbir__use_upsampling(scale_ratio))
+ {
+ float out_pixels_radius = stbir__filter_info_table[filter].support(1 / scale_ratio) * scale_ratio;
+
+ // Looping through out pixels
+ for (n = 0; n < total_contributors; n++)
+ {
+ float in_center_of_out; // Center of the current out pixel in the in pixel space
+ int in_first_pixel, in_last_pixel;
+
+ stbir__calculate_sample_range_upsample(n, out_pixels_radius, scale_ratio, shift, &in_first_pixel, &in_last_pixel, &in_center_of_out);
+
+ stbir__calculate_coefficients_upsample(filter, scale_ratio, in_first_pixel, in_last_pixel, in_center_of_out, stbir__get_contributor(contributors, n), stbir__get_coefficient(coefficients, filter, scale_ratio, n, 0));
+ }
+ }
+ else
+ {
+ float in_pixels_radius = stbir__filter_info_table[filter].support(scale_ratio) / scale_ratio;
+
+ // Looping through in pixels
+ for (n = 0; n < total_contributors; n++)
+ {
+ float out_center_of_in; // Center of the current out pixel in the in pixel space
+ int out_first_pixel, out_last_pixel;
+ int n_adjusted = n - stbir__get_filter_pixel_margin(filter, scale_ratio);
+
+ stbir__calculate_sample_range_downsample(n_adjusted, in_pixels_radius, scale_ratio, shift, &out_first_pixel, &out_last_pixel, &out_center_of_in);
+
+ stbir__calculate_coefficients_downsample(filter, scale_ratio, out_first_pixel, out_last_pixel, out_center_of_in, stbir__get_contributor(contributors, n), stbir__get_coefficient(coefficients, filter, scale_ratio, n, 0));
+ }
+
+ stbir__normalize_downsample_coefficients(contributors, coefficients, filter, scale_ratio, input_size, output_size);
+ }
+}
+
+static float* stbir__get_decode_buffer(stbir__info* stbir_info)
+{
+ // The 0 index of the decode buffer starts after the margin. This makes
+ // it okay to use negative indexes on the decode buffer.
+ return &stbir_info->decode_buffer[stbir_info->horizontal_filter_pixel_margin * stbir_info->channels];
+}
+
+#define STBIR__DECODE(type, colorspace) ((int)(type) * (STBIR_MAX_COLORSPACES) + (int)(colorspace))
+
+static void stbir__decode_scanline(stbir__info* stbir_info, int n)
+{
+ int c;
+ int channels = stbir_info->channels;
+ int alpha_channel = stbir_info->alpha_channel;
+ int type = stbir_info->type;
+ int colorspace = stbir_info->colorspace;
+ int input_w = stbir_info->input_w;
+ size_t input_stride_bytes = stbir_info->input_stride_bytes;
+ float* decode_buffer = stbir__get_decode_buffer(stbir_info);
+ stbir_edge edge_horizontal = stbir_info->edge_horizontal;
+ stbir_edge edge_vertical = stbir_info->edge_vertical;
+ size_t in_buffer_row_offset = stbir__edge_wrap(edge_vertical, n, stbir_info->input_h) * input_stride_bytes;
+ const void* input_data = (char *) stbir_info->input_data + in_buffer_row_offset;
+ int max_x = input_w + stbir_info->horizontal_filter_pixel_margin;
+ int decode = STBIR__DECODE(type, colorspace);
+
+ int x = -stbir_info->horizontal_filter_pixel_margin;
+
+ // special handling for STBIR_EDGE_ZERO because it needs to return an item that doesn't appear in the input,
+ // and we want to avoid paying overhead on every pixel if not STBIR_EDGE_ZERO
+ if (edge_vertical == STBIR_EDGE_ZERO && (n < 0 || n >= stbir_info->input_h))
+ {
+ for (; x < max_x; x++)
+ for (c = 0; c < channels; c++)
+ decode_buffer[x*channels + c] = 0;
+ return;
+ }
+
+ switch (decode)
+ {
+ case STBIR__DECODE(STBIR_TYPE_UINT8, STBIR_COLORSPACE_LINEAR):
+ for (; x < max_x; x++)
+ {
+ int decode_pixel_index = x * channels;
+ int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels;
+ for (c = 0; c < channels; c++)
+ decode_buffer[decode_pixel_index + c] = ((float)((const unsigned char*)input_data)[input_pixel_index + c]) / stbir__max_uint8_as_float;
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_UINT8, STBIR_COLORSPACE_SRGB):
+ for (; x < max_x; x++)
+ {
+ int decode_pixel_index = x * channels;
+ int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels;
+ for (c = 0; c < channels; c++)
+ decode_buffer[decode_pixel_index + c] = stbir__srgb_uchar_to_linear_float[((const unsigned char*)input_data)[input_pixel_index + c]];
+
+ if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
+ decode_buffer[decode_pixel_index + alpha_channel] = ((float)((const unsigned char*)input_data)[input_pixel_index + alpha_channel]) / stbir__max_uint8_as_float;
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_UINT16, STBIR_COLORSPACE_LINEAR):
+ for (; x < max_x; x++)
+ {
+ int decode_pixel_index = x * channels;
+ int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels;
+ for (c = 0; c < channels; c++)
+ decode_buffer[decode_pixel_index + c] = ((float)((const unsigned short*)input_data)[input_pixel_index + c]) / stbir__max_uint16_as_float;
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_UINT16, STBIR_COLORSPACE_SRGB):
+ for (; x < max_x; x++)
+ {
+ int decode_pixel_index = x * channels;
+ int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels;
+ for (c = 0; c < channels; c++)
+ decode_buffer[decode_pixel_index + c] = stbir__srgb_to_linear(((float)((const unsigned short*)input_data)[input_pixel_index + c]) / stbir__max_uint16_as_float);
+
+ if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
+ decode_buffer[decode_pixel_index + alpha_channel] = ((float)((const unsigned short*)input_data)[input_pixel_index + alpha_channel]) / stbir__max_uint16_as_float;
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_UINT32, STBIR_COLORSPACE_LINEAR):
+ for (; x < max_x; x++)
+ {
+ int decode_pixel_index = x * channels;
+ int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels;
+ for (c = 0; c < channels; c++)
+ decode_buffer[decode_pixel_index + c] = (float)(((double)((const unsigned int*)input_data)[input_pixel_index + c]) / stbir__max_uint32_as_float);
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_UINT32, STBIR_COLORSPACE_SRGB):
+ for (; x < max_x; x++)
+ {
+ int decode_pixel_index = x * channels;
+ int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels;
+ for (c = 0; c < channels; c++)
+ decode_buffer[decode_pixel_index + c] = stbir__srgb_to_linear((float)(((double)((const unsigned int*)input_data)[input_pixel_index + c]) / stbir__max_uint32_as_float));
+
+ if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
+ decode_buffer[decode_pixel_index + alpha_channel] = (float)(((double)((const unsigned int*)input_data)[input_pixel_index + alpha_channel]) / stbir__max_uint32_as_float);
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_FLOAT, STBIR_COLORSPACE_LINEAR):
+ for (; x < max_x; x++)
+ {
+ int decode_pixel_index = x * channels;
+ int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels;
+ for (c = 0; c < channels; c++)
+ decode_buffer[decode_pixel_index + c] = ((const float*)input_data)[input_pixel_index + c];
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_FLOAT, STBIR_COLORSPACE_SRGB):
+ for (; x < max_x; x++)
+ {
+ int decode_pixel_index = x * channels;
+ int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels;
+ for (c = 0; c < channels; c++)
+ decode_buffer[decode_pixel_index + c] = stbir__srgb_to_linear(((const float*)input_data)[input_pixel_index + c]);
+
+ if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
+ decode_buffer[decode_pixel_index + alpha_channel] = ((const float*)input_data)[input_pixel_index + alpha_channel];
+ }
+
+ break;
+
+ default:
+ STBIR_ASSERT(!"Unknown type/colorspace/channels combination.");
+ break;
+ }
+
+ if (!(stbir_info->flags & STBIR_FLAG_ALPHA_PREMULTIPLIED))
+ {
+ for (x = -stbir_info->horizontal_filter_pixel_margin; x < max_x; x++)
+ {
+ int decode_pixel_index = x * channels;
+
+ // If the alpha value is 0 it will clobber the color values. Make sure it's not.
+ float alpha = decode_buffer[decode_pixel_index + alpha_channel];
+#ifndef STBIR_NO_ALPHA_EPSILON
+ if (stbir_info->type != STBIR_TYPE_FLOAT) {
+ alpha += STBIR_ALPHA_EPSILON;
+ decode_buffer[decode_pixel_index + alpha_channel] = alpha;
+ }
+#endif
+ for (c = 0; c < channels; c++)
+ {
+ if (c == alpha_channel)
+ continue;
+
+ decode_buffer[decode_pixel_index + c] *= alpha;
+ }
+ }
+ }
+
+ if (edge_horizontal == STBIR_EDGE_ZERO)
+ {
+ for (x = -stbir_info->horizontal_filter_pixel_margin; x < 0; x++)
+ {
+ for (c = 0; c < channels; c++)
+ decode_buffer[x*channels + c] = 0;
+ }
+ for (x = input_w; x < max_x; x++)
+ {
+ for (c = 0; c < channels; c++)
+ decode_buffer[x*channels + c] = 0;
+ }
+ }
+}
+
+static float* stbir__get_ring_buffer_entry(float* ring_buffer, int index, int ring_buffer_length)
+{
+ return &ring_buffer[index * ring_buffer_length];
+}
+
+static float* stbir__add_empty_ring_buffer_entry(stbir__info* stbir_info, int n)
+{
+ int ring_buffer_index;
+ float* ring_buffer;
+
+ stbir_info->ring_buffer_last_scanline = n;
+
+ if (stbir_info->ring_buffer_begin_index < 0)
+ {
+ ring_buffer_index = stbir_info->ring_buffer_begin_index = 0;
+ stbir_info->ring_buffer_first_scanline = n;
+ }
+ else
+ {
+ ring_buffer_index = (stbir_info->ring_buffer_begin_index + (stbir_info->ring_buffer_last_scanline - stbir_info->ring_buffer_first_scanline)) % stbir_info->ring_buffer_num_entries;
+ STBIR_ASSERT(ring_buffer_index != stbir_info->ring_buffer_begin_index);
+ }
+
+ ring_buffer = stbir__get_ring_buffer_entry(stbir_info->ring_buffer, ring_buffer_index, stbir_info->ring_buffer_length_bytes / sizeof(float));
+ memset(ring_buffer, 0, stbir_info->ring_buffer_length_bytes);
+
+ return ring_buffer;
+}
+
+
+static void stbir__resample_horizontal_upsample(stbir__info* stbir_info, float* output_buffer)
+{
+ int x, k;
+ int output_w = stbir_info->output_w;
+ int channels = stbir_info->channels;
+ float* decode_buffer = stbir__get_decode_buffer(stbir_info);
+ stbir__contributors* horizontal_contributors = stbir_info->horizontal_contributors;
+ float* horizontal_coefficients = stbir_info->horizontal_coefficients;
+ int coefficient_width = stbir_info->horizontal_coefficient_width;
+
+ for (x = 0; x < output_w; x++)
+ {
+ int n0 = horizontal_contributors[x].n0;
+ int n1 = horizontal_contributors[x].n1;
+
+ int out_pixel_index = x * channels;
+ int coefficient_group = coefficient_width * x;
+ int coefficient_counter = 0;
+
+ STBIR_ASSERT(n1 >= n0);
+ STBIR_ASSERT(n0 >= -stbir_info->horizontal_filter_pixel_margin);
+ STBIR_ASSERT(n1 >= -stbir_info->horizontal_filter_pixel_margin);
+ STBIR_ASSERT(n0 < stbir_info->input_w + stbir_info->horizontal_filter_pixel_margin);
+ STBIR_ASSERT(n1 < stbir_info->input_w + stbir_info->horizontal_filter_pixel_margin);
+
+ switch (channels) {
+ case 1:
+ for (k = n0; k <= n1; k++)
+ {
+ int in_pixel_index = k * 1;
+ float coefficient = horizontal_coefficients[coefficient_group + coefficient_counter++];
+ STBIR_ASSERT(coefficient != 0);
+ output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient;
+ }
+ break;
+ case 2:
+ for (k = n0; k <= n1; k++)
+ {
+ int in_pixel_index = k * 2;
+ float coefficient = horizontal_coefficients[coefficient_group + coefficient_counter++];
+ STBIR_ASSERT(coefficient != 0);
+ output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient;
+ output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient;
+ }
+ break;
+ case 3:
+ for (k = n0; k <= n1; k++)
+ {
+ int in_pixel_index = k * 3;
+ float coefficient = horizontal_coefficients[coefficient_group + coefficient_counter++];
+ STBIR_ASSERT(coefficient != 0);
+ output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient;
+ output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient;
+ output_buffer[out_pixel_index + 2] += decode_buffer[in_pixel_index + 2] * coefficient;
+ }
+ break;
+ case 4:
+ for (k = n0; k <= n1; k++)
+ {
+ int in_pixel_index = k * 4;
+ float coefficient = horizontal_coefficients[coefficient_group + coefficient_counter++];
+ STBIR_ASSERT(coefficient != 0);
+ output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient;
+ output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient;
+ output_buffer[out_pixel_index + 2] += decode_buffer[in_pixel_index + 2] * coefficient;
+ output_buffer[out_pixel_index + 3] += decode_buffer[in_pixel_index + 3] * coefficient;
+ }
+ break;
+ default:
+ for (k = n0; k <= n1; k++)
+ {
+ int in_pixel_index = k * channels;
+ float coefficient = horizontal_coefficients[coefficient_group + coefficient_counter++];
+ int c;
+ STBIR_ASSERT(coefficient != 0);
+ for (c = 0; c < channels; c++)
+ output_buffer[out_pixel_index + c] += decode_buffer[in_pixel_index + c] * coefficient;
+ }
+ break;
+ }
+ }
+}
+
+static void stbir__resample_horizontal_downsample(stbir__info* stbir_info, float* output_buffer)
+{
+ int x, k;
+ int input_w = stbir_info->input_w;
+ int channels = stbir_info->channels;
+ float* decode_buffer = stbir__get_decode_buffer(stbir_info);
+ stbir__contributors* horizontal_contributors = stbir_info->horizontal_contributors;
+ float* horizontal_coefficients = stbir_info->horizontal_coefficients;
+ int coefficient_width = stbir_info->horizontal_coefficient_width;
+ int filter_pixel_margin = stbir_info->horizontal_filter_pixel_margin;
+ int max_x = input_w + filter_pixel_margin * 2;
+
+ STBIR_ASSERT(!stbir__use_width_upsampling(stbir_info));
+
+ switch (channels) {
+ case 1:
+ for (x = 0; x < max_x; x++)
+ {
+ int n0 = horizontal_contributors[x].n0;
+ int n1 = horizontal_contributors[x].n1;
+
+ int in_x = x - filter_pixel_margin;
+ int in_pixel_index = in_x * 1;
+ int max_n = n1;
+ int coefficient_group = coefficient_width * x;
+
+ for (k = n0; k <= max_n; k++)
+ {
+ int out_pixel_index = k * 1;
+ float coefficient = horizontal_coefficients[coefficient_group + k - n0];
+ output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient;
+ }
+ }
+ break;
+
+ case 2:
+ for (x = 0; x < max_x; x++)
+ {
+ int n0 = horizontal_contributors[x].n0;
+ int n1 = horizontal_contributors[x].n1;
+
+ int in_x = x - filter_pixel_margin;
+ int in_pixel_index = in_x * 2;
+ int max_n = n1;
+ int coefficient_group = coefficient_width * x;
+
+ for (k = n0; k <= max_n; k++)
+ {
+ int out_pixel_index = k * 2;
+ float coefficient = horizontal_coefficients[coefficient_group + k - n0];
+ output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient;
+ output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient;
+ }
+ }
+ break;
+
+ case 3:
+ for (x = 0; x < max_x; x++)
+ {
+ int n0 = horizontal_contributors[x].n0;
+ int n1 = horizontal_contributors[x].n1;
+
+ int in_x = x - filter_pixel_margin;
+ int in_pixel_index = in_x * 3;
+ int max_n = n1;
+ int coefficient_group = coefficient_width * x;
+
+ for (k = n0; k <= max_n; k++)
+ {
+ int out_pixel_index = k * 3;
+ float coefficient = horizontal_coefficients[coefficient_group + k - n0];
+ output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient;
+ output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient;
+ output_buffer[out_pixel_index + 2] += decode_buffer[in_pixel_index + 2] * coefficient;
+ }
+ }
+ break;
+
+ case 4:
+ for (x = 0; x < max_x; x++)
+ {
+ int n0 = horizontal_contributors[x].n0;
+ int n1 = horizontal_contributors[x].n1;
+
+ int in_x = x - filter_pixel_margin;
+ int in_pixel_index = in_x * 4;
+ int max_n = n1;
+ int coefficient_group = coefficient_width * x;
+
+ for (k = n0; k <= max_n; k++)
+ {
+ int out_pixel_index = k * 4;
+ float coefficient = horizontal_coefficients[coefficient_group + k - n0];
+ output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient;
+ output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient;
+ output_buffer[out_pixel_index + 2] += decode_buffer[in_pixel_index + 2] * coefficient;
+ output_buffer[out_pixel_index + 3] += decode_buffer[in_pixel_index + 3] * coefficient;
+ }
+ }
+ break;
+
+ default:
+ for (x = 0; x < max_x; x++)
+ {
+ int n0 = horizontal_contributors[x].n0;
+ int n1 = horizontal_contributors[x].n1;
+
+ int in_x = x - filter_pixel_margin;
+ int in_pixel_index = in_x * channels;
+ int max_n = n1;
+ int coefficient_group = coefficient_width * x;
+
+ for (k = n0; k <= max_n; k++)
+ {
+ int c;
+ int out_pixel_index = k * channels;
+ float coefficient = horizontal_coefficients[coefficient_group + k - n0];
+ for (c = 0; c < channels; c++)
+ output_buffer[out_pixel_index + c] += decode_buffer[in_pixel_index + c] * coefficient;
+ }
+ }
+ break;
+ }
+}
+
+static void stbir__decode_and_resample_upsample(stbir__info* stbir_info, int n)
+{
+ // Decode the nth scanline from the source image into the decode buffer.
+ stbir__decode_scanline(stbir_info, n);
+
+ // Now resample it into the ring buffer.
+ if (stbir__use_width_upsampling(stbir_info))
+ stbir__resample_horizontal_upsample(stbir_info, stbir__add_empty_ring_buffer_entry(stbir_info, n));
+ else
+ stbir__resample_horizontal_downsample(stbir_info, stbir__add_empty_ring_buffer_entry(stbir_info, n));
+
+ // Now it's sitting in the ring buffer ready to be used as source for the vertical sampling.
+}
+
+static void stbir__decode_and_resample_downsample(stbir__info* stbir_info, int n)
+{
+ // Decode the nth scanline from the source image into the decode buffer.
+ stbir__decode_scanline(stbir_info, n);
+
+ memset(stbir_info->horizontal_buffer, 0, stbir_info->output_w * stbir_info->channels * sizeof(float));
+
+ // Now resample it into the horizontal buffer.
+ if (stbir__use_width_upsampling(stbir_info))
+ stbir__resample_horizontal_upsample(stbir_info, stbir_info->horizontal_buffer);
+ else
+ stbir__resample_horizontal_downsample(stbir_info, stbir_info->horizontal_buffer);
+
+ // Now it's sitting in the horizontal buffer ready to be distributed into the ring buffers.
+}
+
+// Get the specified scan line from the ring buffer.
+static float* stbir__get_ring_buffer_scanline(int get_scanline, float* ring_buffer, int begin_index, int first_scanline, int ring_buffer_num_entries, int ring_buffer_length)
+{
+ int ring_buffer_index = (begin_index + (get_scanline - first_scanline)) % ring_buffer_num_entries;
+ return stbir__get_ring_buffer_entry(ring_buffer, ring_buffer_index, ring_buffer_length);
+}
+
+
+static void stbir__encode_scanline(stbir__info* stbir_info, int num_pixels, void *output_buffer, float *encode_buffer, int channels, int alpha_channel, int decode)
+{
+ int x;
+ int n;
+ int num_nonalpha;
+ stbir_uint16 nonalpha[STBIR_MAX_CHANNELS];
+
+ if (!(stbir_info->flags&STBIR_FLAG_ALPHA_PREMULTIPLIED))
+ {
+ for (x=0; x < num_pixels; ++x)
+ {
+ int pixel_index = x*channels;
+
+ float alpha = encode_buffer[pixel_index + alpha_channel];
+ float reciprocal_alpha = alpha ? 1.0f / alpha : 0;
+
+ // unrolling this produced a 1% slowdown upscaling a large RGBA linear-space image on my machine - stb
+ for (n = 0; n < channels; n++)
+ if (n != alpha_channel)
+ encode_buffer[pixel_index + n] *= reciprocal_alpha;
+
+ // We added in a small epsilon to prevent the color channel from being deleted with zero alpha.
+ // Because we only add it for integer types, it will automatically be discarded on integer
+ // conversion, so we don't need to subtract it back out (which would be problematic for
+ // numeric precision reasons).
+ }
+ }
+
+ // build a table of all channels that need colorspace correction, so
+ // we don't perform colorspace correction on channels that don't need it.
+ for (x = 0, num_nonalpha = 0; x < channels; ++x)
+ {
+ if (x != alpha_channel || (stbir_info->flags & STBIR_FLAG_ALPHA_USES_COLORSPACE))
+ {
+ nonalpha[num_nonalpha++] = (stbir_uint16)x;
+ }
+ }
+
+ #define STBIR__ROUND_INT(f) ((int) ((f)+0.5))
+ #define STBIR__ROUND_UINT(f) ((stbir_uint32) ((f)+0.5))
+
+ #ifdef STBIR__SATURATE_INT
+ #define STBIR__ENCODE_LINEAR8(f) stbir__saturate8 (STBIR__ROUND_INT((f) * stbir__max_uint8_as_float ))
+ #define STBIR__ENCODE_LINEAR16(f) stbir__saturate16(STBIR__ROUND_INT((f) * stbir__max_uint16_as_float))
+ #else
+ #define STBIR__ENCODE_LINEAR8(f) (unsigned char ) STBIR__ROUND_INT(stbir__saturate(f) * stbir__max_uint8_as_float )
+ #define STBIR__ENCODE_LINEAR16(f) (unsigned short) STBIR__ROUND_INT(stbir__saturate(f) * stbir__max_uint16_as_float)
+ #endif
+
+ switch (decode)
+ {
+ case STBIR__DECODE(STBIR_TYPE_UINT8, STBIR_COLORSPACE_LINEAR):
+ for (x=0; x < num_pixels; ++x)
+ {
+ int pixel_index = x*channels;
+
+ for (n = 0; n < channels; n++)
+ {
+ int index = pixel_index + n;
+ ((unsigned char*)output_buffer)[index] = STBIR__ENCODE_LINEAR8(encode_buffer[index]);
+ }
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_UINT8, STBIR_COLORSPACE_SRGB):
+ for (x=0; x < num_pixels; ++x)
+ {
+ int pixel_index = x*channels;
+
+ for (n = 0; n < num_nonalpha; n++)
+ {
+ int index = pixel_index + nonalpha[n];
+ ((unsigned char*)output_buffer)[index] = stbir__linear_to_srgb_uchar(encode_buffer[index]);
+ }
+
+ if (!(stbir_info->flags & STBIR_FLAG_ALPHA_USES_COLORSPACE))
+ ((unsigned char *)output_buffer)[pixel_index + alpha_channel] = STBIR__ENCODE_LINEAR8(encode_buffer[pixel_index+alpha_channel]);
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_UINT16, STBIR_COLORSPACE_LINEAR):
+ for (x=0; x < num_pixels; ++x)
+ {
+ int pixel_index = x*channels;
+
+ for (n = 0; n < channels; n++)
+ {
+ int index = pixel_index + n;
+ ((unsigned short*)output_buffer)[index] = STBIR__ENCODE_LINEAR16(encode_buffer[index]);
+ }
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_UINT16, STBIR_COLORSPACE_SRGB):
+ for (x=0; x < num_pixels; ++x)
+ {
+ int pixel_index = x*channels;
+
+ for (n = 0; n < num_nonalpha; n++)
+ {
+ int index = pixel_index + nonalpha[n];
+ ((unsigned short*)output_buffer)[index] = (unsigned short)STBIR__ROUND_INT(stbir__linear_to_srgb(stbir__saturate(encode_buffer[index])) * stbir__max_uint16_as_float);
+ }
+
+ if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
+ ((unsigned short*)output_buffer)[pixel_index + alpha_channel] = STBIR__ENCODE_LINEAR16(encode_buffer[pixel_index + alpha_channel]);
+ }
+
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_UINT32, STBIR_COLORSPACE_LINEAR):
+ for (x=0; x < num_pixels; ++x)
+ {
+ int pixel_index = x*channels;
+
+ for (n = 0; n < channels; n++)
+ {
+ int index = pixel_index + n;
+ ((unsigned int*)output_buffer)[index] = (unsigned int)STBIR__ROUND_UINT(((double)stbir__saturate(encode_buffer[index])) * stbir__max_uint32_as_float);
+ }
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_UINT32, STBIR_COLORSPACE_SRGB):
+ for (x=0; x < num_pixels; ++x)
+ {
+ int pixel_index = x*channels;
+
+ for (n = 0; n < num_nonalpha; n++)
+ {
+ int index = pixel_index + nonalpha[n];
+ ((unsigned int*)output_buffer)[index] = (unsigned int)STBIR__ROUND_UINT(((double)stbir__linear_to_srgb(stbir__saturate(encode_buffer[index]))) * stbir__max_uint32_as_float);
+ }
+
+ if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
+ ((unsigned int*)output_buffer)[pixel_index + alpha_channel] = (unsigned int)STBIR__ROUND_INT(((double)stbir__saturate(encode_buffer[pixel_index + alpha_channel])) * stbir__max_uint32_as_float);
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_FLOAT, STBIR_COLORSPACE_LINEAR):
+ for (x=0; x < num_pixels; ++x)
+ {
+ int pixel_index = x*channels;
+
+ for (n = 0; n < channels; n++)
+ {
+ int index = pixel_index + n;
+ ((float*)output_buffer)[index] = encode_buffer[index];
+ }
+ }
+ break;
+
+ case STBIR__DECODE(STBIR_TYPE_FLOAT, STBIR_COLORSPACE_SRGB):
+ for (x=0; x < num_pixels; ++x)
+ {
+ int pixel_index = x*channels;
+
+ for (n = 0; n < num_nonalpha; n++)
+ {
+ int index = pixel_index + nonalpha[n];
+ ((float*)output_buffer)[index] = stbir__linear_to_srgb(encode_buffer[index]);
+ }
+
+ if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
+ ((float*)output_buffer)[pixel_index + alpha_channel] = encode_buffer[pixel_index + alpha_channel];
+ }
+ break;
+
+ default:
+ STBIR_ASSERT(!"Unknown type/colorspace/channels combination.");
+ break;
+ }
+}
+
+static void stbir__resample_vertical_upsample(stbir__info* stbir_info, int n)
+{
+ int x, k;
+ int output_w = stbir_info->output_w;
+ stbir__contributors* vertical_contributors = stbir_info->vertical_contributors;
+ float* vertical_coefficients = stbir_info->vertical_coefficients;
+ int channels = stbir_info->channels;
+ int alpha_channel = stbir_info->alpha_channel;
+ int type = stbir_info->type;
+ int colorspace = stbir_info->colorspace;
+ int ring_buffer_entries = stbir_info->ring_buffer_num_entries;
+ void* output_data = stbir_info->output_data;
+ float* encode_buffer = stbir_info->encode_buffer;
+ int decode = STBIR__DECODE(type, colorspace);
+ int coefficient_width = stbir_info->vertical_coefficient_width;
+ int coefficient_counter;
+ int contributor = n;
+
+ float* ring_buffer = stbir_info->ring_buffer;
+ int ring_buffer_begin_index = stbir_info->ring_buffer_begin_index;
+ int ring_buffer_first_scanline = stbir_info->ring_buffer_first_scanline;
+ int ring_buffer_length = stbir_info->ring_buffer_length_bytes/sizeof(float);
+
+ int n0,n1, output_row_start;
+ int coefficient_group = coefficient_width * contributor;
+
+ n0 = vertical_contributors[contributor].n0;
+ n1 = vertical_contributors[contributor].n1;
+
+ output_row_start = n * stbir_info->output_stride_bytes;
+
+ STBIR_ASSERT(stbir__use_height_upsampling(stbir_info));
+
+ memset(encode_buffer, 0, output_w * sizeof(float) * channels);
+
+ // I tried reblocking this for better cache usage of encode_buffer
+ // (using x_outer, k, x_inner), but it lost speed. -- stb
+
+ coefficient_counter = 0;
+ switch (channels) {
+ case 1:
+ for (k = n0; k <= n1; k++)
+ {
+ int coefficient_index = coefficient_counter++;
+ float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length);
+ float coefficient = vertical_coefficients[coefficient_group + coefficient_index];
+ for (x = 0; x < output_w; ++x)
+ {
+ int in_pixel_index = x * 1;
+ encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient;
+ }
+ }
+ break;
+ case 2:
+ for (k = n0; k <= n1; k++)
+ {
+ int coefficient_index = coefficient_counter++;
+ float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length);
+ float coefficient = vertical_coefficients[coefficient_group + coefficient_index];
+ for (x = 0; x < output_w; ++x)
+ {
+ int in_pixel_index = x * 2;
+ encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient;
+ encode_buffer[in_pixel_index + 1] += ring_buffer_entry[in_pixel_index + 1] * coefficient;
+ }
+ }
+ break;
+ case 3:
+ for (k = n0; k <= n1; k++)
+ {
+ int coefficient_index = coefficient_counter++;
+ float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length);
+ float coefficient = vertical_coefficients[coefficient_group + coefficient_index];
+ for (x = 0; x < output_w; ++x)
+ {
+ int in_pixel_index = x * 3;
+ encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient;
+ encode_buffer[in_pixel_index + 1] += ring_buffer_entry[in_pixel_index + 1] * coefficient;
+ encode_buffer[in_pixel_index + 2] += ring_buffer_entry[in_pixel_index + 2] * coefficient;
+ }
+ }
+ break;
+ case 4:
+ for (k = n0; k <= n1; k++)
+ {
+ int coefficient_index = coefficient_counter++;
+ float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length);
+ float coefficient = vertical_coefficients[coefficient_group + coefficient_index];
+ for (x = 0; x < output_w; ++x)
+ {
+ int in_pixel_index = x * 4;
+ encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient;
+ encode_buffer[in_pixel_index + 1] += ring_buffer_entry[in_pixel_index + 1] * coefficient;
+ encode_buffer[in_pixel_index + 2] += ring_buffer_entry[in_pixel_index + 2] * coefficient;
+ encode_buffer[in_pixel_index + 3] += ring_buffer_entry[in_pixel_index + 3] * coefficient;
+ }
+ }
+ break;
+ default:
+ for (k = n0; k <= n1; k++)
+ {
+ int coefficient_index = coefficient_counter++;
+ float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length);
+ float coefficient = vertical_coefficients[coefficient_group + coefficient_index];
+ for (x = 0; x < output_w; ++x)
+ {
+ int in_pixel_index = x * channels;
+ int c;
+ for (c = 0; c < channels; c++)
+ encode_buffer[in_pixel_index + c] += ring_buffer_entry[in_pixel_index + c] * coefficient;
+ }
+ }
+ break;
+ }
+ stbir__encode_scanline(stbir_info, output_w, (char *) output_data + output_row_start, encode_buffer, channels, alpha_channel, decode);
+}
+
+static void stbir__resample_vertical_downsample(stbir__info* stbir_info, int n)
+{
+ int x, k;
+ int output_w = stbir_info->output_w;
+ stbir__contributors* vertical_contributors = stbir_info->vertical_contributors;
+ float* vertical_coefficients = stbir_info->vertical_coefficients;
+ int channels = stbir_info->channels;
+ int ring_buffer_entries = stbir_info->ring_buffer_num_entries;
+ float* horizontal_buffer = stbir_info->horizontal_buffer;
+ int coefficient_width = stbir_info->vertical_coefficient_width;
+ int contributor = n + stbir_info->vertical_filter_pixel_margin;
+
+ float* ring_buffer = stbir_info->ring_buffer;
+ int ring_buffer_begin_index = stbir_info->ring_buffer_begin_index;
+ int ring_buffer_first_scanline = stbir_info->ring_buffer_first_scanline;
+ int ring_buffer_length = stbir_info->ring_buffer_length_bytes/sizeof(float);
+ int n0,n1;
+
+ n0 = vertical_contributors[contributor].n0;
+ n1 = vertical_contributors[contributor].n1;
+
+ STBIR_ASSERT(!stbir__use_height_upsampling(stbir_info));
+
+ for (k = n0; k <= n1; k++)
+ {
+ int coefficient_index = k - n0;
+ int coefficient_group = coefficient_width * contributor;
+ float coefficient = vertical_coefficients[coefficient_group + coefficient_index];
+
+ float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length);
+
+ switch (channels) {
+ case 1:
+ for (x = 0; x < output_w; x++)
+ {
+ int in_pixel_index = x * 1;
+ ring_buffer_entry[in_pixel_index + 0] += horizontal_buffer[in_pixel_index + 0] * coefficient;
+ }
+ break;
+ case 2:
+ for (x = 0; x < output_w; x++)
+ {
+ int in_pixel_index = x * 2;
+ ring_buffer_entry[in_pixel_index + 0] += horizontal_buffer[in_pixel_index + 0] * coefficient;
+ ring_buffer_entry[in_pixel_index + 1] += horizontal_buffer[in_pixel_index + 1] * coefficient;
+ }
+ break;
+ case 3:
+ for (x = 0; x < output_w; x++)
+ {
+ int in_pixel_index = x * 3;
+ ring_buffer_entry[in_pixel_index + 0] += horizontal_buffer[in_pixel_index + 0] * coefficient;
+ ring_buffer_entry[in_pixel_index + 1] += horizontal_buffer[in_pixel_index + 1] * coefficient;
+ ring_buffer_entry[in_pixel_index + 2] += horizontal_buffer[in_pixel_index + 2] * coefficient;
+ }
+ break;
+ case 4:
+ for (x = 0; x < output_w; x++)
+ {
+ int in_pixel_index = x * 4;
+ ring_buffer_entry[in_pixel_index + 0] += horizontal_buffer[in_pixel_index + 0] * coefficient;
+ ring_buffer_entry[in_pixel_index + 1] += horizontal_buffer[in_pixel_index + 1] * coefficient;
+ ring_buffer_entry[in_pixel_index + 2] += horizontal_buffer[in_pixel_index + 2] * coefficient;
+ ring_buffer_entry[in_pixel_index + 3] += horizontal_buffer[in_pixel_index + 3] * coefficient;
+ }
+ break;
+ default:
+ for (x = 0; x < output_w; x++)
+ {
+ int in_pixel_index = x * channels;
+
+ int c;
+ for (c = 0; c < channels; c++)
+ ring_buffer_entry[in_pixel_index + c] += horizontal_buffer[in_pixel_index + c] * coefficient;
+ }
+ break;
+ }
+ }
+}
+
+static void stbir__buffer_loop_upsample(stbir__info* stbir_info)
+{
+ int y;
+ float scale_ratio = stbir_info->vertical_scale;
+ float out_scanlines_radius = stbir__filter_info_table[stbir_info->vertical_filter].support(1/scale_ratio) * scale_ratio;
+
+ STBIR_ASSERT(stbir__use_height_upsampling(stbir_info));
+
+ for (y = 0; y < stbir_info->output_h; y++)
+ {
+ float in_center_of_out = 0; // Center of the current out scanline in the in scanline space
+ int in_first_scanline = 0, in_last_scanline = 0;
+
+ stbir__calculate_sample_range_upsample(y, out_scanlines_radius, scale_ratio, stbir_info->vertical_shift, &in_first_scanline, &in_last_scanline, &in_center_of_out);
+
+ STBIR_ASSERT(in_last_scanline - in_first_scanline + 1 <= stbir_info->ring_buffer_num_entries);
+
+ if (stbir_info->ring_buffer_begin_index >= 0)
+ {
+ // Get rid of whatever we don't need anymore.
+ while (in_first_scanline > stbir_info->ring_buffer_first_scanline)
+ {
+ if (stbir_info->ring_buffer_first_scanline == stbir_info->ring_buffer_last_scanline)
+ {
+ // We just popped the last scanline off the ring buffer.
+ // Reset it to the empty state.
+ stbir_info->ring_buffer_begin_index = -1;
+ stbir_info->ring_buffer_first_scanline = 0;
+ stbir_info->ring_buffer_last_scanline = 0;
+ break;
+ }
+ else
+ {
+ stbir_info->ring_buffer_first_scanline++;
+ stbir_info->ring_buffer_begin_index = (stbir_info->ring_buffer_begin_index + 1) % stbir_info->ring_buffer_num_entries;
+ }
+ }
+ }
+
+ // Load in new ones.
+ if (stbir_info->ring_buffer_begin_index < 0)
+ stbir__decode_and_resample_upsample(stbir_info, in_first_scanline);
+
+ while (in_last_scanline > stbir_info->ring_buffer_last_scanline)
+ stbir__decode_and_resample_upsample(stbir_info, stbir_info->ring_buffer_last_scanline + 1);
+
+ // Now all buffers should be ready to write a row of vertical sampling.
+ stbir__resample_vertical_upsample(stbir_info, y);
+
+ STBIR_PROGRESS_REPORT((float)y / stbir_info->output_h);
+ }
+}
+
+static void stbir__empty_ring_buffer(stbir__info* stbir_info, int first_necessary_scanline)
+{
+ int output_stride_bytes = stbir_info->output_stride_bytes;
+ int channels = stbir_info->channels;
+ int alpha_channel = stbir_info->alpha_channel;
+ int type = stbir_info->type;
+ int colorspace = stbir_info->colorspace;
+ int output_w = stbir_info->output_w;
+ void* output_data = stbir_info->output_data;
+ int decode = STBIR__DECODE(type, colorspace);
+
+ float* ring_buffer = stbir_info->ring_buffer;
+ int ring_buffer_length = stbir_info->ring_buffer_length_bytes/sizeof(float);
+
+ if (stbir_info->ring_buffer_begin_index >= 0)
+ {
+ // Get rid of whatever we don't need anymore.
+ while (first_necessary_scanline > stbir_info->ring_buffer_first_scanline)
+ {
+ if (stbir_info->ring_buffer_first_scanline >= 0 && stbir_info->ring_buffer_first_scanline < stbir_info->output_h)
+ {
+ int output_row_start = stbir_info->ring_buffer_first_scanline * output_stride_bytes;
+ float* ring_buffer_entry = stbir__get_ring_buffer_entry(ring_buffer, stbir_info->ring_buffer_begin_index, ring_buffer_length);
+ stbir__encode_scanline(stbir_info, output_w, (char *) output_data + output_row_start, ring_buffer_entry, channels, alpha_channel, decode);
+ STBIR_PROGRESS_REPORT((float)stbir_info->ring_buffer_first_scanline / stbir_info->output_h);
+ }
+
+ if (stbir_info->ring_buffer_first_scanline == stbir_info->ring_buffer_last_scanline)
+ {
+ // We just popped the last scanline off the ring buffer.
+ // Reset it to the empty state.
+ stbir_info->ring_buffer_begin_index = -1;
+ stbir_info->ring_buffer_first_scanline = 0;
+ stbir_info->ring_buffer_last_scanline = 0;
+ break;
+ }
+ else
+ {
+ stbir_info->ring_buffer_first_scanline++;
+ stbir_info->ring_buffer_begin_index = (stbir_info->ring_buffer_begin_index + 1) % stbir_info->ring_buffer_num_entries;
+ }
+ }
+ }
+}
+
+static void stbir__buffer_loop_downsample(stbir__info* stbir_info)
+{
+ int y;
+ float scale_ratio = stbir_info->vertical_scale;
+ int output_h = stbir_info->output_h;
+ float in_pixels_radius = stbir__filter_info_table[stbir_info->vertical_filter].support(scale_ratio) / scale_ratio;
+ int pixel_margin = stbir_info->vertical_filter_pixel_margin;
+ int max_y = stbir_info->input_h + pixel_margin;
+
+ STBIR_ASSERT(!stbir__use_height_upsampling(stbir_info));
+
+ for (y = -pixel_margin; y < max_y; y++)
+ {
+ float out_center_of_in; // Center of the current out scanline in the in scanline space
+ int out_first_scanline, out_last_scanline;
+
+ stbir__calculate_sample_range_downsample(y, in_pixels_radius, scale_ratio, stbir_info->vertical_shift, &out_first_scanline, &out_last_scanline, &out_center_of_in);
+
+ STBIR_ASSERT(out_last_scanline - out_first_scanline + 1 <= stbir_info->ring_buffer_num_entries);
+
+ if (out_last_scanline < 0 || out_first_scanline >= output_h)
+ continue;
+
+ stbir__empty_ring_buffer(stbir_info, out_first_scanline);
+
+ stbir__decode_and_resample_downsample(stbir_info, y);
+
+ // Load in new ones.
+ if (stbir_info->ring_buffer_begin_index < 0)
+ stbir__add_empty_ring_buffer_entry(stbir_info, out_first_scanline);
+
+ while (out_last_scanline > stbir_info->ring_buffer_last_scanline)
+ stbir__add_empty_ring_buffer_entry(stbir_info, stbir_info->ring_buffer_last_scanline + 1);
+
+ // Now the horizontal buffer is ready to write to all ring buffer rows.
+ stbir__resample_vertical_downsample(stbir_info, y);
+ }
+
+ stbir__empty_ring_buffer(stbir_info, stbir_info->output_h);
+}
+
+static void stbir__setup(stbir__info *info, int input_w, int input_h, int output_w, int output_h, int channels)
+{
+ info->input_w = input_w;
+ info->input_h = input_h;
+ info->output_w = output_w;
+ info->output_h = output_h;
+ info->channels = channels;
+}
+
+static void stbir__calculate_transform(stbir__info *info, float s0, float t0, float s1, float t1, float *transform)
+{
+ info->s0 = s0;
+ info->t0 = t0;
+ info->s1 = s1;
+ info->t1 = t1;
+
+ if (transform)
+ {
+ info->horizontal_scale = transform[0];
+ info->vertical_scale = transform[1];
+ info->horizontal_shift = transform[2];
+ info->vertical_shift = transform[3];
+ }
+ else
+ {
+ info->horizontal_scale = ((float)info->output_w / info->input_w) / (s1 - s0);
+ info->vertical_scale = ((float)info->output_h / info->input_h) / (t1 - t0);
+
+ info->horizontal_shift = s0 * info->output_w / (s1 - s0);
+ info->vertical_shift = t0 * info->output_h / (t1 - t0);
+ }
+}
+
+static void stbir__choose_filter(stbir__info *info, stbir_filter h_filter, stbir_filter v_filter)
+{
+ if (h_filter == 0)
+ h_filter = stbir__use_upsampling(info->horizontal_scale) ? STBIR_DEFAULT_FILTER_UPSAMPLE : STBIR_DEFAULT_FILTER_DOWNSAMPLE;
+ if (v_filter == 0)
+ v_filter = stbir__use_upsampling(info->vertical_scale) ? STBIR_DEFAULT_FILTER_UPSAMPLE : STBIR_DEFAULT_FILTER_DOWNSAMPLE;
+ info->horizontal_filter = h_filter;
+ info->vertical_filter = v_filter;
+}
+
+static stbir_uint32 stbir__calculate_memory(stbir__info *info)
+{
+ int pixel_margin = stbir__get_filter_pixel_margin(info->horizontal_filter, info->horizontal_scale);
+ int filter_height = stbir__get_filter_pixel_width(info->vertical_filter, info->vertical_scale);
+
+ info->horizontal_num_contributors = stbir__get_contributors(info->horizontal_scale, info->horizontal_filter, info->input_w, info->output_w);
+ info->vertical_num_contributors = stbir__get_contributors(info->vertical_scale , info->vertical_filter , info->input_h, info->output_h);
+
+ // One extra entry because floating point precision problems sometimes cause an extra to be necessary.
+ info->ring_buffer_num_entries = filter_height + 1;
+
+ info->horizontal_contributors_size = info->horizontal_num_contributors * sizeof(stbir__contributors);
+ info->horizontal_coefficients_size = stbir__get_total_horizontal_coefficients(info) * sizeof(float);
+ info->vertical_contributors_size = info->vertical_num_contributors * sizeof(stbir__contributors);
+ info->vertical_coefficients_size = stbir__get_total_vertical_coefficients(info) * sizeof(float);
+ info->decode_buffer_size = (info->input_w + pixel_margin * 2) * info->channels * sizeof(float);
+ info->horizontal_buffer_size = info->output_w * info->channels * sizeof(float);
+ info->ring_buffer_size = info->output_w * info->channels * info->ring_buffer_num_entries * sizeof(float);
+ info->encode_buffer_size = info->output_w * info->channels * sizeof(float);
+
+ STBIR_ASSERT(info->horizontal_filter != 0);
+ STBIR_ASSERT(info->horizontal_filter < STBIR__ARRAY_SIZE(stbir__filter_info_table)); // this now happens too late
+ STBIR_ASSERT(info->vertical_filter != 0);
+ STBIR_ASSERT(info->vertical_filter < STBIR__ARRAY_SIZE(stbir__filter_info_table)); // this now happens too late
+
+ if (stbir__use_height_upsampling(info))
+ // The horizontal buffer is for when we're downsampling the height and we
+ // can't output the result of sampling the decode buffer directly into the
+ // ring buffers.
+ info->horizontal_buffer_size = 0;
+ else
+ // The encode buffer is to retain precision in the height upsampling method
+ // and isn't used when height downsampling.
+ info->encode_buffer_size = 0;
+
+ return info->horizontal_contributors_size + info->horizontal_coefficients_size
+ + info->vertical_contributors_size + info->vertical_coefficients_size
+ + info->decode_buffer_size + info->horizontal_buffer_size
+ + info->ring_buffer_size + info->encode_buffer_size;
+}
+
+static int stbir__resize_allocated(stbir__info *info,
+ const void* input_data, int input_stride_in_bytes,
+ void* output_data, int output_stride_in_bytes,
+ int alpha_channel, stbir_uint32 flags, stbir_datatype type,
+ stbir_edge edge_horizontal, stbir_edge edge_vertical, stbir_colorspace colorspace,
+ void* tempmem, size_t tempmem_size_in_bytes)
+{
+ size_t memory_required = stbir__calculate_memory(info);
+
+ int width_stride_input = input_stride_in_bytes ? input_stride_in_bytes : info->channels * info->input_w * stbir__type_size[type];
+ int width_stride_output = output_stride_in_bytes ? output_stride_in_bytes : info->channels * info->output_w * stbir__type_size[type];
+
+#ifdef STBIR_DEBUG_OVERWRITE_TEST
+#define OVERWRITE_ARRAY_SIZE 8
+ unsigned char overwrite_output_before_pre[OVERWRITE_ARRAY_SIZE];
+ unsigned char overwrite_tempmem_before_pre[OVERWRITE_ARRAY_SIZE];
+ unsigned char overwrite_output_after_pre[OVERWRITE_ARRAY_SIZE];
+ unsigned char overwrite_tempmem_after_pre[OVERWRITE_ARRAY_SIZE];
+
+ size_t begin_forbidden = width_stride_output * (info->output_h - 1) + info->output_w * info->channels * stbir__type_size[type];
+ memcpy(overwrite_output_before_pre, &((unsigned char*)output_data)[-OVERWRITE_ARRAY_SIZE], OVERWRITE_ARRAY_SIZE);
+ memcpy(overwrite_output_after_pre, &((unsigned char*)output_data)[begin_forbidden], OVERWRITE_ARRAY_SIZE);
+ memcpy(overwrite_tempmem_before_pre, &((unsigned char*)tempmem)[-OVERWRITE_ARRAY_SIZE], OVERWRITE_ARRAY_SIZE);
+ memcpy(overwrite_tempmem_after_pre, &((unsigned char*)tempmem)[tempmem_size_in_bytes], OVERWRITE_ARRAY_SIZE);
+#endif
+
+ STBIR_ASSERT(info->channels >= 0);
+ STBIR_ASSERT(info->channels <= STBIR_MAX_CHANNELS);
+
+ if (info->channels < 0 || info->channels > STBIR_MAX_CHANNELS)
+ return 0;
+
+ STBIR_ASSERT(info->horizontal_filter < STBIR__ARRAY_SIZE(stbir__filter_info_table));
+ STBIR_ASSERT(info->vertical_filter < STBIR__ARRAY_SIZE(stbir__filter_info_table));
+
+ if (info->horizontal_filter >= STBIR__ARRAY_SIZE(stbir__filter_info_table))
+ return 0;
+ if (info->vertical_filter >= STBIR__ARRAY_SIZE(stbir__filter_info_table))
+ return 0;
+
+ if (alpha_channel < 0)
+ flags |= STBIR_FLAG_ALPHA_USES_COLORSPACE | STBIR_FLAG_ALPHA_PREMULTIPLIED;
+
+ if (!(flags&STBIR_FLAG_ALPHA_USES_COLORSPACE) || !(flags&STBIR_FLAG_ALPHA_PREMULTIPLIED)) {
+ STBIR_ASSERT(alpha_channel >= 0 && alpha_channel < info->channels);
+ }
+
+ if (alpha_channel >= info->channels)
+ return 0;
+
+ STBIR_ASSERT(tempmem);
+
+ if (!tempmem)
+ return 0;
+
+ STBIR_ASSERT(tempmem_size_in_bytes >= memory_required);
+
+ if (tempmem_size_in_bytes < memory_required)
+ return 0;
+
+ memset(tempmem, 0, tempmem_size_in_bytes);
+
+ info->input_data = input_data;
+ info->input_stride_bytes = width_stride_input;
+
+ info->output_data = output_data;
+ info->output_stride_bytes = width_stride_output;
+
+ info->alpha_channel = alpha_channel;
+ info->flags = flags;
+ info->type = type;
+ info->edge_horizontal = edge_horizontal;
+ info->edge_vertical = edge_vertical;
+ info->colorspace = colorspace;
+
+ info->horizontal_coefficient_width = stbir__get_coefficient_width (info->horizontal_filter, info->horizontal_scale);
+ info->vertical_coefficient_width = stbir__get_coefficient_width (info->vertical_filter , info->vertical_scale );
+ info->horizontal_filter_pixel_width = stbir__get_filter_pixel_width (info->horizontal_filter, info->horizontal_scale);
+ info->vertical_filter_pixel_width = stbir__get_filter_pixel_width (info->vertical_filter , info->vertical_scale );
+ info->horizontal_filter_pixel_margin = stbir__get_filter_pixel_margin(info->horizontal_filter, info->horizontal_scale);
+ info->vertical_filter_pixel_margin = stbir__get_filter_pixel_margin(info->vertical_filter , info->vertical_scale );
+
+ info->ring_buffer_length_bytes = info->output_w * info->channels * sizeof(float);
+ info->decode_buffer_pixels = info->input_w + info->horizontal_filter_pixel_margin * 2;
+
+#define STBIR__NEXT_MEMPTR(current, newtype) (newtype*)(((unsigned char*)current) + current##_size)
+
+ info->horizontal_contributors = (stbir__contributors *) tempmem;
+ info->horizontal_coefficients = STBIR__NEXT_MEMPTR(info->horizontal_contributors, float);
+ info->vertical_contributors = STBIR__NEXT_MEMPTR(info->horizontal_coefficients, stbir__contributors);
+ info->vertical_coefficients = STBIR__NEXT_MEMPTR(info->vertical_contributors, float);
+ info->decode_buffer = STBIR__NEXT_MEMPTR(info->vertical_coefficients, float);
+
+ if (stbir__use_height_upsampling(info))
+ {
+ info->horizontal_buffer = NULL;
+ info->ring_buffer = STBIR__NEXT_MEMPTR(info->decode_buffer, float);
+ info->encode_buffer = STBIR__NEXT_MEMPTR(info->ring_buffer, float);
+
+ STBIR_ASSERT((size_t)STBIR__NEXT_MEMPTR(info->encode_buffer, unsigned char) == (size_t)tempmem + tempmem_size_in_bytes);
+ }
+ else
+ {
+ info->horizontal_buffer = STBIR__NEXT_MEMPTR(info->decode_buffer, float);
+ info->ring_buffer = STBIR__NEXT_MEMPTR(info->horizontal_buffer, float);
+ info->encode_buffer = NULL;
+
+ STBIR_ASSERT((size_t)STBIR__NEXT_MEMPTR(info->ring_buffer, unsigned char) == (size_t)tempmem + tempmem_size_in_bytes);
+ }
+
+#undef STBIR__NEXT_MEMPTR
+
+ // This signals that the ring buffer is empty
+ info->ring_buffer_begin_index = -1;
+
+ stbir__calculate_filters(info->horizontal_contributors, info->horizontal_coefficients, info->horizontal_filter, info->horizontal_scale, info->horizontal_shift, info->input_w, info->output_w);
+ stbir__calculate_filters(info->vertical_contributors, info->vertical_coefficients, info->vertical_filter, info->vertical_scale, info->vertical_shift, info->input_h, info->output_h);
+
+ STBIR_PROGRESS_REPORT(0);
+
+ if (stbir__use_height_upsampling(info))
+ stbir__buffer_loop_upsample(info);
+ else
+ stbir__buffer_loop_downsample(info);
+
+ STBIR_PROGRESS_REPORT(1);
+
+#ifdef STBIR_DEBUG_OVERWRITE_TEST
+ STBIR_ASSERT(memcmp(overwrite_output_before_pre, &((unsigned char*)output_data)[-OVERWRITE_ARRAY_SIZE], OVERWRITE_ARRAY_SIZE) == 0);
+ STBIR_ASSERT(memcmp(overwrite_output_after_pre, &((unsigned char*)output_data)[begin_forbidden], OVERWRITE_ARRAY_SIZE) == 0);
+ STBIR_ASSERT(memcmp(overwrite_tempmem_before_pre, &((unsigned char*)tempmem)[-OVERWRITE_ARRAY_SIZE], OVERWRITE_ARRAY_SIZE) == 0);
+ STBIR_ASSERT(memcmp(overwrite_tempmem_after_pre, &((unsigned char*)tempmem)[tempmem_size_in_bytes], OVERWRITE_ARRAY_SIZE) == 0);
+#endif
+
+ return 1;
+}
+
+
+static int stbir__resize_arbitrary(
+ void *alloc_context,
+ const void* input_data, int input_w, int input_h, int input_stride_in_bytes,
+ void* output_data, int output_w, int output_h, int output_stride_in_bytes,
+ float s0, float t0, float s1, float t1, float *transform,
+ int channels, int alpha_channel, stbir_uint32 flags, stbir_datatype type,
+ stbir_filter h_filter, stbir_filter v_filter,
+ stbir_edge edge_horizontal, stbir_edge edge_vertical, stbir_colorspace colorspace)
+{
+ stbir__info info;
+ int result;
+ size_t memory_required;
+ void* extra_memory;
+
+ stbir__setup(&info, input_w, input_h, output_w, output_h, channels);
+ stbir__calculate_transform(&info, s0,t0,s1,t1,transform);
+ stbir__choose_filter(&info, h_filter, v_filter);
+ memory_required = stbir__calculate_memory(&info);
+ extra_memory = STBIR_MALLOC(memory_required, alloc_context);
+
+ if (!extra_memory)
+ return 0;
+
+ result = stbir__resize_allocated(&info, input_data, input_stride_in_bytes,
+ output_data, output_stride_in_bytes,
+ alpha_channel, flags, type,
+ edge_horizontal, edge_vertical,
+ colorspace, extra_memory, memory_required);
+
+ STBIR_FREE(extra_memory, alloc_context);
+
+ return result;
+}
+
+STBIRDEF int stbir_resize_uint8( const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels)
+{
+ return stbir__resize_arbitrary(NULL, input_pixels, input_w, input_h, input_stride_in_bytes,
+ output_pixels, output_w, output_h, output_stride_in_bytes,
+ 0,0,1,1,NULL,num_channels,-1,0, STBIR_TYPE_UINT8, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT,
+ STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_LINEAR);
+}
+
+STBIRDEF int stbir_resize_float( const float *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ float *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels)
+{
+ return stbir__resize_arbitrary(NULL, input_pixels, input_w, input_h, input_stride_in_bytes,
+ output_pixels, output_w, output_h, output_stride_in_bytes,
+ 0,0,1,1,NULL,num_channels,-1,0, STBIR_TYPE_FLOAT, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT,
+ STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_LINEAR);
+}
+
+STBIRDEF int stbir_resize_uint8_srgb(const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels, int alpha_channel, int flags)
+{
+ return stbir__resize_arbitrary(NULL, input_pixels, input_w, input_h, input_stride_in_bytes,
+ output_pixels, output_w, output_h, output_stride_in_bytes,
+ 0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_UINT8, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT,
+ STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB);
+}
+
+STBIRDEF int stbir_resize_uint8_srgb_edgemode(const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_wrap_mode)
+{
+ return stbir__resize_arbitrary(NULL, input_pixels, input_w, input_h, input_stride_in_bytes,
+ output_pixels, output_w, output_h, output_stride_in_bytes,
+ 0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_UINT8, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT,
+ edge_wrap_mode, edge_wrap_mode, STBIR_COLORSPACE_SRGB);
+}
+
+STBIRDEF int stbir_resize_uint8_generic( const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space,
+ void *alloc_context)
+{
+ return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes,
+ output_pixels, output_w, output_h, output_stride_in_bytes,
+ 0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_UINT8, filter, filter,
+ edge_wrap_mode, edge_wrap_mode, space);
+}
+
+STBIRDEF int stbir_resize_uint16_generic(const stbir_uint16 *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ stbir_uint16 *output_pixels , int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space,
+ void *alloc_context)
+{
+ return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes,
+ output_pixels, output_w, output_h, output_stride_in_bytes,
+ 0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_UINT16, filter, filter,
+ edge_wrap_mode, edge_wrap_mode, space);
+}
+
+
+STBIRDEF int stbir_resize_float_generic( const float *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ float *output_pixels , int output_w, int output_h, int output_stride_in_bytes,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space,
+ void *alloc_context)
+{
+ return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes,
+ output_pixels, output_w, output_h, output_stride_in_bytes,
+ 0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_FLOAT, filter, filter,
+ edge_wrap_mode, edge_wrap_mode, space);
+}
+
+
+STBIRDEF int stbir_resize( const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ void *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ stbir_datatype datatype,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical,
+ stbir_filter filter_horizontal, stbir_filter filter_vertical,
+ stbir_colorspace space, void *alloc_context)
+{
+ return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes,
+ output_pixels, output_w, output_h, output_stride_in_bytes,
+ 0,0,1,1,NULL,num_channels,alpha_channel,flags, datatype, filter_horizontal, filter_vertical,
+ edge_mode_horizontal, edge_mode_vertical, space);
+}
+
+
+STBIRDEF int stbir_resize_subpixel(const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ void *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ stbir_datatype datatype,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical,
+ stbir_filter filter_horizontal, stbir_filter filter_vertical,
+ stbir_colorspace space, void *alloc_context,
+ float x_scale, float y_scale,
+ float x_offset, float y_offset)
+{
+ float transform[4];
+ transform[0] = x_scale;
+ transform[1] = y_scale;
+ transform[2] = x_offset;
+ transform[3] = y_offset;
+ return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes,
+ output_pixels, output_w, output_h, output_stride_in_bytes,
+ 0,0,1,1,transform,num_channels,alpha_channel,flags, datatype, filter_horizontal, filter_vertical,
+ edge_mode_horizontal, edge_mode_vertical, space);
+}
+
+STBIRDEF int stbir_resize_region( const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
+ void *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
+ stbir_datatype datatype,
+ int num_channels, int alpha_channel, int flags,
+ stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical,
+ stbir_filter filter_horizontal, stbir_filter filter_vertical,
+ stbir_colorspace space, void *alloc_context,
+ float s0, float t0, float s1, float t1)
+{
+ return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes,
+ output_pixels, output_w, output_h, output_stride_in_bytes,
+ s0,t0,s1,t1,NULL,num_channels,alpha_channel,flags, datatype, filter_horizontal, filter_vertical,
+ edge_mode_horizontal, edge_mode_vertical, space);
+}
+
+#endif // STB_IMAGE_RESIZE_IMPLEMENTATION
+
+/*
+------------------------------------------------------------------------------
+This software is available under 2 licenses -- choose whichever you prefer.
+------------------------------------------------------------------------------
+ALTERNATIVE A - MIT License
+Copyright (c) 2017 Sean Barrett
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+------------------------------------------------------------------------------
+ALTERNATIVE B - Public Domain (www.unlicense.org)
+This is free and unencumbered software released into the public domain.
+Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
+software, either in source code form or as a compiled binary, for any purpose,
+commercial or non-commercial, and by any means.
+In jurisdictions that recognize copyright laws, the author or authors of this
+software dedicate any and all copyright interest in the software to the public
+domain. We make this dedication for the benefit of the public at large and to
+the detriment of our heirs and successors. We intend this dedication to be an
+overt act of relinquishment in perpetuity of all present and future rights to
+this software under copyright law.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+------------------------------------------------------------------------------
+*/
