r371 - trunk
DONOTREPLY at icculus.org
DONOTREPLY at icculus.org
Fri Nov 23 22:50:03 EST 2007
Author: icculus
Date: 2007-11-23 22:50:02 -0500 (Fri, 23 Nov 2007)
New Revision: 371
Added:
trunk/stb_image.c
Log:
Hey, look, image decoding code!
Added: trunk/stb_image.c
===================================================================
--- trunk/stb_image.c (rev 0)
+++ trunk/stb_image.c 2007-11-24 03:50:02 UTC (rev 371)
@@ -0,0 +1,3629 @@
+/* stbi-1.08 - public domain JPEG/PNG reader - http://nothings.org/stb_image.c
+ when you control the images you're loading
+
+ QUICK NOTES:
+ Primarily of interest to game developers and other people who can
+ avoid problematic images and only need the trivial interface
+
+ JPEG baseline (no JPEG progressive, no oddball channel decimations)
+ PNG non-interlaced
+ BMP non-1bpp, non-RLE
+ TGA (not sure what subset, if a subset)
+ PSD (composite view only, no extra channels)
+ HDR (radiance rgbE format)
+ writes BMP,TGA (define STBI_NO_WRITE to remove code)
+ decoded from memory or through stdio FILE (define STBI_NO_STDIO to remove code)
+
+ TODO:
+ stbi_info_*
+
+ history:
+ 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 at 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
+*/
+
+
+//// begin header file ////////////////////////////////////////////////////
+//
+// Limitations:
+// - no progressive/interlaced support (jpeg, png)
+// - 8-bit samples only (jpeg, png)
+// - not threadsafe
+// - channel subsampling of at most 2 in each dimension (jpeg)
+// - no delayed line count (jpeg) -- IJG doesn't support either
+//
+// Basic usage (see HDR discussion below):
+// 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
+// stbi_image_free(data)
+//
+// Standard parameters:
+// int *x -- outputs image width in pixels
+// int *y -- outputs image height in pixels
+// int *comp -- outputs # of image components in image file
+// int req_comp -- 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. 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 'req_comp' if req_comp is non-zero, or *comp otherwise.
+// If req_comp is non-zero, *comp has the number of components that _would_
+// have been output otherwise. E.g. if you set req_comp to 4, you will always
+// get RGBA output, but you can check *comp to easily see if it's opaque.
+//
+// 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, *comp 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 and BMP images are automatically depalettized.
+//
+//
+// ===========================================================================
+//
+// HDR image support (disable by defining STBI_NO_HDR)
+//
+// stb_image now supports loading HDR images in general, and currently
+// the Radiance .HDR file format, although the support is provided
+// generically. 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);
+
+
+#ifndef STBI_NO_STDIO
+#include <stdio.h>
+#endif
+
+#ifndef STBI_NO_HDR
+#include <math.h> // ldexp
+#include <string.h> // strcmp
+#endif
+
+enum
+{
+ STBI_default = 0, // only used for req_comp
+
+ STBI_grey = 1,
+ STBI_grey_alpha = 2,
+ STBI_rgb = 3,
+ STBI_rgb_alpha = 4,
+};
+
+typedef unsigned char stbi_uc;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// WRITING API
+
+#if !defined(STBI_NO_WRITE) && !defined(STBI_NO_STDIO)
+// write a BMP/TGA file given tightly packed 'comp' channels (no padding, nor bmp-stride-padding)
+// (you must include the appropriate extension in the filename).
+// returns TRUE on success, FALSE if couldn't open file, error writing file
+extern int stbi_write_bmp (char *filename, int x, int y, int comp, void *data);
+extern int stbi_write_tga (char *filename, int x, int y, int comp, void *data);
+#endif
+
+// PRIMARY API - works on images of any type
+
+// load image by filename, open file, or memory buffer
+#ifndef STBI_NO_STDIO
+extern stbi_uc *stbi_load (char *filename, int *x, int *y, int *comp, int req_comp);
+extern stbi_uc *stbi_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
+extern int stbi_info_from_file (FILE *f, int *x, int *y, int *comp);
+#endif
+extern stbi_uc *stbi_load_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp);
+// for stbi_load_from_file, file pointer is left pointing immediately after image
+
+#ifndef STBI_NO_HDR
+#ifndef STBI_NO_STDIO
+extern float *stbi_loadf (char *filename, int *x, int *y, int *comp, int req_comp);
+extern float *stbi_loadf_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
+#endif
+extern float *stbi_loadf_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp);
+
+extern void stbi_hdr_to_ldr_gamma(float gamma);
+extern void stbi_hdr_to_ldr_scale(float scale);
+
+extern void stbi_ldr_to_hdr_gamma(float gamma);
+extern void stbi_ldr_to_hdr_scale(float scale);
+
+#endif // STBI_NO_HDR
+
+// get a VERY brief reason for failure
+extern char *stbi_failure_reason (void);
+
+// free the loaded image -- this is just free()
+extern void stbi_image_free (void *retval_from_stbi_load);
+
+// get image dimensions & components without fully decoding
+extern int stbi_info_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp);
+extern int stbi_is_hdr_from_memory(stbi_uc *buffer, int len);
+#ifndef STBI_NO_STDIO
+extern int stbi_info (char *filename, int *x, int *y, int *comp);
+extern int stbi_is_hdr (char *filename);
+extern int stbi_is_hdr_from_file(FILE *f);
+#endif
+
+// ZLIB client - used by PNG, available for other purposes
+
+extern char *stbi_zlib_decode_malloc_guesssize(int initial_size, int *outlen);
+extern char *stbi_zlib_decode_malloc(char *buffer, int len, int *outlen);
+extern int stbi_zlib_decode_buffer(char *obuffer, int olen, char *ibuffer, int ilen);
+
+extern char *stbi_zlib_decode_noheader_malloc(char *buffer, int len, int *outlen);
+extern int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, char *ibuffer, int ilen);
+
+
+// TYPE-SPECIFIC ACCESS
+
+// is it a jpeg?
+extern int stbi_jpeg_test_memory (stbi_uc *buffer, int len);
+extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp);
+extern int stbi_jpeg_info_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp);
+
+#ifndef STBI_NO_STDIO
+extern stbi_uc *stbi_jpeg_load (char *filename, int *x, int *y, int *comp, int req_comp);
+extern int stbi_jpeg_test_file (FILE *f);
+extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
+
+extern int stbi_jpeg_info (char *filename, int *x, int *y, int *comp);
+extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp);
+#endif
+
+extern int stbi_jpeg_dc_only; // only decode DC component
+
+// is it a png?
+extern int stbi_png_test_memory (stbi_uc *buffer, int len);
+extern stbi_uc *stbi_png_load_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp);
+extern int stbi_png_info_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp);
+
+#ifndef STBI_NO_STDIO
+extern stbi_uc *stbi_png_load (char *filename, int *x, int *y, int *comp, int req_comp);
+extern int stbi_png_info (char *filename, int *x, int *y, int *comp);
+extern int stbi_png_test_file (FILE *f);
+extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
+extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp);
+#endif
+
+// is it a bmp?
+extern int stbi_bmp_test_memory (stbi_uc *buffer, int len);
+
+extern stbi_uc *stbi_bmp_load (char *filename, int *x, int *y, int *comp, int req_comp);
+extern stbi_uc *stbi_bmp_load_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp);
+#ifndef STBI_NO_STDIO
+extern int stbi_bmp_test_file (FILE *f);
+extern stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
+#endif
+
+// is it a tga?
+extern int stbi_tga_test_memory (stbi_uc *buffer, int len);
+
+extern stbi_uc *stbi_tga_load (char *filename, int *x, int *y, int *comp, int req_comp);
+extern stbi_uc *stbi_tga_load_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp);
+#ifndef STBI_NO_STDIO
+extern int stbi_tga_test_file (FILE *f);
+extern stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
+#endif
+
+// is it a psd?
+extern int stbi_psd_test_memory (stbi_uc *buffer, int len);
+
+extern stbi_uc *stbi_psd_load (char *filename, int *x, int *y, int *comp, int req_comp);
+extern stbi_uc *stbi_psd_load_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp);
+#ifndef STBI_NO_STDIO
+extern int stbi_psd_test_file (FILE *f);
+extern stbi_uc *stbi_psd_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
+#endif
+
+// is it an hdr?
+extern int stbi_hdr_test_memory (stbi_uc *buffer, int len);
+
+extern float * stbi_hdr_load (char *filename, int *x, int *y, int *comp, int req_comp);
+extern float * stbi_hdr_load_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp);
+#ifndef STBI_NO_STDIO
+extern int stbi_hdr_test_file (FILE *f);
+extern float * stbi_hdr_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
+#endif
+
+// define new loaders
+typedef struct
+{
+ int (*test_memory)(stbi_uc *buffer, int len);
+ stbi_uc * (*load_from_memory)(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp);
+ #ifndef STBI_NO_STDIO
+ int (*test_file)(FILE *f);
+ stbi_uc * (*load_from_file)(FILE *f, int *x, int *y, int *comp, int req_comp);
+ #endif
+} stbi_loader;
+
+// register a loader by filling out the above structure (you must defined ALL functions)
+// returns 1 if added or already added, 0 if not added (too many loaders)
+extern int stbi_register_loader(stbi_loader *loader);
+
+#ifdef __cplusplus
+}
+#endif
+
+//
+//
+//// end header file /////////////////////////////////////////////////////
+
+#ifndef STBI_NO_STDIO
+#include <stdio.h>
+#endif
+#include <stdlib.h>
+#include <memory.h>
+#include <assert.h>
+#include <stdarg.h>
+
+#ifndef _MSC_VER
+#define __forceinline
+#endif
+
+// implementation:
+typedef unsigned char uint8;
+typedef unsigned short uint16;
+typedef signed short int16;
+typedef unsigned int uint32;
+typedef signed int int32;
+typedef unsigned int uint;
+
+// should produce compiler error if size is wrong
+typedef unsigned char validate_uint32[sizeof(uint32)==4];
+
+#if defined(STBI_NO_STDIO) && !defined(STBI_NO_WRITE)
+#define STBI_NO_WRITE
+#endif
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// Generic API that works on all image types
+//
+
+static char *failure_reason;
+
+char *stbi_failure_reason(void)
+{
+ return failure_reason;
+}
+
+static int e(char *str)
+{
+ failure_reason = str;
+ return 0;
+}
+
+#ifdef STBI_NO_FAILURE_STRINGS
+ #define e(x,y) 0
+#elif defined(STBI_FAILURE_USERMSG)
+ #define e(x,y) e(y)
+#else
+ #define e(x,y) e(x)
+#endif
+
+#define epf(x,y) ((float *) (e(x,y)?NULL:NULL))
+#define epuc(x,y) ((unsigned char *) (e(x,y)?NULL:NULL))
+
+void stbi_image_free(void *retval_from_stbi_load)
+{
+ free(retval_from_stbi_load);
+}
+
+#define MAX_LOADERS 32
+stbi_loader *loaders[MAX_LOADERS];
+static int max_loaders = 0;
+
+int stbi_register_loader(stbi_loader *loader)
+{
+ int i;
+ for (i=0; i < MAX_LOADERS; ++i) {
+ // already present?
+ if (loaders[i] == loader)
+ return 1;
+ // end of the list?
+ if (loaders[i] == NULL) {
+ loaders[i] = loader;
+ max_loaders = i+1;
+ return 1;
+ }
+ }
+ // no room for it
+ return 0;
+}
+
+#ifndef STBI_NO_HDR
+static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp);
+static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp);
+#endif
+
+#ifndef STBI_NO_STDIO
+unsigned char *stbi_load(char *filename, int *x, int *y, int *comp, int req_comp)
+{
+ FILE *f = fopen(filename, "rb");
+ unsigned char *result;
+ if (!f) return epuc("can't fopen", "Unable to open file");
+ result = stbi_load_from_file(f,x,y,comp,req_comp);
+ fclose(f);
+ return result;
+}
+
+unsigned char *stbi_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
+{
+ int i;
+ if (stbi_jpeg_test_file(f))
+ return stbi_jpeg_load_from_file(f,x,y,comp,req_comp);
+ if (stbi_png_test_file(f))
+ return stbi_png_load_from_file(f,x,y,comp,req_comp);
+ if (stbi_bmp_test_file(f))
+ return stbi_bmp_load_from_file(f,x,y,comp,req_comp);
+ if (stbi_psd_test_file(f))
+ return stbi_psd_load_from_file(f,x,y,comp,req_comp);
+ #ifndef STBI_NO_HDR
+ if (stbi_hdr_test_file(f)) {
+ float *hdr = stbi_hdr_load_from_file(f, x,y,comp,req_comp);
+ return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp);
+ }
+ #endif
+ for (i=0; i < max_loaders; ++i)
+ if (loaders[i]->test_file(f))
+ return loaders[i]->load_from_file(f,x,y,comp,req_comp);
+ // test tga last because it's a crappy test!
+ if (stbi_tga_test_file(f))
+ return stbi_tga_load_from_file(f,x,y,comp,req_comp);
+ return epuc("unknown image type", "Image not of any known type, or corrupt");
+}
+#endif
+
+unsigned char *stbi_load_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ int i;
+ if (stbi_jpeg_test_memory(buffer,len))
+ return stbi_jpeg_load_from_memory(buffer,len,x,y,comp,req_comp);
+ if (stbi_png_test_memory(buffer,len))
+ return stbi_png_load_from_memory(buffer,len,x,y,comp,req_comp);
+ if (stbi_bmp_test_memory(buffer,len))
+ return stbi_bmp_load_from_memory(buffer,len,x,y,comp,req_comp);
+ if (stbi_psd_test_memory(buffer,len))
+ return stbi_psd_load_from_memory(buffer,len,x,y,comp,req_comp);
+ #ifndef STBI_NO_HDR
+ if (stbi_hdr_test_memory(buffer, len)) {
+ float *hdr = stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp);
+ return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp);
+ }
+ #endif
+ for (i=0; i < max_loaders; ++i)
+ if (loaders[i]->test_memory(buffer,len))
+ return loaders[i]->load_from_memory(buffer,len,x,y,comp,req_comp);
+ // test tga last because it's a crappy test!
+ if (stbi_tga_test_memory(buffer,len))
+ return stbi_tga_load_from_memory(buffer,len,x,y,comp,req_comp);
+ return epuc("unknown image type", "Image not of any known type, or corrupt");
+}
+
+#ifndef STBI_NO_HDR
+
+#ifndef STBI_NO_STDIO
+float *stbi_loadf(char *filename, int *x, int *y, int *comp, int req_comp)
+{
+ FILE *f = fopen(filename, "rb");
+ float *result;
+ if (!f) return epf("can't fopen", "Unable to open file");
+ result = stbi_loadf_from_file(f,x,y,comp,req_comp);
+ fclose(f);
+ return result;
+}
+
+float *stbi_loadf_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
+{
+ unsigned char *data;
+ #ifndef STBI_NO_HDR
+ if (stbi_hdr_test_file(f))
+ return stbi_hdr_load_from_file(f,x,y,comp,req_comp);
+ #endif
+ data = stbi_load_from_file(f, x, y, comp, req_comp);
+ if (data)
+ return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp);
+ return epf("unknown image type", "Image not of any known type, or corrupt");
+}
+#endif
+
+float *stbi_loadf_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ stbi_uc *data;
+ #ifndef STBI_NO_HDR
+ if (stbi_hdr_test_memory(buffer, len))
+ return stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp);
+ #endif
+ data = stbi_load_from_memory(buffer, len, x, y, comp, req_comp);
+ if (data)
+ return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp);
+ return epf("unknown image type", "Image not of any known type, or corrupt");
+}
+#endif
+
+// these is-hdr-or-not is defined independent of whether STBI_NO_HDR is
+// defined, for API simplicity; if STBI_NO_HDR is defined, it always
+// reports false!
+
+extern int stbi_is_hdr_from_memory(stbi_uc *buffer, int len)
+{
+ #ifndef STBI_NO_HDR
+ return stbi_hdr_test_memory(buffer, len);
+ #else
+ return 0;
+ #endif
+}
+
+#ifndef STBI_NO_STDIO
+extern int stbi_is_hdr (char *filename)
+{
+ FILE *f = fopen(filename, "rb");
+ int result=0;
+ if (f) {
+ result = stbi_is_hdr_from_file(f);
+ fclose(f);
+ }
+ return result;
+}
+
+extern int stbi_is_hdr_from_file(FILE *f)
+{
+ #ifndef STBI_NO_HDR
+ return stbi_hdr_test_file(f);
+ #else
+ return 0;
+ #endif
+}
+
+#endif
+
+// @TODO: get image dimensions & components without fully decoding
+#ifndef STBI_NO_STDIO
+extern int stbi_info (char *filename, int *x, int *y, int *comp);
+extern int stbi_info_from_file (FILE *f, int *x, int *y, int *comp);
+#endif
+extern int stbi_info_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp);
+
+#ifndef STBI_NO_HDR
+static float h2l_gamma_i=1.0f/2.2f, h2l_scale_i=1.0f;
+static float l2h_gamma=2.2f, l2h_scale=1.0f;
+
+void stbi_hdr_to_ldr_gamma(float gamma) { h2l_gamma_i = 1/gamma; }
+void stbi_hdr_to_ldr_scale(float scale) { h2l_scale_i = 1/scale; }
+
+void stbi_ldr_to_hdr_gamma(float gamma) { l2h_gamma = gamma; }
+void stbi_ldr_to_hdr_scale(float scale) { l2h_scale = scale; }
+#endif
+
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// Common code used by all image loaders
+//
+
+// image width, height, # components
+static uint32 img_x, img_y;
+static int img_n, img_out_n;
+
+enum
+{
+ SCAN_load=0,
+ SCAN_type,
+ SCAN_header,
+};
+
+// An API for reading either from memory or file.
+#ifndef STBI_NO_STDIO
+static FILE *img_file;
+#endif
+static uint8 *img_buffer, *img_buffer_end;
+
+#ifndef STBI_NO_STDIO
+static void start_file(FILE *f)
+{
+ img_file = f;
+}
+#endif
+
+static void start_mem(uint8 *buffer, int len)
+{
+#ifndef STBI_NO_STDIO
+ img_file = NULL;
+#endif
+ img_buffer = buffer;
+ img_buffer_end = buffer+len;
+}
+
+static int get8(void)
+{
+#ifndef STBI_NO_STDIO
+ if (img_file) {
+ int c = fgetc(img_file);
+ return c == EOF ? 0 : c;
+ }
+#endif
+ if (img_buffer < img_buffer_end)
+ return *img_buffer++;
+ return 0;
+}
+
+static int at_eof(void)
+{
+#ifndef STBI_NO_STDIO
+ if (img_file)
+ return feof(img_file);
+#endif
+ return img_buffer >= img_buffer_end;
+}
+
+static uint8 get8u(void)
+{
+ return (uint8) get8();
+}
+
+static void skip(int n)
+{
+#ifndef STBI_NO_STDIO
+ if (img_file)
+ fseek(img_file, n, SEEK_CUR);
+ else
+#endif
+ img_buffer += n;
+}
+
+static int get16(void)
+{
+ int z = get8();
+ return (z << 8) + get8();
+}
+
+static uint32 get32(void)
+{
+ uint32 z = get16();
+ return (z << 16) + get16();
+}
+
+static int get16le(void)
+{
+ int z = get8();
+ return z + (get8() << 8);
+}
+
+static uint32 get32le(void)
+{
+ uint32 z = get16le();
+ return z + (get16le() << 16);
+}
+
+static void getn(stbi_uc *buffer, int n)
+{
+#ifndef STBI_NO_STDIO
+ if (img_file) {
+ fread(buffer, 1, n, img_file);
+ return;
+ }
+#endif
+ memcpy(buffer, img_buffer, n);
+ img_buffer += n;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// 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 uint8 compute_y(int r, int g, int b)
+{
+ return (uint8) (((r*77) + (g*150) + (29*b)) >> 8);
+}
+
+static unsigned char *convert_format(unsigned char *data, int img_n, int req_comp)
+{
+ uint i,j;
+ unsigned char *good;
+
+ if (req_comp == img_n) return data;
+ assert(req_comp >= 1 && req_comp <= 4);
+
+ good = (unsigned char *) malloc(req_comp * img_x * img_y);
+ if (good == NULL) {
+ free(data);
+ return epuc("outofmem", "Out of memory");
+ }
+
+ for (j=0; j < img_y; ++j) {
+ unsigned char *src = data + j * img_x * img_n ;
+ unsigned char *dest = good + j * img_x * req_comp;
+
+ #define COMBO(a,b) ((a)*8+(b))
+ #define CASE(a,b) case COMBO(a,b): for(i=0; i < img_x; ++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(COMBO(img_n, req_comp)) {
+ CASE(1,2) dest[0]=src[0], dest[1]=255; break;
+ CASE(1,3) dest[0]=dest[1]=dest[2]=src[0]; break;
+ CASE(1,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=255; break;
+ CASE(2,1) dest[0]=src[0]; break;
+ CASE(2,3) dest[0]=dest[1]=dest[2]=src[0]; break;
+ CASE(2,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=src[1]; break;
+ CASE(3,4) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2],dest[3]=255; break;
+ CASE(3,1) dest[0]=compute_y(src[0],src[1],src[2]); break;
+ CASE(3,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = 255; break;
+ CASE(4,1) dest[0]=compute_y(src[0],src[1],src[2]); break;
+ CASE(4,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = src[3]; break;
+ CASE(4,3) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2]; break;
+ default: assert(0);
+ }
+ #undef CASE
+ }
+
+ free(data);
+ img_out_n = req_comp;
+ return good;
+}
+
+#ifndef STBI_NO_HDR
+static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp)
+{
+ int i,k,n;
+ float *output = (float *) malloc(x * y * comp * sizeof(float));
+ if (output == NULL) { free(data); return epf("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, l2h_gamma) * l2h_scale;
+ }
+ if (k < comp) output[i*comp + k] = data[i*comp+k]/255.0f;
+ }
+ free(data);
+ return output;
+}
+
+#define float2int(x) ((int) (x))
+static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp)
+{
+ int i,k,n;
+ stbi_uc *output = (stbi_uc *) malloc(x * y * comp);
+ if (output == NULL) { free(data); return epuc("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]*h2l_scale_i, h2l_gamma_i) * 255 + 0.5f;
+ if (z < 0) z = 0;
+ if (z > 255) z = 255;
+ output[i*comp + k] = 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] = float2int(z);
+ }
+ }
+ free(data);
+ return output;
+}
+#endif
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// "baseline" JPEG/JFIF decoder (not actually fully baseline implementation)
+//
+// simple implementation
+// - channel subsampling of at most 2 in each dimension
+// - 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
+// - uses a lot of intermediate memory, could cache poorly
+// - load http://nothings.org/remote/anemones.jpg 3 times on 2.8Ghz P4
+// stb_jpeg: 1.34 seconds (MSVC6, default release build)
+// stb_jpeg: 1.06 seconds (MSVC6, processor = Pentium Pro)
+// IJL11.dll: 1.08 seconds (compiled by intel)
+// IJG 1998: 0.98 seconds (MSVC6, makefile provided by IJG)
+// IJG 1998: 0.95 seconds (MSVC6, makefile + proc=PPro)
+
+int stbi_jpeg_dc_only;
+
+// huffman decoding acceleration
+#define FAST_BITS 9 // larger handles more cases; smaller stomps less cache
+
+typedef struct
+{
+ uint8 fast[1 << FAST_BITS];
+ // weirdly, repacking this into AoS is a 10% speed loss, instead of a win
+ uint16 code[256];
+ uint8 values[256];
+ uint8 size[257];
+ unsigned int maxcode[18];
+ int delta[17]; // old 'firstsymbol' - old 'firstcode'
+} huffman;
+
+static huffman huff_dc[4]; // baseline is 2 tables, extended is 4
+static huffman huff_ac[4];
+static uint8 dequant[4][64];
+
+static int build_huffman(huffman *h, int *count)
+{
+ int i,j,k=0,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++] = (uint8) (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++] = (uint16) (code++);
+ if (code-1 >= (1 << j)) return e("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] = (uint8) i;
+ }
+ }
+ }
+ return 1;
+}
+
+// sizes for components, interleaved MCUs
+static int img_h_max, img_v_max;
+static int img_mcu_x, img_mcu_y;
+static int img_mcu_w, img_mcu_h;
+
+// definition of jpeg image component
+static struct
+{
+ int id;
+ int h,v;
+ int tq;
+ int hd,ha;
+ int dc_pred;
+
+ int x,y,w2,h2;
+ uint8 *data;
+} img_comp[4];
+
+static unsigned long code_buffer; // jpeg entropy-coded buffer
+static int code_bits; // number of valid bits
+static unsigned char marker; // marker seen while filling entropy buffer
+static int nomore; // flag if we saw a marker so must stop
+
+static void grow_buffer_unsafe(void)
+{
+ do {
+ int b = nomore ? 0 : get8();
+ if (b == 0xff) {
+ int c = get8();
+ if (c != 0) {
+ marker = (unsigned char) c;
+ nomore = 1;
+ return;
+ }
+ }
+ code_buffer = (code_buffer << 8) | b;
+ code_bits += 8;
+ } while (code_bits <= 24);
+}
+
+// (1 << n) - 1
+static unsigned long 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
+__forceinline static int decode(huffman *h)
+{
+ unsigned int temp;
+ int c,k;
+
+ if (code_bits < 16) grow_buffer_unsafe();
+
+ // look at the top FAST_BITS and determine what symbol ID it is,
+ // if the code is <= FAST_BITS
+ c = (code_buffer >> (code_bits - FAST_BITS)) & ((1 << FAST_BITS)-1);
+ k = h->fast[c];
+ if (k < 255) {
+ if (h->size[k] > code_bits)
+ return -1;
+ code_bits -= h->size[k];
+ 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.
+ if (code_bits < 16)
+ temp = (code_buffer << (16 - code_bits)) & 0xffff;
+ else
+ temp = (code_buffer >> (code_bits - 16)) & 0xffff;
+ for (k=FAST_BITS+1 ; ; ++k)
+ if (temp < h->maxcode[k])
+ break;
+ if (k == 17) {
+ // error! code not found
+ code_bits -= 16;
+ return -1;
+ }
+
+ if (k > code_bits)
+ return -1;
+
+ // convert the huffman code to the symbol id
+ c = ((code_buffer >> (code_bits - k)) & bmask[k]) + h->delta[k];
+ assert((((code_buffer) >> (code_bits - h->size[c])) & bmask[h->size[c]]) == h->code[c]);
+
+ // convert the id to a symbol
+ code_bits -= k;
+ return h->values[c];
+}
+
+// combined JPEG 'receive' and JPEG 'extend', since baseline
+// always extends everything it receives.
+__forceinline static int extend_receive(int n)
+{
+ unsigned int m = 1 << (n-1);
+ unsigned int k;
+ if (code_bits < n) grow_buffer_unsafe();
+ k = (code_buffer >> (code_bits - n)) & bmask[n];
+ code_bits -= n;
+ // the following test is probably a random branch that won't
+ // predict well. I tried to table accelerate it but failed.
+ // maybe it's compiling as a conditional move?
+ if (k < m)
+ return (-1 << n) + k + 1;
+ else
+ return k;
+}
+
+// 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 uint8 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 decode_block(short data[64], huffman *hdc, huffman *hac, int b)
+{
+ int diff,dc,k;
+ int t = decode(hdc);
+ if (t < 0) return e("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 ? extend_receive(t) : 0;
+ dc = img_comp[b].dc_pred + diff;
+ img_comp[b].dc_pred = dc;
+ data[0] = (short) dc;
+
+ // decode AC components, see JPEG spec
+ k = 1;
+ do {
+ int r,s;
+ int rs = decode(hac);
+ if (rs < 0) return e("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
+ data[dezigzag[k++]] = (short) extend_receive(s);
+ }
+ } while (k < 64);
+ return 1;
+}
+
+// take a -128..127 value and clamp it and convert to 0..255
+__forceinline static uint8 clamp(int x)
+{
+ x += 128;
+ // 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 (uint8) x;
+}
+
+#define f2f(x) (int) (((x) * 4096 + 0.5))
+#define fsh(x) ((x) << 12)
+
+// derived from jidctint -- DCT_ISLOW
+#define 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) * f2f(0.5411961f); \
+ t2 = p1 + p3*f2f(-1.847759065f); \
+ t3 = p1 + p2*f2f( 0.765366865f); \
+ p2 = s0; \
+ p3 = s4; \
+ t0 = fsh(p2+p3); \
+ t1 = 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)*f2f( 1.175875602f); \
+ t0 = t0*f2f( 0.298631336f); \
+ t1 = t1*f2f( 2.053119869f); \
+ t2 = t2*f2f( 3.072711026f); \
+ t3 = t3*f2f( 1.501321110f); \
+ p1 = p5 + p1*f2f(-0.899976223f); \
+ p2 = p5 + p2*f2f(-2.562915447f); \
+ p3 = p3*f2f(-1.961570560f); \
+ p4 = p4*f2f(-0.390180644f); \
+ t3 += p1+p4; \
+ t2 += p2+p3; \
+ t1 += p2+p4; \
+ t0 += p1+p3;
+
+// .344 seconds on 3*anemones.jpg
+static void idct_block(uint8 *out, int out_stride, short data[64], uint8 *dequantize)
+{
+ int i,val[64],*v=val;
+ uint8 *o,*dq = dequantize;
+ short *d = data;
+
+ if (stbi_jpeg_dc_only) {
+ // ok, I don't really know why this is right, but it seems to be:
+ int z = 128 + ((d[0] * dq[0]) >> 3);
+ for (i=0; i < 8; ++i) {
+ out[0] = out[1] = out[2] = out[3] = out[4] = out[5] = out[6] = out[7] = z;
+ out += out_stride;
+ }
+ return;
+ }
+
+ // columns
+ for (i=0; i < 8; ++i,++d,++dq, ++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] * dq[0] << 2;
+ v[0] = v[8] = v[16] = v[24] = v[32] = v[40] = v[48] = v[56] = dcterm;
+ } else {
+ IDCT_1D(d[ 0]*dq[ 0],d[ 8]*dq[ 8],d[16]*dq[16],d[24]*dq[24],
+ d[32]*dq[32],d[40]*dq[40],d[48]*dq[48],d[56]*dq[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
+ 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.
+ x0 += 65536; x1 += 65536; x2 += 65536; x3 += 65536;
+ o[0] = clamp((x0+t3) >> 17);
+ o[7] = clamp((x0-t3) >> 17);
+ o[1] = clamp((x1+t2) >> 17);
+ o[6] = clamp((x1-t2) >> 17);
+ o[2] = clamp((x2+t1) >> 17);
+ o[5] = clamp((x2-t1) >> 17);
+ o[3] = clamp((x3+t0) >> 17);
+ o[4] = clamp((x3-t0) >> 17);
+ }
+}
+
+#define 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 uint8 get_marker(void)
+{
+ uint8 x;
+ if (marker != MARKER_none) { x = marker; marker = MARKER_none; return x; }
+ x = get8u();
+ if (x != 0xff) return MARKER_none;
+ while (x == 0xff)
+ x = get8u();
+ return x;
+}
+
+// in each scan, we'll have scan_n components, and the order
+// of the components is specified by order[]
+static int scan_n, order[4];
+static int restart_interval, todo;
+#define RESTART(x) ((x) >= 0xd0 && (x) <= 0xd7)
+
+// after a restart interval, reset the entropy decoder and
+// the dc prediction
+static void reset(void)
+{
+ code_bits = 0;
+ code_buffer = 0;
+ nomore = 0;
+ img_comp[0].dc_pred = img_comp[1].dc_pred = img_comp[2].dc_pred = 0;
+ marker = MARKER_none;
+ todo = restart_interval ? restart_interval : 0x7fffffff;
+ // 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 parse_entropy_coded_data(void)
+{
+ reset();
+ if (scan_n == 1) {
+ int i,j;
+ short data[64];
+ int n = 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 = (img_comp[n].x+7) >> 3;
+ int h = (img_comp[n].y+7) >> 3;
+ for (j=0; j < h; ++j) {
+ for (i=0; i < w; ++i) {
+ if (!decode_block(data, huff_dc+img_comp[n].hd, huff_ac+img_comp[n].ha, n)) return 0;
+ idct_block(img_comp[n].data+img_comp[n].w2*j*8+i*8, img_comp[n].w2, data, dequant[img_comp[n].tq]);
+ // every data block is an MCU, so countdown the restart interval
+ if (--todo <= 0) {
+ if (code_bits < 24) grow_buffer_unsafe();
+ // if it's NOT a restart, then just bail, so we get corrupt data
+ // rather than no data
+ if (!RESTART(marker)) return 1;
+ reset();
+ }
+ }
+ }
+ } else { // interleaved!
+ int i,j,k,x,y;
+ short data[64];
+ for (j=0; j < img_mcu_y; ++j) {
+ for (i=0; i < img_mcu_x; ++i) {
+ // scan an interleaved mcu... process scan_n components in order
+ for (k=0; k < scan_n; ++k) {
+ int n = 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 < img_comp[n].v; ++y) {
+ for (x=0; x < img_comp[n].h; ++x) {
+ int x2 = (i*img_comp[n].h + x)*8;
+ int y2 = (j*img_comp[n].v + y)*8;
+ if (!decode_block(data, huff_dc+img_comp[n].hd, huff_ac+img_comp[n].ha, n)) return 0;
+ idct_block(img_comp[n].data+img_comp[n].w2*y2+x2, img_comp[n].w2, data, dequant[img_comp[n].tq]);
+ }
+ }
+ }
+ // after all interleaved components, that's an interleaved MCU,
+ // so now count down the restart interval
+ if (--todo <= 0) {
+ if (code_bits < 24) grow_buffer_unsafe();
+ // if it's NOT a restart, then just bail, so we get corrupt data
+ // rather than no data
+ if (!RESTART(marker)) return 1;
+ reset();
+ }
+ }
+ }
+ }
+ return 1;
+}
+
+static int process_marker(int m)
+{
+ int L;
+ switch (m) {
+ case MARKER_none: // no marker found
+ return e("expected marker","Corrupt JPEG");
+
+ case 0xC2: // SOF - progressive
+ return e("progressive jpeg","JPEG format not supported (progressive)");
+
+ case 0xDD: // DRI - specify restart interval
+ if (get16() != 4) return e("bad DRI len","Corrupt JPEG");
+ restart_interval = get16();
+ return 1;
+
+ case 0xDB: // DQT - define quantization table
+ L = get16()-2;
+ while (L > 0) {
+ int z = get8();
+ int p = z >> 4;
+ int t = z & 15,i;
+ if (p != 0) return e("bad DQT type","Corrupt JPEG");
+ if (t > 3) return e("bad DQT table","Corrupt JPEG");
+ for (i=0; i < 64; ++i)
+ dequant[t][dezigzag[i]] = get8u();
+ L -= 65;
+ }
+ return L==0;
+
+ case 0xC4: // DHT - define huffman table
+ L = get16()-2;
+ while (L > 0) {
+ uint8 *v;
+ int sizes[16],i,m=0;
+ int z = get8();
+ int tc = z >> 4;
+ int th = z & 15;
+ if (tc > 1 || th > 3) return e("bad DHT header","Corrupt JPEG");
+ for (i=0; i < 16; ++i) {
+ sizes[i] = get8();
+ m += sizes[i];
+ }
+ L -= 17;
+ if (tc == 0) {
+ if (!build_huffman(huff_dc+th, sizes)) return 0;
+ v = huff_dc[th].values;
+ } else {
+ if (!build_huffman(huff_ac+th, sizes)) return 0;
+ v = huff_ac[th].values;
+ }
+ for (i=0; i < m; ++i)
+ v[i] = get8u();
+ L -= m;
+ }
+ return L==0;
+ }
+ // check for comment block or APP blocks
+ if ((m >= 0xE0 && m <= 0xEF) || m == 0xFE) {
+ skip(get16()-2);
+ return 1;
+ }
+ return 0;
+}
+
+// after we see SOS
+static int process_scan_header(void)
+{
+ int i;
+ int Ls = get16();
+ scan_n = get8();
+ if (scan_n < 1 || scan_n > 4 || scan_n > (int) img_n) return e("bad SOS component count","Corrupt JPEG");
+ if (Ls != 6+2*scan_n) return e("bad SOS len","Corrupt JPEG");
+ for (i=0; i < scan_n; ++i) {
+ int id = get8(), which;
+ int z = get8();
+ for (which = 0; which < img_n; ++which)
+ if (img_comp[which].id == id)
+ break;
+ if (which == img_n) return 0;
+ img_comp[which].hd = z >> 4; if (img_comp[which].hd > 3) return e("bad DC huff","Corrupt JPEG");
+ img_comp[which].ha = z & 15; if (img_comp[which].ha > 3) return e("bad AC huff","Corrupt JPEG");
+ order[i] = which;
+ }
+ if (get8() != 0) return e("bad SOS","Corrupt JPEG");
+ get8(); // should be 63, but might be 0
+ if (get8() != 0) return e("bad SOS","Corrupt JPEG");
+
+ return 1;
+}
+
+static int process_frame_header(int scan)
+{
+ int Lf,p,i,z, h_max=1,v_max=1;
+ Lf = get16(); if (Lf < 11) return e("bad SOF len","Corrupt JPEG"); // JPEG
+ p = get8(); if (p != 8) return e("only 8-bit","JPEG format not supported: 8-bit only"); // JPEG baseline
+ img_y = get16(); if (img_y == 0) return e("no header height", "JPEG format not supported: delayed height"); // Legal, but we don't handle it--but neither does IJG
+ img_x = get16(); if (img_x == 0) return e("0 width","Corrupt JPEG"); // JPEG requires
+ img_n = get8();
+ if (img_n != 3 && img_n != 1) return e("bad component count","Corrupt JPEG"); // JFIF requires
+
+ if (Lf != 8+3*img_n) return e("bad SOF len","Corrupt JPEG");
+
+ for (i=0; i < img_n; ++i) {
+ img_comp[i].id = get8();
+ if (img_comp[i].id != i+1) // JFIF requires
+ if (img_comp[i].id != i) // jpegtran outputs non-JFIF-compliant files!
+ return e("bad component ID","Corrupt JPEG");
+ z = get8();
+ img_comp[i].h = (z >> 4); if (!img_comp[i].h || img_comp[i].h > 4) return e("bad H","Corrupt JPEG");
+ img_comp[i].v = z & 15; if (!img_comp[i].v || img_comp[i].v > 4) return e("bad V","Corrupt JPEG");
+ img_comp[i].tq = get8(); if (img_comp[i].tq > 3) return e("bad TQ","Corrupt JPEG");
+ }
+
+ if (scan != SCAN_load) return 1;
+
+ if ((1 << 30) / img_x / img_n < img_y) return e("too large", "Image too large to decode");
+
+ for (i=0; i < img_n; ++i) {
+ if (img_comp[i].h > h_max) h_max = img_comp[i].h;
+ if (img_comp[i].v > v_max) v_max = img_comp[i].v;
+ }
+
+ // compute interleaved mcu info
+ img_h_max = h_max;
+ img_v_max = v_max;
+ img_mcu_w = h_max * 8;
+ img_mcu_h = v_max * 8;
+ img_mcu_x = (img_x + img_mcu_w-1) / img_mcu_w;
+ img_mcu_y = (img_y + img_mcu_h-1) / img_mcu_h;
+
+ for (i=0; i < img_n; ++i) {
+ // number of effective pixels (e.g. for non-interleaved MCU)
+ img_comp[i].x = (img_x * img_comp[i].h + h_max-1) / h_max;
+ img_comp[i].y = (img_y * 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_comp[i].w2 = img_mcu_x * img_comp[i].h * 8;
+ img_comp[i].h2 = img_mcu_y * img_comp[i].v * 8;
+ img_comp[i].data = (uint8 *) malloc(img_comp[i].w2 * img_comp[i].h2);
+ if (img_comp[i].data == NULL) {
+ for(--i; i >= 0; --i)
+ free(img_comp[i].data);
+ return e("outofmem", "Out of memory");
+ }
+ }
+
+ return 1;
+}
+
+// use comparisons since in some cases we handle more than one case (e.g. SOF)
+#define DNL(x) ((x) == 0xdc)
+#define SOI(x) ((x) == 0xd8)
+#define EOI(x) ((x) == 0xd9)
+#define SOF(x) ((x) == 0xc0 || (x) == 0xc1)
+#define SOS(x) ((x) == 0xda)
+
+static int decode_jpeg_header(int scan)
+{
+ int m;
+ marker = MARKER_none; // initialize cached marker to empty
+ m = get_marker();
+ if (!SOI(m)) return e("no SOI","Corrupt JPEG");
+ if (scan == SCAN_type) return 1;
+ m = get_marker();
+ while (!SOF(m)) {
+ if (!process_marker(m)) return 0;
+ m = get_marker();
+ while (m == MARKER_none) {
+ // some files have extra padding after their blocks, so ok, we'll scan
+ if (at_eof()) return e("no SOF", "Corrupt JPEG");
+ m = get_marker();
+ }
+ }
+ if (!process_frame_header(scan)) return 0;
+ return 1;
+}
+
+static int decode_jpeg_image(void)
+{
+ int m;
+ restart_interval = 0;
+ if (!decode_jpeg_header(SCAN_load)) return 0;
+ m = get_marker();
+ while (!EOI(m)) {
+ if (SOS(m)) {
+ if (!process_scan_header()) return 0;
+ if (!parse_entropy_coded_data()) return 0;
+ } else {
+ if (!process_marker(m)) return 0;
+ }
+ m = get_marker();
+ }
+ return 1;
+}
+
+// static jfif-centered resampling with cross-block smoothing
+// here by cross-block smoothing what I mean is that the resampling
+// is bilerp and crosses blocks; I dunno what IJG means
+
+#define div4(x) ((uint8) ((x) >> 2))
+
+static void resample_v_2(uint8 *out1, uint8 *input, int w, int h, int s)
+{
+ // need to generate two samples vertically for every one in input
+ uint8 *above;
+ uint8 *below;
+ uint8 *source;
+ uint8 *out2;
+ int i,j;
+ source = input;
+ out2 = out1+w;
+ for (j=0; j < h; ++j) {
+ above = source;
+ source = input + j*s;
+ below = source + s; if (j == h-1) below = source;
+ for (i=0; i < w; ++i) {
+ int n = source[i]*3;
+ out1[i] = div4(above[i] + n);
+ out2[i] = div4(below[i] + n);
+ }
+ out1 += w*2;
+ out2 += w*2;
+ }
+}
+
+static void resample_h_2(uint8 *out, uint8 *input, int w, int h, int s)
+{
+ // need to generate two samples horizontally for every one in input
+ int i,j;
+ if (w == 1) {
+ for (j=0; j < h; ++j)
+ out[j*2+0] = out[j*2+1] = input[j*s];
+ return;
+ }
+ for (j=0; j < h; ++j) {
+ out[0] = input[0];
+ out[1] = div4(input[0]*3 + input[1]);
+ for (i=1; i < w-1; ++i) {
+ int n = input[i]*3;
+ out[i*2-2] = div4(input[i-1] + n);
+ out[i*2-1] = div4(input[i+1] + n);
+ }
+ out[w*2-2] = div4(input[w-2]*3 + input[w-1]);
+ out[w*2-1] = input[w-1];
+ out += w*2;
+ input += s;
+ }
+}
+
+// .172 seconds on 3*anemones.jpg
+static void resample_hv_2(uint8 *out, uint8 *input, int w, int h, int s)
+{
+ // need to generate 2x2 samples for every one in input
+ int i,j;
+ int os = w*2;
+ // generate edge samples... @TODO lerp them!
+ for (i=0; i < w; ++i) {
+ out[i*2+0] = out[i*2+1] = input[i];
+ out[i*2+(2*h-1)*os+0] = out[i*2+(2*h-1)*os+1] = input[i+(h-1)*w];
+ }
+ for (j=0; j < h; ++j) {
+ out[j*os*2+0] = out[j*os*2+os+0] = input[j*w];
+ out[j*os*2+os-1] = out[j*os*2+os+os-1] = input[j*w+i-1];
+ }
+ // now generate interior samples; i & j point to top left of input
+ for (j=0; j < h-1; ++j) {
+ uint8 *in1 = input+j*s;
+ uint8 *in2 = in1 + s;
+ uint8 *out1 = out + (j*2+1)*os + 1;
+ uint8 *out2 = out1 + os;
+ for (i=0; i < w-1; ++i) {
+ int p00 = in1[0], p01=in1[1], p10=in2[0], p11=in2[1];
+ int p00_3 = p00*3, p01_3 = p01*3, p10_3 = p10*3, p11_3 = p11*3;
+
+ #define div16(x) ((uint8) ((x) >> 4))
+
+ out1[0] = div16(p00*9 + p01_3 + p10_3 + p11);
+ out1[1] = div16(p01*9 + p00_3 + p01_3 + p10);
+ out2[0] = div16(p10*9 + p11_3 + p00_3 + p01);
+ out2[1] = div16(p11*9 + p10_3 + p01_3 + p00);
+ out1 += 2;
+ out2 += 2;
+ ++in1;
+ ++in2;
+ }
+ }
+}
+
+#define float2fixed(x) ((int) ((x) * 65536 + 0.5))
+
+// 0.38 seconds on 3*anemones.jpg (0.25 with processor = Pro)
+// VC6 without processor=Pro is generating multiple LEAs per multiply!
+static void YCbCr_to_RGB_row(uint8 *out, uint8 *y, uint8 *pcb, uint8 *pcr, int count, int step)
+{
+ int i;
+ for (i=0; i < count; ++i) {
+ int y_fixed = (y[i] << 16) + 32768; // rounding
+ int r,g,b;
+ int cr = pcr[i] - 128;
+ int cb = pcb[i] - 128;
+ r = y_fixed + cr*float2fixed(1.40200f);
+ g = y_fixed - cr*float2fixed(0.71414f) - cb*float2fixed(0.34414f);
+ b = y_fixed + cb*float2fixed(1.77200f);
+ r >>= 16;
+ g >>= 16;
+ b >>= 16;
+ 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] = (uint8)r;
+ out[1] = (uint8)g;
+ out[2] = (uint8)b;
+ if (step == 4) out[3] = 255;
+ out += step;
+ }
+}
+
+// clean up the temporary component buffers
+static void cleanup_jpeg(void)
+{
+ int i;
+ for (i=0; i < img_n; ++i) {
+ if (img_comp[i].data) {
+ free(img_comp[i].data);
+ img_comp[i].data = NULL;
+ }
+ }
+}
+
+static uint8 *load_jpeg_image(int *out_x, int *out_y, int *comp, int req_comp)
+{
+ int i, n;
+ // validate req_comp
+ if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp", "Internal error");
+
+ // load a jpeg image from whichever source
+ if (!decode_jpeg_image()) { cleanup_jpeg(); return NULL; }
+
+ // determine actual number of components to generate
+ n = req_comp ? req_comp : img_n;
+
+ // resample components to full size... memory wasteful, but this
+ // lets us bilerp across blocks while upsampling
+ for (i=0; i < img_n; ++i) {
+ // if we're outputting fewer than 3 components, we're grey not RGB;
+ // in that case, don't bother upsampling Cb or Cr
+ if (n < 3 && i) continue;
+
+ // check if the component scale is less than max; if so it needs upsampling
+ if (img_comp[i].h != img_h_max || img_comp[i].v != img_v_max) {
+ int stride = img_x;
+ // allocate final size; make sure it's big enough for upsampling off
+ // the edges with upsample up to 4x4 (although we only support 2x2
+ // currently)
+ uint8 *new_data = (uint8 *) malloc((img_x+3)*(img_y+3));
+ if (new_data == NULL) {
+ cleanup_jpeg();
+ return epuc("outofmem", "Out of memory (image too large?)");
+ }
+ if (img_comp[i].h*2 == img_h_max && img_comp[i].v*2 == img_v_max) {
+ int tx = (img_x+1)>>1;
+ resample_hv_2(new_data, img_comp[i].data, tx,(img_y+1)>>1, img_comp[i].w2);
+ stride = tx*2;
+ } else if (img_comp[i].h == img_h_max && img_comp[i].v*2 == img_v_max) {
+ resample_v_2(new_data, img_comp[i].data, img_x,(img_y+1)>>1, img_comp[i].w2);
+ } else if (img_comp[i].h*2 == img_h_max && img_comp[i].v == img_v_max) {
+ int tx = (img_x+1)>>1;
+ resample_h_2(new_data, img_comp[i].data, tx,img_y, img_comp[i].w2);
+ stride = tx*2;
+ } else {
+ // @TODO resample uncommon sampling pattern with nearest neighbor
+ free(new_data);
+ cleanup_jpeg();
+ return epuc("uncommon H or V", "JPEG not supported: atypical downsampling mode");
+ }
+ img_comp[i].w2 = stride;
+ free(img_comp[i].data);
+ img_comp[i].data = new_data;
+ }
+ }
+
+ // now convert components to output image
+ {
+ uint32 i,j;
+ uint8 *output = (uint8 *) malloc(n * img_x * img_y + 1);
+ if (n >= 3) { // output STBI_rgb_*
+ for (j=0; j < img_y; ++j) {
+ uint8 *y = img_comp[0].data + j*img_comp[0].w2;
+ uint8 *out = output + n * img_x * j;
+ if (img_n == 3) {
+ uint8 *cb = img_comp[1].data + j*img_comp[1].w2;
+ uint8 *cr = img_comp[2].data + j*img_comp[2].w2;
+ YCbCr_to_RGB_row(out, y, cb, cr, img_x, n);
+ } else {
+ for (i=0; i < img_x; ++i) {
+ out[0] = out[1] = out[2] = y[i];
+ out[3] = 255; // not used if n == 3
+ out += n;
+ }
+ }
+ }
+ } else { // output STBI_grey_*
+ for (j=0; j < img_y; ++j) {
+ uint8 *y = img_comp[0].data + j*img_comp[0].w2;
+ uint8 *out = output + n * img_x * j;
+ if (n == 1)
+ for (i=0; i < img_x; ++i) *out++ = *y++;
+ else
+ for (i=0; i < img_x; ++i) *out++ = *y++, *out++ = 255;
+ }
+ }
+ cleanup_jpeg();
+ *out_x = img_x;
+ *out_y = img_y;
+ if (comp) *comp = img_n; // report original components, not output
+ return output;
+ }
+}
+
+#ifndef STBI_NO_STDIO
+unsigned char *stbi_jpeg_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
+{
+ start_file(f);
+ return load_jpeg_image(x,y,comp,req_comp);
+}
+
+unsigned char *stbi_jpeg_load(char *filename, int *x, int *y, int *comp, int req_comp)
+{
+ unsigned char *data;
+ FILE *f = fopen(filename, "rb");
+ if (!f) return NULL;
+ data = stbi_jpeg_load_from_file(f,x,y,comp,req_comp);
+ fclose(f);
+ return data;
+}
+#endif
+
+unsigned char *stbi_jpeg_load_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ start_mem(buffer,len);
+ return load_jpeg_image(x,y,comp,req_comp);
+}
+
+#ifndef STBI_NO_STDIO
+int stbi_jpeg_test_file(FILE *f)
+{
+ int n,r;
+ n = ftell(f);
+ start_file(f);
+ r = decode_jpeg_header(SCAN_type);
+ fseek(f,n,SEEK_SET);
+ return r;
+}
+#endif
+
+int stbi_jpeg_test_memory(unsigned char *buffer, int len)
+{
+ start_mem(buffer,len);
+ return decode_jpeg_header(SCAN_type);
+}
+
+// @TODO:
+#ifndef STBI_NO_STDIO
+extern int stbi_jpeg_info (char *filename, int *x, int *y, int *comp);
+extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp);
+#endif
+extern int stbi_jpeg_info_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp);
+
+// 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
+
+// fast-way is faster to check than jpeg huffman, but slow way is slower
+#define ZFAST_BITS 9 // accelerate all cases in default tables
+#define ZFAST_MASK ((1 << ZFAST_BITS) - 1)
+
+// zlib-style huffman encoding
+// (jpegs packs from left, zlib from right, so can't share code)
+typedef struct
+{
+ uint16 fast[1 << ZFAST_BITS];
+ uint16 firstcode[16];
+ int maxcode[17];
+ uint16 firstsymbol[16];
+ uint8 size[288];
+ uint16 value[288];
+} zhuffman;
+
+__forceinline static int 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;
+}
+
+__forceinline static int bit_reverse(int v, int bits)
+{
+ assert(bits <= 16);
+ // to bit reverse n bits, reverse 16 and shift
+ // e.g. 11 bits, bit reverse and shift away 5
+ return bitreverse16(v) >> (16-bits);
+}
+
+static int zbuild_huffman(zhuffman *z, uint8 *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, 255, sizeof(z->fast));
+ for (i=0; i < num; ++i)
+ ++sizes[sizelist[i]];
+ sizes[0] = 0;
+ for (i=1; i < 16; ++i)
+ assert(sizes[i] <= (1 << i));
+ code = 0;
+ for (i=1; i < 16; ++i) {
+ next_code[i] = code;
+ z->firstcode[i] = (uint16) code;
+ z->firstsymbol[i] = (uint16) k;
+ code = (code + sizes[i]);
+ if (sizes[i])
+ if (code-1 >= (1 << i)) return e("bad codelengths","Corrupt JPEG");
+ 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];
+ z->size[c] = (uint8)s;
+ z->value[c] = (uint16)i;
+ if (s <= ZFAST_BITS) {
+ int k = bit_reverse(next_code[s],s);
+ while (k < (1 << ZFAST_BITS)) {
+ z->fast[k] = (uint16) c;
+ k += (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
+
+static uint8 *zbuffer, *zbuffer_end;
+
+__forceinline static int zget8(void)
+{
+ if (zbuffer >= zbuffer_end) return 0;
+ return *zbuffer++;
+}
+
+//static unsigned long code_buffer;
+static int num_bits;
+
+static void fill_bits(void)
+{
+ do {
+ assert(code_buffer < (1U << num_bits));
+ code_buffer |= zget8() << num_bits;
+ num_bits += 8;
+ } while (num_bits <= 24);
+}
+
+__forceinline static unsigned int zreceive(int n)
+{
+ unsigned int k;
+ if (num_bits < n) fill_bits();
+ k = code_buffer & ((1 << n) - 1);
+ code_buffer >>= n;
+ num_bits -= n;
+ return k;
+}
+
+__forceinline static int zhuffman_decode(zhuffman *z)
+{
+ int b,s,k;
+ if (num_bits < 16) fill_bits();
+ b = z->fast[code_buffer & ZFAST_MASK];
+ if (b < 0xffff) {
+ s = z->size[b];
+ code_buffer >>= s;
+ num_bits -= s;
+ return z->value[b];
+ }
+
+ // not resolved by fast table, so compute it the slow way
+ // use jpeg approach, which requires MSbits at top
+ k = bit_reverse(code_buffer, 16);
+ for (s=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];
+ assert(z->size[b] == s);
+ code_buffer >>= s;
+ num_bits -= s;
+ return z->value[b];
+}
+
+static char *zout;
+static char *zout_start;
+static char *zout_end;
+static int z_expandable;
+
+static int expand(int n) // need to make room for n bytes
+{
+ char *q;
+ int cur, limit;
+ if (!z_expandable) return e("output buffer limit","Corrupt PNG");
+ cur = (int) (zout - zout_start);
+ limit = (int) (zout_end - zout_start);
+ while (cur + n > limit)
+ limit *= 2;
+ q = (char *) realloc(zout_start, limit);
+ if (q == NULL) return e("outofmem", "Out of memory");
+ zout_start = q;
+ zout = q + cur;
+ zout_end = q + limit;
+ return 1;
+}
+
+static zhuffman z_length, z_distance;
+
+static int length_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 int length_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 int dist_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 int dist_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 parse_huffman_block(void)
+{
+ for(;;) {
+ int z = zhuffman_decode(&z_length);
+ if (z < 256) {
+ if (z < 0) return e("bad huffman code","Corrupt PNG"); // error in huffman codes
+ if (zout >= zout_end) if (!expand(1)) return 0;
+ *zout++ = (char) z;
+ } else {
+ uint8 *p;
+ int len,dist;
+ if (z == 256) return 1;
+ z -= 257;
+ len = length_base[z];
+ if (length_extra[z]) len += zreceive(length_extra[z]);
+ z = zhuffman_decode(&z_distance);
+ if (z < 0) return e("bad huffman code","Corrupt PNG");
+ dist = dist_base[z];
+ if (dist_extra[z]) dist += zreceive(dist_extra[z]);
+ if (zout - zout_start < dist) return e("bad dist","Corrupt PNG");
+ if (zout + len > zout_end) if (!expand(len)) return 0;
+ p = (uint8 *) (zout - dist);
+ while (len--)
+ *zout++ = *p++;
+ }
+ }
+}
+
+static int compute_huffman_codes(void)
+{
+ static uint8 length_dezigzag[19] = { 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 };
+ static zhuffman z_codelength; // static just to save stack space
+ uint8 lencodes[286+32+137];//padding for maximum single op
+ uint8 codelength_sizes[19];
+ int i,n;
+
+ int hlit = zreceive(5) + 257;
+ int hdist = zreceive(5) + 1;
+ int hclen = zreceive(4) + 4;
+
+ memset(codelength_sizes, 0, sizeof(codelength_sizes));
+ for (i=0; i < hclen; ++i) {
+ int s = zreceive(3);
+ codelength_sizes[length_dezigzag[i]] = (uint8) s;
+ }
+ if (!zbuild_huffman(&z_codelength, codelength_sizes, 19)) return 0;
+
+ n = 0;
+ while (n < hlit + hdist) {
+ int c = zhuffman_decode(&z_codelength);
+ assert(c >= 0 && c < 19);
+ if (c < 16)
+ lencodes[n++] = (uint8) c;
+ else if (c == 16) {
+ c = zreceive(2)+3;
+ memset(lencodes+n, lencodes[n-1], c);
+ n += c;
+ } else if (c == 17) {
+ c = zreceive(3)+3;
+ memset(lencodes+n, 0, c);
+ n += c;
+ } else {
+ assert(c == 18);
+ c = zreceive(7)+11;
+ memset(lencodes+n, 0, c);
+ n += c;
+ }
+ }
+ if (n != hlit+hdist) return e("bad codelengths","Corrupt PNG");
+ if (!zbuild_huffman(&z_length, lencodes, hlit)) return 0;
+ if (!zbuild_huffman(&z_distance, lencodes+hlit, hdist)) return 0;
+ return 1;
+}
+
+static int parse_uncompressed_block(void)
+{
+ uint8 header[4];
+ int len,nlen,k;
+ if (num_bits & 7)
+ zreceive(num_bits & 7); // discard
+ // drain the bit-packed data into header
+ k = 0;
+ while (num_bits > 0) {
+ header[k++] = (uint8) (code_buffer & 255); // wtf this warns?
+ code_buffer >>= 8;
+ num_bits -= 8;
+ }
+ assert(num_bits == 0);
+ // now fill header the normal way
+ while (k < 4)
+ header[k++] = (uint8) zget8();
+ len = header[1] * 256 + header[0];
+ nlen = header[3] * 256 + header[2];
+ if (nlen != (len ^ 0xffff)) return e("zlib corrupt","Corrupt PNG");
+ if (zbuffer + len > zbuffer_end) return e("read past buffer","Corrupt PNG");
+ if (zout + len > zout_end)
+ if (!expand(len)) return 0;
+ memcpy(zout, zbuffer, len);
+ zbuffer += len;
+ zout += len;
+ return 1;
+}
+
+static int parse_zlib_header(void)
+{
+ int cmf = zget8();
+ int cm = cmf & 15;
+ /* int cinfo = cmf >> 4; */
+ int flg = zget8();
+ if ((cmf*256+flg) % 31 != 0) return e("bad zlib header","Corrupt PNG"); // zlib spec
+ if (flg & 32) return e("no preset dict","Corrupt PNG"); // preset dictionary not allowed in png
+ if (cm != 8) return e("bad compression","Corrupt PNG"); // DEFLATE required for png
+ // window = 1 << (8 + cinfo)... but who cares, we fully buffer output
+ return 1;
+}
+
+static uint8 default_length[288], default_distance[32];
+static void init_defaults(void)
+{
+ int i; // use <= to match clearly with spec
+ for (i=0; i <= 143; ++i) default_length[i] = 8;
+ for ( ; i <= 255; ++i) default_length[i] = 9;
+ for ( ; i <= 279; ++i) default_length[i] = 7;
+ for ( ; i <= 287; ++i) default_length[i] = 8;
+
+ for (i=0; i <= 31; ++i) default_distance[i] = 5;
+}
+
+static int parse_zlib(int parse_header)
+{
+ int final, type;
+ if (parse_header)
+ if (!parse_zlib_header()) return 0;
+ num_bits = 0;
+ code_buffer = 0;
+ do {
+ final = zreceive(1);
+ type = zreceive(2);
+ if (type == 0) {
+ if (!parse_uncompressed_block()) return 0;
+ } else if (type == 3) {
+ return 0;
+ } else {
+ if (type == 1) {
+ // use fixed code lengths
+ if (!default_length[0]) init_defaults();
+ if (!zbuild_huffman(&z_length , default_length , 288)) return 0;
+ if (!zbuild_huffman(&z_distance, default_distance, 32)) return 0;
+ } else {
+ if (!compute_huffman_codes()) return 0;
+ }
+ if (!parse_huffman_block()) return 0;
+ }
+ } while (!final);
+ return 1;
+}
+
+static int do_zlib(char *obuf, int olen, int exp, int parse_header)
+{
+ zout_start = obuf;
+ zout = obuf;
+ zout_end = obuf + olen;
+ z_expandable = exp;
+
+ return parse_zlib(parse_header);
+}
+
+char *stbi_zlib_decode_malloc_guesssize(int initial_size, int *outlen)
+{
+ char *p = (char *) malloc(initial_size);
+ if (p == NULL) return NULL;
+ if (do_zlib(p, initial_size, 1, 1)) {
+ *outlen = (int) (zout - zout_start);
+ return zout_start;
+ } else {
+ free(zout_start);
+ return NULL;
+ }
+}
+
+char *stbi_zlib_decode_malloc(char *buffer, int len, int *outlen)
+{
+ zbuffer = (uint8 *) buffer;
+ zbuffer_end = (uint8 *) buffer+len;
+ return stbi_zlib_decode_malloc_guesssize(16384, outlen);
+}
+
+int stbi_zlib_decode_buffer(char *obuffer, int olen, char *ibuffer, int ilen)
+{
+ zbuffer = (uint8 *) ibuffer;
+ zbuffer_end = (uint8 *) ibuffer + ilen;
+ if (do_zlib(obuffer, olen, 0, 1))
+ return (int) (zout - zout_start);
+ else
+ return -1;
+}
+
+char *stbi_zlib_decode_noheader_malloc(char *buffer, int len, int *outlen)
+{
+ char *p = (char *) malloc(16384);
+ if (p == NULL) return NULL;
+ zbuffer = (uint8 *) buffer;
+ zbuffer_end = (uint8 *) buffer+len;
+ if (do_zlib(p, 16384, 1, 0)) {
+ *outlen = (int) (zout - zout_start);
+ return zout_start;
+ } else {
+ free(zout_start);
+ return NULL;
+ }
+}
+
+int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, char *ibuffer, int ilen)
+{
+ zbuffer = (uint8 *) ibuffer;
+ zbuffer_end = (uint8 *) ibuffer + ilen;
+ if (do_zlib(obuffer, olen, 0, 0))
+ return (int) (zout - zout_start);
+ else
+ return -1;
+}
+
+// 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
+
+
+typedef struct
+{
+ unsigned long length;
+ unsigned long type;
+} chunk;
+
+#define PNG_TYPE(a,b,c,d) (((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
+
+static chunk get_chunk_header(void)
+{
+ chunk c;
+ c.length = get32();
+ c.type = get32();
+ return c;
+}
+
+static int check_png_header(void)
+{
+ static uint8 png_sig[8] = { 137,80,78,71,13,10,26,10 };
+ int i;
+ for (i=0; i < 8; ++i)
+ if (get8() != png_sig[i]) return e("bad png sig","Not a PNG");
+ return 1;
+}
+
+static uint8 *idata, *expanded, *out;
+
+enum {
+ F_none=0, F_sub=1, F_up=2, F_avg=3, F_paeth=4,
+ F_avg_first, F_paeth_first,
+};
+
+static uint8 first_row_filter[5] =
+{
+ F_none, F_sub, F_none, F_avg_first, F_paeth_first
+};
+
+static int 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;
+}
+
+// create the png data from post-deflated data
+static int create_png_image(uint8 *raw, uint32 raw_len, int out_n)
+{
+ uint32 i,j,stride = img_x*out_n;
+ int k;
+ assert(out_n == img_n || out_n == img_n+1);
+ out = (uint8 *) malloc(img_x * img_y * out_n);
+ if (!out) return e("outofmem", "Out of memory");
+ if (raw_len != (img_n * img_x + 1) * img_y) return e("not enough pixels","Corrupt PNG");
+ for (j=0; j < img_y; ++j) {
+ uint8 *cur = out + stride*j;
+ uint8 *prior = cur - stride;
+ int filter = *raw++;
+ if (filter > 4) return e("invalid filter","Corrupt PNG");
+ // if first row, use special filter that doesn't sample previous row
+ if (j == 0) filter = first_row_filter[filter];
+ // handle first pixel explicitly
+ for (k=0; k < img_n; ++k) {
+ switch(filter) {
+ case F_none : cur[k] = raw[k]; break;
+ case F_sub : cur[k] = raw[k]; break;
+ case F_up : cur[k] = raw[k] + prior[k]; break;
+ case F_avg : cur[k] = raw[k] + (prior[k]>>1); break;
+ case F_paeth : cur[k] = (uint8) (raw[k] + paeth(0,prior[k],0)); break;
+ case F_avg_first : cur[k] = raw[k]; break;
+ case F_paeth_first: cur[k] = raw[k]; break;
+ }
+ }
+ if (img_n != out_n) cur[img_n] = 255;
+ raw += img_n;
+ cur += out_n;
+ prior += out_n;
+ // this is a little gross, so that we don't switch per-pixel or per-component
+ if (img_n == out_n) {
+ #define CASE(f) \
+ case f: \
+ for (i=1; i < img_x; ++i, raw+=img_n,cur+=img_n,prior+=img_n) \
+ for (k=0; k < img_n; ++k)
+ switch(filter) {
+ CASE(F_none) cur[k] = raw[k]; break;
+ CASE(F_sub) cur[k] = raw[k] + cur[k-img_n]; break;
+ CASE(F_up) cur[k] = raw[k] + prior[k]; break;
+ CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-img_n])>>1); break;
+ CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],prior[k],prior[k-img_n])); break;
+ CASE(F_avg_first) cur[k] = raw[k] + (cur[k-img_n] >> 1); break;
+ CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],0,0)); break;
+ }
+ #undef CASE
+ } else {
+ assert(img_n+1 == out_n);
+ #define CASE(f) \
+ case f: \
+ for (i=1; i < img_x; ++i, cur[img_n]=255,raw+=img_n,cur+=out_n,prior+=out_n) \
+ for (k=0; k < img_n; ++k)
+ switch(filter) {
+ CASE(F_none) cur[k] = raw[k]; break;
+ CASE(F_sub) cur[k] = raw[k] + cur[k-out_n]; break;
+ CASE(F_up) cur[k] = raw[k] + prior[k]; break;
+ CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-out_n])>>1); break;
+ CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],prior[k],prior[k-out_n])); break;
+ CASE(F_avg_first) cur[k] = raw[k] + (cur[k-out_n] >> 1); break;
+ CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],0,0)); break;
+ }
+ #undef CASE
+ }
+ }
+ return 1;
+}
+
+static int compute_transparency(uint8 tc[3], int out_n)
+{
+ uint32 i, pixel_count = img_x * img_y;
+ uint8 *p = out;
+
+ // compute color-based transparency, assuming we've
+ // already got 255 as the alpha value in the output
+ assert(out_n == 2 || out_n == 4);
+
+ p = out;
+ 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 expand_palette(uint8 *palette, int len, int pal_img_n)
+{
+ uint32 i, pixel_count = img_x * img_y;
+ uint8 *p, *temp_out, *orig = out;
+
+ p = (uint8 *) malloc(pixel_count * pal_img_n);
+ if (p == NULL) return e("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;
+ }
+ }
+ free(out);
+ out = temp_out;
+ return 1;
+}
+
+static int parse_png_file(int scan, int req_comp)
+{
+ uint8 palette[1024], pal_img_n=0;
+ uint8 has_trans=0, tc[3];
+ uint32 ioff=0, idata_limit=0, i, pal_len=0;
+ int first=1,k;
+
+ if (!check_png_header()) return 0;
+
+ if (scan == SCAN_type) return 1;
+
+ for(;;first=0) {
+ chunk c = get_chunk_header();
+ if (first && c.type != PNG_TYPE('I','H','D','R'))
+ return e("first not IHDR","Corrupt PNG");
+ switch (c.type) {
+ case PNG_TYPE('I','H','D','R'): {
+ int depth,color,interlace,comp,filter;
+ if (!first) return e("multiple IHDR","Corrupt PNG");
+ if (c.length != 13) return e("bad IHDR len","Corrupt PNG");
+ img_x = get32(); if (img_x > (1 << 24)) return e("too large","Very large image (corrupt?)");
+ img_y = get32(); if (img_y > (1 << 24)) return e("too large","Very large image (corrupt?)");
+ depth = get8(); if (depth != 8) return e("8bit only","PNG not supported: 8-bit only");
+ color = get8(); if (color > 6) return e("bad ctype","Corrupt PNG");
+ if (color == 3) pal_img_n = 3; else if (color & 1) return e("bad ctype","Corrupt PNG");
+ comp = get8(); if (comp) return e("bad comp method","Corrupt PNG");
+ filter= get8(); if (filter) return e("bad filter method","Corrupt PNG");
+ interlace = get8(); if (interlace) return e("interlaced","PNG not supported: interlaced mode");
+ if (!img_x || !img_y) return e("0-pixel image","Corrupt PNG");
+ if (!pal_img_n) {
+ img_n = (color & 2 ? 3 : 1) + (color & 4 ? 1 : 0);
+ if ((1 << 30) / img_x / img_n < img_y) return e("too large", "Image too large to decode");
+ if (scan == SCAN_header) return 1;
+ } else {
+ // if paletted, then pal_n is our final components, and
+ // img_n is # components to decompress/filter.
+ img_n = 1;
+ if ((1 << 30) / img_x / 4 < img_y) return e("too large","Corrupt PNG");
+ // if SCAN_header, have to scan to see if we have a tRNS
+ }
+ break;
+ }
+
+ case PNG_TYPE('P','L','T','E'): {
+ if (c.length > 256*3) return e("invalid PLTE","Corrupt PNG");
+ pal_len = c.length / 3;
+ if (pal_len * 3 != c.length) return e("invalid PLTE","Corrupt PNG");
+ for (i=0; i < pal_len; ++i) {
+ palette[i*4+0] = get8u();
+ palette[i*4+1] = get8u();
+ palette[i*4+2] = get8u();
+ palette[i*4+3] = 255;
+ }
+ break;
+ }
+
+ case PNG_TYPE('t','R','N','S'): {
+ if (idata) return e("tRNS after IDAT","Corrupt PNG");
+ if (pal_img_n) {
+ if (scan == SCAN_header) { img_n = 4; return 1; }
+ if (pal_len == 0) return e("tRNS before PLTE","Corrupt PNG");
+ if (c.length > pal_len) return e("bad tRNS len","Corrupt PNG");
+ pal_img_n = 4;
+ for (i=0; i < c.length; ++i)
+ palette[i*4+3] = get8u();
+ } else {
+ if (!(img_n & 1)) return e("tRNS with alpha","Corrupt PNG");
+ if (c.length != (uint32) img_n*2) return e("bad tRNS len","Corrupt PNG");
+ has_trans = 1;
+ for (k=0; k < img_n; ++k)
+ tc[k] = (uint8) get16(); // non 8-bit images will be larger
+ }
+ break;
+ }
+
+ case PNG_TYPE('I','D','A','T'): {
+ if (pal_img_n && !pal_len) return e("no PLTE","Corrupt PNG");
+ if (scan == SCAN_header) { img_n = pal_img_n; return 1; }
+ if (ioff + c.length > idata_limit) {
+ uint8 *p;
+ if (idata_limit == 0) idata_limit = c.length > 4096 ? c.length : 4096;
+ while (ioff + c.length > idata_limit)
+ idata_limit *= 2;
+ p = (uint8 *) realloc(idata, idata_limit); if (p == NULL) return e("outofmem", "Out of memory");
+ idata = p;
+ }
+ #ifndef STBI_NO_STDIO
+ if (img_file)
+ {
+ if (fread(idata+ioff,1,c.length,img_file) != c.length) return e("outofdata","Corrupt PNG");
+ }
+ else
+ #endif
+ {
+ memcpy(idata+ioff, img_buffer, c.length);
+ img_buffer += c.length;
+ }
+ ioff += c.length;
+ break;
+ }
+
+ case PNG_TYPE('I','E','N','D'): {
+ uint32 raw_len;
+ if (scan != SCAN_load) return 1;
+ if (idata == NULL) return e("no IDAT","Corrupt PNG");
+ expanded = (uint8 *) stbi_zlib_decode_malloc((char *) idata, ioff, (int *) &raw_len);
+ if (expanded == NULL) return 0; // zlib should set error
+ free(idata); idata = NULL;
+ if ((req_comp == img_n+1 && req_comp != 3 && !pal_img_n) || has_trans)
+ img_out_n = img_n+1;
+ else
+ img_out_n = img_n;
+ if (!create_png_image(expanded, raw_len, img_out_n)) return 0;
+ if (has_trans)
+ if (!compute_transparency(tc, img_out_n)) return 0;
+ if (pal_img_n) {
+ // pal_img_n == 3 or 4
+ img_n = pal_img_n; // record the actual colors we had
+ img_out_n = pal_img_n;
+ if (req_comp >= 3) img_out_n = req_comp;
+ if (!expand_palette(palette, pal_len, img_out_n))
+ return 0;
+ }
+ free(expanded); expanded = NULL;
+ return 1;
+ }
+
+ default:
+ // if critical, fail
+ if ((c.type & (1 << 29)) == 0) {
+ #ifndef STBI_NO_FAILURE_STRINGS
+ static char invalid_chunk[] = "XXXX chunk not known";
+ invalid_chunk[0] = (uint8) (c.type >> 24);
+ invalid_chunk[1] = (uint8) (c.type >> 16);
+ invalid_chunk[2] = (uint8) (c.type >> 8);
+ invalid_chunk[3] = (uint8) (c.type >> 0);
+ #endif
+ return e(invalid_chunk, "PNG not supported: unknown chunk type");
+ }
+ skip(c.length);
+ break;
+ }
+ // end of chunk, read and skip CRC
+ get8(); get8(); get8(); get8();
+ }
+}
+
+static unsigned char *do_png(int *x, int *y, int *n, int req_comp)
+{
+ unsigned char *result=NULL;
+ if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp", "Internal error");
+ if (parse_png_file(SCAN_load, req_comp)) {
+ result = out;
+ out = NULL;
+ if (req_comp && req_comp != img_out_n) {
+ result = convert_format(result, img_out_n, req_comp);
+ if (result == NULL) return result;
+ }
+ *x = img_x;
+ *y = img_y;
+ if (n) *n = img_n;
+ }
+ free(out); out = NULL;
+ free(expanded); expanded = NULL;
+ free(idata); idata = NULL;
+
+ return result;
+}
+
+#ifndef STBI_NO_STDIO
+unsigned char *stbi_png_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
+{
+ start_file(f);
+ return do_png(x,y,comp,req_comp);
+}
+
+unsigned char *stbi_png_load(char *filename, int *x, int *y, int *comp, int req_comp)
+{
+ unsigned char *data;
+ FILE *f = fopen(filename, "rb");
+ if (!f) return NULL;
+ data = stbi_png_load_from_file(f,x,y,comp,req_comp);
+ fclose(f);
+ return data;
+}
+#endif
+
+unsigned char *stbi_png_load_from_memory(unsigned char *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ start_mem(buffer,len);
+ return do_png(x,y,comp,req_comp);
+}
+
+#ifndef STBI_NO_STDIO
+int stbi_png_test_file(FILE *f)
+{
+ int n,r;
+ n = ftell(f);
+ start_file(f);
+ r = parse_png_file(SCAN_type,STBI_default);
+ fseek(f,n,SEEK_SET);
+ return r;
+}
+#endif
+
+int stbi_png_test_memory(unsigned char *buffer, int len)
+{
+ start_mem(buffer, len);
+ return parse_png_file(SCAN_type,STBI_default);
+}
+
+// TODO: load header from png
+#ifndef STBI_NO_STDIO
+extern int stbi_png_info (char *filename, int *x, int *y, int *comp);
+extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp);
+#endif
+extern int stbi_png_info_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp);
+
+// Microsoft/Windows BMP image
+
+static int bmp_test(void)
+{
+ int sz;
+ if (get8() != 'B') return 0;
+ if (get8() != 'M') return 0;
+ get32le(); // discard filesize
+ get16le(); // discard reserved
+ get16le(); // discard reserved
+ get32le(); // discard data offset
+ sz = get32le();
+ if (sz == 12 || sz == 40 || sz == 56 || sz == 108) return 1;
+ return 0;
+}
+
+#ifndef STBI_NO_STDIO
+int stbi_bmp_test_file (FILE *f)
+{
+ int r,n = ftell(f);
+ start_file(f);
+ r = bmp_test();
+ fseek(f,n,SEEK_SET);
+ return r;
+}
+#endif
+
+int stbi_bmp_test_memory (stbi_uc *buffer, int len)
+{
+ start_mem(buffer, len);
+ return bmp_test();
+}
+
+// returns 0..31 for the highest set bit
+static int 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, z >>= 1;
+ return n;
+}
+
+static int 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;
+}
+
+static int shiftsigned(int v, int shift, int bits)
+{
+ int result;
+ int z=0;
+
+ if (shift < 0) v <<= -shift;
+ else v >>= shift;
+ result = v;
+
+ z = bits;
+ while (z < 8) {
+ result += v >> z;
+ z += bits;
+ }
+ return result;
+}
+
+static stbi_uc *bmp_load(int *x, int *y, int *comp, int req_comp)
+{
+ unsigned int mr=0,mg=0,mb=0,ma=0;
+ stbi_uc pal[256][4];
+ int psize=0,i,j,compress=0,width;
+ int bpp, flip_vertically, pad, target, offset, hsz;
+ if (get8() != 'B' || get8() != 'M') return epuc("not BMP", "Corrupt BMP");
+ get32le(); // discard filesize
+ get16le(); // discard reserved
+ get16le(); // discard reserved
+ offset = get32le();
+ hsz = get32le();
+ if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108) return epuc("unknown BMP", "BMP type not supported: unknown");
+ failure_reason = "bad BMP";
+ if (hsz == 12) {
+ img_x = get16le();
+ img_y = get16le();
+ } else {
+ img_x = get32le();
+ img_y = get32le();
+ }
+ if (get16le() != 1) return 0;
+ bpp = get16le();
+ if (bpp == 1) return epuc("monochrome", "BMP type not supported: 1-bit");
+ flip_vertically = ((int) img_y) > 0;
+ img_y = abs((int) img_y);
+ if (hsz == 12) {
+ if (bpp < 24)
+ psize = (offset - 14 - 24) / 3;
+ } else {
+ compress = get32le();
+ if (compress == 1 || compress == 2) return epuc("BMP RLE", "BMP type not supported: RLE");
+ get32le(); // discard sizeof
+ get32le(); // discard hres
+ get32le(); // discard vres
+ get32le(); // discard colorsused
+ get32le(); // discard max important
+ if (hsz == 40 || hsz == 56) {
+ if (hsz == 56) {
+ get32le();
+ get32le();
+ get32le();
+ get32le();
+ }
+ if (bpp == 16 || bpp == 32) {
+ mr = mg = mb = 0;
+ if (compress == 0) {
+ if (bpp == 32) {
+ mr = 0xff << 16;
+ mg = 0xff << 8;
+ mb = 0xff << 0;
+ } else {
+ mr = 31 << 10;
+ mg = 31 << 5;
+ mb = 31 << 0;
+ }
+ } else if (compress == 3) {
+ mr = get32le();
+ mg = get32le();
+ mb = get32le();
+ // not documented, but generated by photoshop and handled by mspaint
+ if (mr == mg && mg == mb) {
+ // ?!?!?
+ return NULL;
+ }
+ } else
+ return NULL;
+ }
+ } else {
+ assert(hsz == 108);
+ mr = get32le();
+ mg = get32le();
+ mb = get32le();
+ ma = get32le();
+ get32le(); // discard color space
+ for (i=0; i < 12; ++i)
+ get32le(); // discard color space parameters
+ }
+ if (bpp < 16)
+ psize = (offset - 14 - hsz) >> 2;
+ }
+ img_n = ma ? 4 : 3;
+ if (req_comp && req_comp >= 3) // we can directly decode 3 or 4
+ target = req_comp;
+ else
+ target = img_n; // if they want monochrome, we'll post-convert
+ out = (stbi_uc *) malloc(target * img_x * img_y);
+ if (!out) return epuc("outofmem", "Out of memory");
+ if (bpp < 16) {
+ int z=0;
+ if (psize == 0 || psize > 256) return epuc("invalid", "Corrupt BMP");
+ for (i=0; i < psize; ++i) {
+ pal[i][2] = get8();
+ pal[i][1] = get8();
+ pal[i][0] = get8();
+ if (hsz != 12) get8();
+ pal[i][3] = 255;
+ }
+ skip(offset - 14 - hsz - psize * (hsz == 12 ? 3 : 4));
+ if (bpp == 4) width = (img_x + 1) >> 1;
+ else if (bpp == 8) width = img_x;
+ else return epuc("bad bpp", "Corrupt BMP");
+ pad = (-width)&3;
+ for (j=0; j < (int) img_y; ++j) {
+ for (i=0; i < (int) img_x; i += 2) {
+ int v=get8(),v2=0;
+ if (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) img_x) break;
+ v = (bpp == 8) ? get8() : v2;
+ out[z++] = pal[v][0];
+ out[z++] = pal[v][1];
+ out[z++] = pal[v][2];
+ if (target == 4) out[z++] = 255;
+ }
+ skip(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;
+ skip(offset - 14 - hsz);
+ if (bpp == 24) width = 3 * img_x;
+ else if (bpp == 16) width = 2*img_x;
+ else /* bpp = 32 and pad = 0 */ width=0;
+ pad = (-width) & 3;
+ if (bpp == 24) {
+ easy = 1;
+ } else if (bpp == 32) {
+ if (mb == 0xff && mg == 0xff00 && mr == 0xff000000 && ma == 0xff000000)
+ easy = 2;
+ }
+ if (!easy) {
+ if (!mr || !mg || !mb) return epuc("bad masks", "Corrupt BMP");
+ // right shift amt to put high bit in position #7
+ rshift = high_bit(mr)-7; rcount = bitcount(mr);
+ gshift = high_bit(mg)-7; gcount = bitcount(mr);
+ bshift = high_bit(mb)-7; bcount = bitcount(mr);
+ ashift = high_bit(ma)-7; acount = bitcount(mr);
+ }
+ for (j=0; j < (int) img_y; ++j) {
+ if (easy) {
+ for (i=0; i < (int) img_x; ++i) {
+ int a;
+ out[z+2] = get8();
+ out[z+1] = get8();
+ out[z+0] = get8();
+ z += 3;
+ a = (easy == 2 ? get8() : 255);
+ if (target == 4) out[z++] = a;
+ }
+ } else {
+ for (i=0; i < (int) img_x; ++i) {
+ unsigned long v = (bpp == 16 ? get16le() : get32le());
+ int a;
+ out[z++] = shiftsigned(v & mr, rshift, rcount);
+ out[z++] = shiftsigned(v & mg, gshift, gcount);
+ out[z++] = shiftsigned(v & mb, bshift, bcount);
+ a = (ma ? shiftsigned(v & ma, ashift, acount) : 255);
+ if (target == 4) out[z++] = a;
+ }
+ }
+ skip(pad);
+ }
+ }
+ if (flip_vertically) {
+ stbi_uc t;
+ for (j=0; j < (int) img_y>>1; ++j) {
+ stbi_uc *p1 = out + j *img_x*target;
+ stbi_uc *p2 = out + (img_y-1-j)*img_x*target;
+ for (i=0; i < (int) img_x*target; ++i) {
+ t = p1[i], p1[i] = p2[i], p2[i] = t;
+ }
+ }
+ }
+
+ if (req_comp && req_comp != target) {
+ out = convert_format(out, target, req_comp);
+ if (out == NULL) return out; // convert_format frees input on failure
+ }
+
+ *x = img_x;
+ *y = img_y;
+ if (comp) *comp = target;
+ return out;
+}
+
+#ifndef STBI_NO_STDIO
+stbi_uc *stbi_bmp_load (char *filename, int *x, int *y, int *comp, int req_comp)
+{
+ stbi_uc *data;
+ FILE *f = fopen(filename, "rb");
+ if (!f) return NULL;
+ data = stbi_bmp_load_from_file(f, x,y,comp,req_comp);
+ fclose(f);
+ return data;
+}
+
+stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp)
+{
+ start_file(f);
+ return bmp_load(x,y,comp,req_comp);
+}
+#endif
+
+stbi_uc *stbi_bmp_load_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ start_mem(buffer, len);
+ return bmp_load(x,y,comp,req_comp);
+}
+
+// Targa Truevision - TGA
+// by Jonathan Dummer
+
+static int tga_test(void)
+{
+ int sz;
+ get8u(); // discard Offset
+ sz = get8u(); // color type
+ if( sz > 1 ) return 0; // only RGB or indexed allowed
+ sz = get8u(); // image type
+ if( (sz != 1) && (sz != 2) && (sz != 3) && (sz != 9) && (sz != 10) && (sz != 11) ) return 0; // only RGB or grey allowed, +/- RLE
+ get16(); // discard palette start
+ get16(); // discard palette length
+ get8(); // discard bits per palette color entry
+ get16(); // discard x origin
+ get16(); // discard y origin
+ if( get16() < 1 ) return 0; // test width
+ if( get16() < 1 ) return 0; // test height
+ sz = get8(); // bits per pixel
+ if( (sz != 8) && (sz != 16) && (sz != 24) && (sz != 32) ) return 0; // only RGB or RGBA or grey allowed
+ return 1; // seems to have passed everything
+}
+
+#ifndef STBI_NO_STDIO
+int stbi_tga_test_file (FILE *f)
+{
+ int r,n = ftell(f);
+ start_file(f);
+ r = tga_test();
+ fseek(f,n,SEEK_SET);
+ return r;
+}
+#endif
+
+int stbi_tga_test_memory (stbi_uc *buffer, int len)
+{
+ start_mem(buffer, len);
+ return tga_test();
+}
+
+static stbi_uc *tga_load(int *x, int *y, int *comp, int req_comp)
+{
+ // read in the TGA header stuff
+ int tga_offset = get8u();
+ int tga_indexed = get8u();
+ int tga_image_type = get8u();
+ int tga_is_RLE = 0;
+ int tga_palette_start = get16le();
+ int tga_palette_len = get16le();
+ int tga_palette_bits = get8u();
+ int tga_x_origin = get16le();
+ int tga_y_origin = get16le();
+ int tga_width = get16le();
+ int tga_height = get16le();
+ int tga_bits_per_pixel = get8u();
+ int tga_inverted = get8u();
+ // image data
+ unsigned char *tga_data;
+ unsigned char *tga_palette = NULL;
+ int i, j;
+ unsigned char raw_data[4];
+ unsigned char trans_data[4];
+ int RLE_count = 0;
+ int RLE_repeating = 0;
+ int read_next_pixel = 1;
+ // do a tiny bit of precessing
+ if( tga_image_type >= 8 )
+ {
+ tga_image_type -= 8;
+ tga_is_RLE = 1;
+ }
+ /* int tga_alpha_bits = tga_inverted & 15; */
+ tga_inverted = 1 - ((tga_inverted >> 5) & 1);
+
+ // error check
+ if( //(tga_indexed) ||
+ (tga_width < 1) || (tga_height < 1) ||
+ (tga_image_type < 1) || (tga_image_type > 3) ||
+ ((tga_bits_per_pixel != 8) && (tga_bits_per_pixel != 16) &&
+ (tga_bits_per_pixel != 24) && (tga_bits_per_pixel != 32))
+ )
+ {
+ return NULL;
+ }
+
+ // If I'm paletted, then I'll use the number of bits from the palette
+ if( tga_indexed )
+ {
+ tga_bits_per_pixel = tga_palette_bits;
+ }
+
+ // tga info
+ *x = tga_width;
+ *y = tga_height;
+ if( (req_comp < 1) || (req_comp > 4) )
+ {
+ // just use whatever the file was
+ req_comp = tga_bits_per_pixel / 8;
+ *comp = req_comp;
+ } else
+ {
+ // force a new number of components
+ *comp = tga_bits_per_pixel/8;
+ }
+ tga_data = (unsigned char*)malloc( tga_width * tga_height * req_comp );
+
+ // skip to the data's starting position (offset usually = 0)
+ skip( tga_offset );
+ // do I need to load a palette?
+ if( tga_indexed )
+ {
+ // any data to skip? (offset usually = 0)
+ skip( tga_palette_start );
+ // load the palette
+ tga_palette = (unsigned char*)malloc( tga_palette_len * tga_palette_bits / 8 );
+ getn( tga_palette, tga_palette_len * tga_palette_bits / 8 );
+ }
+ // 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 chunk?
+ if( tga_is_RLE )
+ {
+ if( RLE_count == 0 )
+ {
+ // yep, get the next byte as a RLE command
+ int RLE_cmd = get8u();
+ 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 1 byte, then perform the lookup
+ int pal_idx = get8u();
+ if( pal_idx >= tga_palette_len )
+ {
+ // invalid index
+ pal_idx = 0;
+ }
+ pal_idx *= tga_bits_per_pixel / 8;
+ for( j = 0; j*8 < tga_bits_per_pixel; ++j )
+ {
+ raw_data[j] = tga_palette[pal_idx+j];
+ }
+ } else
+ {
+ // read in the data raw
+ for( j = 0; j*8 < tga_bits_per_pixel; ++j )
+ {
+ raw_data[j] = get8u();
+ }
+ }
+ // convert raw to the intermediate format
+ switch( tga_bits_per_pixel )
+ {
+ case 8:
+ // Luminous => RGBA
+ trans_data[0] = raw_data[0];
+ trans_data[1] = raw_data[0];
+ trans_data[2] = raw_data[0];
+ trans_data[3] = 255;
+ break;
+ case 16:
+ // Luminous,Alpha => RGBA
+ trans_data[0] = raw_data[0];
+ trans_data[1] = raw_data[0];
+ trans_data[2] = raw_data[0];
+ trans_data[3] = raw_data[1];
+ break;
+ case 24:
+ // BGR => RGBA
+ trans_data[0] = raw_data[2];
+ trans_data[1] = raw_data[1];
+ trans_data[2] = raw_data[0];
+ trans_data[3] = 255;
+ break;
+ case 32:
+ // BGRA => RGBA
+ trans_data[0] = raw_data[2];
+ trans_data[1] = raw_data[1];
+ trans_data[2] = raw_data[0];
+ trans_data[3] = raw_data[3];
+ break;
+ }
+ // clear the reading flag for the next pixel
+ read_next_pixel = 0;
+ } // end of reading a pixel
+ // convert to final format
+ switch( req_comp )
+ {
+ case 1:
+ // RGBA => Luminance
+ tga_data[i*req_comp+0] = compute_y(trans_data[0],trans_data[1],trans_data[2]);
+ break;
+ case 2:
+ // RGBA => Luminance,Alpha
+ tga_data[i*req_comp+0] = compute_y(trans_data[0],trans_data[1],trans_data[2]);
+ tga_data[i*req_comp+1] = trans_data[3];
+ break;
+ case 3:
+ // RGBA => RGB
+ tga_data[i*req_comp+0] = trans_data[0];
+ tga_data[i*req_comp+1] = trans_data[1];
+ tga_data[i*req_comp+2] = trans_data[2];
+ break;
+ case 4:
+ // RGBA => RGBA
+ tga_data[i*req_comp+0] = trans_data[0];
+ tga_data[i*req_comp+1] = trans_data[1];
+ tga_data[i*req_comp+2] = trans_data[2];
+ tga_data[i*req_comp+3] = trans_data[3];
+ break;
+ }
+ // 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 * req_comp;
+ int index2 = (tga_height - 1 - j) * tga_width * req_comp;
+ for( i = tga_width * req_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 )
+ {
+ free( tga_palette );
+ }
+ // 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;
+ // OK, done
+ return tga_data;
+}
+
+#ifndef STBI_NO_STDIO
+stbi_uc *stbi_tga_load (char *filename, int *x, int *y, int *comp, int req_comp)
+{
+ stbi_uc *data;
+ FILE *f = fopen(filename, "rb");
+ if (!f) return NULL;
+ data = stbi_tga_load_from_file(f, x,y,comp,req_comp);
+ fclose(f);
+ return data;
+}
+
+stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp)
+{
+ start_file(f);
+ return tga_load(x,y,comp,req_comp);
+}
+#endif
+
+stbi_uc *stbi_tga_load_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ start_mem(buffer, len);
+ return tga_load(x,y,comp,req_comp);
+}
+
+
+// *************************************************************************************************
+// Photoshop PSD loader -- PD by Thatcher Ulrich, integration by Nicholas Schulz, tweaked by STB
+
+static int psd_test(void)
+{
+ if (get32() != 0x38425053) return 0; // "8BPS"
+ else return 1;
+}
+
+#ifndef STBI_NO_STDIO
+int stbi_psd_test_file(FILE *f)
+{
+ int r,n = ftell(f);
+ start_file(f);
+ r = psd_test();
+ fseek(f,n,SEEK_SET);
+ return r;
+}
+#endif
+
+int stbi_psd_test_memory(stbi_uc *buffer, int len)
+{
+ start_mem(buffer, len);
+ return psd_test();
+}
+
+static stbi_uc *psd_load(int *x, int *y, int *comp, int req_comp)
+{
+ int pixelCount;
+ int channelCount, compression;
+ int channel, i, count, len;
+ int w,h;
+
+ // Check identifier
+ if (get32() != 0x38425053) // "8BPS"
+ return epuc("not PSD", "Corrupt PSD image");
+
+ // Check file type version.
+ if (get16() != 1)
+ return epuc("wrong version", "Unsupported version of PSD image");
+
+ // Skip 6 reserved bytes.
+ skip( 6 );
+
+ // Read the number of channels (R, G, B, A, etc).
+ channelCount = get16();
+ if (channelCount < 0 || channelCount > 16)
+ return epuc("wrong channel count", "Unsupported number of channels in PSD image");
+
+ // Read the rows and columns of the image.
+ h = get32();
+ w = get32();
+
+ // Make sure the depth is 8 bits.
+ if (get16() != 8)
+ return epuc("unsupported bit depth", "PSD bit depth is not 8 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 (get16() != 3)
+ return epuc("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.)
+ skip(get32() );
+
+ // Skip the image resources. (resolution, pen tool paths, etc)
+ skip( get32() );
+
+ // Skip the reserved data.
+ skip( get32() );
+
+ // Find out if the data is compressed.
+ // Known values:
+ // 0: no compression
+ // 1: RLE compressed
+ compression = get16();
+ if (compression > 1)
+ return epuc("unknown compression type", "PSD has an unknown compression format");
+
+ // Create the destination image.
+ out = (stbi_uc *) malloc(4 * w*h);
+ if (!out) return epuc("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 preceeded by a 2-byte data count for each row in the data,
+ // which we're going to just skip.
+ skip( h * channelCount * 2 );
+
+ // Read the RLE data by channel.
+ for (channel = 0; channel < 4; channel++) {
+ uint8 *p;
+
+ p = out+channel;
+ if (channel >= channelCount) {
+ // Fill this channel with default data.
+ for (i = 0; i < pixelCount; i++) *p = (channel == 3 ? 255 : 0), p += 4;
+ } else {
+ // Read the RLE data.
+ count = 0;
+ while (count < pixelCount) {
+ len = get8();
+ if (len == 128) {
+ // No-op.
+ } else if (len < 128) {
+ // Copy next len+1 bytes literally.
+ len++;
+ count += len;
+ while (len) {
+ *p = get8();
+ p += 4;
+ len--;
+ }
+ } else if (len > 128) {
+ uint32 val;
+ // Next -len+1 bytes in the dest are replicated from next source byte.
+ // (Interpret len as a negative 8-bit int.)
+ len ^= 0x0FF;
+ len += 2;
+ val = get8();
+ count += len;
+ while (len) {
+ *p = val;
+ p += 4;
+ len--;
+ }
+ }
+ }
+ }
+ }
+
+ } 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 value for each pixel in the image.
+
+ // Read the data by channel.
+ for (channel = 0; channel < 4; channel++) {
+ uint8 *p;
+
+ p = out + channel;
+ if (channel > channelCount) {
+ // Fill this channel with default data.
+ for (i = 0; i < pixelCount; i++) *p = channel == 3 ? 255 : 0, p += 4;
+ } else {
+ // Read the data.
+ count = 0;
+ for (i = 0; i < pixelCount; i++)
+ *p = get8(), p += 4;
+ }
+ }
+ }
+
+ if (req_comp && req_comp != 4) {
+ out = convert_format(out, 4, req_comp);
+ if (out == NULL) return out; // convert_format frees input on failure
+ }
+
+ if (comp) *comp = channelCount;
+ *y = h;
+ *x = w;
+
+ return out;
+}
+
+#ifndef STBI_NO_STDIO
+stbi_uc *stbi_psd_load(char *filename, int *x, int *y, int *comp, int req_comp)
+{
+ stbi_uc *data;
+ FILE *f = fopen(filename, "rb");
+ if (!f) return NULL;
+ data = stbi_psd_load_from_file(f, x,y,comp,req_comp);
+ fclose(f);
+ return data;
+}
+
+stbi_uc *stbi_psd_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
+{
+ start_file(f);
+ return psd_load(x,y,comp,req_comp);
+}
+#endif
+
+stbi_uc *stbi_psd_load_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ start_mem(buffer, len);
+ return psd_load(x,y,comp,req_comp);
+}
+
+
+// *************************************************************************************************
+// Radiance RGBE HDR loader
+// originally by Nicolas Schulz
+#ifndef STBI_NO_HDR
+static int hdr_test(void)
+{
+ char *signature = "#?RADIANCE\n";
+ int i;
+ for (i=0; signature[i]; ++i)
+ if (get8() != signature[i])
+ return 0;
+ return 1;
+}
+
+int stbi_hdr_test_memory(stbi_uc *buffer, int len)
+{
+ start_mem(buffer, len);
+ return hdr_test();
+}
+
+#ifndef STBI_NO_STDIO
+int stbi_hdr_test_file(FILE *f)
+{
+ int r,n = ftell(f);
+ start_file(f);
+ r = hdr_test();
+ fseek(f,n,SEEK_SET);
+ return r;
+}
+#endif
+
+#define HDR_BUFLEN 1024
+static char *hdr_gettoken(char *buffer)
+{
+ int len=0;
+ char *s = buffer, c = '\0';
+
+ c = get8();
+
+ while (!at_eof() && c != '\n') {
+ buffer[len++] = c;
+ if (len == HDR_BUFLEN-1) {
+ // flush to end of line
+ while (!at_eof() && get8() != '\n')
+ ;
+ break;
+ }
+ c = get8();
+ }
+
+ buffer[len] = 0;
+ return buffer;
+}
+
+static void 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 *hdr_load(int *x, int *y, int *comp, int req_comp)
+{
+ char buffer[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;
+
+
+ // Check identifier
+ if (strcmp(hdr_gettoken(buffer), "#?RADIANCE") != 0)
+ return epf("not HDR", "Corrupt HDR image");
+
+ // Parse header
+ while(1) {
+ token = hdr_gettoken(buffer);
+ if (token[0] == 0) break;
+ if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1;
+ }
+
+ if (!valid) return epf("unsupported format", "Unsupported HDR format");
+
+ // Parse width and height
+ // can't use sscanf() if we're not using stdio!
+ token = hdr_gettoken(buffer);
+ if (strncmp(token, "-Y ", 3)) return epf("unsupported data layout", "Unsupported HDR format");
+ token += 3;
+ height = strtol(token, &token, 10);
+ while (*token == ' ') ++token;
+ if (strncmp(token, "+X ", 3)) return epf("unsupported data layout", "Unsupported HDR format");
+ token += 3;
+ width = strtol(token, NULL, 10);
+
+ *x = width;
+ *y = height;
+
+ *comp = 3;
+ if (req_comp == 0) req_comp = 3;
+
+ // Read data
+ hdr_data = (float *) malloc(height * width * req_comp * sizeof(float));
+
+ // 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:
+ getn(rgbe, 4);
+ 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 = get8();
+ c2 = get8();
+ len = get8();
+ 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] = { c1,c2,len, get8() };
+ hdr_convert(hdr_data, rgbe, req_comp);
+ i = 1;
+ j = 0;
+ free(scanline);
+ goto main_decode_loop; // yes, this is fucking insane; blame the fucking insane format
+ }
+ len <<= 8;
+ len |= get8();
+ if (len != width) { free(hdr_data); free(scanline); return epf("invalid decoded scanline length", "corrupt HDR"); }
+ if (scanline == NULL) scanline = (stbi_uc *) malloc(width * 4);
+
+ for (k = 0; k < 4; ++k) {
+ i = 0;
+ while (i < width) {
+ count = get8();
+ if (count > 128) {
+ // Run
+ value = get8();
+ count -= 128;
+ for (z = 0; z < count; ++z)
+ scanline[i++ * 4 + k] = value;
+ } else {
+ // Dump
+ for (z = 0; z < count; ++z)
+ scanline[i++ * 4 + k] = get8();
+ }
+ }
+ }
+ for (i=0; i < width; ++i)
+ hdr_convert(hdr_data+(j*width + i)*req_comp, scanline + i*4, req_comp);
+ }
+ free(scanline);
+ }
+
+ return hdr_data;
+}
+
+#ifndef STBI_NO_STDIO
+float *stbi_hdr_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
+{
+ start_file(f);
+ return hdr_load(x,y,comp,req_comp);
+}
+#endif
+
+float *stbi_hdr_load_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ start_mem(buffer, len);
+ return hdr_load(x,y,comp,req_comp);
+}
+
+#endif // STBI_NO_HDR
+
+/////////////////////// write image ///////////////////////
+
+#ifndef STBI_NO_WRITE
+
+static void write8(FILE *f, int x) { uint8 z = (uint8) x; fwrite(&z,1,1,f); }
+
+static void writefv(FILE *f, char *fmt, va_list v)
+{
+ while (*fmt) {
+ switch (*fmt++) {
+ case ' ': break;
+ case '1': { uint8 x = va_arg(v, int); write8(f,x); break; }
+ case '2': { int16 x = va_arg(v, int); write8(f,x); write8(f,x>>8); break; }
+ case '4': { int32 x = va_arg(v, int); write8(f,x); write8(f,x>>8); write8(f,x>>16); write8(f,x>>24); break; }
+ default:
+ assert(0);
+ va_end(v);
+ return;
+ }
+ }
+}
+
+static void writef(FILE *f, char *fmt, ...)
+{
+ va_list v;
+ va_start(v, fmt);
+ writefv(f,fmt,v);
+ va_end(v);
+}
+
+static void write_pixels(FILE *f, int rgb_dir, int vdir, int x, int y, int comp, void *data, int write_alpha, int scanline_pad)
+{
+ uint8 bg[3] = { 255, 0, 255}, px[3];
+ uint32 zero = 0;
+ int i,j,k, j_end;
+
+ if (vdir < 0)
+ j_end = -1, j = y-1;
+ else
+ j_end = y, j = 0;
+
+ for (; j != j_end; j += vdir) {
+ for (i=0; i < x; ++i) {
+ uint8 *d = (uint8 *) data + (j*x+i)*comp;
+ if (write_alpha < 0)
+ fwrite(&d[comp-1], 1, 1, f);
+ switch (comp) {
+ case 1:
+ case 2: writef(f, "111", d[0],d[0],d[0]);
+ break;
+ case 4:
+ if (!write_alpha) {
+ for (k=0; k < 3; ++k)
+ px[k] = bg[k] + ((d[k] - bg[k]) * d[3])/255;
+ writef(f, "111", px[1-rgb_dir],px[1],px[1+rgb_dir]);
+ break;
+ }
+ /* FALLTHROUGH */
+ case 3:
+ writef(f, "111", d[1-rgb_dir],d[1],d[1+rgb_dir]);
+ break;
+ }
+ if (write_alpha > 0)
+ fwrite(&d[comp-1], 1, 1, f);
+ }
+ fwrite(&zero,scanline_pad,1,f);
+ }
+}
+
+static int outfile(char *filename, int rgb_dir, int vdir, int x, int y, int comp, void *data, int alpha, int pad, char *fmt, ...)
+{
+ FILE *f = fopen(filename, "wb");
+ if (f) {
+ va_list v;
+ va_start(v, fmt);
+ writefv(f, fmt, v);
+ va_end(v);
+ write_pixels(f,rgb_dir,vdir,x,y,comp,data,alpha,pad);
+ fclose(f);
+ }
+ return f != NULL;
+}
+
+int stbi_write_bmp(char *filename, int x, int y, int comp, void *data)
+{
+ int pad = (-x*3) & 3;
+ return outfile(filename,-1,-1,x,y,comp,data,0,pad,
+ "11 4 22 4" "4 44 22 444444",
+ 'B', 'M', 14+40+(x*3+pad)*y, 0,0, 14+40, // file header
+ 40, x,y, 1,24, 0,0,0,0,0,0); // bitmap header
+}
+
+int stbi_write_tga(char *filename, int x, int y, int comp, void *data)
+{
+ int has_alpha = !(comp & 1);
+ return outfile(filename, -1,-1, x, y, comp, data, has_alpha, 0,
+ "111 221 2222 11", 0,0,2, 0,0,0, 0,0,x,y, 24+8*has_alpha, 8*has_alpha);
+}
+
+// any other image formats that do interleaved rgb data?
+// PNG: requires adler32,crc32 -- significant amount of code
+// PSD: no, channels output separately
+// TIFF: no, stripwise-interleaved... i think
+
+#endif // STBI_NO_WRITE
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