/* stbi-1.18 - 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 8-bit only BMP non-1bpp, non-RLE TGA (not sure what subset, if a subset) PSD (composited 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) supports installable dequantizing-IDCT, YCbCr-to-RGB conversion (define STBI_SIMD) TODO: stbi_info_* history: 1.18 fix a threading bug (local mutable static) 1.17 support interlaced PNG 1.16 major bugfix - convert_format converted one too many pixels 1.15 initialize some fields for thread safety 1.14 fix threadsafe conversion bug; header-file-only version (#define STBI_HEADER_FILE_ONLY before including) 1.13 threadsafe 1.12 const qualifiers in the API 1.11 Support installable IDCT, colorspace conversion routines 1.10 Fixes for 64-bit (don't use "unsigned long") optimized upsampling by Fabian "ryg" Giesen 1.09 Fix format-conversion for PSD code (bad global variables!) 1.08 Thatcher Ulrich's PSD code integrated by Nicolas Schulz 1.07 attempt to fix C++ warning/errors again 1.06 attempt to fix C++ warning/errors again 1.05 fix TGA loading to return correct *comp and use good luminance calc 1.04 default float alpha is 1, not 255; use 'void *' for stbi_image_free 1.03 bugfixes to STBI_NO_STDIO, STBI_NO_HDR 1.02 support for (subset of) HDR files, float interface for preferred access to them 1.01 fix bug: possible bug in handling right-side up bmps... not sure fix bug: the stbi_bmp_load() and stbi_tga_load() functions didn't work at all 1.00 interface to zlib that skips zlib header 0.99 correct handling of alpha in palette 0.98 TGA loader by lonesock; dynamically add loaders (untested) 0.97 jpeg errors on too large a file; also catch another malloc failure 0.96 fix detection of invalid v value - particleman@mollyrocket forum 0.95 during header scan, seek to markers in case of padding 0.94 STBI_NO_STDIO to disable stdio usage; rename all #defines the same 0.93 handle jpegtran output; verbose errors 0.92 read 4,8,16,24,32-bit BMP files of several formats 0.91 output 24-bit Windows 3.0 BMP files 0.90 fix a few more warnings; bump version number to approach 1.0 0.61 bugfixes due to Marc LeBlanc, Christopher Lloyd 0.60 fix compiling as c++ 0.59 fix warnings: merge Dave Moore's -Wall fixes 0.58 fix bug: zlib uncompressed mode len/nlen was wrong endian 0.57 fix bug: jpg last huffman symbol before marker was >9 bits but less than 16 available 0.56 fix bug: zlib uncompressed mode len vs. nlen 0.55 fix bug: restart_interval not initialized to 0 0.54 allow NULL for 'int *comp' 0.53 fix bug in png 3->4; speedup png decoding 0.52 png handles req_comp=3,4 directly; minor cleanup; jpeg comments 0.51 obey req_comp requests, 1-component jpegs return as 1-component, on 'test' only check type, not whether we support this variant */ #ifndef STBI_INCLUDE_STB_IMAGE_H #define STBI_INCLUDE_STB_IMAGE_H //// 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 #endif #define STBI_VERSION 1 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 const *filename, int x, int y, int comp, void *data); extern int stbi_write_tga (char const *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 const *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 const *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 const *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 const *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 // NOT THREADSAFE 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 const *buffer, int len, int *x, int *y, int *comp); extern int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len); #ifndef STBI_NO_STDIO extern int stbi_info (char const *filename, int *x, int *y, int *comp); extern int stbi_is_hdr (char const *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(const char *buffer, int len, int initial_size, int *outlen); extern char *stbi_zlib_decode_malloc(const char *buffer, int len, int *outlen); extern int stbi_zlib_decode_buffer(char *obuffer, int olen, const char *ibuffer, int ilen); extern char *stbi_zlib_decode_noheader_malloc(const char *buffer, int len, int *outlen); extern int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen); // TYPE-SPECIFIC ACCESS // is it a jpeg? extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len); extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp); #ifndef STBI_NO_STDIO extern stbi_uc *stbi_jpeg_load (char const *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 const *filename, int *x, int *y, int *comp); extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp); #endif // is it a png? extern int stbi_png_test_memory (stbi_uc const *buffer, int len); extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp); extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp); #ifndef STBI_NO_STDIO extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp); extern int stbi_png_info (char const *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 const *buffer, int len); extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp); extern stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *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 const *buffer, int len); extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp); extern stbi_uc *stbi_tga_load_from_memory (stbi_uc const *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 const *buffer, int len); extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp); extern stbi_uc *stbi_psd_load_from_memory (stbi_uc const *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 const *buffer, int len); extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp); extern float * stbi_hdr_load_from_memory (stbi_uc const *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 const *buffer, int len); stbi_uc * (*load_from_memory)(stbi_uc const *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) // NOT THREADSAFE extern int stbi_register_loader(stbi_loader *loader); // define faster low-level operations (typically SIMD support) #if STBI_SIMD typedef void (*stbi_idct_8x8)(uint8 *out, int out_stride, short data[64], unsigned short *dequantize); // compute an integer IDCT on "input" // input[x] = data[x] * dequantize[x] // write results to 'out': 64 samples, each run of 8 spaced by 'out_stride' // CLAMP results to 0..255 typedef void (*stbi_YCbCr_to_RGB_run)(uint8 *output, uint8 const *y, uint8 const *cb, uint8 const *cr, int count, int step); // compute a conversion from YCbCr to RGB // 'count' pixels // write pixels to 'output'; each pixel is 'step' bytes (either 3 or 4; if 4, write '255' as 4th), order R,G,B // y: Y input channel // cb: Cb input channel; scale/biased to be 0..255 // cr: Cr input channel; scale/biased to be 0..255 extern void stbi_install_idct(stbi_idct_8x8 func); extern void stbi_install_YCbCr_to_RGB(stbi_YCbCr_to_RGB_run func); #endif // STBI_SIMD #ifdef __cplusplus } #endif // // //// end header file ///////////////////////////////////////////////////// #endif // STBI_INCLUDE_STB_IMAGE_H #ifndef STBI_HEADER_FILE_ONLY #ifndef STBI_NO_HDR #include // ldexp #include // strcmp #endif #ifndef STBI_NO_STDIO #include #endif #include #include #include #include #ifndef _MSC_VER #ifdef __cplusplus #define __forceinline inline #else #define __forceinline #endif #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 // // this is not threadsafe 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 const *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 const *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 const *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 const *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! int stbi_is_hdr_from_memory(stbi_uc const *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 const *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 const *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 const *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 // enum { SCAN_load=0, SCAN_type, SCAN_header, }; typedef struct { uint32 img_x, img_y; int img_n, img_out_n; #ifndef STBI_NO_STDIO FILE *img_file; #endif uint8 *img_buffer, *img_buffer_end; } stbi; #ifndef STBI_NO_STDIO static void start_file(stbi *s, FILE *f) { s->img_file = f; } #endif static void start_mem(stbi *s, uint8 const *buffer, int len) { #ifndef STBI_NO_STDIO s->img_file = NULL; #endif s->img_buffer = (uint8 *) buffer; s->img_buffer_end = (uint8 *) buffer+len; } __forceinline static int get8(stbi *s) { #ifndef STBI_NO_STDIO if (s->img_file) { int c = fgetc(s->img_file); return c == EOF ? 0 : c; } #endif if (s->img_buffer < s->img_buffer_end) return *s->img_buffer++; return 0; } __forceinline static int at_eof(stbi *s) { #ifndef STBI_NO_STDIO if (s->img_file) return feof(s->img_file); #endif return s->img_buffer >= s->img_buffer_end; } __forceinline static uint8 get8u(stbi *s) { return (uint8) get8(s); } static void skip(stbi *s, int n) { #ifndef STBI_NO_STDIO if (s->img_file) fseek(s->img_file, n, SEEK_CUR); else #endif s->img_buffer += n; } static int get16(stbi *s) { int z = get8(s); return (z << 8) + get8(s); } static uint32 get32(stbi *s) { uint32 z = get16(s); return (z << 16) + get16(s); } static int get16le(stbi *s) { int z = get8(s); return z + (get8(s) << 8); } static uint32 get32le(stbi *s) { uint32 z = get16le(s); return z + (get16le(s) << 16); } static void getn(stbi *s, stbi_uc *buffer, int n) { #ifndef STBI_NO_STDIO if (s->img_file) { fread(buffer, 1, n, s->img_file); return; } #endif memcpy(buffer, s->img_buffer, n); s->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 x, uint y) { int 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 * x * y); if (good == NULL) { free(data); return epuc("outofmem", "Out of memory"); } for (j=0; j < (int) y; ++j) { unsigned char *src = data + j * x * img_n ; unsigned char *dest = good + j * x * req_comp; #define COMBO(a,b) ((a)*8+(b)) #define CASE(a,b) case COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b) // convert source image with img_n components to one with req_comp components; // avoid switch per pixel, so use switch per scanline and massive macros switch(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); 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) // 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; typedef struct { #if STBI_SIMD unsigned short dequant2[4][64]; #endif stbi s; huffman huff_dc[4]; huffman huff_ac[4]; uint8 dequant[4][64]; // sizes for components, interleaved MCUs int img_h_max, img_v_max; int img_mcu_x, img_mcu_y; int img_mcu_w, img_mcu_h; // definition of jpeg image component struct { int id; int h,v; int tq; int hd,ha; int dc_pred; int x,y,w2,h2; uint8 *data; void *raw_data; uint8 *linebuf; } img_comp[4]; uint32 code_buffer; // jpeg entropy-coded buffer int code_bits; // number of valid bits unsigned char marker; // marker seen while filling entropy buffer int nomore; // flag if we saw a marker so must stop int scan_n, order[4]; int restart_interval, todo; } jpeg; 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; } static void grow_buffer_unsafe(jpeg *j) { do { int b = j->nomore ? 0 : get8(&j->s); if (b == 0xff) { int c = get8(&j->s); if (c != 0) { j->marker = (unsigned char) c; j->nomore = 1; return; } } j->code_buffer = (j->code_buffer << 8) | b; j->code_bits += 8; } while (j->code_bits <= 24); } // (1 << n) - 1 static uint32 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(jpeg *j, huffman *h) { unsigned int temp; int c,k; if (j->code_bits < 16) grow_buffer_unsafe(j); // look at the top FAST_BITS and determine what symbol ID it is, // if the code is <= FAST_BITS c = (j->code_buffer >> (j->code_bits - FAST_BITS)) & ((1 << FAST_BITS)-1); k = h->fast[c]; if (k < 255) { if (h->size[k] > j->code_bits) return -1; j->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 (j->code_bits < 16) temp = (j->code_buffer << (16 - j->code_bits)) & 0xffff; else temp = (j->code_buffer >> (j->code_bits - 16)) & 0xffff; for (k=FAST_BITS+1 ; ; ++k) if (temp < h->maxcode[k]) break; if (k == 17) { // error! code not found j->code_bits -= 16; return -1; } if (k > j->code_bits) return -1; // convert the huffman code to the symbol id c = ((j->code_buffer >> (j->code_bits - k)) & bmask[k]) + h->delta[k]; assert((((j->code_buffer) >> (j->code_bits - h->size[c])) & bmask[h->size[c]]) == h->code[c]); // convert the id to a symbol j->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(jpeg *j, int n) { unsigned int m = 1 << (n-1); unsigned int k; if (j->code_bits < n) grow_buffer_unsafe(j); k = (j->code_buffer >> (j->code_bits - n)) & bmask[n]; j->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(jpeg *j, short data[64], huffman *hdc, huffman *hac, int b) { int diff,dc,k; int t = decode(j, 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(j, t) : 0; dc = j->img_comp[b].dc_pred + diff; j->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(j, 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(j,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; #if !STBI_SIMD // .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; // 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); } } #else static void idct_block(uint8 *out, int out_stride, short data[64], unsigned short *dequantize) { int i,val[64],*v=val; uint8 *o; unsigned short *dq = dequantize; short *d = data; // 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); } } static stbi_idct_8x8 stbi_idct_installed = idct_block; extern void stbi_install_idct(stbi_idct_8x8 func) { stbi_idct_installed = func; } #endif #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(jpeg *j) { uint8 x; if (j->marker != MARKER_none) { x = j->marker; j->marker = MARKER_none; return x; } x = get8u(&j->s); if (x != 0xff) return MARKER_none; while (x == 0xff) x = get8u(&j->s); return x; } // in each scan, we'll have scan_n components, and the order // of the components is specified by order[] #define RESTART(x) ((x) >= 0xd0 && (x) <= 0xd7) // after a restart interval, reset the entropy decoder and // the dc prediction static void reset(jpeg *j) { j->code_bits = 0; j->code_buffer = 0; j->nomore = 0; j->img_comp[0].dc_pred = j->img_comp[1].dc_pred = j->img_comp[2].dc_pred = 0; j->marker = MARKER_none; j->todo = j->restart_interval ? j->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(jpeg *z) { reset(z); if (z->scan_n == 1) { int i,j; #if STBI_SIMD __declspec(align(16)) #endif short data[64]; int n = z->order[0]; // non-interleaved data, we just need to process one block at a time, // in trivial scanline order // number of blocks to do just depends on how many actual "pixels" this // component has, independent of interleaved MCU blocking and such int w = (z->img_comp[n].x+7) >> 3; int h = (z->img_comp[n].y+7) >> 3; for (j=0; j < h; ++j) { for (i=0; i < w; ++i) { if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0; #if STBI_SIMD stbi_idct_installed(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data, z->dequant2[z->img_comp[n].tq]); #else idct_block(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data, z->dequant[z->img_comp[n].tq]); #endif // every data block is an MCU, so countdown the restart interval if (--z->todo <= 0) { if (z->code_bits < 24) grow_buffer_unsafe(z); // if it's NOT a restart, then just bail, so we get corrupt data // rather than no data if (!RESTART(z->marker)) return 1; reset(z); } } } } else { // interleaved! int i,j,k,x,y; short data[64]; for (j=0; j < z->img_mcu_y; ++j) { for (i=0; i < z->img_mcu_x; ++i) { // scan an interleaved mcu... process scan_n components in order for (k=0; k < z->scan_n; ++k) { int n = z->order[k]; // scan out an mcu's worth of this component; that's just determined // by the basic H and V specified for the component for (y=0; y < z->img_comp[n].v; ++y) { for (x=0; x < z->img_comp[n].h; ++x) { int x2 = (i*z->img_comp[n].h + x)*8; int y2 = (j*z->img_comp[n].v + y)*8; if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0; #if STBI_SIMD stbi_idct_installed(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data, z->dequant2[z->img_comp[n].tq]); #else idct_block(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data, z->dequant[z->img_comp[n].tq]); #endif } } } // after all interleaved components, that's an interleaved MCU, // so now count down the restart interval if (--z->todo <= 0) { if (z->code_bits < 24) grow_buffer_unsafe(z); // if it's NOT a restart, then just bail, so we get corrupt data // rather than no data if (!RESTART(z->marker)) return 1; reset(z); } } } } return 1; } static int process_marker(jpeg *z, 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(&z->s) != 4) return e("bad DRI len","Corrupt JPEG"); z->restart_interval = get16(&z->s); return 1; case 0xDB: // DQT - define quantization table L = get16(&z->s)-2; while (L > 0) { int q = get8(&z->s); int p = q >> 4; int t = q & 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) z->dequant[t][dezigzag[i]] = get8u(&z->s); #if STBI_SIMD for (i=0; i < 64; ++i) z->dequant2[t][i] = z->dequant[t][i]; #endif L -= 65; } return L==0; case 0xC4: // DHT - define huffman table L = get16(&z->s)-2; while (L > 0) { uint8 *v; int sizes[16],i,m=0; int q = get8(&z->s); int tc = q >> 4; int th = q & 15; if (tc > 1 || th > 3) return e("bad DHT header","Corrupt JPEG"); for (i=0; i < 16; ++i) { sizes[i] = get8(&z->s); m += sizes[i]; } L -= 17; if (tc == 0) { if (!build_huffman(z->huff_dc+th, sizes)) return 0; v = z->huff_dc[th].values; } else { if (!build_huffman(z->huff_ac+th, sizes)) return 0; v = z->huff_ac[th].values; } for (i=0; i < m; ++i) v[i] = get8u(&z->s); L -= m; } return L==0; } // check for comment block or APP blocks if ((m >= 0xE0 && m <= 0xEF) || m == 0xFE) { skip(&z->s, get16(&z->s)-2); return 1; } return 0; } // after we see SOS static int process_scan_header(jpeg *z) { int i; int Ls = get16(&z->s); z->scan_n = get8(&z->s); if (z->scan_n < 1 || z->scan_n > 4 || z->scan_n > (int) z->s.img_n) return e("bad SOS component count","Corrupt JPEG"); if (Ls != 6+2*z->scan_n) return e("bad SOS len","Corrupt JPEG"); for (i=0; i < z->scan_n; ++i) { int id = get8(&z->s), which; int q = get8(&z->s); for (which = 0; which < z->s.img_n; ++which) if (z->img_comp[which].id == id) break; if (which == z->s.img_n) return 0; z->img_comp[which].hd = q >> 4; if (z->img_comp[which].hd > 3) return e("bad DC huff","Corrupt JPEG"); z->img_comp[which].ha = q & 15; if (z->img_comp[which].ha > 3) return e("bad AC huff","Corrupt JPEG"); z->order[i] = which; } if (get8(&z->s) != 0) return e("bad SOS","Corrupt JPEG"); get8(&z->s); // should be 63, but might be 0 if (get8(&z->s) != 0) return e("bad SOS","Corrupt JPEG"); return 1; } static int process_frame_header(jpeg *z, int scan) { stbi *s = &z->s; int Lf,p,i,q, h_max=1,v_max=1,c; Lf = get16(s); if (Lf < 11) return e("bad SOF len","Corrupt JPEG"); // JPEG p = get8(s); if (p != 8) return e("only 8-bit","JPEG format not supported: 8-bit only"); // JPEG baseline s->img_y = get16(s); if (s->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 s->img_x = get16(s); if (s->img_x == 0) return e("0 width","Corrupt JPEG"); // JPEG requires c = get8(s); if (c != 3 && c != 1) return e("bad component count","Corrupt JPEG"); // JFIF requires s->img_n = c; for (i=0; i < c; ++i) { z->img_comp[i].data = NULL; z->img_comp[i].linebuf = NULL; } if (Lf != 8+3*s->img_n) return e("bad SOF len","Corrupt JPEG"); for (i=0; i < s->img_n; ++i) { z->img_comp[i].id = get8(s); if (z->img_comp[i].id != i+1) // JFIF requires if (z->img_comp[i].id != i) // some version of jpegtran outputs non-JFIF-compliant files! return e("bad component ID","Corrupt JPEG"); q = get8(s); z->img_comp[i].h = (q >> 4); if (!z->img_comp[i].h || z->img_comp[i].h > 4) return e("bad H","Corrupt JPEG"); z->img_comp[i].v = q & 15; if (!z->img_comp[i].v || z->img_comp[i].v > 4) return e("bad V","Corrupt JPEG"); z->img_comp[i].tq = get8(s); if (z->img_comp[i].tq > 3) return e("bad TQ","Corrupt JPEG"); } if (scan != SCAN_load) return 1; if ((1 << 30) / s->img_x / s->img_n < s->img_y) return e("too large", "Image too large to decode"); for (i=0; i < s->img_n; ++i) { if (z->img_comp[i].h > h_max) h_max = z->img_comp[i].h; if (z->img_comp[i].v > v_max) v_max = z->img_comp[i].v; } // compute interleaved mcu info z->img_h_max = h_max; z->img_v_max = v_max; z->img_mcu_w = h_max * 8; z->img_mcu_h = v_max * 8; z->img_mcu_x = (s->img_x + z->img_mcu_w-1) / z->img_mcu_w; z->img_mcu_y = (s->img_y + z->img_mcu_h-1) / z->img_mcu_h; for (i=0; i < s->img_n; ++i) { // number of effective pixels (e.g. for non-interleaved MCU) z->img_comp[i].x = (s->img_x * z->img_comp[i].h + h_max-1) / h_max; z->img_comp[i].y = (s->img_y * z->img_comp[i].v + v_max-1) / v_max; // to simplify generation, we'll allocate enough memory to decode // the bogus oversized data from using interleaved MCUs and their // big blocks (e.g. a 16x16 iMCU on an image of width 33); we won't // discard the extra data until colorspace conversion z->img_comp[i].w2 = z->img_mcu_x * z->img_comp[i].h * 8; z->img_comp[i].h2 = z->img_mcu_y * z->img_comp[i].v * 8; z->img_comp[i].raw_data = malloc(z->img_comp[i].w2 * z->img_comp[i].h2+15); if (z->img_comp[i].raw_data == NULL) { for(--i; i >= 0; --i) { free(z->img_comp[i].raw_data); z->img_comp[i].data = NULL; } return e("outofmem", "Out of memory"); } // align blocks for installable-idct using mmx/sse z->img_comp[i].data = (uint8*) (((size_t) z->img_comp[i].raw_data + 15) & ~15); z->img_comp[i].linebuf = NULL; } 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(jpeg *z, int scan) { int m; z->marker = MARKER_none; // initialize cached marker to empty m = get_marker(z); if (!SOI(m)) return e("no SOI","Corrupt JPEG"); if (scan == SCAN_type) return 1; m = get_marker(z); while (!SOF(m)) { if (!process_marker(z,m)) return 0; m = get_marker(z); while (m == MARKER_none) { // some files have extra padding after their blocks, so ok, we'll scan if (at_eof(&z->s)) return e("no SOF", "Corrupt JPEG"); m = get_marker(z); } } if (!process_frame_header(z, scan)) return 0; return 1; } static int decode_jpeg_image(jpeg *j) { int m; j->restart_interval = 0; if (!decode_jpeg_header(j, SCAN_load)) return 0; m = get_marker(j); while (!EOI(m)) { if (SOS(m)) { if (!process_scan_header(j)) return 0; if (!parse_entropy_coded_data(j)) return 0; } else { if (!process_marker(j, m)) return 0; } m = get_marker(j); } return 1; } // static jfif-centered resampling (across block boundaries) typedef uint8 *(*resample_row_func)(uint8 *out, uint8 *in0, uint8 *in1, int w, int hs); #define div4(x) ((uint8) ((x) >> 2)) static uint8 *resample_row_1(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) { return in_near; } static uint8* resample_row_v_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) { // need to generate two samples vertically for every one in input int i; for (i=0; i < w; ++i) out[i] = div4(3*in_near[i] + in_far[i] + 2); return out; } static uint8* resample_row_h_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) { // need to generate two samples horizontally for every one in input int i; uint8 *input = in_near; if (w == 1) { // if only one sample, can't do any interpolation out[0] = out[1] = input[0]; return out; } out[0] = input[0]; out[1] = div4(input[0]*3 + input[1] + 2); for (i=1; i < w-1; ++i) { int n = 3*input[i]+2; out[i*2+0] = div4(n+input[i-1]); out[i*2+1] = div4(n+input[i+1]); } out[i*2+0] = div4(input[w-2]*3 + input[w-1] + 2); out[i*2+1] = input[w-1]; return out; } #define div16(x) ((uint8) ((x) >> 4)) static uint8 *resample_row_hv_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) { // need to generate 2x2 samples for every one in input int i,t0,t1; if (w == 1) { out[0] = out[1] = div4(3*in_near[0] + in_far[0] + 2); return out; } t1 = 3*in_near[0] + in_far[0]; out[0] = div4(t1+2); for (i=1; i < w; ++i) { t0 = t1; t1 = 3*in_near[i]+in_far[i]; out[i*2-1] = div16(3*t0 + t1 + 8); out[i*2 ] = div16(3*t1 + t0 + 8); } out[w*2-1] = div4(t1+2); return out; } static uint8 *resample_row_generic(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs) { // resample with nearest-neighbor int i,j; for (i=0; i < w; ++i) for (j=0; j < hs; ++j) out[i*hs+j] = in_near[i]; return out; } #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, const uint8 *y, const uint8 *pcb, const 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; out[3] = 255; out += step; } } #if STBI_SIMD static stbi_YCbCr_to_RGB_run stbi_YCbCr_installed = YCbCr_to_RGB_row; void stbi_install_YCbCr_to_RGB(stbi_YCbCr_to_RGB_run func) { stbi_YCbCr_installed = func; } #endif // clean up the temporary component buffers static void cleanup_jpeg(jpeg *j) { int i; for (i=0; i < j->s.img_n; ++i) { if (j->img_comp[i].data) { free(j->img_comp[i].raw_data); j->img_comp[i].data = NULL; } if (j->img_comp[i].linebuf) { free(j->img_comp[i].linebuf); j->img_comp[i].linebuf = NULL; } } } typedef struct { resample_row_func resample; uint8 *line0,*line1; int hs,vs; // expansion factor in each axis int w_lores; // horizontal pixels pre-expansion int ystep; // how far through vertical expansion we are int ypos; // which pre-expansion row we're on } stbi_resample; static uint8 *load_jpeg_image(jpeg *z, int *out_x, int *out_y, int *comp, int req_comp) { int n, decode_n; // validate req_comp if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp", "Internal error"); z->s.img_n = 0; // load a jpeg image from whichever source if (!decode_jpeg_image(z)) { cleanup_jpeg(z); return NULL; } // determine actual number of components to generate n = req_comp ? req_comp : z->s.img_n; if (z->s.img_n == 3 && n < 3) decode_n = 1; else decode_n = z->s.img_n; // resample and color-convert { int k; uint i,j; uint8 *output; uint8 *coutput[4]; stbi_resample res_comp[4]; for (k=0; k < decode_n; ++k) { stbi_resample *r = &res_comp[k]; // allocate line buffer big enough for upsampling off the edges // with upsample factor of 4 z->img_comp[k].linebuf = (uint8 *) malloc(z->s.img_x + 3); if (!z->img_comp[k].linebuf) { cleanup_jpeg(z); return epuc("outofmem", "Out of memory"); } r->hs = z->img_h_max / z->img_comp[k].h; r->vs = z->img_v_max / z->img_comp[k].v; r->ystep = r->vs >> 1; r->w_lores = (z->s.img_x + r->hs-1) / r->hs; r->ypos = 0; r->line0 = r->line1 = z->img_comp[k].data; if (r->hs == 1 && r->vs == 1) r->resample = resample_row_1; else if (r->hs == 1 && r->vs == 2) r->resample = resample_row_v_2; else if (r->hs == 2 && r->vs == 1) r->resample = resample_row_h_2; else if (r->hs == 2 && r->vs == 2) r->resample = resample_row_hv_2; else r->resample = resample_row_generic; } // can't error after this so, this is safe output = (uint8 *) malloc(n * z->s.img_x * z->s.img_y + 1); if (!output) { cleanup_jpeg(z); return epuc("outofmem", "Out of memory"); } // now go ahead and resample for (j=0; j < z->s.img_y; ++j) { uint8 *out = output + n * z->s.img_x * j; for (k=0; k < decode_n; ++k) { stbi_resample *r = &res_comp[k]; int y_bot = r->ystep >= (r->vs >> 1); coutput[k] = r->resample(z->img_comp[k].linebuf, y_bot ? r->line1 : r->line0, y_bot ? r->line0 : r->line1, r->w_lores, r->hs); if (++r->ystep >= r->vs) { r->ystep = 0; r->line0 = r->line1; if (++r->ypos < z->img_comp[k].y) r->line1 += z->img_comp[k].w2; } } if (n >= 3) { uint8 *y = coutput[0]; if (z->s.img_n == 3) { #if STBI_SIMD stbi_YCbCr_installed(out, y, coutput[1], coutput[2], z->s.img_x, n); #else YCbCr_to_RGB_row(out, y, coutput[1], coutput[2], z->s.img_x, n); #endif } else for (i=0; i < z->s.img_x; ++i) { out[0] = out[1] = out[2] = y[i]; out[3] = 255; // not used if n==3 out += n; } } else { uint8 *y = coutput[0]; if (n == 1) for (i=0; i < z->s.img_x; ++i) out[i] = y[i]; else for (i=0; i < z->s.img_x; ++i) *out++ = y[i], *out++ = 255; } } cleanup_jpeg(z); *out_x = z->s.img_x; *out_y = z->s.img_y; if (comp) *comp = z->s.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) { jpeg j; start_file(&j.s, f); return load_jpeg_image(&j, x,y,comp,req_comp); } unsigned char *stbi_jpeg_load(char const *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 const *buffer, int len, int *x, int *y, int *comp, int req_comp) { jpeg j; start_mem(&j.s, buffer,len); return load_jpeg_image(&j, x,y,comp,req_comp); } #ifndef STBI_NO_STDIO int stbi_jpeg_test_file(FILE *f) { int n,r; jpeg j; n = ftell(f); start_file(&j.s, f); r = decode_jpeg_header(&j, SCAN_type); fseek(f,n,SEEK_SET); return r; } #endif int stbi_jpeg_test_memory(stbi_uc const *buffer, int len) { jpeg j; start_mem(&j.s, buffer,len); return decode_jpeg_header(&j, SCAN_type); } // @TODO: #ifndef STBI_NO_STDIO extern int stbi_jpeg_info (char const *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 const *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 typedef struct { uint8 *zbuffer, *zbuffer_end; int num_bits; uint32 code_buffer; char *zout; char *zout_start; char *zout_end; int z_expandable; zhuffman z_length, z_distance; } zbuf; __forceinline static int zget8(zbuf *z) { if (z->zbuffer >= z->zbuffer_end) return 0; return *z->zbuffer++; } static void fill_bits(zbuf *z) { do { assert(z->code_buffer < (1U << z->num_bits)); z->code_buffer |= zget8(z) << z->num_bits; z->num_bits += 8; } while (z->num_bits <= 24); } __forceinline static unsigned int zreceive(zbuf *z, int n) { unsigned int k; if (z->num_bits < n) fill_bits(z); k = z->code_buffer & ((1 << n) - 1); z->code_buffer >>= n; z->num_bits -= n; return k; } __forceinline static int zhuffman_decode(zbuf *a, zhuffman *z) { int b,s,k; if (a->num_bits < 16) fill_bits(a); b = z->fast[a->code_buffer & ZFAST_MASK]; if (b < 0xffff) { s = z->size[b]; a->code_buffer >>= s; a->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(a->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); a->code_buffer >>= s; a->num_bits -= s; return z->value[b]; } static int expand(zbuf *z, int n) // need to make room for n bytes { char *q; int cur, limit; if (!z->z_expandable) return e("output buffer limit","Corrupt PNG"); cur = (int) (z->zout - z->zout_start); limit = (int) (z->zout_end - z->zout_start); while (cur + n > limit) limit *= 2; q = (char *) realloc(z->zout_start, limit); if (q == NULL) return e("outofmem", "Out of memory"); z->zout_start = q; z->zout = q + cur; z->zout_end = q + limit; return 1; } 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(zbuf *a) { for(;;) { int z = zhuffman_decode(a, &a->z_length); if (z < 256) { if (z < 0) return e("bad huffman code","Corrupt PNG"); // error in huffman codes if (a->zout >= a->zout_end) if (!expand(a, 1)) return 0; *a->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(a, length_extra[z]); z = zhuffman_decode(a, &a->z_distance); if (z < 0) return e("bad huffman code","Corrupt PNG"); dist = dist_base[z]; if (dist_extra[z]) dist += zreceive(a, dist_extra[z]); if (a->zout - a->zout_start < dist) return e("bad dist","Corrupt PNG"); if (a->zout + len > a->zout_end) if (!expand(a, len)) return 0; p = (uint8 *) (a->zout - dist); while (len--) *a->zout++ = *p++; } } } static int compute_huffman_codes(zbuf *a) { static uint8 length_dezigzag[19] = { 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 }; zhuffman z_codelength; uint8 lencodes[286+32+137];//padding for maximum single op uint8 codelength_sizes[19]; int i,n; int hlit = zreceive(a,5) + 257; int hdist = zreceive(a,5) + 1; int hclen = zreceive(a,4) + 4; memset(codelength_sizes, 0, sizeof(codelength_sizes)); for (i=0; i < hclen; ++i) { int s = zreceive(a,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(a, &z_codelength); assert(c >= 0 && c < 19); if (c < 16) lencodes[n++] = (uint8) c; else if (c == 16) { c = zreceive(a,2)+3; memset(lencodes+n, lencodes[n-1], c); n += c; } else if (c == 17) { c = zreceive(a,3)+3; memset(lencodes+n, 0, c); n += c; } else { assert(c == 18); c = zreceive(a,7)+11; memset(lencodes+n, 0, c); n += c; } } if (n != hlit+hdist) return e("bad codelengths","Corrupt PNG"); if (!zbuild_huffman(&a->z_length, lencodes, hlit)) return 0; if (!zbuild_huffman(&a->z_distance, lencodes+hlit, hdist)) return 0; return 1; } static int parse_uncompressed_block(zbuf *a) { uint8 header[4]; int len,nlen,k; if (a->num_bits & 7) zreceive(a, a->num_bits & 7); // discard // drain the bit-packed data into header k = 0; while (a->num_bits > 0) { header[k++] = (uint8) (a->code_buffer & 255); // wtf this warns? a->code_buffer >>= 8; a->num_bits -= 8; } assert(a->num_bits == 0); // now fill header the normal way while (k < 4) header[k++] = (uint8) zget8(a); len = header[1] * 256 + header[0]; nlen = header[3] * 256 + header[2]; if (nlen != (len ^ 0xffff)) return e("zlib corrupt","Corrupt PNG"); if (a->zbuffer + len > a->zbuffer_end) return e("read past buffer","Corrupt PNG"); if (a->zout + len > a->zout_end) if (!expand(a, len)) return 0; memcpy(a->zout, a->zbuffer, len); a->zbuffer += len; a->zout += len; return 1; } static int parse_zlib_header(zbuf *a) { int cmf = zget8(a); int cm = cmf & 15; /* int cinfo = cmf >> 4; */ int flg = zget8(a); 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; } // @TODO: should statically initialize these for optimal thread safety 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; } int stbi_png_partial; // a quick hack to only allow decoding some of a PNG... I should implement real streaming support instead static int parse_zlib(zbuf *a, int parse_header) { int final, type; if (parse_header) if (!parse_zlib_header(a)) return 0; a->num_bits = 0; a->code_buffer = 0; do { final = zreceive(a,1); type = zreceive(a,2); if (type == 0) { if (!parse_uncompressed_block(a)) return 0; } else if (type == 3) { return 0; } else { if (type == 1) { // use fixed code lengths if (!default_distance[31]) init_defaults(); if (!zbuild_huffman(&a->z_length , default_length , 288)) return 0; if (!zbuild_huffman(&a->z_distance, default_distance, 32)) return 0; } else { if (!compute_huffman_codes(a)) return 0; } if (!parse_huffman_block(a)) return 0; } if (stbi_png_partial && a->zout - a->zout_start > 65536) break; } while (!final); return 1; } static int do_zlib(zbuf *a, char *obuf, int olen, int exp, int parse_header) { a->zout_start = obuf; a->zout = obuf; a->zout_end = obuf + olen; a->z_expandable = exp; return parse_zlib(a, parse_header); } char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen) { zbuf a; char *p = (char *) malloc(initial_size); if (p == NULL) return NULL; a.zbuffer = (uint8 *) buffer; a.zbuffer_end = (uint8 *) buffer + len; if (do_zlib(&a, p, initial_size, 1, 1)) { if (outlen) *outlen = (int) (a.zout - a.zout_start); return a.zout_start; } else { free(a.zout_start); return NULL; } } char *stbi_zlib_decode_malloc(char const *buffer, int len, int *outlen) { return stbi_zlib_decode_malloc_guesssize(buffer, len, 16384, outlen); } int stbi_zlib_decode_buffer(char *obuffer, int olen, char const *ibuffer, int ilen) { zbuf a; a.zbuffer = (uint8 *) ibuffer; a.zbuffer_end = (uint8 *) ibuffer + ilen; if (do_zlib(&a, obuffer, olen, 0, 1)) return (int) (a.zout - a.zout_start); else return -1; } char *stbi_zlib_decode_noheader_malloc(char const *buffer, int len, int *outlen) { zbuf a; char *p = (char *) malloc(16384); if (p == NULL) return NULL; a.zbuffer = (uint8 *) buffer; a.zbuffer_end = (uint8 *) buffer+len; if (do_zlib(&a, p, 16384, 1, 0)) { if (outlen) *outlen = (int) (a.zout - a.zout_start); return a.zout_start; } else { free(a.zout_start); return NULL; } } int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen) { zbuf a; a.zbuffer = (uint8 *) ibuffer; a.zbuffer_end = (uint8 *) ibuffer + ilen; if (do_zlib(&a, obuffer, olen, 0, 0)) return (int) (a.zout - a.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 { uint32 length; uint32 type; } chunk; #define PNG_TYPE(a,b,c,d) (((a) << 24) + ((b) << 16) + ((c) << 8) + (d)) static chunk get_chunk_header(stbi *s) { chunk c; c.length = get32(s); c.type = get32(s); return c; } static int check_png_header(stbi *s) { static uint8 png_sig[8] = { 137,80,78,71,13,10,26,10 }; int i; for (i=0; i < 8; ++i) if (get8(s) != png_sig[i]) return e("bad png sig","Not a PNG"); return 1; } typedef struct { stbi s; uint8 *idata, *expanded, *out; } png; 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_raw(png *a, uint8 *raw, uint32 raw_len, int out_n, uint32 x, uint32 y) { stbi *s = &a->s; uint32 i,j,stride = x*out_n; int k; int img_n = s->img_n; // copy it into a local for later assert(out_n == s->img_n || out_n == s->img_n+1); if (stbi_png_partial) y = 1; a->out = (uint8 *) malloc(x * y * out_n); if (!a->out) return e("outofmem", "Out of memory"); if (!stbi_png_partial) { if (s->img_x == x && s->img_y == y) if (raw_len != (img_n * x + 1) * y) return e("not enough pixels","Corrupt PNG"); else // interlaced: if (raw_len < (img_n * x + 1) * y) return e("not enough pixels","Corrupt PNG"); } for (j=0; j < y; ++j) { uint8 *cur = a->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=x-1; i >= 1; --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=x-1; i >= 1; --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 create_png_image(png *a, uint8 *raw, uint32 raw_len, int out_n, int interlaced) { uint8 *final; int p; int save; if (!interlaced) return create_png_image_raw(a, raw, raw_len, out_n, a->s.img_x, a->s.img_y); save = stbi_png_partial; stbi_png_partial = 0; // de-interlacing final = (uint8 *) malloc(a->s.img_x * a->s.img_y * out_n); for (p=0; p < 7; ++p) { int xorig[] = { 0,4,0,2,0,1,0 }; int yorig[] = { 0,0,4,0,2,0,1 }; int xspc[] = { 8,8,4,4,2,2,1 }; int yspc[] = { 8,8,8,4,4,2,2 }; int i,j,x,y; // pass1_x[4] = 0, pass1_x[5] = 1, pass1_x[12] = 1 x = (a->s.img_x - xorig[p] + xspc[p]-1) / xspc[p]; y = (a->s.img_y - yorig[p] + yspc[p]-1) / yspc[p]; if (x && y) { if (!create_png_image_raw(a, raw, raw_len, out_n, x, y)) { free(final); return 0; } for (j=0; j < y; ++j) for (i=0; i < x; ++i) memcpy(final + (j*yspc[p]+yorig[p])*a->s.img_x*out_n + (i*xspc[p]+xorig[p])*out_n, a->out + (j*x+i)*out_n, out_n); free(a->out); raw += (x*out_n+1)*y; raw_len -= (x*out_n+1)*y; } } a->out = final; stbi_png_partial = save; return 1; } static int compute_transparency(png *z, uint8 tc[3], int out_n) { stbi *s = &z->s; uint32 i, pixel_count = s->img_x * s->img_y; uint8 *p = z->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); 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(png *a, uint8 *palette, int len, int pal_img_n) { uint32 i, pixel_count = a->s.img_x * a->s.img_y; uint8 *p, *temp_out, *orig = a->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(a->out); a->out = temp_out; return 1; } static int parse_png_file(png *z, 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,interlace=0; stbi *s = &z->s; if (!check_png_header(s)) return 0; if (scan == SCAN_type) return 1; for(;;first=0) { chunk c = get_chunk_header(s); 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,comp,filter; if (!first) return e("multiple IHDR","Corrupt PNG"); if (c.length != 13) return e("bad IHDR len","Corrupt PNG"); s->img_x = get32(s); if (s->img_x > (1 << 24)) return e("too large","Very large image (corrupt?)"); s->img_y = get32(s); if (s->img_y > (1 << 24)) return e("too large","Very large image (corrupt?)"); depth = get8(s); if (depth != 8) return e("8bit only","PNG not supported: 8-bit only"); color = get8(s); 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(s); if (comp) return e("bad comp method","Corrupt PNG"); filter= get8(s); if (filter) return e("bad filter method","Corrupt PNG"); interlace = get8(s); if (interlace>1) return e("bad interlace method","Corrupt PNG"); if (!s->img_x || !s->img_y) return e("0-pixel image","Corrupt PNG"); if (!pal_img_n) { s->img_n = (color & 2 ? 3 : 1) + (color & 4 ? 1 : 0); if ((1 << 30) / s->img_x / s->img_n < s->img_y) return 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. s->img_n = 1; if ((1 << 30) / s->img_x / 4 < s->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(s); palette[i*4+1] = get8u(s); palette[i*4+2] = get8u(s); palette[i*4+3] = 255; } break; } case PNG_TYPE('t','R','N','S'): { if (z->idata) return e("tRNS after IDAT","Corrupt PNG"); if (pal_img_n) { if (scan == SCAN_header) { s->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(s); } else { if (!(s->img_n & 1)) return e("tRNS with alpha","Corrupt PNG"); if (c.length != (uint32) s->img_n*2) return e("bad tRNS len","Corrupt PNG"); has_trans = 1; for (k=0; k < s->img_n; ++k) tc[k] = (uint8) get16(s); // 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) { s->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(z->idata, idata_limit); if (p == NULL) return e("outofmem", "Out of memory"); z->idata = p; } #ifndef STBI_NO_STDIO if (s->img_file) { if (fread(z->idata+ioff,1,c.length,s->img_file) != c.length) return e("outofdata","Corrupt PNG"); } else #endif { memcpy(z->idata+ioff, s->img_buffer, c.length); s->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 (z->idata == NULL) return e("no IDAT","Corrupt PNG"); z->expanded = (uint8 *) stbi_zlib_decode_malloc((char *) z->idata, ioff, (int *) &raw_len); if (z->expanded == NULL) return 0; // zlib should set error free(z->idata); z->idata = NULL; if ((req_comp == s->img_n+1 && req_comp != 3 && !pal_img_n) || has_trans) s->img_out_n = s->img_n+1; else s->img_out_n = s->img_n; if (!create_png_image(z, z->expanded, raw_len, s->img_out_n, interlace)) return 0; if (has_trans) if (!compute_transparency(z, tc, s->img_out_n)) return 0; if (pal_img_n) { // pal_img_n == 3 or 4 s->img_n = pal_img_n; // record the actual colors we had s->img_out_n = pal_img_n; if (req_comp >= 3) s->img_out_n = req_comp; if (!expand_palette(z, palette, pal_len, s->img_out_n)) return 0; } free(z->expanded); z->expanded = NULL; return 1; } default: // if critical, fail if ((c.type & (1 << 29)) == 0) { #ifndef STBI_NO_FAILURE_STRINGS // not threadsafe 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(s, c.length); break; } // end of chunk, read and skip CRC get32(s); } } static unsigned char *do_png(png *p, int *x, int *y, int *n, int req_comp) { unsigned char *result=NULL; p->expanded = NULL; p->idata = NULL; p->out = NULL; if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp", "Internal error"); if (parse_png_file(p, SCAN_load, req_comp)) { result = p->out; p->out = NULL; if (req_comp && req_comp != p->s.img_out_n) { result = convert_format(result, p->s.img_out_n, req_comp, p->s.img_x, p->s.img_y); p->s.img_out_n = req_comp; if (result == NULL) return result; } *x = p->s.img_x; *y = p->s.img_y; if (n) *n = p->s.img_n; } free(p->out); p->out = NULL; free(p->expanded); p->expanded = NULL; free(p->idata); p->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) { png p; start_file(&p.s, f); return do_png(&p, x,y,comp,req_comp); } unsigned char *stbi_png_load(char const *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(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) { png p; start_mem(&p.s, buffer,len); return do_png(&p, x,y,comp,req_comp); } #ifndef STBI_NO_STDIO int stbi_png_test_file(FILE *f) { png p; int n,r; n = ftell(f); start_file(&p.s, f); r = parse_png_file(&p, SCAN_type,STBI_default); fseek(f,n,SEEK_SET); return r; } #endif int stbi_png_test_memory(stbi_uc const *buffer, int len) { png p; start_mem(&p.s, buffer, len); return parse_png_file(&p, SCAN_type,STBI_default); } // TODO: load header from png #ifndef STBI_NO_STDIO int stbi_png_info (char const *filename, int *x, int *y, int *comp) { png p; FILE *f = fopen(filename, "rb"); if (!f) return 0; start_file(&p.s, f); if (parse_png_file(&p, SCAN_header, 0)) { if(x) *x = p.s.img_x; if(y) *y = p.s.img_y; if (comp) *comp = p.s.img_n; fclose(f); return 1; } fclose(f); return 0; } 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 const *buffer, int len, int *x, int *y, int *comp); // Microsoft/Windows BMP image static int bmp_test(stbi *s) { int sz; if (get8(s) != 'B') return 0; if (get8(s) != 'M') return 0; get32le(s); // discard filesize get16le(s); // discard reserved get16le(s); // discard reserved get32le(s); // discard data offset sz = get32le(s); if (sz == 12 || sz == 40 || sz == 56 || sz == 108) return 1; return 0; } #ifndef STBI_NO_STDIO int stbi_bmp_test_file (FILE *f) { stbi s; int r,n = ftell(f); start_file(&s,f); r = bmp_test(&s); fseek(f,n,SEEK_SET); return r; } #endif int stbi_bmp_test_memory (stbi_uc const *buffer, int len) { stbi s; start_mem(&s, buffer, len); return bmp_test(&s); } // 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(stbi *s, int *x, int *y, int *comp, int req_comp) { uint8 *out; unsigned int mr=0,mg=0,mb=0,ma=0, fake_a=0; stbi_uc pal[256][4]; int psize=0,i,j,compress=0,width; int bpp, flip_vertically, pad, target, offset, hsz; if (get8(s) != 'B' || get8(s) != 'M') return epuc("not BMP", "Corrupt BMP"); get32le(s); // discard filesize get16le(s); // discard reserved get16le(s); // discard reserved offset = get32le(s); hsz = get32le(s); 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) { s->img_x = get16le(s); s->img_y = get16le(s); } else { s->img_x = get32le(s); s->img_y = get32le(s); } if (get16le(s) != 1) return 0; bpp = get16le(s); if (bpp == 1) return epuc("monochrome", "BMP type not supported: 1-bit"); flip_vertically = ((int) s->img_y) > 0; s->img_y = abs((int) s->img_y); if (hsz == 12) { if (bpp < 24) psize = (offset - 14 - 24) / 3; } else { compress = get32le(s); if (compress == 1 || compress == 2) return epuc("BMP RLE", "BMP type not supported: RLE"); get32le(s); // discard sizeof get32le(s); // discard hres get32le(s); // discard vres get32le(s); // discard colorsused get32le(s); // discard max important if (hsz == 40 || hsz == 56) { if (hsz == 56) { get32le(s); get32le(s); get32le(s); get32le(s); } if (bpp == 16 || bpp == 32) { mr = mg = mb = 0; if (compress == 0) { if (bpp == 32) { mr = 0xff << 16; mg = 0xff << 8; mb = 0xff << 0; ma = 0xff << 24; fake_a = 1; // @TODO: check for cases like alpha value is all 0 and switch it to 255 } else { mr = 31 << 10; mg = 31 << 5; mb = 31 << 0; } } else if (compress == 3) { mr = get32le(s); mg = get32le(s); mb = get32le(s); // 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(s); mg = get32le(s); mb = get32le(s); ma = get32le(s); get32le(s); // discard color space for (i=0; i < 12; ++i) get32le(s); // discard color space parameters } if (bpp < 16) psize = (offset - 14 - hsz) >> 2; } s->img_n = ma ? 4 : 3; if (req_comp && req_comp >= 3) // we can directly decode 3 or 4 target = req_comp; else target = s->img_n; // if they want monochrome, we'll post-convert out = (stbi_uc *) malloc(target * s->img_x * s->img_y); if (!out) return epuc("outofmem", "Out of memory"); if (bpp < 16) { int z=0; if (psize == 0 || psize > 256) { free(out); return epuc("invalid", "Corrupt BMP"); } for (i=0; i < psize; ++i) { pal[i][2] = get8(s); pal[i][1] = get8(s); pal[i][0] = get8(s); if (hsz != 12) get8(s); pal[i][3] = 255; } skip(s, offset - 14 - hsz - psize * (hsz == 12 ? 3 : 4)); if (bpp == 4) width = (s->img_x + 1) >> 1; else if (bpp == 8) width = s->img_x; else { free(out); return epuc("bad bpp", "Corrupt BMP"); } pad = (-width)&3; for (j=0; j < (int) s->img_y; ++j) { for (i=0; i < (int) s->img_x; i += 2) { int v=get8(s),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) s->img_x) break; v = (bpp == 8) ? get8(s) : v2; out[z++] = pal[v][0]; out[z++] = pal[v][1]; out[z++] = pal[v][2]; if (target == 4) out[z++] = 255; } skip(s, pad); } } else { int rshift=0,gshift=0,bshift=0,ashift=0,rcount=0,gcount=0,bcount=0,acount=0; int z = 0; int easy=0; skip(s, offset - 14 - hsz); if (bpp == 24) width = 3 * s->img_x; else if (bpp == 16) width = 2*s->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) s->img_y; ++j) { if (easy) { for (i=0; i < (int) s->img_x; ++i) { int a; out[z+2] = get8(s); out[z+1] = get8(s); out[z+0] = get8(s); z += 3; a = (easy == 2 ? get8(s) : 255); if (target == 4) out[z++] = a; } } else { for (i=0; i < (int) s->img_x; ++i) { uint32 v = (bpp == 16 ? get16le(s) : get32le(s)); 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(s, pad); } } if (flip_vertically) { stbi_uc t; for (j=0; j < (int) s->img_y>>1; ++j) { stbi_uc *p1 = out + j *s->img_x*target; stbi_uc *p2 = out + (s->img_y-1-j)*s->img_x*target; for (i=0; i < (int) s->img_x*target; ++i) { t = p1[i], p1[i] = p2[i], p2[i] = t; } } } if (req_comp && req_comp != target) { out = convert_format(out, target, req_comp, s->img_x, s->img_y); if (out == NULL) return out; // convert_format frees input on failure } *x = s->img_x; *y = s->img_y; if (comp) *comp = target; return out; } #ifndef STBI_NO_STDIO stbi_uc *stbi_bmp_load (char const *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) { stbi s; start_file(&s, f); return bmp_load(&s, x,y,comp,req_comp); } #endif stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) { stbi s; start_mem(&s, buffer, len); return bmp_load(&s, x,y,comp,req_comp); } // Targa Truevision - TGA // by Jonathan Dummer static int tga_test(stbi *s) { int sz; get8u(s); // discard Offset sz = get8u(s); // color type if( sz > 1 ) return 0; // only RGB or indexed allowed sz = get8u(s); // image type if( (sz != 1) && (sz != 2) && (sz != 3) && (sz != 9) && (sz != 10) && (sz != 11) ) return 0; // only RGB or grey allowed, +/- RLE get16(s); // discard palette start get16(s); // discard palette length get8(s); // discard bits per palette color entry get16(s); // discard x origin get16(s); // discard y origin if( get16(s) < 1 ) return 0; // test width if( get16(s) < 1 ) return 0; // test height sz = get8(s); // 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) { stbi s; int r,n = ftell(f); start_file(&s, f); r = tga_test(&s); fseek(f,n,SEEK_SET); return r; } #endif int stbi_tga_test_memory (stbi_uc const *buffer, int len) { stbi s; start_mem(&s, buffer, len); return tga_test(&s); } static stbi_uc *tga_load(stbi *s, int *x, int *y, int *comp, int req_comp) { // read in the TGA header stuff int tga_offset = get8u(s); int tga_indexed = get8u(s); int tga_image_type = get8u(s); int tga_is_RLE = 0; int tga_palette_start = get16le(s); int tga_palette_len = get16le(s); int tga_palette_bits = get8u(s); int tga_x_origin = get16le(s); int tga_y_origin = get16le(s); int tga_width = get16le(s); int tga_height = get16le(s); int tga_bits_per_pixel = get8u(s); int tga_inverted = get8u(s); // 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(s, tga_offset ); // do I need to load a palette? if( tga_indexed ) { // any data to skip? (offset usually = 0) skip(s, tga_palette_start ); // load the palette tga_palette = (unsigned char*)malloc( tga_palette_len * tga_palette_bits / 8 ); getn(s, 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(s); RLE_count = 1 + (RLE_cmd & 127); RLE_repeating = RLE_cmd >> 7; read_next_pixel = 1; } else if( !RLE_repeating ) { read_next_pixel = 1; } } else { read_next_pixel = 1; } // OK, if I need to read a pixel, do it now if( read_next_pixel ) { // load however much data we did have if( tga_indexed ) { // read in 1 byte, then perform the lookup int pal_idx = get8u(s); 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(s); } } // 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 const *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) { stbi s; start_file(&s, f); return tga_load(&s, x,y,comp,req_comp); } #endif stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) { stbi s; start_mem(&s, buffer, len); return tga_load(&s, x,y,comp,req_comp); } // ************************************************************************************************* // Photoshop PSD loader -- PD by Thatcher Ulrich, integration by Nicholas Schulz, tweaked by STB static int psd_test(stbi *s) { if (get32(s) != 0x38425053) return 0; // "8BPS" else return 1; } #ifndef STBI_NO_STDIO int stbi_psd_test_file(FILE *f) { stbi s; int r,n = ftell(f); start_file(&s, f); r = psd_test(&s); fseek(f,n,SEEK_SET); return r; } #endif int stbi_psd_test_memory(stbi_uc const *buffer, int len) { stbi s; start_mem(&s, buffer, len); return psd_test(&s); } static stbi_uc *psd_load(stbi *s, int *x, int *y, int *comp, int req_comp) { int pixelCount; int channelCount, compression; int channel, i, count, len; int w,h; uint8 *out; // Check identifier if (get32(s) != 0x38425053) // "8BPS" return epuc("not PSD", "Corrupt PSD image"); // Check file type version. if (get16(s) != 1) return epuc("wrong version", "Unsupported version of PSD image"); // Skip 6 reserved bytes. skip(s, 6 ); // Read the number of channels (R, G, B, A, etc). channelCount = get16(s); 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(s); w = get32(s); // Make sure the depth is 8 bits. if (get16(s) != 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(s) != 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(s,get32(s) ); // Skip the image resources. (resolution, pen tool paths, etc) skip(s, get32(s) ); // Skip the reserved data. skip(s, get32(s) ); // Find out if the data is compressed. // Known values: // 0: no compression // 1: RLE compressed compression = get16(s); if (compression > 1) return epuc("bad compression", "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(s, 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(s); if (len == 128) { // No-op. } else if (len < 128) { // Copy next len+1 bytes literally. len++; count += len; while (len) { *p = get8(s); 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(s); 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(s), p += 4; } } } if (req_comp && req_comp != 4) { out = convert_format(out, 4, req_comp, w, h); 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 const *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) { stbi s; start_file(&s, f); return psd_load(&s, x,y,comp,req_comp); } #endif stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) { stbi s; start_mem(&s, buffer, len); return psd_load(&s, x,y,comp,req_comp); } // ************************************************************************************************* // Radiance RGBE HDR loader // originally by Nicolas Schulz #ifndef STBI_NO_HDR static int hdr_test(stbi *s) { char *signature = "#?RADIANCE\n"; int i; for (i=0; signature[i]; ++i) if (get8(s) != signature[i]) return 0; return 1; } int stbi_hdr_test_memory(stbi_uc const *buffer, int len) { stbi s; start_mem(&s, buffer, len); return hdr_test(&s); } #ifndef STBI_NO_STDIO int stbi_hdr_test_file(FILE *f) { stbi s; int r,n = ftell(f); start_file(&s, f); r = hdr_test(&s); fseek(f,n,SEEK_SET); return r; } #endif #define HDR_BUFLEN 1024 static char *hdr_gettoken(stbi *z, char *buffer) { int len=0; char *s = buffer, c = '\0'; c = get8(z); while (!at_eof(z) && c != '\n') { buffer[len++] = c; if (len == HDR_BUFLEN-1) { // flush to end of line while (!at_eof(z) && get8(z) != '\n') ; break; } c = get8(z); } 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(stbi *s, 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(s,buffer), "#?RADIANCE") != 0) return epf("not HDR", "Corrupt HDR image"); // Parse header while(1) { token = hdr_gettoken(s,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(s,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(s, 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(s); c2 = get8(s); len = get8(s); if (c1 != 2 || c2 != 2 || (len & 0x80)) { // not run-length encoded, so we have to actually use THIS data as a decoded // pixel (note this can't be a valid pixel--one of RGB must be >= 128) stbi_uc rgbe[4] = { c1,c2,len, get8(s) }; 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(s); 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(s); if (count > 128) { // Run value = get8(s); 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(s); } } } 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) { stbi s; start_file(&s,f); return hdr_load(&s,x,y,comp,req_comp); } #endif float *stbi_hdr_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp) { stbi s; start_mem(&s,buffer, len); return hdr_load(&s,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 const *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 const *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 const *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 #endif // STBI_HEADER_FILE_ONLY