/xbmc/visualizations/XBMCProjectM/libprojectM/stb_image_aug.c
C | 3163 lines | 2541 code | 280 blank | 342 comment | 812 complexity | 0a67e6320b93c9e60a9dfaff421fd43a MD5 | raw file
Possible License(s): GPL-3.0, CC-BY-SA-3.0, LGPL-2.0, 0BSD, Unlicense, GPL-2.0, AGPL-1.0, BSD-3-Clause, LGPL-2.1, LGPL-3.0
- /* stbi-1.03 - public domain JPEG/PNG reader - http://nothings.org/stb_image.c
- when you control the images you're loading
- QUICK NOTES:
- Primarily of interest to game developers and other people who can
- avoid problematic images and only need the trivial interface
- JPEG baseline (no JPEG progressive, no oddball channel decimations)
- PNG non-interlaced
- BMP non-1bpp, non-RLE
- TGA (not sure what subset, if a subset)
- HDR (radiance rgbE format)
- writes BMP,TGA (define STBI_NO_WRITE to remove code)
- decoded from memory or through stdio FILE (define STBI_NO_STDIO to remove code)
- TODO:
- stbi_info_*
- PSD loader
- history:
- 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
- */
- #include "stb_image_aug.h"
- #ifndef STBI_NO_STDIO
- #include <stdio.h>
- #endif
- #include <stdlib.h>
- #include <memory.h>
- #include <assert.h>
- #include <stdarg.h>
- #ifndef _MSC_VER
- #define __forceinline
- #endif
- // implementation:
- typedef unsigned char uint8;
- typedef unsigned short uint16;
- typedef signed short int16;
- typedef unsigned int uint32;
- typedef signed int int32;
- typedef unsigned int uint;
- // should produce compiler error if size is wrong
- typedef unsigned char validate_uint32[sizeof(uint32)==4];
- #if defined(STBI_NO_STDIO) && !defined(STBI_NO_WRITE)
- #define STBI_NO_WRITE
- #endif
- #ifndef STBI_NO_DDS
- #include "stbi_DDS_aug.h"
- #endif
- // I (JLD) want full messages for SOIL
- #define STBI_FAILURE_USERMSG 1
- //////////////////////////////////////////////////////////////////////////////
- //
- // Generic API that works on all image types
- //
- static char *failure_reason;
- char *stbi_failure_reason(void)
- {
- return failure_reason;
- }
- static int e(char *str)
- {
- failure_reason = str;
- return 0;
- }
- #ifdef STBI_NO_FAILURE_STRINGS
- #define e(x,y) 0
- #elif defined(STBI_FAILURE_USERMSG)
- #define e(x,y) e(y)
- #else
- #define e(x,y) e(x)
- #endif
- #define ep(x,y) (e(x,y)?NULL:NULL)
- void stbi_image_free(unsigned char *retval_from_stbi_load)
- {
- free(retval_from_stbi_load);
- }
- #define MAX_LOADERS 32
- stbi_loader *loaders[MAX_LOADERS];
- static int max_loaders = 0;
- int stbi_register_loader(stbi_loader *loader)
- {
- int i;
- for (i=0; i < MAX_LOADERS; ++i) {
- // already present?
- if (loaders[i] == loader)
- return 1;
- // end of the list?
- if (loaders[i] == NULL) {
- loaders[i] = loader;
- max_loaders = i+1;
- return 1;
- }
- }
- // no room for it
- return 0;
- }
- #ifndef STBI_NO_HDR
- static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp);
- static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp);
- #endif
- #ifndef STBI_NO_STDIO
- unsigned char *stbi_load(char *filename, int *x, int *y, int *comp, int req_comp)
- {
- FILE *f = fopen(filename, "rb");
- unsigned char *result;
- if (!f) return ep("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);
- #ifndef STBI_NO_DDS
- if (stbi_dds_test_file(f))
- return stbi_dds_load_from_file(f,x,y,comp,req_comp);
- #endif
- #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 ep("unknown image type", "Image not of any known type, or corrupt");
- }
- #endif
- unsigned char *stbi_load_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
- {
- int i;
- if (stbi_jpeg_test_memory(buffer,len))
- return stbi_jpeg_load_from_memory(buffer,len,x,y,comp,req_comp);
- if (stbi_png_test_memory(buffer,len))
- return stbi_png_load_from_memory(buffer,len,x,y,comp,req_comp);
- if (stbi_bmp_test_memory(buffer,len))
- return stbi_bmp_load_from_memory(buffer,len,x,y,comp,req_comp);
- #ifndef STBI_NO_DDS
- if (stbi_dds_test_memory(buffer,len))
- return stbi_dds_load_from_memory(buffer,len,x,y,comp,req_comp);
- #endif
- #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 ep("unknown image type", "Image not of any known type, or corrupt");
- }
- #ifndef STBI_NO_HDR
- #ifndef STBI_NO_STDIO
- float *stbi_loadf(char *filename, int *x, int *y, int *comp, int req_comp)
- {
- FILE *f = fopen(filename, "rb");
- float *result;
- if (!f) return ep("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 ep("unknown image type", "Image not of any known type, or corrupt");
- }
- #endif
- float *stbi_loadf_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
- {
- stbi_uc *data;
- #ifndef STBI_NO_HDR
- if (stbi_hdr_test_memory(buffer, len))
- return stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp);
- #endif
- data = stbi_load_from_memory(buffer, len, x, y, comp, req_comp);
- if (data)
- return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp);
- return ep("unknown image type", "Image not of any known type, or corrupt");
- }
- #endif
- // these is-hdr-or-not is defined independent of whether STBI_NO_HDR is
- // defined, for API simplicity; if STBI_NO_HDR is defined, it always
- // reports false!
- extern int stbi_is_hdr_from_memory(stbi_uc *buffer, int len)
- {
- #ifndef STBI_NO_HDR
- return stbi_hdr_test_memory(buffer, len);
- #else
- return 0;
- #endif
- }
- #ifndef STBI_NO_STDIO
- extern int stbi_is_hdr (char *filename)
- {
- FILE *f = fopen(filename, "rb");
- int result=0;
- if (f) {
- result = stbi_is_hdr_from_file(f);
- fclose(f);
- }
- return result;
- }
- extern int stbi_is_hdr_from_file(FILE *f)
- {
- #ifndef STBI_NO_HDR
- return stbi_hdr_test_file(f);
- #else
- return 0;
- #endif
- }
- #endif
- // @TODO: get image dimensions & components without fully decoding
- #ifndef STBI_NO_STDIO
- extern int stbi_info (char *filename, int *x, int *y, int *comp);
- extern int stbi_info_from_file (FILE *f, int *x, int *y, int *comp);
- #endif
- extern int stbi_info_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp);
- #ifndef STBI_NO_HDR
- static float h2l_gamma_i=1.0f/2.2f, h2l_scale_i=1.0f;
- static float l2h_gamma=2.2f, l2h_scale=1.0f;
- void stbi_hdr_to_ldr_gamma(float gamma) { h2l_gamma_i = 1/gamma; }
- void stbi_hdr_to_ldr_scale(float scale) { h2l_scale_i = 1/scale; }
- void stbi_ldr_to_hdr_gamma(float gamma) { l2h_gamma = gamma; }
- void stbi_ldr_to_hdr_scale(float scale) { l2h_scale = scale; }
- #endif
- //////////////////////////////////////////////////////////////////////////////
- //
- // Common code used by all image loaders
- //
- // image width, height, # components
- static uint32 img_x, img_y;
- static int img_n, img_out_n;
- enum
- {
- SCAN_load=0,
- SCAN_type,
- SCAN_header,
- };
- // An API for reading either from memory or file.
- #ifndef STBI_NO_STDIO
- static FILE *img_file;
- #endif
- static uint8 *img_buffer, *img_buffer_end;
- #ifndef STBI_NO_STDIO
- static void start_file(FILE *f)
- {
- img_file = f;
- }
- #endif
- static void start_mem(uint8 *buffer, int len)
- {
- #ifndef STBI_NO_STDIO
- img_file = NULL;
- #endif
- img_buffer = buffer;
- img_buffer_end = buffer+len;
- }
- static int get8(void)
- {
- #ifndef STBI_NO_STDIO
- if (img_file) {
- int c = fgetc(img_file);
- return c == EOF ? 0 : c;
- }
- #endif
- if (img_buffer < img_buffer_end)
- return *img_buffer++;
- return 0;
- }
- static int at_eof(void)
- {
- #ifndef STBI_NO_STDIO
- if (img_file)
- return feof(img_file);
- #endif
- return img_buffer >= img_buffer_end;
- }
- static uint8 get8u(void)
- {
- return (uint8) get8();
- }
- static void skip(int n)
- {
- #ifndef STBI_NO_STDIO
- if (img_file)
- fseek(img_file, n, SEEK_CUR);
- else
- #endif
- img_buffer += n;
- }
- static int get16(void)
- {
- int z = get8();
- return (z << 8) + get8();
- }
- static uint32 get32(void)
- {
- uint32 z = get16();
- return (z << 16) + get16();
- }
- static int get16le(void)
- {
- int z = get8();
- return z + (get8() << 8);
- }
- static uint32 get32le(void)
- {
- uint32 z = get16le();
- return z + (get16le() << 16);
- }
- static void getn(stbi_uc *buffer, int n)
- {
- #ifndef STBI_NO_STDIO
- if (img_file) {
- fread(buffer, 1, n, img_file);
- return;
- }
- #endif
- memcpy(buffer, img_buffer, n);
- img_buffer += n;
- }
- //////////////////////////////////////////////////////////////////////////////
- //
- // generic converter from built-in img_n to req_comp
- // individual types do this automatically as much as possible (e.g. jpeg
- // does all cases internally since it needs to colorspace convert anyway,
- // and it never has alpha, so very few cases ). png can automatically
- // interleave an alpha=255 channel, but falls back to this for other cases
- //
- // assume data buffer is malloced, so malloc a new one and free that one
- // only failure mode is malloc failing
- static uint8 compute_y(int r, int g, int b)
- {
- return (uint8) (((r*77) + (g*150) + (29*b)) >> 8);
- }
- static unsigned char *convert_format(unsigned char *data, int img_n, int req_comp)
- {
- uint i,j;
- unsigned char *good;
- if (req_comp == img_n) return data;
- assert(req_comp >= 1 && req_comp <= 4);
- good = (unsigned char *) malloc(req_comp * img_x * img_y);
- if (good == NULL) {
- free(data);
- return ep("outofmem", "Out of memory");
- }
- for (j=0; j < img_y; ++j) {
- unsigned char *src = data + j * img_x * img_n ;
- unsigned char *dest = good + j * img_x * req_comp;
- #define COMBO(a,b) ((a)*8+(b))
- #define CASE(a,b) case COMBO(a,b): for(i=0; i < img_x; ++i, src += a, dest += b)
- // convert source image with img_n components to one with req_comp components;
- // avoid switch per pixel, so use switch per scanline and massive macros
- switch(COMBO(img_n, req_comp)) {
- CASE(1,2) dest[0]=src[0], dest[1]=255; break;
- CASE(1,3) dest[0]=dest[1]=dest[2]=src[0]; break;
- CASE(1,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=255; break;
- CASE(2,1) dest[0]=src[0]; break;
- CASE(2,3) dest[0]=dest[1]=dest[2]=src[0]; break;
- CASE(2,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=src[1]; break;
- CASE(3,4) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2],dest[3]=255; break;
- CASE(3,1) dest[0]=compute_y(src[0],src[1],src[2]); break;
- CASE(3,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = 255; break;
- CASE(4,1) dest[0]=compute_y(src[0],src[1],src[2]); break;
- CASE(4,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = src[3]; break;
- CASE(4,3) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2]; break;
- default: assert(0);
- }
- #undef CASE
- }
- free(data);
- img_out_n = req_comp;
- return good;
- }
- #ifndef STBI_NO_HDR
- static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp)
- {
- int i,k,n;
- float *output = (float *) malloc(x * y * comp * sizeof(float));
- if (output == NULL) { free(data); return ep("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]/255.0, 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 ep("outofmem", "Out of memory"); }
- // compute number of non-alpha components
- if (comp & 1) n = comp; else n = comp-1;
- for (i=0; i < x*y; ++i) {
- for (k=0; k < n; ++k) {
- float z = (float) pow(data[i*comp+k]*h2l_scale_i, h2l_gamma_i) * 255 + 0.5f;
- if (z < 0) z = 0;
- if (z > 255) z = 255;
- output[i*comp + k] = float2int(z);
- }
- if (k < comp) {
- float z = data[i*comp+k] * 255 + 0.5f;
- if (z < 0) z = 0;
- if (z > 255) z = 255;
- output[i*comp + k] = float2int(z);
- }
- }
- free(data);
- return output;
- }
- #endif
- //////////////////////////////////////////////////////////////////////////////
- //
- // "baseline" JPEG/JFIF decoder (not actually fully baseline implementation)
- //
- // simple implementation
- // - channel subsampling of at most 2 in each dimension
- // - doesn't support delayed output of y-dimension
- // - simple interface (only one output format: 8-bit interleaved RGB)
- // - doesn't try to recover corrupt jpegs
- // - doesn't allow partial loading, loading multiple at once
- // - still fast on x86 (copying globals into locals doesn't help x86)
- // - allocates lots of intermediate memory (full size of all components)
- // - non-interleaved case requires this anyway
- // - allows good upsampling (see next)
- // high-quality
- // - upsampled channels are bilinearly interpolated, even across blocks
- // - quality integer IDCT derived from IJG's 'slow'
- // performance
- // - fast huffman; reasonable integer IDCT
- // - uses a lot of intermediate memory, could cache poorly
- // - load http://nothings.org/remote/anemones.jpg 3 times on 2.8Ghz P4
- // stb_jpeg: 1.34 seconds (MSVC6, default release build)
- // stb_jpeg: 1.06 seconds (MSVC6, processor = Pentium Pro)
- // IJL11.dll: 1.08 seconds (compiled by intel)
- // IJG 1998: 0.98 seconds (MSVC6, makefile provided by IJG)
- // IJG 1998: 0.95 seconds (MSVC6, makefile + proc=PPro)
- int stbi_jpeg_dc_only;
- // huffman decoding acceleration
- #define FAST_BITS 9 // larger handles more cases; smaller stomps less cache
- typedef struct
- {
- uint8 fast[1 << FAST_BITS];
- // weirdly, repacking this into AoS is a 10% speed loss, instead of a win
- uint16 code[256];
- uint8 values[256];
- uint8 size[257];
- unsigned int maxcode[18];
- int delta[17]; // old 'firstsymbol' - old 'firstcode'
- } huffman;
- static huffman huff_dc[4]; // baseline is 2 tables, extended is 4
- static huffman huff_ac[4];
- static uint8 dequant[4][64];
- static int build_huffman(huffman *h, int *count)
- {
- int i,j,k=0,code;
- // build size list for each symbol (from JPEG spec)
- for (i=0; i < 16; ++i)
- for (j=0; j < count[i]; ++j)
- h->size[k++] = (uint8) (i+1);
- h->size[k] = 0;
- // compute actual symbols (from jpeg spec)
- code = 0;
- k = 0;
- for(j=1; j <= 16; ++j) {
- // compute delta to add to code to compute symbol id
- h->delta[j] = k - code;
- if (h->size[k] == j) {
- while (h->size[k] == j)
- h->code[k++] = (uint16) (code++);
- if (code-1 >= (1 << j)) return e("bad code lengths","Corrupt JPEG");
- }
- // compute largest code + 1 for this size, preshifted as needed later
- h->maxcode[j] = code << (16-j);
- code <<= 1;
- }
- h->maxcode[j] = 0xffffffff;
- // build non-spec acceleration table; 255 is flag for not-accelerated
- memset(h->fast, 255, 1 << FAST_BITS);
- for (i=0; i < k; ++i) {
- int s = h->size[i];
- if (s <= FAST_BITS) {
- int c = h->code[i] << (FAST_BITS-s);
- int m = 1 << (FAST_BITS-s);
- for (j=0; j < m; ++j) {
- h->fast[c+j] = (uint8) i;
- }
- }
- }
- return 1;
- }
- // sizes for components, interleaved MCUs
- static int img_h_max, img_v_max;
- static int img_mcu_x, img_mcu_y;
- static int img_mcu_w, img_mcu_h;
- // definition of jpeg image component
- static struct
- {
- int id;
- int h,v;
- int tq;
- int hd,ha;
- int dc_pred;
- int x,y,w2,h2;
- uint8 *data;
- } img_comp[4];
- static unsigned long code_buffer; // jpeg entropy-coded buffer
- static int code_bits; // number of valid bits
- static unsigned char marker; // marker seen while filling entropy buffer
- static int nomore; // flag if we saw a marker so must stop
- static void grow_buffer_unsafe(void)
- {
- do {
- int b = nomore ? 0 : get8();
- if (b == 0xff) {
- int c = get8();
- if (c != 0) {
- marker = (unsigned char) c;
- nomore = 1;
- return;
- }
- }
- code_buffer = (code_buffer << 8) | b;
- code_bits += 8;
- } while (code_bits <= 24);
- }
- // (1 << n) - 1
- static unsigned long bmask[17]={0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535};
- // decode a jpeg huffman value from the bitstream
- __forceinline static int decode(huffman *h)
- {
- unsigned int temp;
- int c,k;
- if (code_bits < 16) grow_buffer_unsafe();
- // look at the top FAST_BITS and determine what symbol ID it is,
- // if the code is <= FAST_BITS
- c = (code_buffer >> (code_bits - FAST_BITS)) & ((1 << FAST_BITS)-1);
- k = h->fast[c];
- if (k < 255) {
- if (h->size[k] > code_bits)
- return -1;
- code_bits -= h->size[k];
- return h->values[k];
- }
- // naive test is to shift the code_buffer down so k bits are
- // valid, then test against maxcode. To speed this up, we've
- // preshifted maxcode left so that it has (16-k) 0s at the
- // end; in other words, regardless of the number of bits, it
- // wants to be compared against something shifted to have 16;
- // that way we don't need to shift inside the loop.
- if (code_bits < 16)
- temp = (code_buffer << (16 - code_bits)) & 0xffff;
- else
- temp = (code_buffer >> (code_bits - 16)) & 0xffff;
- for (k=FAST_BITS+1 ; ; ++k)
- if (temp < h->maxcode[k])
- break;
- if (k == 17) {
- // error! code not found
- code_bits -= 16;
- return -1;
- }
- if (k > code_bits)
- return -1;
- // convert the huffman code to the symbol id
- c = ((code_buffer >> (code_bits - k)) & bmask[k]) + h->delta[k];
- assert((((code_buffer) >> (code_bits - h->size[c])) & bmask[h->size[c]]) == h->code[c]);
- // convert the id to a symbol
- code_bits -= k;
- return h->values[c];
- }
- // combined JPEG 'receive' and JPEG 'extend', since baseline
- // always extends everything it receives.
- __forceinline static int extend_receive(int n)
- {
- unsigned int m = 1 << (n-1);
- unsigned int k;
- if (code_bits < n) grow_buffer_unsafe();
- k = (code_buffer >> (code_bits - n)) & bmask[n];
- code_bits -= n;
- // the following test is probably a random branch that won't
- // predict well. I tried to table accelerate it but failed.
- // maybe it's compiling as a conditional move?
- if (k < m)
- return (-1 << n) + k + 1;
- else
- return k;
- }
- // given a value that's at position X in the zigzag stream,
- // where does it appear in the 8x8 matrix coded as row-major?
- static uint8 dezigzag[64+15] =
- {
- 0, 1, 8, 16, 9, 2, 3, 10,
- 17, 24, 32, 25, 18, 11, 4, 5,
- 12, 19, 26, 33, 40, 48, 41, 34,
- 27, 20, 13, 6, 7, 14, 21, 28,
- 35, 42, 49, 56, 57, 50, 43, 36,
- 29, 22, 15, 23, 30, 37, 44, 51,
- 58, 59, 52, 45, 38, 31, 39, 46,
- 53, 60, 61, 54, 47, 55, 62, 63,
- // let corrupt input sample past end
- 63, 63, 63, 63, 63, 63, 63, 63,
- 63, 63, 63, 63, 63, 63, 63
- };
- // decode one 64-entry block--
- static int decode_block(short data[64], huffman *hdc, huffman *hac, int b)
- {
- int diff,dc,k;
- int t = decode(hdc);
- if (t < 0) return e("bad huffman code","Corrupt JPEG");
- // 0 all the ac values now so we can do it 32-bits at a time
- memset(data,0,64*sizeof(data[0]));
- diff = t ? extend_receive(t) : 0;
- dc = img_comp[b].dc_pred + diff;
- img_comp[b].dc_pred = dc;
- data[0] = (short) dc;
- // decode AC components, see JPEG spec
- k = 1;
- do {
- int r,s;
- int rs = decode(hac);
- if (rs < 0) return e("bad huffman code","Corrupt JPEG");
- s = rs & 15;
- r = rs >> 4;
- if (s == 0) {
- if (rs != 0xf0) break; // end block
- k += 16;
- } else {
- k += r;
- // decode into unzigzag'd location
- data[dezigzag[k++]] = (short) extend_receive(s);
- }
- } while (k < 64);
- return 1;
- }
- // take a -128..127 value and clamp it and convert to 0..255
- __forceinline static uint8 clamp(int x)
- {
- x += 128;
- // trick to use a single test to catch both cases
- if ((unsigned int) x > 255) {
- if (x < 0) return 0;
- if (x > 255) return 255;
- }
- return (uint8) x;
- }
- #define f2f(x) (int) (((x) * 4096 + 0.5))
- #define fsh(x) ((x) << 12)
- // derived from jidctint -- DCT_ISLOW
- #define IDCT_1D(s0,s1,s2,s3,s4,s5,s6,s7) \
- int t0,t1,t2,t3,p1,p2,p3,p4,p5,x0,x1,x2,x3; \
- p2 = s2; \
- p3 = s6; \
- p1 = (p2+p3) * f2f(0.5411961f); \
- t2 = p1 + p3*f2f(-1.847759065f); \
- t3 = p1 + p2*f2f( 0.765366865f); \
- p2 = s0; \
- p3 = s4; \
- t0 = fsh(p2+p3); \
- t1 = fsh(p2-p3); \
- x0 = t0+t3; \
- x3 = t0-t3; \
- x1 = t1+t2; \
- x2 = t1-t2; \
- t0 = s7; \
- t1 = s5; \
- t2 = s3; \
- t3 = s1; \
- p3 = t0+t2; \
- p4 = t1+t3; \
- p1 = t0+t3; \
- p2 = t1+t2; \
- p5 = (p3+p4)*f2f( 1.175875602f); \
- t0 = t0*f2f( 0.298631336f); \
- t1 = t1*f2f( 2.053119869f); \
- t2 = t2*f2f( 3.072711026f); \
- t3 = t3*f2f( 1.501321110f); \
- p1 = p5 + p1*f2f(-0.899976223f); \
- p2 = p5 + p2*f2f(-2.562915447f); \
- p3 = p3*f2f(-1.961570560f); \
- p4 = p4*f2f(-0.390180644f); \
- t3 += p1+p4; \
- t2 += p2+p3; \
- t1 += p2+p4; \
- t0 += p1+p3;
- // .344 seconds on 3*anemones.jpg
- static void idct_block(uint8 *out, int out_stride, short data[64], uint8 *dequantize)
- {
- int i,val[64],*v=val;
- uint8 *o,*dq = dequantize;
- short *d = data;
- if (stbi_jpeg_dc_only) {
- // ok, I don't really know why this is right, but it seems to be:
- int z = 128 + ((d[0] * dq[0]) >> 3);
- for (i=0; i < 8; ++i) {
- out[0] = out[1] = out[2] = out[3] = out[4] = out[5] = out[6] = out[7] = z;
- out += out_stride;
- }
- return;
- }
- // columns
- for (i=0; i < 8; ++i,++d,++dq, ++v) {
- // if all zeroes, shortcut -- this avoids dequantizing 0s and IDCTing
- if (d[ 8]==0 && d[16]==0 && d[24]==0 && d[32]==0
- && d[40]==0 && d[48]==0 && d[56]==0) {
- // no shortcut 0 seconds
- // (1|2|3|4|5|6|7)==0 0 seconds
- // all separate -0.047 seconds
- // 1 && 2|3 && 4|5 && 6|7: -0.047 seconds
- int dcterm = d[0] * dq[0] << 2;
- v[0] = v[8] = v[16] = v[24] = v[32] = v[40] = v[48] = v[56] = dcterm;
- } else {
- IDCT_1D(d[ 0]*dq[ 0],d[ 8]*dq[ 8],d[16]*dq[16],d[24]*dq[24],
- d[32]*dq[32],d[40]*dq[40],d[48]*dq[48],d[56]*dq[56])
- // constants scaled things up by 1<<12; let's bring them back
- // down, but keep 2 extra bits of precision
- x0 += 512; x1 += 512; x2 += 512; x3 += 512;
- v[ 0] = (x0+t3) >> 10;
- v[56] = (x0-t3) >> 10;
- v[ 8] = (x1+t2) >> 10;
- v[48] = (x1-t2) >> 10;
- v[16] = (x2+t1) >> 10;
- v[40] = (x2-t1) >> 10;
- v[24] = (x3+t0) >> 10;
- v[32] = (x3-t0) >> 10;
- }
- }
- for (i=0, v=val, o=out; i < 8; ++i,v+=8,o+=out_stride) {
- // no fast case since the first 1D IDCT spread components out
- IDCT_1D(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7])
- // constants scaled things up by 1<<12, plus we had 1<<2 from first
- // loop, plus horizontal and vertical each scale by sqrt(8) so together
- // we've got an extra 1<<3, so 1<<17 total we need to remove.
- x0 += 65536; x1 += 65536; x2 += 65536; x3 += 65536;
- o[0] = clamp((x0+t3) >> 17);
- o[7] = clamp((x0-t3) >> 17);
- o[1] = clamp((x1+t2) >> 17);
- o[6] = clamp((x1-t2) >> 17);
- o[2] = clamp((x2+t1) >> 17);
- o[5] = clamp((x2-t1) >> 17);
- o[3] = clamp((x3+t0) >> 17);
- o[4] = clamp((x3-t0) >> 17);
- }
- }
- #define MARKER_none 0xff
- // if there's a pending marker from the entropy stream, return that
- // otherwise, fetch from the stream and get a marker. if there's no
- // marker, return 0xff, which is never a valid marker value
- static uint8 get_marker(void)
- {
- uint8 x;
- if (marker != MARKER_none) { x = marker; marker = MARKER_none; return x; }
- x = get8u();
- if (x != 0xff) return MARKER_none;
- while (x == 0xff)
- x = get8u();
- return x;
- }
- // in each scan, we'll have scan_n components, and the order
- // of the components is specified by order[]
- static int scan_n, order[4];
- static int restart_interval, todo;
- #define RESTART(x) ((x) >= 0xd0 && (x) <= 0xd7)
- // after a restart interval, reset the entropy decoder and
- // the dc prediction
- static void reset(void)
- {
- code_bits = 0;
- code_buffer = 0;
- nomore = 0;
- img_comp[0].dc_pred = img_comp[1].dc_pred = img_comp[2].dc_pred = 0;
- marker = MARKER_none;
- todo = restart_interval ? restart_interval : 0x7fffffff;
- // no more than 1<<31 MCUs if no restart_interal? that's plenty safe,
- // since we don't even allow 1<<30 pixels
- }
- static int parse_entropy_coded_data(void)
- {
- reset();
- if (scan_n == 1) {
- int i,j;
- short data[64];
- int n = order[0];
- // non-interleaved data, we just need to process one block at a time,
- // in trivial scanline order
- // number of blocks to do just depends on how many actual "pixels" this
- // component has, independent of interleaved MCU blocking and such
- int w = (img_comp[n].x+7) >> 3;
- int h = (img_comp[n].y+7) >> 3;
- for (j=0; j < h; ++j) {
- for (i=0; i < w; ++i) {
- if (!decode_block(data, huff_dc+img_comp[n].hd, huff_ac+img_comp[n].ha, n)) return 0;
- idct_block(img_comp[n].data+img_comp[n].w2*j*8+i*8, img_comp[n].w2, data, dequant[img_comp[n].tq]);
- // every data block is an MCU, so countdown the restart interval
- if (--todo <= 0) {
- if (code_bits < 24) grow_buffer_unsafe();
- // if it's NOT a restart, then just bail, so we get corrupt data
- // rather than no data
- if (!RESTART(marker)) return 1;
- reset();
- }
- }
- }
- } else { // interleaved!
- int i,j,k,x,y;
- short data[64];
- for (j=0; j < img_mcu_y; ++j) {
- for (i=0; i < img_mcu_x; ++i) {
- // scan an interleaved mcu... process scan_n components in order
- for (k=0; k < scan_n; ++k) {
- int n = order[k];
- // scan out an mcu's worth of this component; that's just determined
- // by the basic H and V specified for the component
- for (y=0; y < img_comp[n].v; ++y) {
- for (x=0; x < img_comp[n].h; ++x) {
- int x2 = (i*img_comp[n].h + x)*8;
- int y2 = (j*img_comp[n].v + y)*8;
- if (!decode_block(data, huff_dc+img_comp[n].hd, huff_ac+img_comp[n].ha, n)) return 0;
- idct_block(img_comp[n].data+img_comp[n].w2*y2+x2, img_comp[n].w2, data, dequant[img_comp[n].tq]);
- }
- }
- }
- // after all interleaved components, that's an interleaved MCU,
- // so now count down the restart interval
- if (--todo <= 0) {
- if (code_bits < 24) grow_buffer_unsafe();
- // if it's NOT a restart, then just bail, so we get corrupt data
- // rather than no data
- if (!RESTART(marker)) return 1;
- reset();
- }
- }
- }
- }
- return 1;
- }
- static int process_marker(int m)
- {
- int L;
- switch (m) {
- case MARKER_none: // no marker found
- return e("expected marker","Corrupt JPEG");
- case 0xC2: // SOF - progressive
- return e("progressive jpeg","JPEG format not supported (progressive)");
- case 0xDD: // DRI - specify restart interval
- if (get16() != 4) return e("bad DRI len","Corrupt JPEG");
- restart_interval = get16();
- return 1;
- case 0xDB: // DQT - define quantization table
- L = get16()-2;
- while (L > 0) {
- int z = get8();
- int p = z >> 4;
- int t = z & 15,i;
- if (p != 0) return e("bad DQT type","Corrupt JPEG");
- if (t > 3) return e("bad DQT table","Corrupt JPEG");
- for (i=0; i < 64; ++i)
- dequant[t][dezigzag[i]] = get8u();
- L -= 65;
- }
- return L==0;
- case 0xC4: // DHT - define huffman table
- L = get16()-2;
- while (L > 0) {
- uint8 *v;
- int sizes[16],i,m=0;
- int z = get8();
- int tc = z >> 4;
- int th = z & 15;
- if (tc > 1 || th > 3) return e("bad DHT header","Corrupt JPEG");
- for (i=0; i < 16; ++i) {
- sizes[i] = get8();
- m += sizes[i];
- }
- L -= 17;
- if (tc == 0) {
- if (!build_huffman(huff_dc+th, sizes)) return 0;
- v = huff_dc[th].values;
- } else {
- if (!build_huffman(huff_ac+th, sizes)) return 0;
- v = huff_ac[th].values;
- }
- for (i=0; i < m; ++i)
- v[i] = get8u();
- L -= m;
- }
- return L==0;
- }
- // check for comment block or APP blocks
- if ((m >= 0xE0 && m <= 0xEF) || m == 0xFE) {
- skip(get16()-2);
- return 1;
- }
- return 0;
- }
- // after we see SOS
- static int process_scan_header(void)
- {
- int i;
- int Ls = get16();
- scan_n = get8();
- if (scan_n < 1 || scan_n > 4 || scan_n > (int) img_n) return e("bad SOS component count","Corrupt JPEG");
- if (Ls != 6+2*scan_n) return e("bad SOS len","Corrupt JPEG");
- for (i=0; i < scan_n; ++i) {
- int id = get8(), which;
- int z = get8();
- for (which = 0; which < img_n; ++which)
- if (img_comp[which].id == id)
- break;
- if (which == img_n) return 0;
- img_comp[which].hd = z >> 4; if (img_comp[which].hd > 3) return e("bad DC huff","Corrupt JPEG");
- img_comp[which].ha = z & 15; if (img_comp[which].ha > 3) return e("bad AC huff","Corrupt JPEG");
- order[i] = which;
- }
- if (get8() != 0) return e("bad SOS","Corrupt JPEG");
- get8(); // should be 63, but might be 0
- if (get8() != 0) return e("bad SOS","Corrupt JPEG");
- return 1;
- }
- static int process_frame_header(int scan)
- {
- int Lf,p,i,z, h_max=1,v_max=1;
- Lf = get16(); if (Lf < 11) return e("bad SOF len","Corrupt JPEG"); // JPEG
- p = get8(); if (p != 8) return e("only 8-bit","JPEG format not supported: 8-bit only"); // JPEG baseline
- img_y = get16(); if (img_y == 0) return e("no header height", "JPEG format not supported: delayed height"); // Legal, but we don't handle it--but neither does IJG
- img_x = get16(); if (img_x == 0) return e("0 width","Corrupt JPEG"); // JPEG requires
- img_n = get8();
- if (img_n != 3 && img_n != 1) return e("bad component count","Corrupt JPEG"); // JFIF requires
- if (Lf != 8+3*img_n) return e("bad SOF len","Corrupt JPEG");
- for (i=0; i < img_n; ++i) {
- img_comp[i].id = get8();
- if (img_comp[i].id != i+1) // JFIF requires
- if (img_comp[i].id != i) // jpegtran outputs non-JFIF-compliant files!
- return e("bad component ID","Corrupt JPEG");
- z = get8();
- img_comp[i].h = (z >> 4); if (!img_comp[i].h || img_comp[i].h > 4) return e("bad H","Corrupt JPEG");
- img_comp[i].v = z & 15; if (!img_comp[i].v || img_comp[i].v > 4) return e("bad V","Corrupt JPEG");
- img_comp[i].tq = get8(); if (img_comp[i].tq > 3) return e("bad TQ","Corrupt JPEG");
- }
- if (scan != SCAN_load) return 1;
- if ((1 << 30) / img_x / img_n < img_y) return e("too large", "Image too large to decode");
- for (i=0; i < img_n; ++i) {
- if (img_comp[i].h > h_max) h_max = img_comp[i].h;
- if (img_comp[i].v > v_max) v_max = img_comp[i].v;
- }
- // compute interleaved mcu info
- img_h_max = h_max;
- img_v_max = v_max;
- img_mcu_w = h_max * 8;
- img_mcu_h = v_max * 8;
- img_mcu_x = (img_x + img_mcu_w-1) / img_mcu_w;
- img_mcu_y = (img_y + img_mcu_h-1) / img_mcu_h;
- for (i=0; i < img_n; ++i) {
- // number of effective pixels (e.g. for non-interleaved MCU)
- img_comp[i].x = (img_x * img_comp[i].h + h_max-1) / h_max;
- img_comp[i].y = (img_y * img_comp[i].v + v_max-1) / v_max;
- // to simplify generation, we'll allocate enough memory to decode
- // the bogus oversized data from using interleaved MCUs and their
- // big blocks (e.g. a 16x16 iMCU on an image of width 33); we won't
- // discard the extra data until colorspace conversion
- img_comp[i].w2 = img_mcu_x * img_comp[i].h * 8;
- img_comp[i].h2 = img_mcu_y * img_comp[i].v * 8;
- img_comp[i].data = (uint8 *) malloc(img_comp[i].w2 * img_comp[i].h2);
- if (img_comp[i].data == NULL) {
- for(--i; i >= 0; --i)
- free(img_comp[i].data);
- return e("outofmem", "Out of memory");
- }
- }
- return 1;
- }
- // use comparisons since in some cases we handle more than one case (e.g. SOF)
- #define DNL(x) ((x) == 0xdc)
- #define SOI(x) ((x) == 0xd8)
- #define EOI(x) ((x) == 0xd9)
- #define SOF(x) ((x) == 0xc0 || (x) == 0xc1)
- #define SOS(x) ((x) == 0xda)
- static int decode_jpeg_header(int scan)
- {
- int m;
- marker = MARKER_none; // initialize cached marker to empty
- m = get_marker();
- if (!SOI(m)) return e("no SOI","Corrupt JPEG");
- if (scan == SCAN_type) return 1;
- m = get_marker();
- while (!SOF(m)) {
- if (!process_marker(m)) return 0;
- m = get_marker();
- while (m == MARKER_none) {
- // some files have extra padding after their blocks, so ok, we'll scan
- if (at_eof()) return e("no SOF", "Corrupt JPEG");
- m = get_marker();
- }
- }
- if (!process_frame_header(scan)) return 0;
- return 1;
- }
- static int decode_jpeg_image(void)
- {
- int m;
- restart_interval = 0;
- if (!decode_jpeg_header(SCAN_load)) return 0;
- m = get_marker();
- while (!EOI(m)) {
- if (SOS(m)) {
- if (!process_scan_header()) return 0;
- if (!parse_entropy_coded_data()) return 0;
- } else {
- if (!process_marker(m)) return 0;
- }
- m = get_marker();
- }
- return 1;
- }
- // static jfif-centered resampling with cross-block smoothing
- // here by cross-block smoothing what I mean is that the resampling
- // is bilerp and crosses blocks; I dunno what IJG means
- #define div4(x) ((uint8) ((x) >> 2))
- static void resample_v_2(uint8 *out1, uint8 *input, int w, int h, int s)
- {
- // need to generate two samples vertically for every one in input
- uint8 *above;
- uint8 *below;
- uint8 *source;
- uint8 *out2;
- int i,j;
- source = input;
- out2 = out1+w;
- for (j=0; j < h; ++j) {
- above = source;
- source = input + j*s;
- below = source + s; if (j == h-1) below = source;
- for (i=0; i < w; ++i) {
- int n = source[i]*3;
- out1[i] = div4(above[i] + n);
- out2[i] = div4(below[i] + n);
- }
- out1 += w*2;
- out2 += w*2;
- }
- }
- static void resample_h_2(uint8 *out, uint8 *input, int w, int h, int s)
- {
- // need to generate two samples horizontally for every one in input
- int i,j;
- if (w == 1) {
- for (j=0; j < h; ++j)
- out[j*2+0] = out[j*2+1] = input[j*s];
- return;
- }
- for (j=0; j < h; ++j) {
- out[0] = input[0];
- out[1] = div4(input[0]*3 + input[1]);
- for (i=1; i < w-1; ++i) {
- int n = input[i]*3;
- out[i*2-2] = div4(input[i-1] + n);
- out[i*2-1] = div4(input[i+1] + n);
- }
- out[w*2-2] = div4(input[w-2]*3 + input[w-1]);
- out[w*2-1] = input[w-1];
- out += w*2;
- input += s;
- }
- }
- // .172 seconds on 3*anemones.jpg
- static void resample_hv_2(uint8 *out, uint8 *input, int w, int h, int s)
- {
- // need to generate 2x2 samples for every one in input
- int i,j;
- int os = w*2;
- // generate edge samples... @TODO lerp them!
- for (i=0; i < w; ++i) {
- out[i*2+0] = out[i*2+1] = input[i];
- out[i*2+(2*h-1)*os+0] = out[i*2+(2*h-1)*os+1] = input[i+(h-1)*w];
- }
- for (j=0; j < h; ++j) {
- out[j*os*2+0] = out[j*os*2+os+0] = input[j*w];
- out[j*os*2+os-1] = out[j*os*2+os+os-1] = input[j*w+i-1];
- }
- // now generate interior samples; i & j point to top left of input
- for (j=0; j < h-1; ++j) {
- uint8 *in1 = input+j*s;
- uint8 *in2 = in1 + s;
- uint8 *out1 = out + (j*2+1)*os + 1;
- uint8 *out2 = out1 + os;
- for (i=0; i < w-1; ++i) {
- int p00 = in1[0], p01=in1[1], p10=in2[0], p11=in2[1];
- int p00_3 = p00*3, p01_3 = p01*3, p10_3 = p10*3, p11_3 = p11*3;
- #define div16(x) ((uint8) ((x) >> 4))
- out1[0] = div16(p00*9 + p01_3 + p10_3 + p11);
- out1[1] = div16(p01*9 + p00_3 + p01_3 + p10);
- out2[0] = div16(p10*9 + p11_3 + p00_3 + p01);
- out2[1] = div16(p11*9 + p10_3 + p01_3 + p00);
- out1 += 2;
- out2 += 2;
- ++in1;
- ++in2;
- }
- }
- }
- #define float2fixed(x) ((int) ((x) * 65536 + 0.5))
- // 0.38 seconds on 3*anemones.jpg (0.25 with processor = Pro)
- // VC6 without processor=Pro is generating multiple LEAs per multiply!
- static void YCbCr_to_RGB_row(uint8 *out, uint8 *y, uint8 *pcb, uint8 *pcr, int count, int step)
- {
- int i;
- for (i=0; i < count; ++i) {
- int y_fixed = (y[i] << 16) + 32768; // rounding
- int r,g,b;
- int cr = pcr[i] - 128;
- int cb = pcb[i] - 128;
- r = y_fixed + cr*float2fixed(1.40200f);
- g = y_fixed - cr*float2fixed(0.71414f) - cb*float2fixed(0.34414f);
- b = y_fixed + cb*float2fixed(1.77200f);
- r >>= 16;
- g >>= 16;
- b >>= 16;
- if ((unsigned) r > 255) { if (r < 0) r = 0; else r = 255; }
- if ((unsigned) g > 255) { if (g < 0) g = 0; else g = 255; }
- if ((unsigned) b > 255) { if (b < 0) b = 0; else b = 255; }
- out[0] = (uint8)r;
- out[1] = (uint8)g;
- out[2] = (uint8)b;
- if (step == 4) out[3] = 255;
- out += step;
- }
- }
- // clean up the temporary component buffers
- static void cleanup_jpeg(void)
- {
- int i;
- for (i=0; i < img_n; ++i) {
- if (img_comp[i].data) {
- free(img_comp[i].data);
- img_comp[i].data = NULL;
- }
- }
- }
- static uint8 *load_jpeg_image(int *out_x, int *out_y, int *comp, int req_comp)
- {
- int i, n;
- // validate req_comp
- if (req_comp < 0 || req_comp > 4) return ep("bad req_comp", "Internal error");
- // load a jpeg image from whichever source
- if (!decode_jpeg_image()) { cleanup_jpeg(); return NULL; }
- // determine actual number of components to generate
- n = req_comp ? req_comp : img_n;
- // resample components to full size... memory wasteful, but this
- // lets us bilerp across blocks while upsampling
- for (i=0; i < img_n; ++i) {
- // if we're outputting fewer than 3 components, we're grey not RGB;
- // in that case, don't bother upsampling Cb or Cr
- if (n < 3 && i) continue;
- // check if the component scale is less than max; if so it needs upsampling
- if (img_comp[i].h != img_h_max || img_comp[i].v != img_v_max) {
- int stride = img_x;
- // allocate final size; make sure it's big enough for upsampling off
- // the edges with upsample up to 4x4 (although we only support 2x2
- // currently)
- uint8 *new_data = (uint8 *) malloc((img_x+3)*(img_y+3));
- if (new_data == NULL) {
- cleanup_jpeg();
- return ep("outofmem", "Out of memory (image too large?)");
- }
- if (img_comp[i].h*2 == img_h_max && img_comp[i].v*2 == img_v_max) {
- int tx = (img_x+1)>>1;
- resample_hv_2(new_data, img_comp[i].data, tx,(img_y+1)>>1, img_comp[i].w2);
- stride = tx*2;
- } else if (img_comp[i].h == img_h_max && img_comp[i].v*2 == img_v_max) {
- resample_v_2(new_data, img_comp[i].data, img_x,(img_y+1)>>1, img_comp[i].w2);
- } else if (img_comp[i].h*2 == img_h_max && img_comp[i].v == img_v_max) {
- int tx = (img_x+1)>>1;
- resample_h_2(new_data, img_comp[i].data, tx,img_y, img_comp[i].w2);
- stride = tx*2;
- } else {
- // @TODO resample uncommon sampling pattern with nearest neighbor
- free(new_data);
- cleanup_jpeg();
- return ep("uncommon H or V", "JPEG not supported: atypical downsampling mode");
- }
- img_comp[i].w2 = stride;
- free(img_comp[i].data);
- img_comp[i].data = new_data;
- }
- }
- // now convert components to output image
- {
- uint32 i,j;
- uint8 *output = (uint8 *) malloc(n * img_x * img_y + 1);
- if (n >= 3) { // output STBI_rgb_*
- for (j=0; j < img_y; ++j) {
- uint8 *y = img_comp[0].data + j*img_comp[0].w2;
- uint8 *out = output + n * img_x * j;
- if (img_n == 3) {
- uint8 *cb = img_comp[1].data + j*img_comp[1].w2;
- uint8 *cr = img_comp[2].data + j*img_comp[2].w2;
- YCbCr_to_RGB_row(out, y, cb, cr, img_x, n);
- } else {
- for (i=0; i < img_x; ++i) {
- out[0] = out[1] = out[2] = y[i];
- out[3] = 255; // not used if n == 3
- out += n;
- }
- }
- }
- } else { // output STBI_grey_*
- for (j=0; j < img_y; ++j) {
- uint8 *y = img_comp[0].data + j*img_comp[0].w2;
- uint8 *out = output + n * img_x * j;
- if (n == 1)
- for (i=0; i < img_x; ++i) *out++ = *y++;
- else
- for (i=0; i < img_x; ++i) *out++ = *y++, *out++ = 255;
- }
- }
- cleanup_jpeg();
- *out_x = img_x;
- *out_y = img_y;
- if (comp) *comp = n; // Changed JLD: report output components
- //if (comp) *comp = img_n; // report original components, not output
- return output;
- }
- }
- #ifndef STBI_NO_STDIO
- unsigned char *stbi_jpeg_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
- {
- start_file(f);
- return load_jpeg_image(x,y,comp,req_comp);
- }
- unsigned char *stbi_jpeg_load(char *filename, int *x, int *y, int *comp, int req_comp)
- {
- unsigned char *data;
- FILE *f = fopen(filename, "rb");
- if (!f) return NULL;
- data = stbi_jpeg_load_from_file(f,x,y,comp,req_comp);
- fclose(f);
- return data;
- }
- #endif
- unsigned char *stbi_jpeg_load_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
- {
- start_mem(buffer,len);
- return load_jpeg_image(x,y,comp,req_comp);
- }
- #ifndef STBI_NO_STDIO
- int stbi_jpeg_test_file(FILE *f)
- {
- int n,r;
- n = ftell(f);
- start_file(f);
- r = decode_jpeg_header(SCAN_type);
- fseek(f,n,SEEK_SET);
- return r;
- }
- #endif
- int stbi_jpeg_test_memory(unsigned char *buffer, int len)
- {
- start_mem(buffer,len);
- return decode_jpeg_header(SCAN_type);
- }
- // @TODO:
- #ifndef STBI_NO_STDIO
- extern int stbi_jpeg_info (char *filename, int *x, int *y, int *comp);
- extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp);
- #endif
- extern int stbi_jpeg_info_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp);
- // public domain zlib decode v0.2 Sean Barrett 2006-11-18
- // simple implementation
- // - all input must be provided in an upfront buffer
- // - all output is written to a single output buffer (can malloc/realloc)
- // performance
- // - fast huffman
- // fast-way is faster to check than jpeg huffman, but slow way is slower
- #define ZFAST_BITS 9 // accelerate all cases in default tables
- #define ZFAST_MASK ((1 << ZFAST_BITS) - 1)
- // zlib-style huffman encoding
- // (jpegs packs from left, zlib from right, so can't share code)
- typedef struct
- {
- uint16 fast[1 << ZFAST_BITS];
- uint16 firstcode[16];
- int maxcode[17];
- uint16 firstsymbol[16];
- uint8 size[288];
- uint16 value[288];
- } zhuffman;
- __forceinline static int bitreverse16(int n)
- {
- n = ((n & 0xAAAA) >> 1) | ((n & 0x5555) << 1);
- n = ((n & 0xCCCC) >> 2) | ((n & 0x3333) << 2);
- n = ((n & 0xF0F0) >> 4) | ((n & 0x0F0F) << 4);
- n = ((n & 0xFF00) >> 8) | ((n & 0x00FF) << 8);
- return n;
- }
- __forceinline static int bit_reverse(int v, int bits)
- {
- assert(bits <= 16);
- // to bit reverse n bits, reverse 16 and shift
- // e.g. 11 bits, bit reverse and shift away 5
- return bitreverse16(v) >> (16-bits);
- }
- static int zbuild_huffman(zhuffman *z, uint8 *sizelist, int num)
- {
- int i,k=0;
- int code, next_code[16], sizes[17];
- // DEFLATE spec for generating codes
- memset(sizes, 0, sizeof(sizes));
- memset(z->fast, 255, sizeof(z->fast));
- for (i=0; i < num; ++i)
- ++sizes[sizelist[i]];
- sizes[0] = 0;
- for (i=1; i < 16; ++i)
- assert(sizes[i] <= (1 << i));
- code = 0;
- for (i=1; i < 16; ++i) {
- next_code[i] = code;
- z->firstcode[i] = (uint16) code;
- z->firstsymbol[i] = (uint16) k;
- code = (code + sizes[i]);
- if (sizes[i])
- if (code-1 >= (1 << i)) return e("bad codelengths","Corrupt JPEG");
- z->maxcode[i] = code << (16-i); // preshift for inner loop
- code <<= 1;
- k += sizes[i];
- }
- z->maxcode[16] = 0x10000; // sentinel
- for (i=0; i < num; ++i) {
- int s = sizelist[i];
- if (s) {
- int c = next_code[s] - z->firstcode[s] + z->firstsymbol[s];
- z->size[c] = (uint8)s;
- z->value[c] = (uint16)i;
- if (s <= ZFAST_BITS) {
- int k = bit_reverse(next_code[s],s);
- while (k < (1 << ZFAST_BITS)) {
- z->fast[k] = (uint16) c;
- k += (1 << s);
- }
- }
- ++next_code[s];
- }
- }
- return 1;
- }
- // zlib-from-memory implementation for PNG reading
- // because PNG allows splitting the zlib stream arbitrarily,
- // and it's annoying structurally to have PNG call ZLIB call PNG,
- // we require PNG read all the IDATs and combine them into a single
- // memory buffer
- static uint8 *zbuffer, *zbuffer_end;
- __forceinline static int zget8(void)
- {
- if (zbuffer >= zbuffer_end) return 0;
- return *zbuffer++;
- }
- //static unsigned long code_buffer;
- static int num_bits;
- static void fill_bits(void)
- {
- do {
- assert(code_buffer < (1U << num_bits));
- code_buffer |= zget8() << num_bits;
- num_bits += 8;
- } while (num_bits <= 24);
- }
- __forceinline static unsigned int zreceive(int n)
- {
- unsigned int k;
- if (num_bits < n) fill_bits();
- k = code_buffer & ((1 << n) - 1);
- code_buffer >>= n;
- num_bits -= n;
- return k;
- }
- __forceinline static int zhuffman_decode(zhuffman *z)
- {
- int b,s,k;
- if (num_bits < 16) fill_bits();
- b = z->fast[code_buffer & ZFAST_MASK];
- if (b < 0xffff) {
- s = z->size[b];
- code_buffer >>= s;
- num_bits -= s;
- return z->value[b];
- }
- // not resolved by fast table, so compute it the slow way
- // use jpeg approach, which requires MSbits at top
- k = bit_reverse(code_buffer, 16);
- for (s=ZFAST_BITS+1; ; ++s)
- if (k < z->maxcode[s])
- break;
- if (s == 16) return -1; // invalid code!
- // code size is s, so:
- b = (k >> (16-s)) - z->firstcode[s] + z->firstsymbol[s];
- assert(z->size[b] == s);
- code_buffer >>= s;
- num_bits -= s;
- return z->value[b];
- }
- static char *zout;
- static char *zout_start;
- static char *zout_end;
- static int z_expandable;
- static int expand(int n) // need to make room for n bytes
- {
- char *q;
- int cur, limit;
- if (!z_expandable) return e("output buffer limit","Corrupt PNG");
- cur = (int) (zout - zout_start);
- limit = (int) (zout_end - zout_start);
- while (cur + n > limit)
- limit *= 2;
- q = (char *) realloc(zout_start, limit);
- if (q == NULL) return e("outofmem", "Out of memory");
- zout_start = q;
- zout = q + cur;
- zout_end = q + limit;
- return 1;
- }
- static zhuffman z_length, z_distance;
- static int length_base[31] = {
- 3,4,5,6,7,8,9,10,11,13,
- 15,17,19,23,27,31,35,43,51,59,
- 67,83,99,115,131,163,195,227,258,0,0 };
- static int length_extra[31]=
- { 0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0,0,0 };
- static int dist_base[32] = { 1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,
- 257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577,0,0};
- static int dist_extra[32] =
- { 0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};
- static int parse_huffman_block(void)
- {
- for(;;) {
- int z = zhuffman_decode(&z_length);
- if (z < 256) {
- if (z < 0) return e("bad huffman code","Corrupt PNG"); // error in huffman codes
- if (zout >= zout_end) if (!expand(1)) return 0;
- *zout++ = (char) z;
- } else {
- uint8 *p;
- int len,dist;
- if (z == 256) return 1;
- z -= 257;
- len = length_base[z];
- if (length_extra[z]) len += zreceive(length_extra[z]);
- z = zhuffman_decode(&z_distance);
- if (z < 0) return e("bad huffman code","Corrupt PNG");
- dist = dist_base[z];
- if (dist_extra[z]) dist += zreceive(dist_extra[z]);
- if (zout - zout_start < dist) return e("bad dist","Corrupt PNG");
- if (zout + len > zout_end) if (!expand(len)) return 0;
- p = (uint8 *) (zout - dist);
- while (len--)
- *zout++ = *p++;
- }
- }
- }
- static int compute_huffman_codes(void)
- {
- static uint8 length_dezigzag[19] = { 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 };
- static zhuffman z_codelength; // static just to save stack space
- uint8 lencodes[286+32+137];//padding for maximum single op
- uint8 codelength_sizes[19];
- int i,n;
- int hlit = zreceive(5) + 257;
- int hdist = zreceive(5) + 1;
- int hclen = zreceive(4) + 4;
- memset(codelength_sizes, 0, sizeof(codelength_sizes));
- for (i=0; i < hclen; ++i) {
- int s = zreceive(3);
- codelength_sizes[length_dezigzag[i]] = (uint8) s;
- }
- if (!zbuild_huffman(&z_codelength, codelength_sizes, 19)) return 0;
- n = 0;
- while (n < hlit + hdist) {
- int c = zhuffman_decode(&z_codelength);
- assert(c >= 0 && c < 19);
- if (c < 16)
- lencodes[n++] = (uint8) c;
- else if (c == 16) {
- c = zreceive(2)+3;
- memset(lencodes+n, lencodes[n-1], c);
- n += c;
- } else if (c == 17) {
- c = zreceive(3)+3;
- memset(lencodes+n, 0, c);
- n += c;
- } else {
- assert(c == 18);
- c = zreceive(7)+11;
- memset(lencodes+n, 0, c);
- n += c;
- }
- }
- if (n != hlit+hdist) return e("bad codelengths","Corrupt PNG");
- if (!zbuild_huffman(&z_length, lencodes, hlit)) return 0;
- if (!zbuild_huffman(&z_distance, lencodes+hlit, hdist)) return 0;
- return 1;
- }
- static int parse_uncompressed_block(void)
- {
- uint8 header[4];
- int len,nlen,k;
- if (num_bits & 7)
- zreceive(num_bits & 7); // discard
- // drain the bit-packed data into header
- k = 0;
- while (num_bits > 0) {
- header[k++] = (uint8) (code_buffer & 255); // wtf this warns?
- code_buffer >>= 8;
- num_bits -= 8;
- }
- assert(num_bits == 0);
- // now fill header the normal way
- while (k < 4)
- header[k++] = (uint8) zget8();
- len = header[1] * 256 + header[0];
- nlen = header[3] * 256 + header[2];
- if (nlen != (len ^ 0xffff)) return e("zlib corrupt","Corrupt PNG");
- if (zbuffer + len > zbuffer_end) return e("read past buffer","Corrupt PNG");
- if (zout + len > zout_end)
- if (!expand(len)) return 0;
- memcpy(zout, zbuffer, len);
- zbuffer += len;
- zout += len;
- return 1;
- }
- static int parse_zlib_header(void)
- {
- int cmf = zget8();
- int cm = cmf & 15;
- /* int cinfo = cmf >> 4; */
- int flg = zget8();
- if ((cmf*256+flg) % 31 != 0) return e("bad zlib header","Corrupt PNG"); // zlib spec
- if (flg & 32) return e("no preset dict","Corrupt PNG"); // preset dictionary not allowed in png
- if (cm != 8) return e("bad compression","Corrupt PNG"); // DEFLATE required for png
- // window = 1 << (8 + cinfo)... but who cares, we fully buffer output
- return 1;
- }
- static uint8 default_length[288], default_distance[32];
- static void init_defaults(void)
- {
- int i; // use <= to match clearly with spec
- for (i=0; i <= 143; ++i) default_length[i] = 8;
- for ( ; i <= 255; ++i) default_length[i] = 9;
- for ( ; i <= 279; ++i) default_length[i] = 7;
- for ( ; i <= 287; ++i) default_length[i] = 8;
- for (i=0; i <= 31; ++i) default_distance[i] = 5;
- }
- static int parse_zlib(int parse_header)
- {
- int final, type;
- if (parse_header)
- if (!parse_zlib_header()) return 0;
- num_bits = 0;
- code_buffer = 0;
- do {
- final = zreceive(1);
- type = zreceive(2);
- if (type == 0) {
- if (!parse_uncompressed_block()) return 0;
- } else if (type == 3) {
- return 0;
- } else {
- if (type == 1) {
- // use fixed code lengths
- if (!default_length[0]) init_defaults();
- if (!zbuild_huffman(&z_length , default_length , 288)) return 0;
- if (!zbuild_huffman(&z_distance, default_distance, 32)) return 0;
- } else {
- if (!compute_huffman_codes()) return 0;
- }
- if (!parse_huffman_block()) return 0;
- }
- } while (!final);
- return 1;
- }
- static int do_zlib(char *obuf, int olen, int exp, int parse_header)
- {
- zout_start = obuf;
- zout = obuf;
- zout_end = obuf + olen;
- z_expandable = exp;
- return parse_zlib(parse_header);
- }
- char *stbi_zlib_decode_malloc_guesssize(int initial_size, int *outlen)
- {
- char *p = (char *) malloc(initial_size);
- if (p == NULL) return NULL;
- if (do_zlib(p, initial_size, 1, 1)) {
- *outlen = (int) (zout - zout_start);
- return zout_start;
- } else {
- free(zout_start);
- return NULL;
- }
- }
- char *stbi_zlib_decode_malloc(char *buffer, int len, int *outlen)
- {
- zbuffer = (uint8 *) buffer;
- zbuffer_end = (uint8 *) buffer+len;
- return stbi_zlib_decode_malloc_guesssize(16384, outlen);
- }
- int stbi_zlib_decode_buffer(char *obuffer, int olen, char *ibuffer, int ilen)
- {
- zbuffer = (uint8 *) ibuffer;
- zbuffer_end = (uint8 *) ibuffer + ilen;
- if (do_zlib(obuffer, olen, 0, 1))
- return (int) (zout - zout_start);
- else
- return -1;
- }
- char *stbi_zlib_decode_noheader_malloc(char *buffer, int len, int *outlen)
- {
- char *p = (char *) malloc(16384);
- if (p == NULL) return NULL;
- zbuffer = (uint8 *) buffer;
- zbuffer_end = (uint8 *) buffer+len;
- if (do_zlib(p, 16384, 1, 0)) {
- *outlen = (int) (zout - zout_start);
- return zout_start;
- } else {
- free(zout_start);
- return NULL;
- }
- }
- int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, char *ibuffer, int ilen)
- {
- zbuffer = (uint8 *) ibuffer;
- zbuffer_end = (uint8 *) ibuffer + ilen;
- if (do_zlib(obuffer, olen, 0, 0))
- return (int) (zout - zout_start);
- else
- return -1;
- }
- // public domain "baseline" PNG decoder v0.10 Sean Barrett 2006-11-18
- // simple implementation
- // - only 8-bit samples
- // - no CRC checking
- // - allocates lots of intermediate memory
- // - avoids problem of streaming data between subsystems
- // - avoids explicit window management
- // performance
- // - uses stb_zlib, a PD zlib implementation with fast huffman decoding
- typedef struct
- {
- unsigned long length;
- unsigned long type;
- } chunk;
- #define PNG_TYPE(a,b,c,d) (((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
- static chunk get_chunk_header(void)
- {
- chunk c;
- c.length = get32();
- c.type = get32();
- return c;
- }
- static int check_png_header(void)
- {
- static uint8 png_sig[8] = { 137,80,78,71,13,10,26,10 };
- int i;
- for (i=0; i < 8; ++i)
- if (get8() != png_sig[i]) return e("bad png sig","Not a PNG");
- return 1;
- }
- static uint8 *idata, *expanded, *out;
- enum {
- F_none=0, F_sub=1, F_up=2, F_avg=3, F_paeth=4,
- F_avg_first, F_paeth_first,
- };
- static uint8 first_row_filter[5] =
- {
- F_none, F_sub, F_none, F_avg_first, F_paeth_first
- };
- static int paeth(int a, int b, int c)
- {
- int p = a + b - c;
- int pa = abs(p-a);
- int pb = abs(p-b);
- int pc = abs(p-c);
- if (pa <= pb && pa <= pc) return a;
- if (pb <= pc) return b;
- return c;
- }
- // create the png data from post-deflated data
- static int create_png_image(uint8 *raw, uint32 raw_len, int out_n)
- {
- uint32 i,j,stride = img_x*out_n;
- int k;
- assert(out_n == img_n || out_n == img_n+1);
- out = (uint8 *) malloc(img_x * img_y * out_n);
- if (!out) return e("outofmem", "Out of memory");
- if (raw_len != (img_n * img_x + 1) * img_y) return e("not enough pixels","Corrupt PNG");
- for (j=0; j < img_y; ++j) {
- uint8 *cur = out + stride*j;
- uint8 *prior = cur - stride;
- int filter = *raw++;
- if (filter > 4) return e("invalid filter","Corrupt PNG");
- // if first row, use special filter that doesn't sample previous row
- if (j == 0) filter = first_row_filter[filter];
- // handle first pixel explicitly
- for (k=0; k < img_n; ++k) {
- switch(filter) {
- case F_none : cur[k] = raw[k]; break;
- case F_sub : cur[k] = raw[k]; break;
- case F_up : cur[k] = raw[k] + prior[k]; break;
- case F_avg : cur[k] = raw[k] + (prior[k]>>1); break;
- case F_paeth : cur[k] = (uint8) (raw[k] + paeth(0,prior[k],0)); break;
- case F_avg_first : cur[k] = raw[k]; break;
- case F_paeth_first: cur[k] = raw[k]; break;
- }
- }
- if (img_n != out_n) cur[img_n] = 255;
- raw += img_n;
- cur += out_n;
- prior += out_n;
- // this is a little gross, so that we don't switch per-pixel or per-component
- if (img_n == out_n) {
- #define CASE(f) \
- case f: \
- for (i=1; i < img_x; ++i, raw+=img_n,cur+=img_n,prior+=img_n) \
- for (k=0; k < img_n; ++k)
- switch(filter) {
- CASE(F_none) cur[k] = raw[k]; break;
- CASE(F_sub) cur[k] = raw[k] + cur[k-img_n]; break;
- CASE(F_up) cur[k] = raw[k] + prior[k]; break;
- CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-img_n])>>1); break;
- CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],prior[k],prior[k-img_n])); break;
- CASE(F_avg_first) cur[k] = raw[k] + (cur[k-img_n] >> 1); break;
- CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],0,0)); break;
- }
- #undef CASE
- } else {
- assert(img_n+1 == out_n);
- #define CASE(f) \
- case f: \
- for (i=1; i < img_x; ++i, cur[img_n]=255,raw+=img_n,cur+=out_n,prior+=out_n) \
- for (k=0; k < img_n; ++k)
- switch(filter) {
- CASE(F_none) cur[k] = raw[k]; break;
- CASE(F_sub) cur[k] = raw[k] + cur[k-out_n]; break;
- CASE(F_up) cur[k] = raw[k] + prior[k]; break;
- CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-out_n])>>1); break;
- CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],prior[k],prior[k-out_n])); break;
- CASE(F_avg_first) cur[k] = raw[k] + (cur[k-out_n] >> 1); break;
- CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],0,0)); break;
- }
- #undef CASE
- }
- }
- return 1;
- }
- static int compute_transparency(uint8 tc[3], int out_n)
- {
- uint32 i, pixel_count = img_x * img_y;
- uint8 *p = out;
- // compute color-based transparency, assuming we've
- // already got 255 as the alpha value in the output
- assert(out_n == 2 || out_n == 4);
- p = out;
- if (out_n == 2) {
- for (i=0; i < pixel_count; ++i) {
- p[1] = (p[0] == tc[0] ? 0 : 255);
- p += 2;
- }
- } else {
- for (i=0; i < pixel_count; ++i) {
- if (p[0] == tc[0] && p[1] == tc[1] && p[2] == tc[2])
- p[3] = 0;
- p += 4;
- }
- }
- return 1;
- }
- static int expand_palette(uint8 *palette, int len, int pal_img_n)
- {
- uint32 i, pixel_count = img_x * img_y;
- uint8 *p, *temp_out, *orig = out;
- p = (uint8 *) malloc(pixel_count * pal_img_n);
- if (p == NULL) return e("outofmem", "Out of memory");
- // between here and free(out) below, exitting would leak
- temp_out = p;
- if (pal_img_n == 3) {
- for (i=0; i < pixel_count; ++i) {
- int n = orig[i]*4;
- p[0] = palette[n ];
- p[1] = palette[n+1];
- p[2] = palette[n+2];
- p += 3;
- }
- } else {
- for (i=0; i < pixel_count; ++i) {
- int n = orig[i]*4;
- p[0] = palette[n ];
- p[1] = palette[n+1];
- p[2] = palette[n+2];
- p[3] = palette[n+3];
- p += 4;
- }
- }
- free(out);
- out = temp_out;
- return 1;
- }
- static int parse_png_file(int scan, int req_comp)
- {
- uint8 palette[1024], pal_img_n=0;
- uint8 has_trans=0, tc[3];
- uint32 ioff=0, idata_limit=0, i, pal_len=0;
- int first=1,k;
- if (!check_png_header()) return 0;
- if (scan == SCAN_type) return 1;
- for(;;first=0) {
- chunk c = get_chunk_header();
- if (first && c.type != PNG_TYPE('I','H','D','R'))
- return e("first not IHDR","Corrupt PNG");
- switch (c.type) {
- case PNG_TYPE('I','H','D','R'): {
- int depth,color,interlace,comp,filter;
- if (!first) return e("multiple IHDR","Corrupt PNG");
- if (c.length != 13) return e("bad IHDR len","Corrupt PNG");
- img_x = get32(); if (img_x > (1 << 24)) return e("too large","Very large image (corrupt?)");
- img_y = get32(); if (img_y > (1 << 24)) return e("too large","Very large image (corrupt?)");
- depth = get8(); if (depth != 8) return e("8bit only","PNG not supported: 8-bit only");
- color = get8(); if (color > 6) return e("bad ctype","Corrupt PNG");
- if (color == 3) pal_img_n = 3; else if (color & 1) return e("bad ctype","Corrupt PNG");
- comp = get8(); if (comp) return e("bad comp method","Corrupt PNG");
- filter= get8(); if (filter) return e("bad filter method","Corrupt PNG");
- interlace = get8(); if (interlace) return e("interlaced","PNG not supported: interlaced mode");
- if (!img_x || !img_y) return e("0-pixel image","Corrupt PNG");
- if (!pal_img_n) {
- img_n = (color & 2 ? 3 : 1) + (color & 4 ? 1 : 0);
- if ((1 << 30) / img_x / img_n < img_y) return e("too large", "Image too large to decode");
- if (scan == SCAN_header) return 1;
- } else {
- // if paletted, then pal_n is our final components, and
- // img_n is # components to decompress/filter.
- img_n = 1;
- if ((1 << 30) / img_x / 4 < img_y) return e("too large","Corrupt PNG");
- // if SCAN_header, have to scan to see if we have a tRNS
- }
- break;
- }
- case PNG_TYPE('P','L','T','E'): {
- if (c.length > 256*3) return e("invalid PLTE","Corrupt PNG");
- pal_len = c.length / 3;
- if (pal_len * 3 != c.length) return e("invalid PLTE","Corrupt PNG");
- for (i=0; i < pal_len; ++i) {
- palette[i*4+0] = get8u();
- palette[i*4+1] = get8u();
- palette[i*4+2] = get8u();
- palette[i*4+3] = 255;
- }
- break;
- }
- case PNG_TYPE('t','R','N','S'): {
- if (idata) return e("tRNS after IDAT","Corrupt PNG");
- if (pal_img_n) {
- if (scan == SCAN_header) { img_n = 4; return 1; }
- if (pal_len == 0) return e("tRNS before PLTE","Corrupt PNG");
- if (c.length > pal_len) return e("bad tRNS len","Corrupt PNG");
- pal_img_n = 4;
- for (i=0; i < c.length; ++i)
- palette[i*4+3] = get8u();
- } else {
- if (!(img_n & 1)) return e("tRNS with alpha","Corrupt PNG");
- if (c.length != (uint32) img_n*2) return e("bad tRNS len","Corrupt PNG");
- has_trans = 1;
- for (k=0; k < img_n; ++k)
- tc[k] = (uint8) get16(); // non 8-bit images will be larger
- }
- break;
- }
- case PNG_TYPE('I','D','A','T'): {
- if (pal_img_n && !pal_len) return e("no PLTE","Corrupt PNG");
- if (scan == SCAN_header) { img_n = pal_img_n; return 1; }
- if (ioff + c.length > idata_limit) {
- uint8 *p;
- if (idata_limit == 0) idata_limit = c.length > 4096 ? c.length : 4096;
- while (ioff + c.length > idata_limit)
- idata_limit *= 2;
- p = (uint8 *) realloc(idata, idata_limit); if (p == NULL) return e("outofmem", "Out of memory");
- idata = p;
- }
- #ifndef STBI_NO_STDIO
- if (img_file)
- {
- if (fread(idata+ioff,1,c.length,img_file) != c.length) return e("outofdata","Corrupt PNG");
- }
- else
- #endif
- {
- memcpy(idata+ioff, img_buffer, c.length);
- img_buffer += c.length;
- }
- ioff += c.length;
- break;
- }
- case PNG_TYPE('I','E','N','D'): {
- uint32 raw_len;
- if (scan != SCAN_load) return 1;
- if (idata == NULL) return e("no IDAT","Corrupt PNG");
- expanded = (uint8 *) stbi_zlib_decode_malloc((char *) idata, ioff, (int *) &raw_len);
- if (expanded == NULL) return 0; // zlib should set error
- free(idata); idata = NULL;
- if ((req_comp == img_n+1 && req_comp != 3 && !pal_img_n) || has_trans)
- img_out_n = img_n+1;
- else
- img_out_n = img_n;
- if (!create_png_image(expanded, raw_len, img_out_n)) return 0;
- if (has_trans)
- if (!compute_transparency(tc, img_out_n)) return 0;
- if (pal_img_n) {
- // pal_img_n == 3 or 4
- img_n = pal_img_n; // record the actual colors we had
- img_out_n = pal_img_n;
- if (req_comp >= 3) img_out_n = req_comp;
- if (!expand_palette(palette, pal_len, img_out_n))
- return 0;
- }
- free(expanded); expanded = NULL;
- return 1;
- }
- default:
- // if critical, fail
- if ((c.type & (1 << 29)) == 0) {
- #ifndef STBI_NO_FAILURE_STRINGS
- static char invalid_chunk[] = "XXXX chunk not known";
- invalid_chunk[0] = (uint8) (c.type >> 24);
- invalid_chunk[1] = (uint8) (c.type >> 16);
- invalid_chunk[2] = (uint8) (c.type >> 8);
- invalid_chunk[3] = (uint8) (c.type >> 0);
- #endif
- return e(invalid_chunk, "PNG not supported: unknown chunk type");
- }
- skip(c.length);
- break;
- }
- // end of chunk, read and skip CRC
- get8(); get8(); get8(); get8();
- }
- }
- static unsigned char *do_png(int *x, int *y, int *n, int req_comp)
- {
- unsigned char *result=NULL;
- if (req_comp < 0 || req_comp > 4) return ep("bad req_comp", "Internal error");
- if (parse_png_file(SCAN_load, req_comp)) {
- result = out;
- out = NULL;
- if (req_comp && req_comp != img_out_n) {
- result = convert_format(result, img_out_n, req_comp);
- if (result == NULL) return result;
- }
- *x = img_x;
- *y = img_y;
- if (n) *n = img_n;
- }
- free(out); out = NULL;
- free(expanded); expanded = NULL;
- free(idata); idata = NULL;
- return result;
- }
- #ifndef STBI_NO_STDIO
- unsigned char *stbi_png_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
- {
- start_file(f);
- return do_png(x,y,comp,req_comp);
- }
- unsigned char *stbi_png_load(char *filename, int *x, int *y, int *comp, int req_comp)
- {
- unsigned char *data;
- FILE *f = fopen(filename, "rb");
- if (!f) return NULL;
- data = stbi_png_load_from_file(f,x,y,comp,req_comp);
- fclose(f);
- return data;
- }
- #endif
- unsigned char *stbi_png_load_from_memory(unsigned char *buffer, int len, int *x, int *y, int *comp, int req_comp)
- {
- start_mem(buffer,len);
- return do_png(x,y,comp,req_comp);
- }
- #ifndef STBI_NO_STDIO
- int stbi_png_test_file(FILE *f)
- {
- int n,r;
- n = ftell(f);
- start_file(f);
- r = parse_png_file(SCAN_type,STBI_default);
- fseek(f,n,SEEK_SET);
- return r;
- }
- #endif
- int stbi_png_test_memory(unsigned char *buffer, int len)
- {
- start_mem(buffer, len);
- return parse_png_file(SCAN_type,STBI_default);
- }
- // TODO: load header from png
- #ifndef STBI_NO_STDIO
- extern int stbi_png_info (char *filename, int *x, int *y, int *comp);
- extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp);
- #endif
- extern int stbi_png_info_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp);
- // Microsoft/Windows BMP image
- static int bmp_test(void)
- {
- int sz;
- if (get8() != 'B') return 0;
- if (get8() != 'M') return 0;
- get32le(); // discard filesize
- get16le(); // discard reserved
- get16le(); // discard reserved
- get32le(); // discard data offset
- sz = get32le();
- if (sz == 12 || sz == 40 || sz == 56 || sz == 108) return 1;
- return 0;
- }
- #ifndef STBI_NO_STDIO
- int stbi_bmp_test_file (FILE *f)
- {
- int r,n = ftell(f);
- start_file(f);
- r = bmp_test();
- fseek(f,n,SEEK_SET);
- return r;
- }
- #endif
- int stbi_bmp_test_memory (stbi_uc *buffer, int len)
- {
- start_mem(buffer, len);
- return bmp_test();
- }
- // returns 0..31 for the highest set bit
- static int high_bit(unsigned int z)
- {
- int n=0;
- if (z == 0) return -1;
- if (z >= 0x10000) n += 16, z >>= 16;
- if (z >= 0x00100) n += 8, z >>= 8;
- if (z >= 0x00010) n += 4, z >>= 4;
- if (z >= 0x00004) n += 2, z >>= 2;
- if (z >= 0x00002) n += 1, z >>= 1;
- return n;
- }
- static int bitcount(unsigned int a)
- {
- a = (a & 0x55555555) + ((a >> 1) & 0x55555555); // max 2
- a = (a & 0x33333333) + ((a >> 2) & 0x33333333); // max 4
- a = (a + (a >> 4)) & 0x0f0f0f0f; // max 8 per 4, now 8 bits
- a = (a + (a >> 8)); // max 16 per 8 bits
- a = (a + (a >> 16)); // max 32 per 8 bits
- return a & 0xff;
- }
- static int shiftsigned(int v, int shift, int bits)
- {
- int result;
- int z=0;
- if (shift < 0) v <<= -shift;
- else v >>= shift;
- result = v;
- z = bits;
- while (z < 8) {
- result += v >> z;
- z += bits;
- }
- return result;
- }
- static stbi_uc *bmp_load(int *x, int *y, int *comp, int req_comp)
- {
- unsigned int mr=0,mg=0,mb=0,ma=0;
- stbi_uc pal[256][4];
- int psize=0,i,j,compress=0,width;
- int bpp, flip_vertically, pad, target, offset, hsz;
- if (get8() != 'B' || get8() != 'M') return ep("not BMP", "Corrupt BMP");
- get32le(); // discard filesize
- get16le(); // discard reserved
- get16le(); // discard reserved
- offset = get32le();
- hsz = get32le();
- if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108) return ep("unknown BMP", "BMP type not supported: unknown");
- failure_reason = "bad BMP";
- if (hsz == 12) {
- img_x = get16le();
- img_y = get16le();
- } else {
- img_x = get32le();
- img_y = get32le();
- }
- if (get16le() != 1) return 0;
- bpp = get16le();
- if (bpp == 1) return ep("monochrome", "BMP type not supported: 1-bit");
- flip_vertically = ((int) img_y) > 0;
- img_y = abs((int) img_y);
- if (hsz == 12) {
- if (bpp < 24)
- psize = (offset - 14 - 24) / 3;
- } else {
- compress = get32le();
- if (compress == 1 || compress == 2) return ep("BMP RLE", "BMP type not supported: RLE");
- get32le(); // discard sizeof
- get32le(); // discard hres
- get32le(); // discard vres
- get32le(); // discard colorsused
- get32le(); // discard max important
- if (hsz == 40 || hsz == 56) {
- if (hsz == 56) {
- get32le();
- get32le();
- get32le();
- get32le();
- }
- if (bpp == 16 || bpp == 32) {
- mr = mg = mb = 0;
- if (compress == 0) {
- if (bpp == 32) {
- mr = 0xff << 16;
- mg = 0xff << 8;
- mb = 0xff << 0;
- } else {
- mr = 31 << 10;
- mg = 31 << 5;
- mb = 31 << 0;
- }
- } else if (compress == 3) {
- mr = get32le();
- mg = get32le();
- mb = get32le();
- // not documented, but generated by photoshop and handled by mspaint
- if (mr == mg && mg == mb) {
- // ?!?!?
- return NULL;
- }
- } else
- return NULL;
- }
- } else {
- assert(hsz == 108);
- mr = get32le();
- mg = get32le();
- mb = get32le();
- ma = get32le();
- get32le(); // discard color space
- for (i=0; i < 12; ++i)
- get32le(); // discard color space parameters
- }
- if (bpp < 16)
- psize = (offset - 14 - hsz) >> 2;
- }
- img_n = ma ? 4 : 3;
- if (req_comp && req_comp >= 3) // we can directly decode 3 or 4
- target = req_comp;
- else
- target = img_n; // if they want monochrome, we'll post-convert
- out = (stbi_uc *) malloc(target * img_x * img_y);
- if (!out) return ep("outofmem", "Out of memory");
- if (bpp < 16) {
- int z=0;
- if (psize == 0 || psize > 256) return ep("invalid", "Corrupt BMP");
- for (i=0; i < psize; ++i) {
- pal[i][2] = get8();
- pal[i][1] = get8();
- pal[i][0] = get8();
- if (hsz != 12) get8();
- pal[i][3] = 255;
- }
- skip(offset - 14 - hsz - psize * (hsz == 12 ? 3 : 4));
- if (bpp == 4) width = (img_x + 1) >> 1;
- else if (bpp == 8) width = img_x;
- else return ep("bad bpp", "Corrupt BMP");
- pad = (-width)&3;
- for (j=0; j < (int) img_y; ++j) {
- for (i=0; i < (int) img_x; i += 2) {
- int v=get8(),v2=0;
- if (bpp == 4) {
- v2 = v & 15;
- v >>= 4;
- }
- out[z++] = pal[v][0];
- out[z++] = pal[v][1];
- out[z++] = pal[v][2];
- if (target == 4) out[z++] = 255;
- if (i+1 == (int) img_x) break;
- v = (bpp == 8) ? get8() : v2;
- out[z++] = pal[v][0];
- out[z++] = pal[v][1];
- out[z++] = pal[v][2];
- if (target == 4) out[z++] = 255;
- }
- skip(pad);
- }
- } else {
- int rshift=0,gshift=0,bshift=0,ashift=0,rcount=0,gcount=0,bcount=0,acount=0;
- int z = 0;
- int easy=0;
- skip(offset - 14 - hsz);
- if (bpp == 24) width = 3 * img_x;
- else if (bpp == 16) width = 2*img_x;
- else /* bpp = 32 and pad = 0 */ width=0;
- pad = (-width) & 3;
- if (bpp == 24) {
- easy = 1;
- } else if (bpp == 32) {
- if (mb == 0xff && mg == 0xff00 && mr == 0xff000000 && ma == 0xff000000)
- easy = 2;
- }
- if (!easy) {
- if (!mr || !mg || !mb) return ep("bad masks", "Corrupt BMP");
- // right shift amt to put high bit in position #7
- rshift = high_bit(mr)-7; rcount = bitcount(mr);
- gshift = high_bit(mg)-7; gcount = bitcount(mr);
- bshift = high_bit(mb)-7; bcount = bitcount(mr);
- ashift = high_bit(ma)-7; acount = bitcount(mr);
- }
- for (j=0; j < (int) img_y; ++j) {
- if (easy) {
- for (i=0; i < (int) img_x; ++i) {
- int a;
- out[z+2] = get8();
- out[z+1] = get8();
- out[z+0] = get8();
- z += 3;
- a = (easy == 2 ? get8() : 255);
- if (target == 4) out[z++] = a;
- }
- } else {
- for (i=0; i < (int) img_x; ++i) {
- unsigned long v = (bpp == 16 ? get16le() : get32le());
- int a;
- out[z++] = shiftsigned(v & mr, rshift, rcount);
- out[z++] = shiftsigned(v & mg, gshift, gcount);
- out[z++] = shiftsigned(v & mb, bshift, bcount);
- a = (ma ? shiftsigned(v & ma, ashift, acount) : 255);
- if (target == 4) out[z++] = a;
- }
- }
- skip(pad);
- }
- }
- if (flip_vertically) {
- stbi_uc t;
- for (j=0; j < (int) img_y>>1; ++j) {
- stbi_uc *p1 = out + j *img_x*target;
- stbi_uc *p2 = out + (img_y-1-j)*img_x*target;
- for (i=0; i < (int) img_x*target; ++i) {
- t = p1[i], p1[i] = p2[i], p2[i] = t;
- }
- }
- }
- if (req_comp && req_comp != target) {
- out = convert_format(out, target, req_comp);
- if (out == NULL) return out; // convert_format frees input on failure
- }
- *x = img_x;
- *y = img_y;
- if (comp) *comp = target;
- return out;
- }
- #ifndef STBI_NO_STDIO
- stbi_uc *stbi_bmp_load (char *filename, int *x, int *y, int *comp, int req_comp)
- {
- stbi_uc *data;
- FILE *f = fopen(filename, "rb");
- if (!f) return NULL;
- data = stbi_bmp_load_from_file(f, x,y,comp,req_comp);
- fclose(f);
- return data;
- }
- stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp)
- {
- start_file(f);
- return bmp_load(x,y,comp,req_comp);
- }
- #endif
- stbi_uc *stbi_bmp_load_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
- {
- start_mem(buffer, len);
- return bmp_load(x,y,comp,req_comp);
- }
- // Targa Truevision - TGA
- // by Jonathan Dummer
- static int tga_test(void)
- {
- int sz;
- get8u(); // discard Offset
- sz = get8u(); // color type
- if( sz > 1 ) return 0; // only RGB or indexed allowed
- sz = get8u(); // image type
- if( (sz != 1) && (sz != 2) && (sz != 3) && (sz != 9) && (sz != 10) && (sz != 11) ) return 0; // only RGB or grey allowed, +/- RLE
- get16(); // discard palette start
- get16(); // discard palette length
- get8(); // discard bits per palette color entry
- get16(); // discard x origin
- get16(); // discard y origin
- if( get16() < 1 ) return 0; // test width
- if( get16() < 1 ) return 0; // test height
- sz = get8(); // bits per pixel
- if( (sz != 8) && (sz != 16) && (sz != 24) && (sz != 32) ) return 0; // only RGB or RGBA or grey allowed
- return 1; // seems to have passed everything
- }
- #ifndef STBI_NO_STDIO
- int stbi_tga_test_file (FILE *f)
- {
- int r,n = ftell(f);
- start_file(f);
- r = tga_test();
- fseek(f,n,SEEK_SET);
- return r;
- }
- #endif
- int stbi_tga_test_memory (stbi_uc *buffer, int len)
- {
- start_mem(buffer, len);
- return tga_test();
- }
- static stbi_uc *tga_load(int *x, int *y, int *comp, int req_comp)
- {
- // read in the TGA header stuff
- int tga_offset = get8u();
- int tga_indexed = get8u();
- int tga_image_type = get8u();
- int tga_is_RLE = 0;
- int tga_palette_start = get16le();
- int tga_palette_len = get16le();
- int tga_palette_bits = get8u();
- int tga_x_origin = get16le();
- int tga_y_origin = get16le();
- int tga_width = get16le();
- int tga_height = get16le();
- int tga_bits_per_pixel = get8u();
- int tga_inverted = get8u();
- // image data
- unsigned char *tga_data;
- unsigned char *tga_palette = NULL;
- int i, j;
- unsigned char raw_data[4];
- unsigned char trans_data[] = { 0, 0, 0, 0 };
- 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 = req_comp;
- }
- tga_data = (unsigned char*)malloc( tga_width * tga_height * req_comp );
- // skip to the data's starting position (offset usually = 0)
- skip( tga_offset );
- // do I need to load a palette?
- if( tga_indexed )
- {
- // any data to skip? (offset usually = 0)
- skip( tga_palette_start );
- // load the palette
- tga_palette = (unsigned char*)malloc( tga_palette_len * tga_palette_bits / 8 );
- getn( tga_palette, tga_palette_len * tga_palette_bits / 8 );
- }
- // load the data
- for( i = 0; i < tga_width * tga_height; ++i )
- {
- // if I'm in RLE mode, do I need to get a RLE chunk?
- if( tga_is_RLE )
- {
- if( RLE_count == 0 )
- {
- // yep, get the next byte as a RLE command
- int RLE_cmd = get8u();
- RLE_count = 1 + (RLE_cmd & 127);
- RLE_repeating = RLE_cmd >> 7;
- read_next_pixel = 1;
- } else if( !RLE_repeating )
- {
- read_next_pixel = 1;
- }
- } else
- {
- read_next_pixel = 1;
- }
- // OK, if I need to read a pixel, do it now
- if( read_next_pixel )
- {
- // load however much data we did have
- if( tga_indexed )
- {
- // read in 1 byte, then perform the lookup
- int pal_idx = get8u();
- if( pal_idx >= tga_palette_len )
- {
- // invalid index
- pal_idx = 0;
- }
- pal_idx *= tga_bits_per_pixel / 8;
- for( j = 0; j*8 < tga_bits_per_pixel; ++j )
- {
- raw_data[j] = tga_palette[pal_idx+j];
- }
- } else
- {
- // read in the data raw
- for( j = 0; j*8 < tga_bits_per_pixel; ++j )
- {
- raw_data[j] = get8u();
- }
- }
- // convert raw to the intermediate format
- switch( tga_bits_per_pixel )
- {
- case 8:
- // Luminous => RGBA
- trans_data[0] = raw_data[0];
- trans_data[1] = raw_data[0];
- trans_data[2] = raw_data[0];
- trans_data[3] = 255;
- break;
- case 16:
- // Luminous,Alpha => RGBA
- trans_data[0] = raw_data[0];
- trans_data[1] = raw_data[0];
- trans_data[2] = raw_data[0];
- trans_data[3] = raw_data[1];
- break;
- case 24:
- // BGR => RGBA
- trans_data[0] = raw_data[2];
- trans_data[1] = raw_data[1];
- trans_data[2] = raw_data[0];
- trans_data[3] = 255;
- break;
- case 32:
- // BGRA => RGBA
- trans_data[0] = raw_data[2];
- trans_data[1] = raw_data[1];
- trans_data[2] = raw_data[0];
- trans_data[3] = raw_data[3];
- break;
- }
- // clear the reading flag for the next pixel
- read_next_pixel = 0;
- } // end of reading a pixel
- // convert to final format
- switch( req_comp )
- {
- case 1:
- // RGBA => Luminous
- tga_data[i*req_comp+0] = (trans_data[0] + trans_data[1] + trans_data[2]) / 3;
- break;
- case 2:
- // RGBA => Luminous,Alpha
- tga_data[i*req_comp+0] = (trans_data[0] + trans_data[1] + trans_data[2]) / 3;
- tga_data[i*req_comp+1] = trans_data[3];
- break;
- case 3:
- // RGBA => RGB
- tga_data[i*req_comp+0] = trans_data[0];
- tga_data[i*req_comp+1] = trans_data[1];
- tga_data[i*req_comp+2] = trans_data[2];
- break;
- case 4:
- // RGBA => RGBA
- tga_data[i*req_comp+0] = trans_data[0];
- tga_data[i*req_comp+1] = trans_data[1];
- tga_data[i*req_comp+2] = trans_data[2];
- tga_data[i*req_comp+3] = trans_data[3];
- break;
- }
- // in case we're in RLE mode, keep counting down
- --RLE_count;
- }
- // do I need to invert the image?
- if( tga_inverted )
- {
- for( j = 0; j*2 < tga_height; ++j )
- {
- int index1 = j * tga_width * req_comp;
- int index2 = (tga_height - 1 - j) * tga_width * req_comp;
- for( i = tga_width * req_comp; i > 0; --i )
- {
- unsigned char temp = tga_data[index1];
- tga_data[index1] = tga_data[index2];
- tga_data[index2] = temp;
- ++index1;
- ++index2;
- }
- }
- }
- // clear my palette, if I had one
- if( tga_palette != NULL )
- {
- free( tga_palette );
- }
- // the things I do to get rid of an error message, and yet keep
- // Microsoft's C compilers happy... [8^(
- tga_palette_start = tga_palette_len = tga_palette_bits =
- tga_x_origin = tga_y_origin = 0;
- // OK, done
- return tga_data;
- }
- #ifndef STBI_NO_STDIO
- stbi_uc *stbi_tga_load (char *filename, int *x, int *y, int *comp, int req_comp)
- {
- stbi_uc *data;
- FILE *f = fopen(filename, "rb");
- if (!f) return NULL;
- data = stbi_tga_load_from_file(f, x,y,comp,req_comp);
- fclose(f);
- return data;
- }
- stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp)
- {
- start_file(f);
- return tga_load(x,y,comp,req_comp);
- }
- #endif
- stbi_uc *stbi_tga_load_from_memory (stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
- {
- start_mem(buffer, len);
- return tga_load(x,y,comp,req_comp);
- }
- // *************************************************************************************************
- // Radiance RGBE HDR loader
- // originally by Nicolas Schulz
- #ifndef STBI_NO_HDR
- static int hdr_test(void)
- {
- char *signature = "#?RADIANCE\n";
- int i;
- for (i=0; signature[i]; ++i)
- if (get8() != signature[i])
- return 0;
- return 1;
- }
- int stbi_hdr_test_memory(stbi_uc *buffer, int len)
- {
- start_mem(buffer, len);
- return hdr_test();
- }
- #ifndef STBI_NO_STDIO
- int stbi_hdr_test_file(FILE *f)
- {
- int r,n = ftell(f);
- start_file(f);
- r = hdr_test();
- fseek(f,n,SEEK_SET);
- return r;
- }
- #endif
- #define HDR_BUFLEN 1024
- static char *hdr_gettoken(char *buffer)
- {
- int len=0;
- /*char *s = buffer, */
- char c = '\0';
- c = get8();
- while (!at_eof() && c != '\n') {
- buffer[len++] = c;
- if (len == HDR_BUFLEN-1) {
- // flush to end of line
- while (!at_eof() && get8() != '\n')
- ;
- break;
- }
- c = get8();
- }
- buffer[len] = 0;
- return buffer;
- }
- static void hdr_convert(float *output, stbi_uc *input, int req_comp)
- {
- if( input[3] != 0 ) {
- float f1;
- // Exponent
- f1 = (float) ldexp(1.0f, input[3] - (int)(128 + 8));
- if (req_comp <= 2)
- output[0] = (input[0] + input[1] + input[2]) * f1 / 3;
- else {
- output[0] = input[0] * f1;
- output[1] = input[1] * f1;
- output[2] = input[2] * f1;
- }
- if (req_comp == 2) output[1] = 1;
- if (req_comp == 4) output[3] = 1;
- } else {
- switch (req_comp) {
- case 4: output[3] = 255; /* fallthrough */
- case 3: output[0] = output[1] = output[2] = 0;
- break;
- case 2: output[1] = 255; /* fallthrough */
- case 1: output[0] = 0;
- break;
- }
- }
- }
- static float *hdr_load(int *x, int *y, int *comp, int req_comp)
- {
- char buffer[HDR_BUFLEN];
- char *token;
- int valid = 0;
- int width, height;
- stbi_uc *scanline;
- float *hdr_data;
- int len;
- unsigned char count, value;
- int i, j, k, c1,c2, z;
- // Check identifier
- if (strcmp(hdr_gettoken(buffer), "#?RADIANCE") != 0)
- return ep("not HDR", "Corrupt HDR image");
- // Parse header
- while(1) {
- token = hdr_gettoken(buffer);
- if (token[0] == 0) break;
- if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1;
- }
- if (!valid) return ep("unsupported format", "Unsupported HDR format");
- // Parse width and height
- // can't use sscanf() if we're not using stdio!
- token = hdr_gettoken(buffer);
- if (strncmp(token, "-Y ", 3)) return ep("unsupported data layout", "Unsupported HDR format");
- token += 3;
- height = strtol(token, &token, 10);
- while (*token == ' ') ++token;
- if (strncmp(token, "+X ", 3)) return ep("unsupported data layout", "Unsupported HDR format");
- token += 3;
- width = strtol(token, NULL, 10);
- *x = width;
- *y = height;
- *comp = 3;
- if (req_comp == 0) req_comp = 3;
- // Read data
- hdr_data = (float *) malloc(height * width * req_comp * sizeof(float));
- // Load image data
- // image data is stored as some number of sca
- if( width < 8 || width >= 32768) {
- // Read flat data
- for (j=0; j < height; ++j) {
- for (i=0; i < width; ++i) {
- stbi_uc rgbe[4];
- main_decode_loop:
- getn(rgbe, 4);
- hdr_convert(hdr_data + j * width * req_comp + i * req_comp, rgbe, req_comp);
- }
- }
- } else {
- // Read RLE-encoded data
- scanline = NULL;
- for (j = 0; j < height; ++j) {
- c1 = get8();
- c2 = get8();
- len = get8();
- if (c1 != 2 || c2 != 2 || (len & 0x80)) {
- // not run-length encoded, so we have to actually use THIS data as a decoded
- // pixel (note this can't be a valid pixel--one of RGB must be >= 128)
- stbi_uc rgbe[4] = { c1,c2,len, get8() };
- hdr_convert(hdr_data, rgbe, req_comp);
- i = 1;
- j = 0;
- free(scanline);
- goto main_decode_loop; // yes, this is fucking insane; blame the fucking insane format
- }
- len <<= 8;
- len |= get8();
- if (len != width) { free(hdr_data); free(scanline); return ep("invalid decoded scanline length", "corrupt HDR"); }
- if (scanline == NULL) scanline = (stbi_uc *) malloc(width * 4);
- for (k = 0; k < 4; ++k) {
- i = 0;
- while (i < width) {
- count = get8();
- if (count > 128) {
- // Run
- value = get8();
- count -= 128;
- for (z = 0; z < count; ++z)
- scanline[i++ * 4 + k] = value;
- } else {
- // Dump
- for (z = 0; z < count; ++z)
- scanline[i++ * 4 + k] = get8();
- }
- }
- }
- for (i=0; i < width; ++i)
- hdr_convert(hdr_data+(j*width + i)*req_comp, scanline + i*4, req_comp);
- }
- free(scanline);
- }
- return hdr_data;
- }
- #ifndef STBI_NO_STDIO
- float *stbi_hdr_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
- {
- start_file(f);
- return hdr_load(x,y,comp,req_comp);
- }
- #endif
- float *stbi_hdr_load_from_memory(stbi_uc *buffer, int len, int *x, int *y, int *comp, int req_comp)
- {
- start_mem(buffer, len);
- return hdr_load(x,y,comp,req_comp);
- }
- #endif // STBI_NO_HDR
- /////////////////////// write image ///////////////////////
- #ifndef STBI_NO_WRITE
- static void write8(FILE *f, int x) { uint8 z = (uint8) x; fwrite(&z,1,1,f); }
- static void writefv(FILE *f, char *fmt, va_list v)
- {
- while (*fmt) {
- switch (*fmt++) {
- case ' ': break;
- case '1': { uint8 x = va_arg(v, int); write8(f,x); break; }
- case '2': { int16 x = va_arg(v, int); write8(f,x); write8(f,x>>8); break; }
- case '4': { int32 x = va_arg(v, int); write8(f,x); write8(f,x>>8); write8(f,x>>16); write8(f,x>>24); break; }
- default:
- assert(0);
- va_end(v);
- return;
- }
- }
- }
- static void writef(FILE *f, char *fmt, ...)
- {
- va_list v;
- va_start(v, fmt);
- writefv(f,fmt,v);
- va_end(v);
- }
- static void write_pixels(FILE *f, int rgb_dir, int vdir, int x, int y, int comp, void *data, int write_alpha, int scanline_pad)
- {
- uint8 bg[3] = { 255, 0, 255}, px[3];
- uint32 zero = 0;
- int i,j,k, j_end;
- if (vdir < 0)
- j_end = -1, j = y-1;
- else
- j_end = y, j = 0;
- for (; j != j_end; j += vdir) {
- for (i=0; i < x; ++i) {
- uint8 *d = (uint8 *) data + (j*x+i)*comp;
- if (write_alpha < 0)
- fwrite(&d[comp-1], 1, 1, f);
- switch (comp) {
- case 1:
- case 2: writef(f, "111", d[0],d[0],d[0]);
- break;
- case 4:
- if (!write_alpha) {
- for (k=0; k < 3; ++k)
- px[k] = bg[k] + ((d[k] - bg[k]) * d[3])/255;
- writef(f, "111", px[1-rgb_dir],px[1],px[1+rgb_dir]);
- break;
- }
- /* FALLTHROUGH */
- case 3:
- writef(f, "111", d[1-rgb_dir],d[1],d[1+rgb_dir]);
- break;
- }
- if (write_alpha > 0)
- fwrite(&d[comp-1], 1, 1, f);
- }
- fwrite(&zero,scanline_pad,1,f);
- }
- }
- static int outfile(char *filename, int rgb_dir, int vdir, int x, int y, int comp, void *data, int alpha, int pad, char *fmt, ...)
- {
- FILE *f = fopen(filename, "wb");
- if (f) {
- va_list v;
- va_start(v, fmt);
- writefv(f, fmt, v);
- va_end(v);
- write_pixels(f,rgb_dir,vdir,x,y,comp,data,alpha,pad);
- fclose(f);
- }
- return f != NULL;
- }
- int stbi_write_bmp(char *filename, int x, int y, int comp, void *data)
- {
- int pad = (-x*3) & 3;
- return outfile(filename,-1,-1,x,y,comp,data,0,pad,
- "11 4 22 4" "4 44 22 444444",
- 'B', 'M', 14+40+(x*3+pad)*y, 0,0, 14+40, // file header
- 40, x,y, 1,24, 0,0,0,0,0,0); // bitmap header
- }
- int stbi_write_tga(char *filename, int x, int y, int comp, void *data)
- {
- int has_alpha = !(comp & 1);
- return outfile(filename, -1,-1, x, y, comp, data, has_alpha, 0,
- "111 221 2222 11", 0,0,2, 0,0,0, 0,0,x,y, 24+8*has_alpha, 8*has_alpha);
- }
- // any other image formats that do interleaved rgb data?
- // PNG: requires adler32,crc32 -- significant amount of code
- // PSD: no, channels output separately
- // TIFF: no, stripwise-interleaved... i think
- #endif /* STBI_NO_WRITE */
- // add in my DDS loading support
- #ifndef STBI_NO_DDS
- #include "stbi_DDS_aug_c.h"
- #endif