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-rw-r--r--externals/stb/stb_image_write.h1435
1 files changed, 1431 insertions, 4 deletions
diff --git a/externals/stb/stb_image_write.h b/externals/stb/stb_image_write.h
index b81082bba..e4b32ed1b 100644
--- a/externals/stb/stb_image_write.h
+++ b/externals/stb/stb_image_write.h
@@ -1,6 +1,3 @@
-// SPDX-FileCopyrightText: stb http://nothings.org/stb
-// SPDX-License-Identifier: MIT
-
/* stb_image_write - v1.16 - public domain - http://nothings.org/stb
writes out PNG/BMP/TGA/JPEG/HDR images to C stdio - Sean Barrett 2010-2015
no warranty implied; use at your own risk
@@ -194,12 +191,1442 @@ STBIWDEF int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w,
STBIWDEF int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
STBIWDEF int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data);
STBIWDEF int stbi_write_jpg_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int quality);
-STBIWDEF unsigned char *stbi_write_png_to_mem(const unsigned char *pixels, int stride_bytes, int x, int y, int n, int *out_len);
STBIWDEF void stbi_flip_vertically_on_write(int flip_boolean);
#endif//INCLUDE_STB_IMAGE_WRITE_H
+#ifdef STB_IMAGE_WRITE_IMPLEMENTATION
+
+#ifdef _WIN32
+ #ifndef _CRT_SECURE_NO_WARNINGS
+ #define _CRT_SECURE_NO_WARNINGS
+ #endif
+ #ifndef _CRT_NONSTDC_NO_DEPRECATE
+ #define _CRT_NONSTDC_NO_DEPRECATE
+ #endif
+#endif
+
+#ifndef STBI_WRITE_NO_STDIO
+#include <stdio.h>
+#endif // STBI_WRITE_NO_STDIO
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#if defined(STBIW_MALLOC) && defined(STBIW_FREE) && (defined(STBIW_REALLOC) || defined(STBIW_REALLOC_SIZED))
+// ok
+#elif !defined(STBIW_MALLOC) && !defined(STBIW_FREE) && !defined(STBIW_REALLOC) && !defined(STBIW_REALLOC_SIZED)
+// ok
+#else
+#error "Must define all or none of STBIW_MALLOC, STBIW_FREE, and STBIW_REALLOC (or STBIW_REALLOC_SIZED)."
+#endif
+
+#ifndef STBIW_MALLOC
+#define STBIW_MALLOC(sz) malloc(sz)
+#define STBIW_REALLOC(p,newsz) realloc(p,newsz)
+#define STBIW_FREE(p) free(p)
+#endif
+
+#ifndef STBIW_REALLOC_SIZED
+#define STBIW_REALLOC_SIZED(p,oldsz,newsz) STBIW_REALLOC(p,newsz)
+#endif
+
+
+#ifndef STBIW_MEMMOVE
+#define STBIW_MEMMOVE(a,b,sz) memmove(a,b,sz)
+#endif
+
+
+#ifndef STBIW_ASSERT
+#include <assert.h>
+#define STBIW_ASSERT(x) assert(x)
+#endif
+
+#define STBIW_UCHAR(x) (unsigned char) ((x) & 0xff)
+
+#ifdef STB_IMAGE_WRITE_STATIC
+static int stbi_write_png_compression_level = 8;
+static int stbi_write_tga_with_rle = 1;
+static int stbi_write_force_png_filter = -1;
+#else
+int stbi_write_png_compression_level = 8;
+int stbi_write_tga_with_rle = 1;
+int stbi_write_force_png_filter = -1;
+#endif
+
+static int stbi__flip_vertically_on_write = 0;
+
+STBIWDEF void stbi_flip_vertically_on_write(int flag)
+{
+ stbi__flip_vertically_on_write = flag;
+}
+
+typedef struct
+{
+ stbi_write_func *func;
+ void *context;
+ unsigned char buffer[64];
+ int buf_used;
+} stbi__write_context;
+
+// initialize a callback-based context
+static void stbi__start_write_callbacks(stbi__write_context *s, stbi_write_func *c, void *context)
+{
+ s->func = c;
+ s->context = context;
+}
+
+#ifndef STBI_WRITE_NO_STDIO
+
+static void stbi__stdio_write(void *context, void *data, int size)
+{
+ fwrite(data,1,size,(FILE*) context);
+}
+
+#if defined(_WIN32) && defined(STBIW_WINDOWS_UTF8)
+#ifdef __cplusplus
+#define STBIW_EXTERN extern "C"
+#else
+#define STBIW_EXTERN extern
+#endif
+STBIW_EXTERN __declspec(dllimport) int __stdcall MultiByteToWideChar(unsigned int cp, unsigned long flags, const char *str, int cbmb, wchar_t *widestr, int cchwide);
+STBIW_EXTERN __declspec(dllimport) int __stdcall WideCharToMultiByte(unsigned int cp, unsigned long flags, const wchar_t *widestr, int cchwide, char *str, int cbmb, const char *defchar, int *used_default);
+
+STBIWDEF int stbiw_convert_wchar_to_utf8(char *buffer, size_t bufferlen, const wchar_t* input)
+{
+ return WideCharToMultiByte(65001 /* UTF8 */, 0, input, -1, buffer, (int) bufferlen, NULL, NULL);
+}
+#endif
+
+static FILE *stbiw__fopen(char const *filename, char const *mode)
+{
+ FILE *f;
+#if defined(_WIN32) && defined(STBIW_WINDOWS_UTF8)
+ wchar_t wMode[64];
+ wchar_t wFilename[1024];
+ if (0 == MultiByteToWideChar(65001 /* UTF8 */, 0, filename, -1, wFilename, sizeof(wFilename)/sizeof(*wFilename)))
+ return 0;
+
+ if (0 == MultiByteToWideChar(65001 /* UTF8 */, 0, mode, -1, wMode, sizeof(wMode)/sizeof(*wMode)))
+ return 0;
+
+#if defined(_MSC_VER) && _MSC_VER >= 1400
+ if (0 != _wfopen_s(&f, wFilename, wMode))
+ f = 0;
+#else
+ f = _wfopen(wFilename, wMode);
+#endif
+
+#elif defined(_MSC_VER) && _MSC_VER >= 1400
+ if (0 != fopen_s(&f, filename, mode))
+ f=0;
+#else
+ f = fopen(filename, mode);
+#endif
+ return f;
+}
+
+static int stbi__start_write_file(stbi__write_context *s, const char *filename)
+{
+ FILE *f = stbiw__fopen(filename, "wb");
+ stbi__start_write_callbacks(s, stbi__stdio_write, (void *) f);
+ return f != NULL;
+}
+
+static void stbi__end_write_file(stbi__write_context *s)
+{
+ fclose((FILE *)s->context);
+}
+
+#endif // !STBI_WRITE_NO_STDIO
+
+typedef unsigned int stbiw_uint32;
+typedef int stb_image_write_test[sizeof(stbiw_uint32)==4 ? 1 : -1];
+
+static void stbiw__writefv(stbi__write_context *s, const char *fmt, va_list v)
+{
+ while (*fmt) {
+ switch (*fmt++) {
+ case ' ': break;
+ case '1': { unsigned char x = STBIW_UCHAR(va_arg(v, int));
+ s->func(s->context,&x,1);
+ break; }
+ case '2': { int x = va_arg(v,int);
+ unsigned char b[2];
+ b[0] = STBIW_UCHAR(x);
+ b[1] = STBIW_UCHAR(x>>8);
+ s->func(s->context,b,2);
+ break; }
+ case '4': { stbiw_uint32 x = va_arg(v,int);
+ unsigned char b[4];
+ b[0]=STBIW_UCHAR(x);
+ b[1]=STBIW_UCHAR(x>>8);
+ b[2]=STBIW_UCHAR(x>>16);
+ b[3]=STBIW_UCHAR(x>>24);
+ s->func(s->context,b,4);
+ break; }
+ default:
+ STBIW_ASSERT(0);
+ return;
+ }
+ }
+}
+
+static void stbiw__writef(stbi__write_context *s, const char *fmt, ...)
+{
+ va_list v;
+ va_start(v, fmt);
+ stbiw__writefv(s, fmt, v);
+ va_end(v);
+}
+
+static void stbiw__write_flush(stbi__write_context *s)
+{
+ if (s->buf_used) {
+ s->func(s->context, &s->buffer, s->buf_used);
+ s->buf_used = 0;
+ }
+}
+
+static void stbiw__putc(stbi__write_context *s, unsigned char c)
+{
+ s->func(s->context, &c, 1);
+}
+
+static void stbiw__write1(stbi__write_context *s, unsigned char a)
+{
+ if ((size_t)s->buf_used + 1 > sizeof(s->buffer))
+ stbiw__write_flush(s);
+ s->buffer[s->buf_used++] = a;
+}
+
+static void stbiw__write3(stbi__write_context *s, unsigned char a, unsigned char b, unsigned char c)
+{
+ int n;
+ if ((size_t)s->buf_used + 3 > sizeof(s->buffer))
+ stbiw__write_flush(s);
+ n = s->buf_used;
+ s->buf_used = n+3;
+ s->buffer[n+0] = a;
+ s->buffer[n+1] = b;
+ s->buffer[n+2] = c;
+}
+
+static void stbiw__write_pixel(stbi__write_context *s, int rgb_dir, int comp, int write_alpha, int expand_mono, unsigned char *d)
+{
+ unsigned char bg[3] = { 255, 0, 255}, px[3];
+ int k;
+
+ if (write_alpha < 0)
+ stbiw__write1(s, d[comp - 1]);
+
+ switch (comp) {
+ case 2: // 2 pixels = mono + alpha, alpha is written separately, so same as 1-channel case
+ case 1:
+ if (expand_mono)
+ stbiw__write3(s, d[0], d[0], d[0]); // monochrome bmp
+ else
+ stbiw__write1(s, d[0]); // monochrome TGA
+ break;
+ case 4:
+ if (!write_alpha) {
+ // composite against pink background
+ for (k = 0; k < 3; ++k)
+ px[k] = bg[k] + ((d[k] - bg[k]) * d[3]) / 255;
+ stbiw__write3(s, px[1 - rgb_dir], px[1], px[1 + rgb_dir]);
+ break;
+ }
+ /* FALLTHROUGH */
+ case 3:
+ stbiw__write3(s, d[1 - rgb_dir], d[1], d[1 + rgb_dir]);
+ break;
+ }
+ if (write_alpha > 0)
+ stbiw__write1(s, d[comp - 1]);
+}
+
+static void stbiw__write_pixels(stbi__write_context *s, int rgb_dir, int vdir, int x, int y, int comp, void *data, int write_alpha, int scanline_pad, int expand_mono)
+{
+ stbiw_uint32 zero = 0;
+ int i,j, j_end;
+
+ if (y <= 0)
+ return;
+
+ if (stbi__flip_vertically_on_write)
+ vdir *= -1;
+
+ 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) {
+ unsigned char *d = (unsigned char *) data + (j*x+i)*comp;
+ stbiw__write_pixel(s, rgb_dir, comp, write_alpha, expand_mono, d);
+ }
+ stbiw__write_flush(s);
+ s->func(s->context, &zero, scanline_pad);
+ }
+}
+
+static int stbiw__outfile(stbi__write_context *s, int rgb_dir, int vdir, int x, int y, int comp, int expand_mono, void *data, int alpha, int pad, const char *fmt, ...)
+{
+ if (y < 0 || x < 0) {
+ return 0;
+ } else {
+ va_list v;
+ va_start(v, fmt);
+ stbiw__writefv(s, fmt, v);
+ va_end(v);
+ stbiw__write_pixels(s,rgb_dir,vdir,x,y,comp,data,alpha,pad, expand_mono);
+ return 1;
+ }
+}
+
+static int stbi_write_bmp_core(stbi__write_context *s, int x, int y, int comp, const void *data)
+{
+ if (comp != 4) {
+ // write RGB bitmap
+ int pad = (-x*3) & 3;
+ return stbiw__outfile(s,-1,-1,x,y,comp,1,(void *) 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
+ } else {
+ // RGBA bitmaps need a v4 header
+ // use BI_BITFIELDS mode with 32bpp and alpha mask
+ // (straight BI_RGB with alpha mask doesn't work in most readers)
+ return stbiw__outfile(s,-1,-1,x,y,comp,1,(void *)data,1,0,
+ "11 4 22 4" "4 44 22 444444 4444 4 444 444 444 444",
+ 'B', 'M', 14+108+x*y*4, 0, 0, 14+108, // file header
+ 108, x,y, 1,32, 3,0,0,0,0,0, 0xff0000,0xff00,0xff,0xff000000u, 0, 0,0,0, 0,0,0, 0,0,0, 0,0,0); // bitmap V4 header
+ }
+}
+
+STBIWDEF int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data)
+{
+ stbi__write_context s = { 0 };
+ stbi__start_write_callbacks(&s, func, context);
+ return stbi_write_bmp_core(&s, x, y, comp, data);
+}
+
+#ifndef STBI_WRITE_NO_STDIO
+STBIWDEF int stbi_write_bmp(char const *filename, int x, int y, int comp, const void *data)
+{
+ stbi__write_context s = { 0 };
+ if (stbi__start_write_file(&s,filename)) {
+ int r = stbi_write_bmp_core(&s, x, y, comp, data);
+ stbi__end_write_file(&s);
+ return r;
+ } else
+ return 0;
+}
+#endif //!STBI_WRITE_NO_STDIO
+
+static int stbi_write_tga_core(stbi__write_context *s, int x, int y, int comp, void *data)
+{
+ int has_alpha = (comp == 2 || comp == 4);
+ int colorbytes = has_alpha ? comp-1 : comp;
+ int format = colorbytes < 2 ? 3 : 2; // 3 color channels (RGB/RGBA) = 2, 1 color channel (Y/YA) = 3
+
+ if (y < 0 || x < 0)
+ return 0;
+
+ if (!stbi_write_tga_with_rle) {
+ return stbiw__outfile(s, -1, -1, x, y, comp, 0, (void *) data, has_alpha, 0,
+ "111 221 2222 11", 0, 0, format, 0, 0, 0, 0, 0, x, y, (colorbytes + has_alpha) * 8, has_alpha * 8);
+ } else {
+ int i,j,k;
+ int jend, jdir;
+
+ stbiw__writef(s, "111 221 2222 11", 0,0,format+8, 0,0,0, 0,0,x,y, (colorbytes + has_alpha) * 8, has_alpha * 8);
+
+ if (stbi__flip_vertically_on_write) {
+ j = 0;
+ jend = y;
+ jdir = 1;
+ } else {
+ j = y-1;
+ jend = -1;
+ jdir = -1;
+ }
+ for (; j != jend; j += jdir) {
+ unsigned char *row = (unsigned char *) data + j * x * comp;
+ int len;
+
+ for (i = 0; i < x; i += len) {
+ unsigned char *begin = row + i * comp;
+ int diff = 1;
+ len = 1;
+
+ if (i < x - 1) {
+ ++len;
+ diff = memcmp(begin, row + (i + 1) * comp, comp);
+ if (diff) {
+ const unsigned char *prev = begin;
+ for (k = i + 2; k < x && len < 128; ++k) {
+ if (memcmp(prev, row + k * comp, comp)) {
+ prev += comp;
+ ++len;
+ } else {
+ --len;
+ break;
+ }
+ }
+ } else {
+ for (k = i + 2; k < x && len < 128; ++k) {
+ if (!memcmp(begin, row + k * comp, comp)) {
+ ++len;
+ } else {
+ break;
+ }
+ }
+ }
+ }
+
+ if (diff) {
+ unsigned char header = STBIW_UCHAR(len - 1);
+ stbiw__write1(s, header);
+ for (k = 0; k < len; ++k) {
+ stbiw__write_pixel(s, -1, comp, has_alpha, 0, begin + k * comp);
+ }
+ } else {
+ unsigned char header = STBIW_UCHAR(len - 129);
+ stbiw__write1(s, header);
+ stbiw__write_pixel(s, -1, comp, has_alpha, 0, begin);
+ }
+ }
+ }
+ stbiw__write_flush(s);
+ }
+ return 1;
+}
+
+STBIWDEF int stbi_write_tga_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data)
+{
+ stbi__write_context s = { 0 };
+ stbi__start_write_callbacks(&s, func, context);
+ return stbi_write_tga_core(&s, x, y, comp, (void *) data);
+}
+
+#ifndef STBI_WRITE_NO_STDIO
+STBIWDEF int stbi_write_tga(char const *filename, int x, int y, int comp, const void *data)
+{
+ stbi__write_context s = { 0 };
+ if (stbi__start_write_file(&s,filename)) {
+ int r = stbi_write_tga_core(&s, x, y, comp, (void *) data);
+ stbi__end_write_file(&s);
+ return r;
+ } else
+ return 0;
+}
+#endif
+
+// *************************************************************************************************
+// Radiance RGBE HDR writer
+// by Baldur Karlsson
+
+#define stbiw__max(a, b) ((a) > (b) ? (a) : (b))
+
+#ifndef STBI_WRITE_NO_STDIO
+
+static void stbiw__linear_to_rgbe(unsigned char *rgbe, float *linear)
+{
+ int exponent;
+ float maxcomp = stbiw__max(linear[0], stbiw__max(linear[1], linear[2]));
+
+ if (maxcomp < 1e-32f) {
+ rgbe[0] = rgbe[1] = rgbe[2] = rgbe[3] = 0;
+ } else {
+ float normalize = (float) frexp(maxcomp, &exponent) * 256.0f/maxcomp;
+
+ rgbe[0] = (unsigned char)(linear[0] * normalize);
+ rgbe[1] = (unsigned char)(linear[1] * normalize);
+ rgbe[2] = (unsigned char)(linear[2] * normalize);
+ rgbe[3] = (unsigned char)(exponent + 128);
+ }
+}
+
+static void stbiw__write_run_data(stbi__write_context *s, int length, unsigned char databyte)
+{
+ unsigned char lengthbyte = STBIW_UCHAR(length+128);
+ STBIW_ASSERT(length+128 <= 255);
+ s->func(s->context, &lengthbyte, 1);
+ s->func(s->context, &databyte, 1);
+}
+
+static void stbiw__write_dump_data(stbi__write_context *s, int length, unsigned char *data)
+{
+ unsigned char lengthbyte = STBIW_UCHAR(length);
+ STBIW_ASSERT(length <= 128); // inconsistent with spec but consistent with official code
+ s->func(s->context, &lengthbyte, 1);
+ s->func(s->context, data, length);
+}
+
+static void stbiw__write_hdr_scanline(stbi__write_context *s, int width, int ncomp, unsigned char *scratch, float *scanline)
+{
+ unsigned char scanlineheader[4] = { 2, 2, 0, 0 };
+ unsigned char rgbe[4];
+ float linear[3];
+ int x;
+
+ scanlineheader[2] = (width&0xff00)>>8;
+ scanlineheader[3] = (width&0x00ff);
+
+ /* skip RLE for images too small or large */
+ if (width < 8 || width >= 32768) {
+ for (x=0; x < width; x++) {
+ switch (ncomp) {
+ case 4: /* fallthrough */
+ case 3: linear[2] = scanline[x*ncomp + 2];
+ linear[1] = scanline[x*ncomp + 1];
+ linear[0] = scanline[x*ncomp + 0];
+ break;
+ default:
+ linear[0] = linear[1] = linear[2] = scanline[x*ncomp + 0];
+ break;
+ }
+ stbiw__linear_to_rgbe(rgbe, linear);
+ s->func(s->context, rgbe, 4);
+ }
+ } else {
+ int c,r;
+ /* encode into scratch buffer */
+ for (x=0; x < width; x++) {
+ switch(ncomp) {
+ case 4: /* fallthrough */
+ case 3: linear[2] = scanline[x*ncomp + 2];
+ linear[1] = scanline[x*ncomp + 1];
+ linear[0] = scanline[x*ncomp + 0];
+ break;
+ default:
+ linear[0] = linear[1] = linear[2] = scanline[x*ncomp + 0];
+ break;
+ }
+ stbiw__linear_to_rgbe(rgbe, linear);
+ scratch[x + width*0] = rgbe[0];
+ scratch[x + width*1] = rgbe[1];
+ scratch[x + width*2] = rgbe[2];
+ scratch[x + width*3] = rgbe[3];
+ }
+
+ s->func(s->context, scanlineheader, 4);
+
+ /* RLE each component separately */
+ for (c=0; c < 4; c++) {
+ unsigned char *comp = &scratch[width*c];
+
+ x = 0;
+ while (x < width) {
+ // find first run
+ r = x;
+ while (r+2 < width) {
+ if (comp[r] == comp[r+1] && comp[r] == comp[r+2])
+ break;
+ ++r;
+ }
+ if (r+2 >= width)
+ r = width;
+ // dump up to first run
+ while (x < r) {
+ int len = r-x;
+ if (len > 128) len = 128;
+ stbiw__write_dump_data(s, len, &comp[x]);
+ x += len;
+ }
+ // if there's a run, output it
+ if (r+2 < width) { // same test as what we break out of in search loop, so only true if we break'd
+ // find next byte after run
+ while (r < width && comp[r] == comp[x])
+ ++r;
+ // output run up to r
+ while (x < r) {
+ int len = r-x;
+ if (len > 127) len = 127;
+ stbiw__write_run_data(s, len, comp[x]);
+ x += len;
+ }
+ }
+ }
+ }
+ }
+}
+
+static int stbi_write_hdr_core(stbi__write_context *s, int x, int y, int comp, float *data)
+{
+ if (y <= 0 || x <= 0 || data == NULL)
+ return 0;
+ else {
+ // Each component is stored separately. Allocate scratch space for full output scanline.
+ unsigned char *scratch = (unsigned char *) STBIW_MALLOC(x*4);
+ int i, len;
+ char buffer[128];
+ char header[] = "#?RADIANCE\n# Written by stb_image_write.h\nFORMAT=32-bit_rle_rgbe\n";
+ s->func(s->context, header, sizeof(header)-1);
+
+#ifdef __STDC_LIB_EXT1__
+ len = sprintf_s(buffer, sizeof(buffer), "EXPOSURE= 1.0000000000000\n\n-Y %d +X %d\n", y, x);
+#else
+ len = sprintf(buffer, "EXPOSURE= 1.0000000000000\n\n-Y %d +X %d\n", y, x);
+#endif
+ s->func(s->context, buffer, len);
+
+ for(i=0; i < y; i++)
+ stbiw__write_hdr_scanline(s, x, comp, scratch, data + comp*x*(stbi__flip_vertically_on_write ? y-1-i : i));
+ STBIW_FREE(scratch);
+ return 1;
+ }
+}
+
+STBIWDEF int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const float *data)
+{
+ stbi__write_context s = { 0 };
+ stbi__start_write_callbacks(&s, func, context);
+ return stbi_write_hdr_core(&s, x, y, comp, (float *) data);
+}
+
+STBIWDEF int stbi_write_hdr(char const *filename, int x, int y, int comp, const float *data)
+{
+ stbi__write_context s = { 0 };
+ if (stbi__start_write_file(&s,filename)) {
+ int r = stbi_write_hdr_core(&s, x, y, comp, (float *) data);
+ stbi__end_write_file(&s);
+ return r;
+ } else
+ return 0;
+}
+#endif // STBI_WRITE_NO_STDIO
+
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// PNG writer
+//
+
+#ifndef STBIW_ZLIB_COMPRESS
+// stretchy buffer; stbiw__sbpush() == vector<>::push_back() -- stbiw__sbcount() == vector<>::size()
+#define stbiw__sbraw(a) ((int *) (void *) (a) - 2)
+#define stbiw__sbm(a) stbiw__sbraw(a)[0]
+#define stbiw__sbn(a) stbiw__sbraw(a)[1]
+
+#define stbiw__sbneedgrow(a,n) ((a)==0 || stbiw__sbn(a)+n >= stbiw__sbm(a))
+#define stbiw__sbmaybegrow(a,n) (stbiw__sbneedgrow(a,(n)) ? stbiw__sbgrow(a,n) : 0)
+#define stbiw__sbgrow(a,n) stbiw__sbgrowf((void **) &(a), (n), sizeof(*(a)))
+
+#define stbiw__sbpush(a, v) (stbiw__sbmaybegrow(a,1), (a)[stbiw__sbn(a)++] = (v))
+#define stbiw__sbcount(a) ((a) ? stbiw__sbn(a) : 0)
+#define stbiw__sbfree(a) ((a) ? STBIW_FREE(stbiw__sbraw(a)),0 : 0)
+
+static void *stbiw__sbgrowf(void **arr, int increment, int itemsize)
+{
+ int m = *arr ? 2*stbiw__sbm(*arr)+increment : increment+1;
+ void *p = STBIW_REALLOC_SIZED(*arr ? stbiw__sbraw(*arr) : 0, *arr ? (stbiw__sbm(*arr)*itemsize + sizeof(int)*2) : 0, itemsize * m + sizeof(int)*2);
+ STBIW_ASSERT(p);
+ if (p) {
+ if (!*arr) ((int *) p)[1] = 0;
+ *arr = (void *) ((int *) p + 2);
+ stbiw__sbm(*arr) = m;
+ }
+ return *arr;
+}
+
+static unsigned char *stbiw__zlib_flushf(unsigned char *data, unsigned int *bitbuffer, int *bitcount)
+{
+ while (*bitcount >= 8) {
+ stbiw__sbpush(data, STBIW_UCHAR(*bitbuffer));
+ *bitbuffer >>= 8;
+ *bitcount -= 8;
+ }
+ return data;
+}
+
+static int stbiw__zlib_bitrev(int code, int codebits)
+{
+ int res=0;
+ while (codebits--) {
+ res = (res << 1) | (code & 1);
+ code >>= 1;
+ }
+ return res;
+}
+
+static unsigned int stbiw__zlib_countm(unsigned char *a, unsigned char *b, int limit)
+{
+ int i;
+ for (i=0; i < limit && i < 258; ++i)
+ if (a[i] != b[i]) break;
+ return i;
+}
+
+static unsigned int stbiw__zhash(unsigned char *data)
+{
+ stbiw_uint32 hash = data[0] + (data[1] << 8) + (data[2] << 16);
+ hash ^= hash << 3;
+ hash += hash >> 5;
+ hash ^= hash << 4;
+ hash += hash >> 17;
+ hash ^= hash << 25;
+ hash += hash >> 6;
+ return hash;
+}
+
+#define stbiw__zlib_flush() (out = stbiw__zlib_flushf(out, &bitbuf, &bitcount))
+#define stbiw__zlib_add(code,codebits) \
+ (bitbuf |= (code) << bitcount, bitcount += (codebits), stbiw__zlib_flush())
+#define stbiw__zlib_huffa(b,c) stbiw__zlib_add(stbiw__zlib_bitrev(b,c),c)
+// default huffman tables
+#define stbiw__zlib_huff1(n) stbiw__zlib_huffa(0x30 + (n), 8)
+#define stbiw__zlib_huff2(n) stbiw__zlib_huffa(0x190 + (n)-144, 9)
+#define stbiw__zlib_huff3(n) stbiw__zlib_huffa(0 + (n)-256,7)
+#define stbiw__zlib_huff4(n) stbiw__zlib_huffa(0xc0 + (n)-280,8)
+#define stbiw__zlib_huff(n) ((n) <= 143 ? stbiw__zlib_huff1(n) : (n) <= 255 ? stbiw__zlib_huff2(n) : (n) <= 279 ? stbiw__zlib_huff3(n) : stbiw__zlib_huff4(n))
+#define stbiw__zlib_huffb(n) ((n) <= 143 ? stbiw__zlib_huff1(n) : stbiw__zlib_huff2(n))
+
+#define stbiw__ZHASH 16384
+
+#endif // STBIW_ZLIB_COMPRESS
+
+STBIWDEF unsigned char * stbi_zlib_compress(unsigned char *data, int data_len, int *out_len, int quality)
+{
+#ifdef STBIW_ZLIB_COMPRESS
+ // user provided a zlib compress implementation, use that
+ return STBIW_ZLIB_COMPRESS(data, data_len, out_len, quality);
+#else // use builtin
+ static unsigned short lengthc[] = { 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, 259 };
+ static unsigned char lengtheb[]= { 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 };
+ static unsigned short distc[] = { 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, 32768 };
+ static unsigned char disteb[] = { 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 };
+ unsigned int bitbuf=0;
+ int i,j, bitcount=0;
+ unsigned char *out = NULL;
+ unsigned char ***hash_table = (unsigned char***) STBIW_MALLOC(stbiw__ZHASH * sizeof(unsigned char**));
+ if (hash_table == NULL)
+ return NULL;
+ if (quality < 5) quality = 5;
+
+ stbiw__sbpush(out, 0x78); // DEFLATE 32K window
+ stbiw__sbpush(out, 0x5e); // FLEVEL = 1
+ stbiw__zlib_add(1,1); // BFINAL = 1
+ stbiw__zlib_add(1,2); // BTYPE = 1 -- fixed huffman
+
+ for (i=0; i < stbiw__ZHASH; ++i)
+ hash_table[i] = NULL;
+
+ i=0;
+ while (i < data_len-3) {
+ // hash next 3 bytes of data to be compressed
+ int h = stbiw__zhash(data+i)&(stbiw__ZHASH-1), best=3;
+ unsigned char *bestloc = 0;
+ unsigned char **hlist = hash_table[h];
+ int n = stbiw__sbcount(hlist);
+ for (j=0; j < n; ++j) {
+ if (hlist[j]-data > i-32768) { // if entry lies within window
+ int d = stbiw__zlib_countm(hlist[j], data+i, data_len-i);
+ if (d >= best) { best=d; bestloc=hlist[j]; }
+ }
+ }
+ // when hash table entry is too long, delete half the entries
+ if (hash_table[h] && stbiw__sbn(hash_table[h]) == 2*quality) {
+ STBIW_MEMMOVE(hash_table[h], hash_table[h]+quality, sizeof(hash_table[h][0])*quality);
+ stbiw__sbn(hash_table[h]) = quality;
+ }
+ stbiw__sbpush(hash_table[h],data+i);
+
+ if (bestloc) {
+ // "lazy matching" - check match at *next* byte, and if it's better, do cur byte as literal
+ h = stbiw__zhash(data+i+1)&(stbiw__ZHASH-1);
+ hlist = hash_table[h];
+ n = stbiw__sbcount(hlist);
+ for (j=0; j < n; ++j) {
+ if (hlist[j]-data > i-32767) {
+ int e = stbiw__zlib_countm(hlist[j], data+i+1, data_len-i-1);
+ if (e > best) { // if next match is better, bail on current match
+ bestloc = NULL;
+ break;
+ }
+ }
+ }
+ }
+
+ if (bestloc) {
+ int d = (int) (data+i - bestloc); // distance back
+ STBIW_ASSERT(d <= 32767 && best <= 258);
+ for (j=0; best > lengthc[j+1]-1; ++j);
+ stbiw__zlib_huff(j+257);
+ if (lengtheb[j]) stbiw__zlib_add(best - lengthc[j], lengtheb[j]);
+ for (j=0; d > distc[j+1]-1; ++j);
+ stbiw__zlib_add(stbiw__zlib_bitrev(j,5),5);
+ if (disteb[j]) stbiw__zlib_add(d - distc[j], disteb[j]);
+ i += best;
+ } else {
+ stbiw__zlib_huffb(data[i]);
+ ++i;
+ }
+ }
+ // write out final bytes
+ for (;i < data_len; ++i)
+ stbiw__zlib_huffb(data[i]);
+ stbiw__zlib_huff(256); // end of block
+ // pad with 0 bits to byte boundary
+ while (bitcount)
+ stbiw__zlib_add(0,1);
+
+ for (i=0; i < stbiw__ZHASH; ++i)
+ (void) stbiw__sbfree(hash_table[i]);
+ STBIW_FREE(hash_table);
+
+ // store uncompressed instead if compression was worse
+ if (stbiw__sbn(out) > data_len + 2 + ((data_len+32766)/32767)*5) {
+ stbiw__sbn(out) = 2; // truncate to DEFLATE 32K window and FLEVEL = 1
+ for (j = 0; j < data_len;) {
+ int blocklen = data_len - j;
+ if (blocklen > 32767) blocklen = 32767;
+ stbiw__sbpush(out, data_len - j == blocklen); // BFINAL = ?, BTYPE = 0 -- no compression
+ stbiw__sbpush(out, STBIW_UCHAR(blocklen)); // LEN
+ stbiw__sbpush(out, STBIW_UCHAR(blocklen >> 8));
+ stbiw__sbpush(out, STBIW_UCHAR(~blocklen)); // NLEN
+ stbiw__sbpush(out, STBIW_UCHAR(~blocklen >> 8));
+ memcpy(out+stbiw__sbn(out), data+j, blocklen);
+ stbiw__sbn(out) += blocklen;
+ j += blocklen;
+ }
+ }
+
+ {
+ // compute adler32 on input
+ unsigned int s1=1, s2=0;
+ int blocklen = (int) (data_len % 5552);
+ j=0;
+ while (j < data_len) {
+ for (i=0; i < blocklen; ++i) { s1 += data[j+i]; s2 += s1; }
+ s1 %= 65521; s2 %= 65521;
+ j += blocklen;
+ blocklen = 5552;
+ }
+ stbiw__sbpush(out, STBIW_UCHAR(s2 >> 8));
+ stbiw__sbpush(out, STBIW_UCHAR(s2));
+ stbiw__sbpush(out, STBIW_UCHAR(s1 >> 8));
+ stbiw__sbpush(out, STBIW_UCHAR(s1));
+ }
+ *out_len = stbiw__sbn(out);
+ // make returned pointer freeable
+ STBIW_MEMMOVE(stbiw__sbraw(out), out, *out_len);
+ return (unsigned char *) stbiw__sbraw(out);
+#endif // STBIW_ZLIB_COMPRESS
+}
+
+static unsigned int stbiw__crc32(unsigned char *buffer, int len)
+{
+#ifdef STBIW_CRC32
+ return STBIW_CRC32(buffer, len);
+#else
+ static unsigned int crc_table[256] =
+ {
+ 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
+ 0x0eDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
+ 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
+ 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
+ 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
+ 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
+ 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
+ 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
+ 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
+ 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
+ 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
+ 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
+ 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
+ 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
+ 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
+ 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
+ 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
+ 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
+ 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
+ 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
+ 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
+ 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
+ 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
+ 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
+ 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
+ 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
+ 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
+ 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
+ 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
+ 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
+ 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
+ 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
+ };
+
+ unsigned int crc = ~0u;
+ int i;
+ for (i=0; i < len; ++i)
+ crc = (crc >> 8) ^ crc_table[buffer[i] ^ (crc & 0xff)];
+ return ~crc;
+#endif
+}
+
+#define stbiw__wpng4(o,a,b,c,d) ((o)[0]=STBIW_UCHAR(a),(o)[1]=STBIW_UCHAR(b),(o)[2]=STBIW_UCHAR(c),(o)[3]=STBIW_UCHAR(d),(o)+=4)
+#define stbiw__wp32(data,v) stbiw__wpng4(data, (v)>>24,(v)>>16,(v)>>8,(v));
+#define stbiw__wptag(data,s) stbiw__wpng4(data, s[0],s[1],s[2],s[3])
+
+static void stbiw__wpcrc(unsigned char **data, int len)
+{
+ unsigned int crc = stbiw__crc32(*data - len - 4, len+4);
+ stbiw__wp32(*data, crc);
+}
+
+static unsigned char stbiw__paeth(int a, int b, int c)
+{
+ int p = a + b - c, pa = abs(p-a), pb = abs(p-b), pc = abs(p-c);
+ if (pa <= pb && pa <= pc) return STBIW_UCHAR(a);
+ if (pb <= pc) return STBIW_UCHAR(b);
+ return STBIW_UCHAR(c);
+}
+
+// @OPTIMIZE: provide an option that always forces left-predict or paeth predict
+static void stbiw__encode_png_line(unsigned char *pixels, int stride_bytes, int width, int height, int y, int n, int filter_type, signed char *line_buffer)
+{
+ static int mapping[] = { 0,1,2,3,4 };
+ static int firstmap[] = { 0,1,0,5,6 };
+ int *mymap = (y != 0) ? mapping : firstmap;
+ int i;
+ int type = mymap[filter_type];
+ unsigned char *z = pixels + stride_bytes * (stbi__flip_vertically_on_write ? height-1-y : y);
+ int signed_stride = stbi__flip_vertically_on_write ? -stride_bytes : stride_bytes;
+
+ if (type==0) {
+ memcpy(line_buffer, z, width*n);
+ return;
+ }
+
+ // first loop isn't optimized since it's just one pixel
+ for (i = 0; i < n; ++i) {
+ switch (type) {
+ case 1: line_buffer[i] = z[i]; break;
+ case 2: line_buffer[i] = z[i] - z[i-signed_stride]; break;
+ case 3: line_buffer[i] = z[i] - (z[i-signed_stride]>>1); break;
+ case 4: line_buffer[i] = (signed char) (z[i] - stbiw__paeth(0,z[i-signed_stride],0)); break;
+ case 5: line_buffer[i] = z[i]; break;
+ case 6: line_buffer[i] = z[i]; break;
+ }
+ }
+ switch (type) {
+ case 1: for (i=n; i < width*n; ++i) line_buffer[i] = z[i] - z[i-n]; break;
+ case 2: for (i=n; i < width*n; ++i) line_buffer[i] = z[i] - z[i-signed_stride]; break;
+ case 3: for (i=n; i < width*n; ++i) line_buffer[i] = z[i] - ((z[i-n] + z[i-signed_stride])>>1); break;
+ case 4: for (i=n; i < width*n; ++i) line_buffer[i] = z[i] - stbiw__paeth(z[i-n], z[i-signed_stride], z[i-signed_stride-n]); break;
+ case 5: for (i=n; i < width*n; ++i) line_buffer[i] = z[i] - (z[i-n]>>1); break;
+ case 6: for (i=n; i < width*n; ++i) line_buffer[i] = z[i] - stbiw__paeth(z[i-n], 0,0); break;
+ }
+}
+
+STBIWDEF unsigned char *stbi_write_png_to_mem(const unsigned char *pixels, int stride_bytes, int x, int y, int n, int *out_len)
+{
+ int force_filter = stbi_write_force_png_filter;
+ int ctype[5] = { -1, 0, 4, 2, 6 };
+ unsigned char sig[8] = { 137,80,78,71,13,10,26,10 };
+ unsigned char *out,*o, *filt, *zlib;
+ signed char *line_buffer;
+ int j,zlen;
+
+ if (stride_bytes == 0)
+ stride_bytes = x * n;
+
+ if (force_filter >= 5) {
+ force_filter = -1;
+ }
+
+ filt = (unsigned char *) STBIW_MALLOC((x*n+1) * y); if (!filt) return 0;
+ line_buffer = (signed char *) STBIW_MALLOC(x * n); if (!line_buffer) { STBIW_FREE(filt); return 0; }
+ for (j=0; j < y; ++j) {
+ int filter_type;
+ if (force_filter > -1) {
+ filter_type = force_filter;
+ stbiw__encode_png_line((unsigned char*)(pixels), stride_bytes, x, y, j, n, force_filter, line_buffer);
+ } else { // Estimate the best filter by running through all of them:
+ int best_filter = 0, best_filter_val = 0x7fffffff, est, i;
+ for (filter_type = 0; filter_type < 5; filter_type++) {
+ stbiw__encode_png_line((unsigned char*)(pixels), stride_bytes, x, y, j, n, filter_type, line_buffer);
+
+ // Estimate the entropy of the line using this filter; the less, the better.
+ est = 0;
+ for (i = 0; i < x*n; ++i) {
+ est += abs((signed char) line_buffer[i]);
+ }
+ if (est < best_filter_val) {
+ best_filter_val = est;
+ best_filter = filter_type;
+ }
+ }
+ if (filter_type != best_filter) { // If the last iteration already got us the best filter, don't redo it
+ stbiw__encode_png_line((unsigned char*)(pixels), stride_bytes, x, y, j, n, best_filter, line_buffer);
+ filter_type = best_filter;
+ }
+ }
+ // when we get here, filter_type contains the filter type, and line_buffer contains the data
+ filt[j*(x*n+1)] = (unsigned char) filter_type;
+ STBIW_MEMMOVE(filt+j*(x*n+1)+1, line_buffer, x*n);
+ }
+ STBIW_FREE(line_buffer);
+ zlib = stbi_zlib_compress(filt, y*( x*n+1), &zlen, stbi_write_png_compression_level);
+ STBIW_FREE(filt);
+ if (!zlib) return 0;
+
+ // each tag requires 12 bytes of overhead
+ out = (unsigned char *) STBIW_MALLOC(8 + 12+13 + 12+zlen + 12);
+ if (!out) return 0;
+ *out_len = 8 + 12+13 + 12+zlen + 12;
+
+ o=out;
+ STBIW_MEMMOVE(o,sig,8); o+= 8;
+ stbiw__wp32(o, 13); // header length
+ stbiw__wptag(o, "IHDR");
+ stbiw__wp32(o, x);
+ stbiw__wp32(o, y);
+ *o++ = 8;
+ *o++ = STBIW_UCHAR(ctype[n]);
+ *o++ = 0;
+ *o++ = 0;
+ *o++ = 0;
+ stbiw__wpcrc(&o,13);
+
+ stbiw__wp32(o, zlen);
+ stbiw__wptag(o, "IDAT");
+ STBIW_MEMMOVE(o, zlib, zlen);
+ o += zlen;
+ STBIW_FREE(zlib);
+ stbiw__wpcrc(&o, zlen);
+
+ stbiw__wp32(o,0);
+ stbiw__wptag(o, "IEND");
+ stbiw__wpcrc(&o,0);
+
+ STBIW_ASSERT(o == out + *out_len);
+
+ return out;
+}
+
+#ifndef STBI_WRITE_NO_STDIO
+STBIWDEF int stbi_write_png(char const *filename, int x, int y, int comp, const void *data, int stride_bytes)
+{
+ FILE *f;
+ int len;
+ unsigned char *png = stbi_write_png_to_mem((const unsigned char *) data, stride_bytes, x, y, comp, &len);
+ if (png == NULL) return 0;
+
+ f = stbiw__fopen(filename, "wb");
+ if (!f) { STBIW_FREE(png); return 0; }
+ fwrite(png, 1, len, f);
+ fclose(f);
+ STBIW_FREE(png);
+ return 1;
+}
+#endif
+
+STBIWDEF int stbi_write_png_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int stride_bytes)
+{
+ int len;
+ unsigned char *png = stbi_write_png_to_mem((const unsigned char *) data, stride_bytes, x, y, comp, &len);
+ if (png == NULL) return 0;
+ func(context, png, len);
+ STBIW_FREE(png);
+ return 1;
+}
+
+
+/* ***************************************************************************
+ *
+ * JPEG writer
+ *
+ * This is based on Jon Olick's jo_jpeg.cpp:
+ * public domain Simple, Minimalistic JPEG writer - http://www.jonolick.com/code.html
+ */
+
+static const unsigned char stbiw__jpg_ZigZag[] = { 0,1,5,6,14,15,27,28,2,4,7,13,16,26,29,42,3,8,12,17,25,30,41,43,9,11,18,
+ 24,31,40,44,53,10,19,23,32,39,45,52,54,20,22,33,38,46,51,55,60,21,34,37,47,50,56,59,61,35,36,48,49,57,58,62,63 };
+
+static void stbiw__jpg_writeBits(stbi__write_context *s, int *bitBufP, int *bitCntP, const unsigned short *bs) {
+ int bitBuf = *bitBufP, bitCnt = *bitCntP;
+ bitCnt += bs[1];
+ bitBuf |= bs[0] << (24 - bitCnt);
+ while(bitCnt >= 8) {
+ unsigned char c = (bitBuf >> 16) & 255;
+ stbiw__putc(s, c);
+ if(c == 255) {
+ stbiw__putc(s, 0);
+ }
+ bitBuf <<= 8;
+ bitCnt -= 8;
+ }
+ *bitBufP = bitBuf;
+ *bitCntP = bitCnt;
+}
+
+static void stbiw__jpg_DCT(float *d0p, float *d1p, float *d2p, float *d3p, float *d4p, float *d5p, float *d6p, float *d7p) {
+ float d0 = *d0p, d1 = *d1p, d2 = *d2p, d3 = *d3p, d4 = *d4p, d5 = *d5p, d6 = *d6p, d7 = *d7p;
+ float z1, z2, z3, z4, z5, z11, z13;
+
+ float tmp0 = d0 + d7;
+ float tmp7 = d0 - d7;
+ float tmp1 = d1 + d6;
+ float tmp6 = d1 - d6;
+ float tmp2 = d2 + d5;
+ float tmp5 = d2 - d5;
+ float tmp3 = d3 + d4;
+ float tmp4 = d3 - d4;
+
+ // Even part
+ float tmp10 = tmp0 + tmp3; // phase 2
+ float tmp13 = tmp0 - tmp3;
+ float tmp11 = tmp1 + tmp2;
+ float tmp12 = tmp1 - tmp2;
+
+ d0 = tmp10 + tmp11; // phase 3
+ d4 = tmp10 - tmp11;
+
+ z1 = (tmp12 + tmp13) * 0.707106781f; // c4
+ d2 = tmp13 + z1; // phase 5
+ d6 = tmp13 - z1;
+
+ // Odd part
+ tmp10 = tmp4 + tmp5; // phase 2
+ tmp11 = tmp5 + tmp6;
+ tmp12 = tmp6 + tmp7;
+
+ // The rotator is modified from fig 4-8 to avoid extra negations.
+ z5 = (tmp10 - tmp12) * 0.382683433f; // c6
+ z2 = tmp10 * 0.541196100f + z5; // c2-c6
+ z4 = tmp12 * 1.306562965f + z5; // c2+c6
+ z3 = tmp11 * 0.707106781f; // c4
+
+ z11 = tmp7 + z3; // phase 5
+ z13 = tmp7 - z3;
+
+ *d5p = z13 + z2; // phase 6
+ *d3p = z13 - z2;
+ *d1p = z11 + z4;
+ *d7p = z11 - z4;
+
+ *d0p = d0; *d2p = d2; *d4p = d4; *d6p = d6;
+}
+
+static void stbiw__jpg_calcBits(int val, unsigned short bits[2]) {
+ int tmp1 = val < 0 ? -val : val;
+ val = val < 0 ? val-1 : val;
+ bits[1] = 1;
+ while(tmp1 >>= 1) {
+ ++bits[1];
+ }
+ bits[0] = val & ((1<<bits[1])-1);
+}
+
+static int stbiw__jpg_processDU(stbi__write_context *s, int *bitBuf, int *bitCnt, float *CDU, int du_stride, float *fdtbl, int DC, const unsigned short HTDC[256][2], const unsigned short HTAC[256][2]) {
+ const unsigned short EOB[2] = { HTAC[0x00][0], HTAC[0x00][1] };
+ const unsigned short M16zeroes[2] = { HTAC[0xF0][0], HTAC[0xF0][1] };
+ int dataOff, i, j, n, diff, end0pos, x, y;
+ int DU[64];
+
+ // DCT rows
+ for(dataOff=0, n=du_stride*8; dataOff<n; dataOff+=du_stride) {
+ stbiw__jpg_DCT(&CDU[dataOff], &CDU[dataOff+1], &CDU[dataOff+2], &CDU[dataOff+3], &CDU[dataOff+4], &CDU[dataOff+5], &CDU[dataOff+6], &CDU[dataOff+7]);
+ }
+ // DCT columns
+ for(dataOff=0; dataOff<8; ++dataOff) {
+ stbiw__jpg_DCT(&CDU[dataOff], &CDU[dataOff+du_stride], &CDU[dataOff+du_stride*2], &CDU[dataOff+du_stride*3], &CDU[dataOff+du_stride*4],
+ &CDU[dataOff+du_stride*5], &CDU[dataOff+du_stride*6], &CDU[dataOff+du_stride*7]);
+ }
+ // Quantize/descale/zigzag the coefficients
+ for(y = 0, j=0; y < 8; ++y) {
+ for(x = 0; x < 8; ++x,++j) {
+ float v;
+ i = y*du_stride+x;
+ v = CDU[i]*fdtbl[j];
+ // DU[stbiw__jpg_ZigZag[j]] = (int)(v < 0 ? ceilf(v - 0.5f) : floorf(v + 0.5f));
+ // ceilf() and floorf() are C99, not C89, but I /think/ they're not needed here anyway?
+ DU[stbiw__jpg_ZigZag[j]] = (int)(v < 0 ? v - 0.5f : v + 0.5f);
+ }
+ }
+
+ // Encode DC
+ diff = DU[0] - DC;
+ if (diff == 0) {
+ stbiw__jpg_writeBits(s, bitBuf, bitCnt, HTDC[0]);
+ } else {
+ unsigned short bits[2];
+ stbiw__jpg_calcBits(diff, bits);
+ stbiw__jpg_writeBits(s, bitBuf, bitCnt, HTDC[bits[1]]);
+ stbiw__jpg_writeBits(s, bitBuf, bitCnt, bits);
+ }
+ // Encode ACs
+ end0pos = 63;
+ for(; (end0pos>0)&&(DU[end0pos]==0); --end0pos) {
+ }
+ // end0pos = first element in reverse order !=0
+ if(end0pos == 0) {
+ stbiw__jpg_writeBits(s, bitBuf, bitCnt, EOB);
+ return DU[0];
+ }
+ for(i = 1; i <= end0pos; ++i) {
+ int startpos = i;
+ int nrzeroes;
+ unsigned short bits[2];
+ for (; DU[i]==0 && i<=end0pos; ++i) {
+ }
+ nrzeroes = i-startpos;
+ if ( nrzeroes >= 16 ) {
+ int lng = nrzeroes>>4;
+ int nrmarker;
+ for (nrmarker=1; nrmarker <= lng; ++nrmarker)
+ stbiw__jpg_writeBits(s, bitBuf, bitCnt, M16zeroes);
+ nrzeroes &= 15;
+ }
+ stbiw__jpg_calcBits(DU[i], bits);
+ stbiw__jpg_writeBits(s, bitBuf, bitCnt, HTAC[(nrzeroes<<4)+bits[1]]);
+ stbiw__jpg_writeBits(s, bitBuf, bitCnt, bits);
+ }
+ if(end0pos != 63) {
+ stbiw__jpg_writeBits(s, bitBuf, bitCnt, EOB);
+ }
+ return DU[0];
+}
+
+static int stbi_write_jpg_core(stbi__write_context *s, int width, int height, int comp, const void* data, int quality) {
+ // Constants that don't pollute global namespace
+ static const unsigned char std_dc_luminance_nrcodes[] = {0,0,1,5,1,1,1,1,1,1,0,0,0,0,0,0,0};
+ static const unsigned char std_dc_luminance_values[] = {0,1,2,3,4,5,6,7,8,9,10,11};
+ static const unsigned char std_ac_luminance_nrcodes[] = {0,0,2,1,3,3,2,4,3,5,5,4,4,0,0,1,0x7d};
+ static const unsigned char std_ac_luminance_values[] = {
+ 0x01,0x02,0x03,0x00,0x04,0x11,0x05,0x12,0x21,0x31,0x41,0x06,0x13,0x51,0x61,0x07,0x22,0x71,0x14,0x32,0x81,0x91,0xa1,0x08,
+ 0x23,0x42,0xb1,0xc1,0x15,0x52,0xd1,0xf0,0x24,0x33,0x62,0x72,0x82,0x09,0x0a,0x16,0x17,0x18,0x19,0x1a,0x25,0x26,0x27,0x28,
+ 0x29,0x2a,0x34,0x35,0x36,0x37,0x38,0x39,0x3a,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4a,0x53,0x54,0x55,0x56,0x57,0x58,0x59,
+ 0x5a,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,0x83,0x84,0x85,0x86,0x87,0x88,0x89,
+ 0x8a,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9a,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xb2,0xb3,0xb4,0xb5,0xb6,
+ 0xb7,0xb8,0xb9,0xba,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xd2,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9,0xda,0xe1,0xe2,
+ 0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,0xea,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9,0xfa
+ };
+ static const unsigned char std_dc_chrominance_nrcodes[] = {0,0,3,1,1,1,1,1,1,1,1,1,0,0,0,0,0};
+ static const unsigned char std_dc_chrominance_values[] = {0,1,2,3,4,5,6,7,8,9,10,11};
+ static const unsigned char std_ac_chrominance_nrcodes[] = {0,0,2,1,2,4,4,3,4,7,5,4,4,0,1,2,0x77};
+ static const unsigned char std_ac_chrominance_values[] = {
+ 0x00,0x01,0x02,0x03,0x11,0x04,0x05,0x21,0x31,0x06,0x12,0x41,0x51,0x07,0x61,0x71,0x13,0x22,0x32,0x81,0x08,0x14,0x42,0x91,
+ 0xa1,0xb1,0xc1,0x09,0x23,0x33,0x52,0xf0,0x15,0x62,0x72,0xd1,0x0a,0x16,0x24,0x34,0xe1,0x25,0xf1,0x17,0x18,0x19,0x1a,0x26,
+ 0x27,0x28,0x29,0x2a,0x35,0x36,0x37,0x38,0x39,0x3a,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4a,0x53,0x54,0x55,0x56,0x57,0x58,
+ 0x59,0x5a,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,0x82,0x83,0x84,0x85,0x86,0x87,
+ 0x88,0x89,0x8a,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9a,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xb2,0xb3,0xb4,
+ 0xb5,0xb6,0xb7,0xb8,0xb9,0xba,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xd2,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9,0xda,
+ 0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,0xea,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9,0xfa
+ };
+ // Huffman tables
+ static const unsigned short YDC_HT[256][2] = { {0,2},{2,3},{3,3},{4,3},{5,3},{6,3},{14,4},{30,5},{62,6},{126,7},{254,8},{510,9}};
+ static const unsigned short UVDC_HT[256][2] = { {0,2},{1,2},{2,2},{6,3},{14,4},{30,5},{62,6},{126,7},{254,8},{510,9},{1022,10},{2046,11}};
+ static const unsigned short YAC_HT[256][2] = {
+ {10,4},{0,2},{1,2},{4,3},{11,4},{26,5},{120,7},{248,8},{1014,10},{65410,16},{65411,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {12,4},{27,5},{121,7},{502,9},{2038,11},{65412,16},{65413,16},{65414,16},{65415,16},{65416,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {28,5},{249,8},{1015,10},{4084,12},{65417,16},{65418,16},{65419,16},{65420,16},{65421,16},{65422,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {58,6},{503,9},{4085,12},{65423,16},{65424,16},{65425,16},{65426,16},{65427,16},{65428,16},{65429,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {59,6},{1016,10},{65430,16},{65431,16},{65432,16},{65433,16},{65434,16},{65435,16},{65436,16},{65437,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {122,7},{2039,11},{65438,16},{65439,16},{65440,16},{65441,16},{65442,16},{65443,16},{65444,16},{65445,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {123,7},{4086,12},{65446,16},{65447,16},{65448,16},{65449,16},{65450,16},{65451,16},{65452,16},{65453,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {250,8},{4087,12},{65454,16},{65455,16},{65456,16},{65457,16},{65458,16},{65459,16},{65460,16},{65461,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {504,9},{32704,15},{65462,16},{65463,16},{65464,16},{65465,16},{65466,16},{65467,16},{65468,16},{65469,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {505,9},{65470,16},{65471,16},{65472,16},{65473,16},{65474,16},{65475,16},{65476,16},{65477,16},{65478,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {506,9},{65479,16},{65480,16},{65481,16},{65482,16},{65483,16},{65484,16},{65485,16},{65486,16},{65487,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {1017,10},{65488,16},{65489,16},{65490,16},{65491,16},{65492,16},{65493,16},{65494,16},{65495,16},{65496,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {1018,10},{65497,16},{65498,16},{65499,16},{65500,16},{65501,16},{65502,16},{65503,16},{65504,16},{65505,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {2040,11},{65506,16},{65507,16},{65508,16},{65509,16},{65510,16},{65511,16},{65512,16},{65513,16},{65514,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {65515,16},{65516,16},{65517,16},{65518,16},{65519,16},{65520,16},{65521,16},{65522,16},{65523,16},{65524,16},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {2041,11},{65525,16},{65526,16},{65527,16},{65528,16},{65529,16},{65530,16},{65531,16},{65532,16},{65533,16},{65534,16},{0,0},{0,0},{0,0},{0,0},{0,0}
+ };
+ static const unsigned short UVAC_HT[256][2] = {
+ {0,2},{1,2},{4,3},{10,4},{24,5},{25,5},{56,6},{120,7},{500,9},{1014,10},{4084,12},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {11,4},{57,6},{246,8},{501,9},{2038,11},{4085,12},{65416,16},{65417,16},{65418,16},{65419,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {26,5},{247,8},{1015,10},{4086,12},{32706,15},{65420,16},{65421,16},{65422,16},{65423,16},{65424,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {27,5},{248,8},{1016,10},{4087,12},{65425,16},{65426,16},{65427,16},{65428,16},{65429,16},{65430,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {58,6},{502,9},{65431,16},{65432,16},{65433,16},{65434,16},{65435,16},{65436,16},{65437,16},{65438,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {59,6},{1017,10},{65439,16},{65440,16},{65441,16},{65442,16},{65443,16},{65444,16},{65445,16},{65446,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {121,7},{2039,11},{65447,16},{65448,16},{65449,16},{65450,16},{65451,16},{65452,16},{65453,16},{65454,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {122,7},{2040,11},{65455,16},{65456,16},{65457,16},{65458,16},{65459,16},{65460,16},{65461,16},{65462,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {249,8},{65463,16},{65464,16},{65465,16},{65466,16},{65467,16},{65468,16},{65469,16},{65470,16},{65471,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {503,9},{65472,16},{65473,16},{65474,16},{65475,16},{65476,16},{65477,16},{65478,16},{65479,16},{65480,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {504,9},{65481,16},{65482,16},{65483,16},{65484,16},{65485,16},{65486,16},{65487,16},{65488,16},{65489,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {505,9},{65490,16},{65491,16},{65492,16},{65493,16},{65494,16},{65495,16},{65496,16},{65497,16},{65498,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {506,9},{65499,16},{65500,16},{65501,16},{65502,16},{65503,16},{65504,16},{65505,16},{65506,16},{65507,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {2041,11},{65508,16},{65509,16},{65510,16},{65511,16},{65512,16},{65513,16},{65514,16},{65515,16},{65516,16},{0,0},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {16352,14},{65517,16},{65518,16},{65519,16},{65520,16},{65521,16},{65522,16},{65523,16},{65524,16},{65525,16},{0,0},{0,0},{0,0},{0,0},{0,0},
+ {1018,10},{32707,15},{65526,16},{65527,16},{65528,16},{65529,16},{65530,16},{65531,16},{65532,16},{65533,16},{65534,16},{0,0},{0,0},{0,0},{0,0},{0,0}
+ };
+ static const int YQT[] = {16,11,10,16,24,40,51,61,12,12,14,19,26,58,60,55,14,13,16,24,40,57,69,56,14,17,22,29,51,87,80,62,18,22,
+ 37,56,68,109,103,77,24,35,55,64,81,104,113,92,49,64,78,87,103,121,120,101,72,92,95,98,112,100,103,99};
+ static const int UVQT[] = {17,18,24,47,99,99,99,99,18,21,26,66,99,99,99,99,24,26,56,99,99,99,99,99,47,66,99,99,99,99,99,99,
+ 99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99,99};
+ static const float aasf[] = { 1.0f * 2.828427125f, 1.387039845f * 2.828427125f, 1.306562965f * 2.828427125f, 1.175875602f * 2.828427125f,
+ 1.0f * 2.828427125f, 0.785694958f * 2.828427125f, 0.541196100f * 2.828427125f, 0.275899379f * 2.828427125f };
+
+ int row, col, i, k, subsample;
+ float fdtbl_Y[64], fdtbl_UV[64];
+ unsigned char YTable[64], UVTable[64];
+
+ if(!data || !width || !height || comp > 4 || comp < 1) {
+ return 0;
+ }
+
+ quality = quality ? quality : 90;
+ subsample = quality <= 90 ? 1 : 0;
+ quality = quality < 1 ? 1 : quality > 100 ? 100 : quality;
+ quality = quality < 50 ? 5000 / quality : 200 - quality * 2;
+
+ for(i = 0; i < 64; ++i) {
+ int uvti, yti = (YQT[i]*quality+50)/100;
+ YTable[stbiw__jpg_ZigZag[i]] = (unsigned char) (yti < 1 ? 1 : yti > 255 ? 255 : yti);
+ uvti = (UVQT[i]*quality+50)/100;
+ UVTable[stbiw__jpg_ZigZag[i]] = (unsigned char) (uvti < 1 ? 1 : uvti > 255 ? 255 : uvti);
+ }
+
+ for(row = 0, k = 0; row < 8; ++row) {
+ for(col = 0; col < 8; ++col, ++k) {
+ fdtbl_Y[k] = 1 / (YTable [stbiw__jpg_ZigZag[k]] * aasf[row] * aasf[col]);
+ fdtbl_UV[k] = 1 / (UVTable[stbiw__jpg_ZigZag[k]] * aasf[row] * aasf[col]);
+ }
+ }
+
+ // Write Headers
+ {
+ static const unsigned char head0[] = { 0xFF,0xD8,0xFF,0xE0,0,0x10,'J','F','I','F',0,1,1,0,0,1,0,1,0,0,0xFF,0xDB,0,0x84,0 };
+ static const unsigned char head2[] = { 0xFF,0xDA,0,0xC,3,1,0,2,0x11,3,0x11,0,0x3F,0 };
+ const unsigned char head1[] = { 0xFF,0xC0,0,0x11,8,(unsigned char)(height>>8),STBIW_UCHAR(height),(unsigned char)(width>>8),STBIW_UCHAR(width),
+ 3,1,(unsigned char)(subsample?0x22:0x11),0,2,0x11,1,3,0x11,1,0xFF,0xC4,0x01,0xA2,0 };
+ s->func(s->context, (void*)head0, sizeof(head0));
+ s->func(s->context, (void*)YTable, sizeof(YTable));
+ stbiw__putc(s, 1);
+ s->func(s->context, UVTable, sizeof(UVTable));
+ s->func(s->context, (void*)head1, sizeof(head1));
+ s->func(s->context, (void*)(std_dc_luminance_nrcodes+1), sizeof(std_dc_luminance_nrcodes)-1);
+ s->func(s->context, (void*)std_dc_luminance_values, sizeof(std_dc_luminance_values));
+ stbiw__putc(s, 0x10); // HTYACinfo
+ s->func(s->context, (void*)(std_ac_luminance_nrcodes+1), sizeof(std_ac_luminance_nrcodes)-1);
+ s->func(s->context, (void*)std_ac_luminance_values, sizeof(std_ac_luminance_values));
+ stbiw__putc(s, 1); // HTUDCinfo
+ s->func(s->context, (void*)(std_dc_chrominance_nrcodes+1), sizeof(std_dc_chrominance_nrcodes)-1);
+ s->func(s->context, (void*)std_dc_chrominance_values, sizeof(std_dc_chrominance_values));
+ stbiw__putc(s, 0x11); // HTUACinfo
+ s->func(s->context, (void*)(std_ac_chrominance_nrcodes+1), sizeof(std_ac_chrominance_nrcodes)-1);
+ s->func(s->context, (void*)std_ac_chrominance_values, sizeof(std_ac_chrominance_values));
+ s->func(s->context, (void*)head2, sizeof(head2));
+ }
+
+ // Encode 8x8 macroblocks
+ {
+ static const unsigned short fillBits[] = {0x7F, 7};
+ int DCY=0, DCU=0, DCV=0;
+ int bitBuf=0, bitCnt=0;
+ // comp == 2 is grey+alpha (alpha is ignored)
+ int ofsG = comp > 2 ? 1 : 0, ofsB = comp > 2 ? 2 : 0;
+ const unsigned char *dataR = (const unsigned char *)data;
+ const unsigned char *dataG = dataR + ofsG;
+ const unsigned char *dataB = dataR + ofsB;
+ int x, y, pos;
+ if(subsample) {
+ for(y = 0; y < height; y += 16) {
+ for(x = 0; x < width; x += 16) {
+ float Y[256], U[256], V[256];
+ for(row = y, pos = 0; row < y+16; ++row) {
+ // row >= height => use last input row
+ int clamped_row = (row < height) ? row : height - 1;
+ int base_p = (stbi__flip_vertically_on_write ? (height-1-clamped_row) : clamped_row)*width*comp;
+ for(col = x; col < x+16; ++col, ++pos) {
+ // if col >= width => use pixel from last input column
+ int p = base_p + ((col < width) ? col : (width-1))*comp;
+ float r = dataR[p], g = dataG[p], b = dataB[p];
+ Y[pos]= +0.29900f*r + 0.58700f*g + 0.11400f*b - 128;
+ U[pos]= -0.16874f*r - 0.33126f*g + 0.50000f*b;
+ V[pos]= +0.50000f*r - 0.41869f*g - 0.08131f*b;
+ }
+ }
+ DCY = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, Y+0, 16, fdtbl_Y, DCY, YDC_HT, YAC_HT);
+ DCY = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, Y+8, 16, fdtbl_Y, DCY, YDC_HT, YAC_HT);
+ DCY = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, Y+128, 16, fdtbl_Y, DCY, YDC_HT, YAC_HT);
+ DCY = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, Y+136, 16, fdtbl_Y, DCY, YDC_HT, YAC_HT);
+
+ // subsample U,V
+ {
+ float subU[64], subV[64];
+ int yy, xx;
+ for(yy = 0, pos = 0; yy < 8; ++yy) {
+ for(xx = 0; xx < 8; ++xx, ++pos) {
+ int j = yy*32+xx*2;
+ subU[pos] = (U[j+0] + U[j+1] + U[j+16] + U[j+17]) * 0.25f;
+ subV[pos] = (V[j+0] + V[j+1] + V[j+16] + V[j+17]) * 0.25f;
+ }
+ }
+ DCU = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, subU, 8, fdtbl_UV, DCU, UVDC_HT, UVAC_HT);
+ DCV = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, subV, 8, fdtbl_UV, DCV, UVDC_HT, UVAC_HT);
+ }
+ }
+ }
+ } else {
+ for(y = 0; y < height; y += 8) {
+ for(x = 0; x < width; x += 8) {
+ float Y[64], U[64], V[64];
+ for(row = y, pos = 0; row < y+8; ++row) {
+ // row >= height => use last input row
+ int clamped_row = (row < height) ? row : height - 1;
+ int base_p = (stbi__flip_vertically_on_write ? (height-1-clamped_row) : clamped_row)*width*comp;
+ for(col = x; col < x+8; ++col, ++pos) {
+ // if col >= width => use pixel from last input column
+ int p = base_p + ((col < width) ? col : (width-1))*comp;
+ float r = dataR[p], g = dataG[p], b = dataB[p];
+ Y[pos]= +0.29900f*r + 0.58700f*g + 0.11400f*b - 128;
+ U[pos]= -0.16874f*r - 0.33126f*g + 0.50000f*b;
+ V[pos]= +0.50000f*r - 0.41869f*g - 0.08131f*b;
+ }
+ }
+
+ DCY = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, Y, 8, fdtbl_Y, DCY, YDC_HT, YAC_HT);
+ DCU = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, U, 8, fdtbl_UV, DCU, UVDC_HT, UVAC_HT);
+ DCV = stbiw__jpg_processDU(s, &bitBuf, &bitCnt, V, 8, fdtbl_UV, DCV, UVDC_HT, UVAC_HT);
+ }
+ }
+ }
+
+ // Do the bit alignment of the EOI marker
+ stbiw__jpg_writeBits(s, &bitBuf, &bitCnt, fillBits);
+ }
+
+ // EOI
+ stbiw__putc(s, 0xFF);
+ stbiw__putc(s, 0xD9);
+
+ return 1;
+}
+
+STBIWDEF int stbi_write_jpg_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data, int quality)
+{
+ stbi__write_context s = { 0 };
+ stbi__start_write_callbacks(&s, func, context);
+ return stbi_write_jpg_core(&s, x, y, comp, (void *) data, quality);
+}
+
+
+#ifndef STBI_WRITE_NO_STDIO
+STBIWDEF int stbi_write_jpg(char const *filename, int x, int y, int comp, const void *data, int quality)
+{
+ stbi__write_context s = { 0 };
+ if (stbi__start_write_file(&s,filename)) {
+ int r = stbi_write_jpg_core(&s, x, y, comp, data, quality);
+ stbi__end_write_file(&s);
+ return r;
+ } else
+ return 0;
+}
+#endif
+
+#endif // STB_IMAGE_WRITE_IMPLEMENTATION
+
/* Revision history
1.16 (2021-07-11)
make Deflate code emit uncompressed blocks when it would otherwise expand