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Merge branch 'test'

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Sean Barrett ago%!(EXTRA string=11 years)
parent f392ec7d36 edd5e6700d
commit d91cbdf662
1 changed files with 187 additions and 9 deletions
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  1. 196
      stb_image_write.h

196
stb_image_write.h
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@ -1,16 +1,16 @@
/* stb_image_write - v0.95 - public domain - http://nothings.org/stb/stb_image_write.h
/* stb_image_write - v0.96 - public domain - http://nothings.org/stb/stb_image_write.h
writes out PNG/BMP/TGA images to C stdio - Sean Barrett 2010
no warranty implied; use at your own risk
Before including,
Before #including,
#define STB_IMAGE_WRITE_IMPLEMENTATION
#define STB_IMAGE_WRITE_IMPLEMENTATION
in the file that you want to have the implementation.
in the file that you want to have the implementation.
Will probably not work correctly with strict-aliasing optimizations.
Will probably not work correctly with strict-aliasing optimizations.
ABOUT:
@ -24,11 +24,12 @@ ABOUT:
USAGE:
There are three functions, one for each image file format:
There are four functions, one for each image file format:
int stbi_write_png(char const *filename, int w, int h, int comp, const void *data, int stride_in_bytes);
int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
int stbi_write_hdr(char const *filename, int w, int h, int comp, const void *data);
Each function returns 0 on failure and non-0 on success.
@ -51,6 +52,21 @@ USAGE:
formats do not. (Thus you cannot write a native-format BMP through the BMP
writer, both because it is in BGR order and because it may have padding
at the end of the line.)
HDR expects linear float data. Since the format is always 32-bit rgb(e)
data, alpha (if provided) is discarded, and for monochrome data it is
replicated across all three channels.
CREDITS:
PNG/BMP/TGA
Sean Barrett
HDR
Baldur Karlsson
TGA monochrome:
Jean-Sebastien Guay
Bugfixes:
Chribba@github
*/
#ifndef INCLUDE_STB_IMAGE_WRITE_H
@ -60,9 +76,10 @@ USAGE:
extern "C" {
#endif
extern int stbi_write_png(char const *filename, int w, int h, int comp, const void *data, int stride_in_bytes);
extern int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
extern int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
extern int stbi_write_png(char const *filename, int w, int h, int comp, const void *data, int stride_in_bytes);
extern int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
extern int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
extern int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data);
#ifdef __cplusplus
}
@ -77,6 +94,7 @@ extern int stbi_write_tga(char const *filename, int w, int h, int comp, const vo
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <math.h>
typedef unsigned int stbiw_uint32;
typedef int stb_image_write_test[sizeof(stbiw_uint32)==4 ? 1 : -1];
@ -189,6 +207,163 @@ int stbi_write_tga(char const *filename, int x, int y, int comp, const void *dat
"111 221 2222 11", 0,0,format, 0,0,0, 0,0,x,y, (colorbytes+has_alpha)*8, has_alpha*8);
}
// *************************************************************************************************
// Radiance RGBE HDR writer
// by Baldur Karlsson
#define stbiw__max(a, b) ((a) > (b) ? (a) : (b))
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-32) {
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] * maxcomp);
rgbe[1] = (unsigned char)(linear[1] * maxcomp);
rgbe[2] = (unsigned char)(linear[2] * maxcomp);
rgbe[3] = (unsigned char)(exponent + 128);
}
}
void stbiw__write_rle_data(FILE *f, int length, unsigned char databyte)
{
unsigned char lengthbyte = 0x80 | (unsigned char)(length & 0x7f);
assert(length <= 0x7f);
fwrite(&lengthbyte, 1, 1, f);
fwrite(&databyte, 1, 1, f);
}
void stbiw__write_nonrle_data(FILE *f, int length, unsigned char *data)
{
unsigned char lengthbyte = (unsigned char )(length & 0xff);
assert(length <= 0x7f);
fwrite(&lengthbyte, 1, 1, f);
fwrite(data, length, 1, f);
}
void stbiw__write_hdr_scanline(FILE *f, int width, int comp, unsigned char *scratch, const 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 (comp) {
case 4: /* fallthrough */
case 3: linear[2] = scanline[x*comp + 2];
linear[1] = scanline[x*comp + 1];
linear[0] = scanline[x*comp + 0];
break;
case 2: /* fallthrough */
case 1: linear[0] = linear[1] = linear[2] = scanline[x*comp + 0];
break;
}
stbiw__linear_to_rgbe(rgbe, linear);
fwrite(rgbe, 4, 1, f);
}
} else {
/* encode into scratch buffer */
for (x=0; x < width; x++) {
switch(comp) {
case 4: /* fallthrough */
case 3: linear[2] = scanline[x*comp + 2];
linear[1] = scanline[x*comp + 1];
linear[0] = scanline[x*comp + 0];
break;
case 2: /* fallthrough */
case 1: linear[0] = linear[1] = linear[2] = scanline[x*comp + 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];
}
fwrite(scanlineheader, 4, 1, f);
/* RLE each component separately */
for (x=0; x < 4; x++) {
unsigned char *comp = &scratch[width*x];
int runstart = 0, head = 0, rlerun = 0;
while (head < width) {
head++;
if (head - runstart == 127 && rlerun == 1) {
// max length RLE run
stbiw__write_rle_data(f, head - runstart, comp[runstart]);
rlerun = 0;
runstart = head;
} else if (head - runstart == 128 && rlerun == 0) {
// max length non-RLE run
stbiw__write_nonrle_data(f, head - runstart, comp+runstart);
rlerun = 0;
runstart = head;
} else if (comp[head] != comp[head-1] && rlerun == 1) {
// end of RLE run
stbiw__write_rle_data(f, head - runstart, comp[runstart]);
rlerun = 0;
runstart = head;
} else {
// continue accumulating RLE run
if (rlerun == 1) continue;
// see if we can start an RLE run, at least 3 bytes same
if (rlerun == 0 && head - runstart >= 2
&& comp[head] == comp[head-1]
&& comp[head] == comp[head-2]) {
// found a run. Flush non-run (if there is anything) and then start an RLE run
if (head - runstart > 2) {
stbiw__write_nonrle_data(f, head-2 - runstart, comp+runstart);
}
rlerun = 1;
runstart = head-2;
}
}
}
// flush remaining sequence (if any)
if (rlerun == 1) stbiw__write_rle_data(f, head - runstart, comp[runstart]);
else if (head - runstart > 0) stbiw__write_nonrle_data(f, head - runstart, comp+runstart);
}
}
}
int stbi_write_hdr(char const *filename, int x, int y, int comp, const float *data)
{
int i;
FILE *f;
if (y <= 0 || x <= 0 || data == NULL) return 0;
f = fopen(filename, "wb");
if (f) {
/* Each component is stored separately. Allocate scratch space for full output scanline. */
unsigned char *scratch = (unsigned char *) malloc(x*4);
fprintf(f, "#?RADIANCE\n# Written by stb_image_write.h\nFORMAT=32-bit_rle_rgbe\n" );
fprintf(f, "EXPOSURE= 1.0000000000000\n\n-Y %d +X %d\n" , y, x);
for(i=0; i < y; i++)
stbiw__write_hdr_scanline(f, x, comp, scratch, data + comp*i*x);
free(scratch);
fclose(f);
}
return f != NULL;
}
/////////////////////////////////////////////////////////
// PNG
// stretchy buffer; stbiw__sbpush() == vector<>::push_back() -- stbiw__sbcount() == vector<>::size()
#define stbiw__sbraw(a) ((int *) (a) - 2)
#define stbiw__sbm(a) stbiw__sbraw(a)[0]
@ -511,6 +686,9 @@ int stbi_write_png(char const *filename, int x, int y, int comp, const void *dat
/* Revision history
0.96 (2015-01-17)
add HDR output
fix monochrome BMP
0.95 (2014-08-17)
add monochrome TGA output
0.94 (2014-05-31)

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