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			512 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			512 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* stbiw-0.92 - public domain - http://nothings.org/stb/stb_image_write.h
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|    writes out PNG/BMP/TGA images to C stdio - Sean Barrett 2010
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|                             no warranty implied; use at your own risk
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| 
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| 
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| Before including,
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| 
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|     #define STB_IMAGE_WRITE_IMPLEMENTATION
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| 
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| in the file that you want to have the implementation.
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| 
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| 
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| ABOUT:
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| 
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|    This header file is a library for writing images to C stdio. It could be
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|    adapted to write to memory or a general streaming interface; let me know.
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| 
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|    The PNG output is not optimal; it is 20-50% larger than the file
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|    written by a decent optimizing implementation. This library is designed
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|    for source code compactness and simplicitly, not optimal image file size
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|    or run-time performance.
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| 
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| USAGE:
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| 
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|    There are three functions, one for each image file format:
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| 
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|      int stbi_write_png(char const *filename, int w, int h, int comp, const void *data, int stride_in_bytes);
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|      int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
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|      int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
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| 
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|    Each function returns 0 on failure and non-0 on success.
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|    
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|    The functions create an image file defined by the parameters. The image
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|    is a rectangle of pixels stored from left-to-right, top-to-bottom.
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|    Each pixel contains 'comp' channels of data stored interleaved with 8-bits
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|    per channel, in the following order: 1=Y, 2=YA, 3=RGB, 4=RGBA. (Y is
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|    monochrome color.) The rectangle is 'w' pixels wide and 'h' pixels tall.
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|    The *data pointer points to the first byte of the top-left-most pixel.
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|    For PNG, "stride_in_bytes" is the distance in bytes from the first byte of
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|    a row of pixels to the first byte of the next row of pixels.
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| 
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|    PNG creates output files with the same number of components as the input.
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|    The BMP and TGA formats expand Y to RGB in the file format. BMP does not
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|    output alpha.
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|    
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|    PNG supports writing rectangles of data even when the bytes storing rows of
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|    data are not consecutive in memory (e.g. sub-rectangles of a larger image),
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|    by supplying the stride between the beginning of adjacent rows. The other
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|    formats do not. (Thus you cannot write a native-format BMP through the BMP
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|    writer, both because it is in BGR order and because it may have padding
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|    at the end of the line.)
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| */
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| 
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| #ifndef INCLUDE_STB_IMAGE_WRITE_H
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| #define INCLUDE_STB_IMAGE_WRITE_H
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| 
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| #ifdef __cplusplus
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| extern "C" {
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| #endif
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| 
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| extern int stbi_write_png(char const *filename, int w, int h, int comp, const void *data, int stride_in_bytes);
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| extern int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
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| extern int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
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| 
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| #ifdef __cplusplus
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| }
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| #endif
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| 
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| #endif//INCLUDE_STB_IMAGE_WRITE_H
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| 
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| #ifdef STB_IMAGE_WRITE_IMPLEMENTATION
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| 
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| #include <stdarg.h>
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| #include <stdlib.h>
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| #include <stdio.h>
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| #include <string.h>
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| #include <assert.h>
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| 
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| typedef unsigned int stbiw_uint32;
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| typedef int stb_image_write_test[sizeof(stbiw_uint32)==4 ? 1 : -1];
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| 
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| static void writefv(FILE *f, const char *fmt, va_list v)
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| {
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|    while (*fmt) {
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|       switch (*fmt++) {
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|          case ' ': break;
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|          case '1': { unsigned char x = (unsigned char) va_arg(v, int); fputc(x,f); break; }
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|          case '2': { int x = va_arg(v,int); unsigned char b[2];
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|                      b[0] = (unsigned char) x; b[1] = (unsigned char) (x>>8);
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|                      fwrite(b,2,1,f); break; }
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|          case '4': { stbiw_uint32 x = va_arg(v,int); unsigned char b[4];
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|                      b[0]=(unsigned char)x; b[1]=(unsigned char)(x>>8);
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|                      b[2]=(unsigned char)(x>>16); b[3]=(unsigned char)(x>>24);
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|                      fwrite(b,4,1,f); break; }
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|          default:
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|             assert(0);
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|             return;
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|       }
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|    }
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| }
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| 
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| static void write3(FILE *f, unsigned char a, unsigned char b, unsigned char c)
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| {
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|    unsigned char arr[3];
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|    arr[0] = a, arr[1] = b, arr[2] = c;
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|    fwrite(arr, 3, 1, f);
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| }
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| 
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| 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)
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| {
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|    unsigned char bg[3] = { 255, 0, 255}, px[3];
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|    stbiw_uint32 zero = 0;
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|    int i,j,k, j_end;
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| 
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|    if (y <= 0)
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|       return;
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| 
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|    if (vdir < 0) 
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|       j_end = -1, j = y-1;
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|    else
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|       j_end =  y, j = 0;
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| 
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|    for (; j != j_end; j += vdir) {
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|       for (i=0; i < x; ++i) {
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|          unsigned char *d = (unsigned char *) data + (j*x+i)*comp;
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|          if (write_alpha < 0)
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|             fwrite(&d[comp-1], 1, 1, f);
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|          switch (comp) {
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|             case 1:
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|             case 2: write3(f, d[0],d[0],d[0]);
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|                     break;
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|             case 4:
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|                if (!write_alpha) {
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|                   // composite against pink background
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|                   for (k=0; k < 3; ++k)
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|                      px[k] = bg[k] + ((d[k] - bg[k]) * d[3])/255;
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|                   write3(f, px[1-rgb_dir],px[1],px[1+rgb_dir]);
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|                   break;
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|                }
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|                /* FALLTHROUGH */
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|             case 3:
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|                write3(f, d[1-rgb_dir],d[1],d[1+rgb_dir]);
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|                break;
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|          }
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|          if (write_alpha > 0)
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|             fwrite(&d[comp-1], 1, 1, f);
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|       }
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|       fwrite(&zero,scanline_pad,1,f);
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|    }
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| }
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| 
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| static int outfile(char const *filename, int rgb_dir, int vdir, int x, int y, int comp, void *data, int alpha, int pad, const char *fmt, ...)
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| {
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|    FILE *f;
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|    if (y < 0 || x < 0) return 0;
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|    f = fopen(filename, "wb");
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|    if (f) {
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|       va_list v;
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|       va_start(v, fmt);
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|       writefv(f, fmt, v);
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|       va_end(v);
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|       write_pixels(f,rgb_dir,vdir,x,y,comp,data,alpha,pad);
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|       fclose(f);
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|    }
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|    return f != NULL;
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| }
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| 
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| int stbi_write_bmp(char const *filename, int x, int y, int comp, const void *data)
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| {
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|    int pad = (-x*3) & 3;
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|    return outfile(filename,-1,-1,x,y,comp,(void *) data,0,pad,
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|            "11 4 22 4" "4 44 22 444444",
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|            'B', 'M', 14+40+(x*3+pad)*y, 0,0, 14+40,  // file header
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|             40, x,y, 1,24, 0,0,0,0,0,0);             // bitmap header
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| }
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| 
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| int stbi_write_tga(char const *filename, int x, int y, int comp, const void *data)
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| {
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|    int has_alpha = !(comp & 1);
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|    return outfile(filename, -1,-1, x, y, comp, (void *) data, has_alpha, 0,
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|                   "111 221 2222 11", 0,0,2, 0,0,0, 0,0,x,y, 24+8*has_alpha, 8*has_alpha);
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| }
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| 
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| // stretchy buffer; stbi__sbpush() == vector<>::push_back() -- stbi__sbcount() == vector<>::size()
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| #define stbi__sbraw(a) ((int *) (a) - 2)
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| #define stbi__sbm(a)   stbi__sbraw(a)[0]
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| #define stbi__sbn(a)   stbi__sbraw(a)[1]
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| 
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| #define stbi__sbneedgrow(a,n)  ((a)==0 || stbi__sbn(a)+n >= stbi__sbm(a))
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| #define stbi__sbmaybegrow(a,n) (stbi__sbneedgrow(a,(n)) ? stbi__sbgrow(a,n) : 0)
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| #define stbi__sbgrow(a,n)  stbi__sbgrowf((void **) &(a), (n), sizeof(*(a)))
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| 
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| #define stbi__sbpush(a, v)      (stbi__sbmaybegrow(a,1), (a)[stbi__sbn(a)++] = (v))
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| #define stbi__sbcount(a)        ((a) ? stbi__sbn(a) : 0)
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| #define stbi__sbfree(a)         ((a) ? free(stbi__sbraw(a)),0 : 0)
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| 
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| static void *stbi__sbgrowf(void **arr, int increment, int itemsize)
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| {
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|    int m = *arr ? 2*stbi__sbm(*arr)+increment : increment+1;
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|    void *p = realloc(*arr ? stbi__sbraw(*arr) : 0, itemsize * m + sizeof(int)*2);
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|    assert(p);
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|    if (p) {
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|       if (!*arr) ((int *) p)[1] = 0;
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|       *arr = (void *) ((int *) p + 2);
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|       stbi__sbm(*arr) = m;
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|    }
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|    return *arr;
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| }
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| 
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| static unsigned char *stbi__zlib_flushf(unsigned char *data, unsigned int *bitbuffer, int *bitcount)
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| {
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|    while (*bitcount >= 8) {
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|       stbi__sbpush(data, (unsigned char) *bitbuffer);
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|       *bitbuffer >>= 8;
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|       *bitcount -= 8;
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|    }
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|    return data;
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| }
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| 
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| static int stbi__zlib_bitrev(int code, int codebits)
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| {
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|    int res=0;
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|    while (codebits--) {
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|       res = (res << 1) | (code & 1);
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|       code >>= 1;
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|    }
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|    return res;
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| }
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| 
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| static unsigned int stbi__zlib_countm(unsigned char *a, unsigned char *b, int limit)
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| {
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|    int i;
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|    for (i=0; i < limit && i < 258; ++i)
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|       if (a[i] != b[i]) break;
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|    return i;
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| }
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| 
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| static unsigned int stbi__zhash(unsigned char *data)
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| {
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|    stbiw_uint32 hash = data[0] + (data[1] << 8) + (data[2] << 16);
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|    hash ^= hash << 3;
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|    hash += hash >> 5;
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|    hash ^= hash << 4;
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|    hash += hash >> 17;
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|    hash ^= hash << 25;
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|    hash += hash >> 6;
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|    return hash;
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| }
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| 
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| #define stbi__zlib_flush() (out = stbi__zlib_flushf(out, &bitbuf, &bitcount))
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| #define stbi__zlib_add(code,codebits) \
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|       (bitbuf |= (code) << bitcount, bitcount += (codebits), stbi__zlib_flush())
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| #define stbi__zlib_huffa(b,c)  stbi__zlib_add(stbi__zlib_bitrev(b,c),c)
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| // default huffman tables
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| #define stbi__zlib_huff1(n)  stbi__zlib_huffa(0x30 + (n), 8)
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| #define stbi__zlib_huff2(n)  stbi__zlib_huffa(0x190 + (n)-144, 9)
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| #define stbi__zlib_huff3(n)  stbi__zlib_huffa(0 + (n)-256,7)
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| #define stbi__zlib_huff4(n)  stbi__zlib_huffa(0xc0 + (n)-280,8)
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| #define stbi__zlib_huff(n)  ((n) <= 143 ? stbi__zlib_huff1(n) : (n) <= 255 ? stbi__zlib_huff2(n) : (n) <= 279 ? stbi__zlib_huff3(n) : stbi__zlib_huff4(n))
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| #define stbi__zlib_huffb(n) ((n) <= 143 ? stbi__zlib_huff1(n) : stbi__zlib_huff2(n))
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| 
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| #define stbi__ZHASH   16384
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| 
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| unsigned char * stbi_zlib_compress(unsigned char *data, int data_len, int *out_len, int quality)
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| {
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|    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 };
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|    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 };
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|    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 };
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|    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 };
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|    unsigned int bitbuf=0;
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|    int i,j, bitcount=0;
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|    unsigned char *out = NULL;
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|    unsigned char **hash_table[stbi__ZHASH]; // 64KB on the stack!
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|    if (quality < 5) quality = 5;
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| 
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|    stbi__sbpush(out, 0x78);   // DEFLATE 32K window
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|    stbi__sbpush(out, 0x5e);   // FLEVEL = 1
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|    stbi__zlib_add(1,1);  // BFINAL = 1
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|    stbi__zlib_add(1,2);  // BTYPE = 1 -- fixed huffman
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| 
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|    for (i=0; i < stbi__ZHASH; ++i)
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|       hash_table[i] = NULL;
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| 
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|    i=0;
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|    while (i < data_len-3) {
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|       // hash next 3 bytes of data to be compressed 
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|       int h = stbi__zhash(data+i)&(stbi__ZHASH-1), best=3;
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|       unsigned char *bestloc = 0;
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|       unsigned char **hlist = hash_table[h];
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|       int n = stbi__sbcount(hlist);
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|       for (j=0; j < n; ++j) {
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|          if (hlist[j]-data > i-32768) { // if entry lies within window
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|             int d = stbi__zlib_countm(hlist[j], data+i, data_len-i);
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|             if (d >= best) best=d,bestloc=hlist[j];
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|          }
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|       }
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|       // when hash table entry is too long, delete half the entries
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|       if (hash_table[h] && stbi__sbn(hash_table[h]) == 2*quality) {
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|          memcpy(hash_table[h], hash_table[h]+quality, sizeof(hash_table[h][0])*quality);
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|          stbi__sbn(hash_table[h]) = quality;
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|       }
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|       stbi__sbpush(hash_table[h],data+i);
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| 
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|       if (bestloc) {
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|          // "lazy matching" - check match at *next* byte, and if it's better, do cur byte as literal
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|          h = stbi__zhash(data+i+1)&(stbi__ZHASH-1);
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|          hlist = hash_table[h];
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|          n = stbi__sbcount(hlist);
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|          for (j=0; j < n; ++j) {
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|             if (hlist[j]-data > i-32767) {
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|                int e = stbi__zlib_countm(hlist[j], data+i+1, data_len-i-1);
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|                if (e > best) { // if next match is better, bail on current match
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|                   bestloc = NULL;
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|                   break;
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|                }
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|             }
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|          }
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|       }
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| 
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|       if (bestloc) {
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|          int d = data+i - bestloc; // distance back
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|          assert(d <= 32767 && best <= 258);
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|          for (j=0; best > lengthc[j+1]-1; ++j);
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|          stbi__zlib_huff(j+257);
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|          if (lengtheb[j]) stbi__zlib_add(best - lengthc[j], lengtheb[j]);
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|          for (j=0; d > distc[j+1]-1; ++j);
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|          stbi__zlib_add(stbi__zlib_bitrev(j,5),5);
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|          if (disteb[j]) stbi__zlib_add(d - distc[j], disteb[j]);
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|          i += best;
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|       } else {
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|          stbi__zlib_huffb(data[i]);
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|          ++i;
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|       }
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|    }
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|    // write out final bytes
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|    for (;i < data_len; ++i)
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|       stbi__zlib_huffb(data[i]);
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|    stbi__zlib_huff(256); // end of block
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|    // pad with 0 bits to byte boundary
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|    while (bitcount)
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|       stbi__zlib_add(0,1);
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| 
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|    for (i=0; i < stbi__ZHASH; ++i)
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|       (void) stbi__sbfree(hash_table[i]);
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| 
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|    {
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|       // compute adler32 on input
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|       unsigned int i=0, s1=1, s2=0, blocklen = data_len % 5552;
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|       int j=0;
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|       while (j < data_len) {
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|          for (i=0; i < blocklen; ++i) s1 += data[j+i], s2 += s1;
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|          s1 %= 65521, s2 %= 65521;
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|          j += blocklen;
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|          blocklen = 5552;
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|       }
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|       stbi__sbpush(out, (unsigned char) (s2 >> 8));
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|       stbi__sbpush(out, (unsigned char) s2);
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|       stbi__sbpush(out, (unsigned char) (s1 >> 8));
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|       stbi__sbpush(out, (unsigned char) s1);
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|    }
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|    *out_len = stbi__sbn(out);
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|    // make returned pointer freeable
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|    memmove(stbi__sbraw(out), out, *out_len);
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|    return (unsigned char *) stbi__sbraw(out);
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| }
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| 
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| unsigned int stbi__crc32(unsigned char *buffer, int len)
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| {
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|    static unsigned int crc_table[256];
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|    unsigned int crc = ~0u;
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|    int i,j;
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|    if (crc_table[1] == 0)
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|       for(i=0; i < 256; i++)
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|          for (crc_table[i]=i, j=0; j < 8; ++j)
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|             crc_table[i] = (crc_table[i] >> 1) ^ (crc_table[i] & 1 ? 0xedb88320 : 0);
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|    for (i=0; i < len; ++i)
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|       crc = (crc >> 8) ^ crc_table[buffer[i] ^ (crc & 0xff)];
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|    return ~crc;
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| }
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| 
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| #define stbi__wpng4(o,a,b,c,d) ((o)[0]=(unsigned char)(a),(o)[1]=(unsigned char)(b),(o)[2]=(unsigned char)(c),(o)[3]=(unsigned char)(d),(o)+=4)
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| #define stbi__wp32(data,v) stbi__wpng4(data, (v)>>24,(v)>>16,(v)>>8,(v));
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| #define stbi__wptag(data,s) stbi__wpng4(data, s[0],s[1],s[2],s[3])
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| 
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| static void stbi__wpcrc(unsigned char **data, int len)
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| {
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|    unsigned int crc = stbi__crc32(*data - len - 4, len+4);
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|    stbi__wp32(*data, crc);
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| }
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| 
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| static unsigned char stbi__paeth(int a, int b, int c)
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| {
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|    int p = a + b - c, pa = abs(p-a), pb = abs(p-b), pc = abs(p-c);
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|    if (pa <= pb && pa <= pc) return (unsigned char) a;
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|    if (pb <= pc) return (unsigned char) b;
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|    return (unsigned char) c;
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| }
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| 
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| unsigned char *stbi_write_png_to_mem(unsigned char *pixels, int stride_bytes, int x, int y, int n, int *out_len)
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| {
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|    int ctype[5] = { -1, 0, 4, 2, 6 };
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|    unsigned char sig[8] = { 137,80,78,71,13,10,26,10 };
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|    unsigned char *out,*o, *filt, *zlib;
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|    signed char *line_buffer;
 | |
|    int i,j,k,p,zlen;
 | |
| 
 | |
|    if (stride_bytes == 0)
 | |
|       stride_bytes = x * n;
 | |
| 
 | |
|    filt = (unsigned char *) malloc((x*n+1) * y); if (!filt) return 0;
 | |
|    line_buffer = (signed char *) malloc(x * n); if (!line_buffer) { free(filt); return 0; }
 | |
|    for (j=0; j < y; ++j) {
 | |
|       static int mapping[] = { 0,1,2,3,4 };
 | |
|       static int firstmap[] = { 0,1,0,5,6 };
 | |
|       int *mymap = j ? mapping : firstmap;
 | |
|       int best = 0, bestval = 0x7fffffff;
 | |
|       for (p=0; p < 2; ++p) {
 | |
|          for (k= p?best:0; k < 5; ++k) {
 | |
|             int type = mymap[k],est=0;
 | |
|             unsigned char *z = pixels + stride_bytes*j;
 | |
|             for (i=0; i < n; ++i)
 | |
|                switch (type) {
 | |
|                   case 0: line_buffer[i] = z[i]; break;
 | |
|                   case 1: line_buffer[i] = z[i]; break;
 | |
|                   case 2: line_buffer[i] = z[i] - z[i-stride_bytes]; break;
 | |
|                   case 3: line_buffer[i] = z[i] - (z[i-stride_bytes]>>1); break;
 | |
|                   case 4: line_buffer[i] = (signed char) (z[i] - stbi__paeth(0,z[i-stride_bytes],0)); break;
 | |
|                   case 5: line_buffer[i] = z[i]; break;
 | |
|                   case 6: line_buffer[i] = z[i]; break;
 | |
|                }
 | |
|             for (i=n; i < x*n; ++i) {
 | |
|                switch (type) {
 | |
|                   case 0: line_buffer[i] = z[i]; break;
 | |
|                   case 1: line_buffer[i] = z[i] - z[i-n]; break;
 | |
|                   case 2: line_buffer[i] = z[i] - z[i-stride_bytes]; break;
 | |
|                   case 3: line_buffer[i] = z[i] - ((z[i-n] + z[i-stride_bytes])>>1); break;
 | |
|                   case 4: line_buffer[i] = z[i] - stbi__paeth(z[i-n], z[i-stride_bytes], z[i-stride_bytes-n]); break;
 | |
|                   case 5: line_buffer[i] = z[i] - (z[i-n]>>1); break;
 | |
|                   case 6: line_buffer[i] = z[i] - stbi__paeth(z[i-n], 0,0); break;
 | |
|                }
 | |
|             }
 | |
|             if (p) break;
 | |
|             for (i=0; i < x*n; ++i)
 | |
|                est += abs((signed char) line_buffer[i]);
 | |
|             if (est < bestval) { bestval = est; best = k; }
 | |
|          }
 | |
|       }
 | |
|       // when we get here, best contains the filter type, and line_buffer contains the data
 | |
|       filt[j*(x*n+1)] = (unsigned char) best;
 | |
|       memcpy(filt+j*(x*n+1)+1, line_buffer, x*n);
 | |
|    }
 | |
|    free(line_buffer);
 | |
|    zlib = stbi_zlib_compress(filt, y*( x*n+1), &zlen, 8); // increase 8 to get smaller but use more memory
 | |
|    free(filt);
 | |
|    if (!zlib) return 0;
 | |
| 
 | |
|    // each tag requires 12 bytes of overhead
 | |
|    out = (unsigned char *) malloc(8 + 12+13 + 12+zlen + 12); 
 | |
|    if (!out) return 0;
 | |
|    *out_len = 8 + 12+13 + 12+zlen + 12;
 | |
| 
 | |
|    o=out;
 | |
|    memcpy(o,sig,8); o+= 8;
 | |
|    stbi__wp32(o, 13); // header length
 | |
|    stbi__wptag(o, "IHDR");
 | |
|    stbi__wp32(o, x);
 | |
|    stbi__wp32(o, y);
 | |
|    *o++ = 8;
 | |
|    *o++ = (unsigned char) ctype[n];
 | |
|    *o++ = 0;
 | |
|    *o++ = 0;
 | |
|    *o++ = 0;
 | |
|    stbi__wpcrc(&o,13);
 | |
| 
 | |
|    stbi__wp32(o, zlen);
 | |
|    stbi__wptag(o, "IDAT");
 | |
|    memcpy(o, zlib, zlen); o += zlen; free(zlib);
 | |
|    stbi__wpcrc(&o, zlen);
 | |
| 
 | |
|    stbi__wp32(o,0);
 | |
|    stbi__wptag(o, "IEND");
 | |
|    stbi__wpcrc(&o,0);
 | |
| 
 | |
|    assert(o == out + *out_len);
 | |
| 
 | |
|    return out;
 | |
| }
 | |
| 
 | |
| 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((unsigned char *) data, stride_bytes, x, y, comp, &len);
 | |
|    if (!png) return 0;
 | |
|    f = fopen(filename, "wb");
 | |
|    if (!f) { free(png); return 0; }
 | |
|    fwrite(png, 1, len, f);
 | |
|    fclose(f);
 | |
|    free(png);
 | |
|    return 1;
 | |
| }
 | |
| #endif // STB_IMAGE_WRITE_IMPLEMENTATION
 | |
| 
 | |
| /* Revision history
 | |
| 
 | |
|       0.92 (2010-08-01)
 | |
|              casts to unsigned char to fix warnings
 | |
|       0.91 (2010-07-17)
 | |
|              first public release
 | |
|       0.90   first internal release
 | |
| */
 | 
