Adding STB image tools.
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Ben Vanik
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/* stb_image_write - v1.00 - 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 2010-2015
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no warranty implied; use at your own risk
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Before #including,
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#define STB_IMAGE_WRITE_IMPLEMENTATION
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in the file that you want to have the implementation.
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Will probably not work correctly with strict-aliasing optimizations.
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ABOUT:
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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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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 simplicity, not optimal image file size
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or run-time performance.
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BUILDING:
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You can #define STBIW_ASSERT(x) before the #include to avoid using assert.h.
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You can #define STBIW_MALLOC(), STBIW_REALLOC(), and STBIW_FREE() to replace
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malloc,realloc,free.
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You can define STBIW_MEMMOVE() to replace memmove()
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USAGE:
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There are four functions, one for each image file format:
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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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int stbi_write_hdr(char const *filename, int w, int h, int comp, const void *data);
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There are also four equivalent functions that use an arbitrary write function. You are
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expected to open/close your file-equivalent before and after calling these:
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int stbi_write_png_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data, int stride_in_bytes);
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int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data);
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where the callback is:
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void stbi_write_func(void *context, void *data, int size);
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You can define STBI_WRITE_NO_STDIO to disable the file variant of these
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functions, so the library will not use stdio.h at all. However, this will
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also disable HDR writing, because it requires stdio for formatted output.
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Each function returns 0 on failure and non-0 on success.
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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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PNG creates output files with the same number of components as the input.
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The BMP format expands Y to RGB in the file format and does not
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output alpha.
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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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HDR expects linear float data. Since the format is always 32-bit rgb(e)
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data, alpha (if provided) is discarded, and for monochrome data it is
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replicated across all three channels.
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TGA supports RLE or non-RLE compressed data. To use non-RLE-compressed
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data, set the global variable 'stbi_write_tga_with_rle' to 0.
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CREDITS:
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PNG/BMP/TGA
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Sean Barrett
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HDR
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Baldur Karlsson
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TGA monochrome:
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Jean-Sebastien Guay
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misc enhancements:
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Tim Kelsey
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TGA RLE
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Alan Hickman
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initial file IO callback implementation
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Emmanuel Julien
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bugfixes:
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github:Chribba
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Guillaume Chereau
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github:jry2
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LICENSE
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This software is in the public domain. Where that dedication is not
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recognized, you are granted a perpetual, irrevocable license to copy,
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distribute, and modify this file as you see fit.
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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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#ifdef __cplusplus
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extern "C" {
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#endif
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#ifdef STB_IMAGE_WRITE_STATIC
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#define STBIWDEF static
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#else
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#define STBIWDEF extern
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extern int stbi_write_tga_with_rle;
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#endif
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#ifndef STBI_WRITE_NO_STDIO
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STBIWDEF int stbi_write_png(char const *filename, int w, int h, int comp, const void *data, int stride_in_bytes);
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STBIWDEF int stbi_write_bmp(char const *filename, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_tga(char const *filename, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_hdr(char const *filename, int w, int h, int comp, const float *data);
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#endif
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typedef void stbi_write_func(void *context, void *data, int size);
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STBIWDEF int stbi_write_png_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data, int stride_in_bytes);
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STBIWDEF int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_tga_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const void *data);
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STBIWDEF int stbi_write_hdr_to_func(stbi_write_func *func, void *context, int w, int h, int comp, const float *data);
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#ifdef __cplusplus
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}
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#endif
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#endif//INCLUDE_STB_IMAGE_WRITE_H
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#ifdef STB_IMAGE_WRITE_IMPLEMENTATION
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#ifdef _WIN32
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#define _CRT_SECURE_NO_WARNINGS
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#define _CRT_NONSTDC_NO_DEPRECATE
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#endif
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#ifndef STBI_WRITE_NO_STDIO
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#include <stdio.h>
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#endif // STBI_WRITE_NO_STDIO
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#include <stdarg.h>
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#include <stdlib.h>
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#include <string.h>
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#include <math.h>
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#if defined(STBIW_MALLOC) && defined(STBIW_FREE) && defined(STBIW_REALLOC)
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// ok
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#elif !defined(STBIW_MALLOC) && !defined(STBIW_FREE) && !defined(STBIW_REALLOC)
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// ok
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#else
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#error "Must define all or none of STBIW_MALLOC, STBIW_FREE, and STBIW_REALLOC."
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#endif
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#ifndef STBIW_MALLOC
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#define STBIW_MALLOC(sz) malloc(sz)
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#define STBIW_REALLOC(p,sz) realloc(p,sz)
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#define STBIW_FREE(p) free(p)
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#endif
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#ifndef STBIW_MEMMOVE
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#define STBIW_MEMMOVE(a,b,sz) memmove(a,b,sz)
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#endif
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#ifndef STBIW_ASSERT
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#include <assert.h>
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#define STBIW_ASSERT(x) assert(x)
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#endif
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typedef struct
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{
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stbi_write_func *func;
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void *context;
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} stbi__write_context;
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// initialize a callback-based context
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static void stbi__start_write_callbacks(stbi__write_context *s, stbi_write_func *c, void *context)
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{
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s->func = c;
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s->context = context;
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}
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#ifndef STBI_WRITE_NO_STDIO
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static void stbi__stdio_write(void *context, void *data, int size)
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{
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fwrite(data,1,size,(FILE*) context);
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}
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static int stbi__start_write_file(stbi__write_context *s, const char *filename)
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{
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FILE *f = fopen(filename, "wb");
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stbi__start_write_callbacks(s, stbi__stdio_write, (void *) f);
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return f != NULL;
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}
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static void stbi__end_write_file(stbi__write_context *s)
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{
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fclose((FILE *)s->context);
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}
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#endif // !STBI_WRITE_NO_STDIO
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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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#ifdef STB_IMAGE_WRITE_STATIC
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static int stbi_write_tga_with_rle = 1;
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#else
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int stbi_write_tga_with_rle = 1;
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#endif
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static void stbiw__writefv(stbi__write_context *s, 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);
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s->func(s->context,&x,1);
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break; }
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case '2': { int x = va_arg(v,int);
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unsigned char b[2];
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b[0] = (unsigned char) x;
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b[1] = (unsigned char) (x>>8);
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s->func(s->context,b,2);
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break; }
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case '4': { stbiw_uint32 x = va_arg(v,int);
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unsigned char b[4];
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b[0]=(unsigned char)x;
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b[1]=(unsigned char)(x>>8);
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b[2]=(unsigned char)(x>>16);
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b[3]=(unsigned char)(x>>24);
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s->func(s->context,b,4);
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break; }
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default:
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STBIW_ASSERT(0);
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return;
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}
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}
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}
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static void stbiw__writef(stbi__write_context *s, const char *fmt, ...)
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{
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va_list v;
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va_start(v, fmt);
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stbiw__writefv(s, fmt, v);
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va_end(v);
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}
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static void stbiw__write3(stbi__write_context *s, 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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s->func(s->context, arr, 3);
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}
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static void stbiw__write_pixel(stbi__write_context *s, int rgb_dir, int comp, int write_alpha, int expand_mono, unsigned char *d)
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{
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unsigned char bg[3] = { 255, 0, 255}, px[3];
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int k;
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if (write_alpha < 0)
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s->func(s->context, &d[comp - 1], 1);
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switch (comp) {
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case 1:
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s->func(s->context,d,1);
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break;
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case 2:
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if (expand_mono)
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stbiw__write3(s, d[0], d[0], d[0]); // monochrome bmp
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else
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s->func(s->context, d, 1); // monochrome TGA
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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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stbiw__write3(s, 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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stbiw__write3(s, 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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s->func(s->context, &d[comp - 1], 1);
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}
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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)
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{
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stbiw_uint32 zero = 0;
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int i,j, j_end;
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if (y <= 0)
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return;
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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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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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stbiw__write_pixel(s, rgb_dir, comp, write_alpha, expand_mono, d);
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}
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s->func(s->context, &zero, scanline_pad);
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}
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}
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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, ...)
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{
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if (y < 0 || x < 0) {
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return 0;
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} else {
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va_list v;
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va_start(v, fmt);
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stbiw__writefv(s, fmt, v);
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va_end(v);
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stbiw__write_pixels(s,rgb_dir,vdir,x,y,comp,data,alpha,pad, expand_mono);
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return 1;
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}
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}
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static int stbi_write_bmp_core(stbi__write_context *s, 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 stbiw__outfile(s,-1,-1,x,y,comp,1,(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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STBIWDEF int stbi_write_bmp_to_func(stbi_write_func *func, void *context, int x, int y, int comp, const void *data)
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{
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stbi__write_context s;
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stbi__start_write_callbacks(&s, func, context);
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return stbi_write_bmp_core(&s, x, y, comp, data);
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}
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#ifndef STBI_WRITE_NO_STDIO
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||||||
|
STBIWDEF int stbi_write_bmp(char const *filename, int x, int y, int comp, const void *data)
|
||||||
|
{
|
||||||
|
stbi__write_context s;
|
||||||
|
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;
|
||||||
|
|
||||||
|
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);
|
||||||
|
|
||||||
|
for (j = y - 1; j >= 0; --j) {
|
||||||
|
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 = (unsigned char) (len - 1);
|
||||||
|
s->func(s->context, &header, 1);
|
||||||
|
for (k = 0; k < len; ++k) {
|
||||||
|
stbiw__write_pixel(s, -1, comp, has_alpha, 0, begin + k * comp);
|
||||||
|
}
|
||||||
|
} else {
|
||||||
|
unsigned char header = (unsigned char) (len - 129);
|
||||||
|
s->func(s->context, &header, 1);
|
||||||
|
stbiw__write_pixel(s, -1, comp, has_alpha, 0, begin);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
return 1;
|
||||||
|
}
|
||||||
|
|
||||||
|
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;
|
||||||
|
stbi__start_write_callbacks(&s, func, context);
|
||||||
|
return stbi_write_tga_core(&s, x, y, comp, (void *) data);
|
||||||
|
}
|
||||||
|
|
||||||
|
#ifndef STBI_WRITE_NO_STDIO
|
||||||
|
int stbi_write_tga(char const *filename, int x, int y, int comp, const void *data)
|
||||||
|
{
|
||||||
|
stbi__write_context s;
|
||||||
|
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
|
||||||
|
#ifndef STBI_WRITE_NO_STDIO
|
||||||
|
|
||||||
|
#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] * normalize);
|
||||||
|
rgbe[1] = (unsigned char)(linear[1] * normalize);
|
||||||
|
rgbe[2] = (unsigned char)(linear[2] * normalize);
|
||||||
|
rgbe[3] = (unsigned char)(exponent + 128);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
void stbiw__write_run_data(stbi__write_context *s, int length, unsigned char databyte)
|
||||||
|
{
|
||||||
|
unsigned char lengthbyte = (unsigned char) (length+128);
|
||||||
|
STBIW_ASSERT(length+128 <= 255);
|
||||||
|
s->func(s->context, &lengthbyte, 1);
|
||||||
|
s->func(s->context, &databyte, 1);
|
||||||
|
}
|
||||||
|
|
||||||
|
void stbiw__write_dump_data(stbi__write_context *s, int length, unsigned char *data)
|
||||||
|
{
|
||||||
|
unsigned char lengthbyte = (unsigned char )(length & 0xff);
|
||||||
|
STBIW_ASSERT(length <= 128); // inconsistent with spec but consistent with official code
|
||||||
|
s->func(s->context, &lengthbyte, 1);
|
||||||
|
s->func(s->context, data, length);
|
||||||
|
}
|
||||||
|
|
||||||
|
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);
|
||||||
|
|
||||||
|
len = sprintf(buffer, "EXPOSURE= 1.0000000000000\n\n-Y %d +X %d\n", y, x);
|
||||||
|
s->func(s->context, buffer, len);
|
||||||
|
|
||||||
|
for(i=0; i < y; i++)
|
||||||
|
stbiw__write_hdr_scanline(s, x, comp, scratch, data + comp*i*x);
|
||||||
|
STBIW_FREE(scratch);
|
||||||
|
return 1;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
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;
|
||||||
|
stbi__start_write_callbacks(&s, func, context);
|
||||||
|
return stbi_write_hdr_core(&s, x, y, comp, (float *) data);
|
||||||
|
}
|
||||||
|
|
||||||
|
int stbi_write_hdr(char const *filename, int x, int y, int comp, const float *data)
|
||||||
|
{
|
||||||
|
stbi__write_context s;
|
||||||
|
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
|
||||||
|
//
|
||||||
|
|
||||||
|
// 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]
|
||||||
|
#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(*arr ? stbiw__sbraw(*arr) : 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, (unsigned char) *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
|
||||||
|
|
||||||
|
unsigned char * stbi_zlib_compress(unsigned char *data, int data_len, int *out_len, int quality)
|
||||||
|
{
|
||||||
|
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[stbiw__ZHASH]; // 64KB on the stack!
|
||||||
|
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]);
|
||||||
|
|
||||||
|
{
|
||||||
|
// compute adler32 on input
|
||||||
|
unsigned int k=0, 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, (unsigned char) (s2 >> 8));
|
||||||
|
stbiw__sbpush(out, (unsigned char) s2);
|
||||||
|
stbiw__sbpush(out, (unsigned char) (s1 >> 8));
|
||||||
|
stbiw__sbpush(out, (unsigned char) s1);
|
||||||
|
}
|
||||||
|
*out_len = stbiw__sbn(out);
|
||||||
|
// make returned pointer freeable
|
||||||
|
STBIW_MEMMOVE(stbiw__sbraw(out), out, *out_len);
|
||||||
|
return (unsigned char *) stbiw__sbraw(out);
|
||||||
|
}
|
||||||
|
|
||||||
|
unsigned int stbiw__crc32(unsigned char *buffer, int len)
|
||||||
|
{
|
||||||
|
static unsigned int crc_table[256];
|
||||||
|
unsigned int crc = ~0u;
|
||||||
|
int i,j;
|
||||||
|
if (crc_table[1] == 0)
|
||||||
|
for(i=0; i < 256; i++)
|
||||||
|
for (crc_table[i]=i, j=0; j < 8; ++j)
|
||||||
|
crc_table[i] = (crc_table[i] >> 1) ^ (crc_table[i] & 1 ? 0xedb88320 : 0);
|
||||||
|
for (i=0; i < len; ++i)
|
||||||
|
crc = (crc >> 8) ^ crc_table[buffer[i] ^ (crc & 0xff)];
|
||||||
|
return ~crc;
|
||||||
|
}
|
||||||
|
|
||||||
|
#define stbiw__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)
|
||||||
|
#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 (unsigned char) a;
|
||||||
|
if (pb <= pc) return (unsigned char) b;
|
||||||
|
return (unsigned char) c;
|
||||||
|
}
|
||||||
|
|
||||||
|
unsigned char *stbi_write_png_to_mem(unsigned char *pixels, int stride_bytes, int x, int y, int n, int *out_len)
|
||||||
|
{
|
||||||
|
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 i,j,k,p,zlen;
|
||||||
|
|
||||||
|
if (stride_bytes == 0)
|
||||||
|
stride_bytes = x * n;
|
||||||
|
|
||||||
|
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) {
|
||||||
|
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] - stbiw__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] - stbiw__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] - stbiw__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;
|
||||||
|
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, 8); // increase 8 to get smaller but use more memory
|
||||||
|
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++ = (unsigned char) 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((unsigned char *) data, stride_bytes, x, y, comp, &len);
|
||||||
|
if (png == NULL) return 0;
|
||||||
|
f = 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((unsigned char *) data, stride_bytes, x, y, comp, &len);
|
||||||
|
if (png == NULL) return 0;
|
||||||
|
func(context, png, len);
|
||||||
|
STBIW_FREE(png);
|
||||||
|
return 1;
|
||||||
|
}
|
||||||
|
|
||||||
|
#endif // STB_IMAGE_WRITE_IMPLEMENTATION
|
||||||
|
|
||||||
|
/* Revision history
|
||||||
|
1.00 (2015-09-14)
|
||||||
|
installable file IO function
|
||||||
|
0.99 (2015-09-13)
|
||||||
|
warning fixes; TGA rle support
|
||||||
|
0.98 (2015-04-08)
|
||||||
|
added STBIW_MALLOC, STBIW_ASSERT etc
|
||||||
|
0.97 (2015-01-18)
|
||||||
|
fixed HDR asserts, rewrote HDR rle logic
|
||||||
|
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)
|
||||||
|
rename private functions to avoid conflicts with stb_image.h
|
||||||
|
0.93 (2014-05-27)
|
||||||
|
warning fixes
|
||||||
|
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
|
||||||
|
*/
|
||||||
Loading…
Reference in New Issue