355 lines
16 KiB
C
355 lines
16 KiB
C
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/* stbi-1.16 - public domain JPEG/PNG reader - http://nothings.org/stb_image.c
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when you control the images you're loading
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QUICK NOTES:
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Primarily of interest to game developers and other people who can
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avoid problematic images and only need the trivial interface
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JPEG baseline (no JPEG progressive, no oddball channel decimations)
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PNG non-interlaced
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BMP non-1bpp, non-RLE
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TGA (not sure what subset, if a subset)
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PSD (composited view only, no extra channels)
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HDR (radiance rgbE format)
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writes BMP,TGA (define STBI_NO_WRITE to remove code)
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decoded from memory or through stdio FILE (define STBI_NO_STDIO to remove code)
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supports installable dequantizing-IDCT, YCbCr-to-RGB conversion (define STBI_SIMD)
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TODO:
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stbi_info_*
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history:
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1.16 major bugfix - convert_format converted one too many pixels
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1.15 initialize some fields for thread safety
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1.14 fix threadsafe conversion bug; header-file-only version (#define STBI_HEADER_FILE_ONLY before including)
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1.13 threadsafe
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1.12 const qualifiers in the API
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1.11 Support installable IDCT, colorspace conversion routines
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1.10 Fixes for 64-bit (don't use "unsigned long")
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optimized upsampling by Fabian "ryg" Giesen
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1.09 Fix format-conversion for PSD code (bad global variables!)
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1.08 Thatcher Ulrich's PSD code integrated by Nicolas Schulz
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1.07 attempt to fix C++ warning/errors again
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1.06 attempt to fix C++ warning/errors again
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1.05 fix TGA loading to return correct *comp and use good luminance calc
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1.04 default float alpha is 1, not 255; use 'void *' for stbi_image_free
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1.03 bugfixes to STBI_NO_STDIO, STBI_NO_HDR
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1.02 support for (subset of) HDR files, float interface for preferred access to them
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1.01 fix bug: possible bug in handling right-side up bmps... not sure
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fix bug: the stbi_bmp_load() and stbi_tga_load() functions didn't work at all
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1.00 interface to zlib that skips zlib header
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0.99 correct handling of alpha in palette
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0.98 TGA loader by lonesock; dynamically add loaders (untested)
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0.97 jpeg errors on too large a file; also catch another malloc failure
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0.96 fix detection of invalid v value - particleman@mollyrocket forum
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0.95 during header scan, seek to markers in case of padding
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0.94 STBI_NO_STDIO to disable stdio usage; rename all #defines the same
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0.93 handle jpegtran output; verbose errors
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0.92 read 4,8,16,24,32-bit BMP files of several formats
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0.91 output 24-bit Windows 3.0 BMP files
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0.90 fix a few more warnings; bump version number to approach 1.0
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0.61 bugfixes due to Marc LeBlanc, Christopher Lloyd
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0.60 fix compiling as c++
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0.59 fix warnings: merge Dave Moore's -Wall fixes
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0.58 fix bug: zlib uncompressed mode len/nlen was wrong endian
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0.57 fix bug: jpg last huffman symbol before marker was >9 bits but less
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than 16 available
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0.56 fix bug: zlib uncompressed mode len vs. nlen
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0.55 fix bug: restart_interval not initialized to 0
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0.54 allow NULL for 'int *comp'
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0.53 fix bug in png 3->4; speedup png decoding
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0.52 png handles req_comp=3,4 directly; minor cleanup; jpeg comments
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0.51 obey req_comp requests, 1-component jpegs return as 1-component,
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on 'test' only check type, not whether we support this variant
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*/
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#ifndef HEADER_STB_IMAGE_AUGMENTED
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#define HEADER_STB_IMAGE_AUGMENTED
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//// begin header file ////////////////////////////////////////////////////
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//
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// Limitations:
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// - no progressive/interlaced support (jpeg, png)
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// - 8-bit samples only (jpeg, png)
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// - not threadsafe
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// - channel subsampling of at most 2 in each dimension (jpeg)
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// - no delayed line count (jpeg) -- IJG doesn't support either
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//
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// Basic usage (see HDR discussion below):
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// int x,y,n;
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// unsigned char *data = stbi_load(filename, &x, &y, &n, 0);
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// // ... process data if not NULL ...
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// // ... x = width, y = height, n = # 8-bit components per pixel ...
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// // ... replace '0' with '1'..'4' to force that many components per pixel
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// stbi_image_free(data)
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//
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// Standard parameters:
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// int *x -- outputs image width in pixels
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// int *y -- outputs image height in pixels
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// int *comp -- outputs # of image components in image file
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// int req_comp -- if non-zero, # of image components requested in result
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//
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// The return value from an image loader is an 'unsigned char *' which points
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// to the pixel data. The pixel data consists of *y scanlines of *x pixels,
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// with each pixel consisting of N interleaved 8-bit components; the first
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// pixel pointed to is top-left-most in the image. There is no padding between
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// image scanlines or between pixels, regardless of format. The number of
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// components N is 'req_comp' if req_comp is non-zero, or *comp otherwise.
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// If req_comp is non-zero, *comp has the number of components that _would_
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// have been output otherwise. E.g. if you set req_comp to 4, you will always
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// get RGBA output, but you can check *comp to easily see if it's opaque.
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//
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// An output image with N components has the following components interleaved
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// in this order in each pixel:
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//
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// N=#comp components
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// 1 grey
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// 2 grey, alpha
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// 3 red, green, blue
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// 4 red, green, blue, alpha
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//
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// If image loading fails for any reason, the return value will be NULL,
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// and *x, *y, *comp will be unchanged. The function stbi_failure_reason()
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// can be queried for an extremely brief, end-user unfriendly explanation
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// of why the load failed. Define STBI_NO_FAILURE_STRINGS to avoid
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// compiling these strings at all, and STBI_FAILURE_USERMSG to get slightly
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// more user-friendly ones.
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//
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// Paletted PNG and BMP images are automatically depalettized.
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//
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//
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// ===========================================================================
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//
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// HDR image support (disable by defining STBI_NO_HDR)
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//
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// stb_image now supports loading HDR images in general, and currently
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// the Radiance .HDR file format, although the support is provided
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// generically. You can still load any file through the existing interface;
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// if you attempt to load an HDR file, it will be automatically remapped to
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// LDR, assuming gamma 2.2 and an arbitrary scale factor defaulting to 1;
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// both of these constants can be reconfigured through this interface:
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//
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// stbi_hdr_to_ldr_gamma(2.2f);
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// stbi_hdr_to_ldr_scale(1.0f);
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//
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// (note, do not use _inverse_ constants; stbi_image will invert them
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// appropriately).
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//
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// Additionally, there is a new, parallel interface for loading files as
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// (linear) floats to preserve the full dynamic range:
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//
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// float *data = stbi_loadf(filename, &x, &y, &n, 0);
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//
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// If you load LDR images through this interface, those images will
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// be promoted to floating point values, run through the inverse of
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// constants corresponding to the above:
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//
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// stbi_ldr_to_hdr_scale(1.0f);
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// stbi_ldr_to_hdr_gamma(2.2f);
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//
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// Finally, given a filename (or an open file or memory block--see header
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// file for details) containing image data, you can query for the "most
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// appropriate" interface to use (that is, whether the image is HDR or
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// not), using:
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//
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// stbi_is_hdr(char *filename);
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#ifndef STBI_NO_STDIO
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#include <stdio.h>
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#endif
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#define STBI_VERSION 1
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enum
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{
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STBI_default = 0, // only used for req_comp
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STBI_grey = 1,
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STBI_grey_alpha = 2,
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STBI_rgb = 3,
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STBI_rgb_alpha = 4,
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};
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typedef unsigned char stbi_uc;
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#ifdef __cplusplus
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extern "C" {
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#endif
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// WRITING API
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#if !defined(STBI_NO_WRITE) && !defined(STBI_NO_STDIO)
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// write a BMP/TGA file given tightly packed 'comp' channels (no padding, nor bmp-stride-padding)
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// (you must include the appropriate extension in the filename).
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// returns TRUE on success, FALSE if couldn't open file, error writing file
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extern int stbi_write_bmp (char const *filename, int x, int y, int comp, void *data);
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extern int stbi_write_tga (char const *filename, int x, int y, int comp, void *data);
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#endif
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// PRIMARY API - works on images of any type
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// load image by filename, open file, or memory buffer
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#ifndef STBI_NO_STDIO
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extern stbi_uc *stbi_load (char const *filename, int *x, int *y, int *comp, int req_comp);
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extern stbi_uc *stbi_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
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extern int stbi_info_from_file (FILE *f, int *x, int *y, int *comp);
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#endif
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extern stbi_uc *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
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// for stbi_load_from_file, file pointer is left pointing immediately after image
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#ifndef STBI_NO_HDR
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#ifndef STBI_NO_STDIO
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extern float *stbi_loadf (char const *filename, int *x, int *y, int *comp, int req_comp);
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extern float *stbi_loadf_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
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#endif
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extern float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
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extern void stbi_hdr_to_ldr_gamma(float gamma);
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extern void stbi_hdr_to_ldr_scale(float scale);
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extern void stbi_ldr_to_hdr_gamma(float gamma);
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extern void stbi_ldr_to_hdr_scale(float scale);
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#endif // STBI_NO_HDR
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// get a VERY brief reason for failure
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// NOT THREADSAFE
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extern char *stbi_failure_reason (void);
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// free the loaded image -- this is just free()
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extern void stbi_image_free (void *retval_from_stbi_load);
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// get image dimensions & components without fully decoding
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extern int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp);
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extern int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len);
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#ifndef STBI_NO_STDIO
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extern int stbi_info (char const *filename, int *x, int *y, int *comp);
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extern int stbi_is_hdr (char const *filename);
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extern int stbi_is_hdr_from_file(FILE *f);
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#endif
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// ZLIB client - used by PNG, available for other purposes
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extern char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen);
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extern char *stbi_zlib_decode_malloc(const char *buffer, int len, int *outlen);
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extern int stbi_zlib_decode_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
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extern char *stbi_zlib_decode_noheader_malloc(const char *buffer, int len, int *outlen);
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extern int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
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// TYPE-SPECIFIC ACCESS
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// is it a jpeg?
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extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len);
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extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
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extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp);
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#ifndef STBI_NO_STDIO
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extern stbi_uc *stbi_jpeg_load (char const *filename, int *x, int *y, int *comp, int req_comp);
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extern int stbi_jpeg_test_file (FILE *f);
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extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
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extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp);
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extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp);
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#endif
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// is it a png?
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extern int stbi_png_test_memory (stbi_uc const *buffer, int len);
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extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
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extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp);
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#ifndef STBI_NO_STDIO
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extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp);
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extern int stbi_png_info (char const *filename, int *x, int *y, int *comp);
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extern int stbi_png_test_file (FILE *f);
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extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
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extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp);
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#endif
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// is it a bmp?
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extern int stbi_bmp_test_memory (stbi_uc const *buffer, int len);
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extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp);
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extern stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
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#ifndef STBI_NO_STDIO
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extern int stbi_bmp_test_file (FILE *f);
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extern stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
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#endif
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// is it a tga?
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extern int stbi_tga_test_memory (stbi_uc const *buffer, int len);
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extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp);
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extern stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
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#ifndef STBI_NO_STDIO
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extern int stbi_tga_test_file (FILE *f);
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extern stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
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#endif
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// is it a psd?
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extern int stbi_psd_test_memory (stbi_uc const *buffer, int len);
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extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp);
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extern stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
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#ifndef STBI_NO_STDIO
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extern int stbi_psd_test_file (FILE *f);
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extern stbi_uc *stbi_psd_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
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#endif
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// is it an hdr?
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extern int stbi_hdr_test_memory (stbi_uc const *buffer, int len);
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extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp);
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extern float * stbi_hdr_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
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extern stbi_uc *stbi_hdr_load_rgbe (char const *filename, int *x, int *y, int *comp, int req_comp);
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extern float * stbi_hdr_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
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#ifndef STBI_NO_STDIO
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extern int stbi_hdr_test_file (FILE *f);
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extern float * stbi_hdr_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
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extern stbi_uc *stbi_hdr_load_rgbe_file (FILE *f, int *x, int *y, int *comp, int req_comp);
|
||
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#endif
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// define new loaders
|
||
|
|
typedef struct
|
||
|
|
{
|
||
|
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int (*test_memory)(stbi_uc const *buffer, int len);
|
||
|
|
stbi_uc * (*load_from_memory)(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
|
||
|
|
#ifndef STBI_NO_STDIO
|
||
|
|
int (*test_file)(FILE *f);
|
||
|
|
stbi_uc * (*load_from_file)(FILE *f, int *x, int *y, int *comp, int req_comp);
|
||
|
|
#endif
|
||
|
|
} stbi_loader;
|
||
|
|
|
||
|
|
// register a loader by filling out the above structure (you must defined ALL functions)
|
||
|
|
// returns 1 if added or already added, 0 if not added (too many loaders)
|
||
|
|
// NOT THREADSAFE
|
||
|
|
extern int stbi_register_loader(stbi_loader *loader);
|
||
|
|
|
||
|
|
// define faster low-level operations (typically SIMD support)
|
||
|
|
#if STBI_SIMD
|
||
|
|
typedef void (*stbi_idct_8x8)(uint8 *out, int out_stride, short data[64], unsigned short *dequantize);
|
||
|
|
// compute an integer IDCT on "input"
|
||
|
|
// input[x] = data[x] * dequantize[x]
|
||
|
|
// write results to 'out': 64 samples, each run of 8 spaced by 'out_stride'
|
||
|
|
// CLAMP results to 0..255
|
||
|
|
typedef void (*stbi_YCbCr_to_RGB_run)(uint8 *output, uint8 const *y, uint8 const *cb, uint8 const *cr, int count, int step);
|
||
|
|
// compute a conversion from YCbCr to RGB
|
||
|
|
// 'count' pixels
|
||
|
|
// write pixels to 'output'; each pixel is 'step' bytes (either 3 or 4; if 4, write '255' as 4th), order R,G,B
|
||
|
|
// y: Y input channel
|
||
|
|
// cb: Cb input channel; scale/biased to be 0..255
|
||
|
|
// cr: Cr input channel; scale/biased to be 0..255
|
||
|
|
|
||
|
|
extern void stbi_install_idct(stbi_idct_8x8 func);
|
||
|
|
extern void stbi_install_YCbCr_to_RGB(stbi_YCbCr_to_RGB_run func);
|
||
|
|
#endif // STBI_SIMD
|
||
|
|
|
||
|
|
#ifdef __cplusplus
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
//
|
||
|
|
//
|
||
|
|
//// end header file /////////////////////////////////////////////////////
|
||
|
|
#endif // STBI_INCLUDE_STB_IMAGE_H
|