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stb_image.c
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stb_image.c
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/* stbi-1.28 - public domain JPEG/PNG reader - http://nothings.org/stb_image.c
when you control the images you're loading
no warranty implied; use at your own risk
QUICK NOTES:
Primarily of interest to game developers and other people who can
avoid problematic images and only need the trivial interface
JPEG baseline (no JPEG progressive)
PNG 8-bit only
TGA (not sure what subset, if a subset)
BMP non-1bpp, non-RLE
PSD (composited view only, no extra channels)
GIF (*comp always reports as 4-channel)
HDR (radiance rgbE format)
PIC (Softimage PIC)
- decoded from memory or through stdio FILE (define STBI_NO_STDIO to remove code)
- supports installable dequantizing-IDCT, YCbCr-to-RGB conversion (define STBI_SIMD)
Latest revisions:
1.28 (2010-08-01) fix bug in GIF palette transparency (SpartanJ)
1.27 (2010-08-01) cast-to-uint8 to fix warnings (Laurent Gomila)
allow trailing 0s at end of image data (Laurent Gomila)
1.26 (2010-07-24) fix bug in file buffering for PNG reported by SpartanJ
1.25 (2010-07-17) refix trans_data warning (Won Chun)
1.24 (2010-07-12) perf improvements reading from files
minor perf improvements for jpeg
deprecated type-specific functions in hope of feedback
attempt to fix trans_data warning (Won Chun)
1.23 fixed bug in iPhone support
1.22 (2010-07-10) removed image *writing* support to stb_image_write.h
stbi_info support from Jetro Lauha
GIF support from Jean-Marc Lienher
iPhone PNG-extensions from James Brown
warning-fixes from Nicolas Schulz and Janez Zemva
1.21 fix use of 'uint8' in header (reported by jon blow)
1.20 added support for Softimage PIC, by Tom Seddon
See end of file for full revision history.
TODO:
stbi_info support for BMP,PSD,HDR,PIC
rewrite stbi_info and load_file variations to share file handling code
(current system allows individual functions to be called directly,
since each does all the work, but I doubt anyone uses this in practice)
============================ Contributors =========================
Image formats Optimizations & bugfixes
Sean Barrett (jpeg, png, bmp) Fabian "ryg" Giesen
Nicolas Schulz (hdr, psd)
Jonathan Dummer (tga) Bug fixes & warning fixes
Jean-Marc Lienher (gif) Marc LeBlanc
Tom Seddon (pic) Christpher Lloyd
Thatcher Ulrich (psd) Dave Moore
Won Chun
the Horde3D community
Extensions, features Janez Zemva
Jetro Lauha (stbi_info) Jonathan Blow
James "moose2000" Brown (iPhone PNG) Laurent Gomila
If your name should be here but isn't, let Sean know.
*/
#ifndef STBI_INCLUDE_STB_IMAGE_H
#define STBI_INCLUDE_STB_IMAGE_H
// To get a header file for this, either cut and paste the header,
// or create stb_image.h, #define STBI_HEADER_FILE_ONLY, and
// then include stb_image.c from it.
//// begin header file ////////////////////////////////////////////////////
//
// Limitations:
// - no jpeg progressive support
// - non-HDR formats support 8-bit samples only (jpeg, png)
// - no delayed line count (jpeg) -- IJG doesn't support either
// - no 1-bit BMP
// - GIF always returns *comp=4
//
// Basic usage (see HDR discussion below):
// int x,y,n;
// unsigned char *data = stbi_load(filename, &x, &y, &n, 0);
// // ... process data if not NULL ...
// // ... x = width, y = height, n = # 8-bit components per pixel ...
// // ... replace '0' with '1'..'4' to force that many components per pixel
// stbi_image_free(data)
//
// Standard parameters:
// int *x -- outputs image width in pixels
// int *y -- outputs image height in pixels
// int *comp -- outputs # of image components in image file
// int req_comp -- if non-zero, # of image components requested in result
//
// The return value from an image loader is an 'unsigned char *' which points
// to the pixel data. The pixel data consists of *y scanlines of *x pixels,
// with each pixel consisting of N interleaved 8-bit components; the first
// pixel pointed to is top-left-most in the image. There is no padding between
// image scanlines or between pixels, regardless of format. The number of
// components N is 'req_comp' if req_comp is non-zero, or *comp otherwise.
// If req_comp is non-zero, *comp has the number of components that _would_
// have been output otherwise. E.g. if you set req_comp to 4, you will always
// get RGBA output, but you can check *comp to easily see if it's opaque.
//
// An output image with N components has the following components interleaved
// in this order in each pixel:
//
// N=#comp components
// 1 grey
// 2 grey, alpha
// 3 red, green, blue
// 4 red, green, blue, alpha
//
// If image loading fails for any reason, the return value will be NULL,
// and *x, *y, *comp will be unchanged. The function stbi_failure_reason()
// can be queried for an extremely brief, end-user unfriendly explanation
// of why the load failed. Define STBI_NO_FAILURE_STRINGS to avoid
// compiling these strings at all, and STBI_FAILURE_USERMSG to get slightly
// more user-friendly ones.
//
// Paletted PNG, BMP, GIF, and PIC images are automatically depalettized.
//
// ===========================================================================
//
// iPhone PNG support:
//
// By default we convert iphone-formatted PNGs back to RGB; nominally they
// would silently load as BGR, except the existing code should have just
// failed on such iPhone PNGs. But you can disable this conversion by
// by calling stbi_convert_iphone_png_to_rgb(0), in which case
// you will always just get the native iphone "format" through.
//
// Call stbi_set_unpremultiply_on_load(1) as well to force a divide per
// pixel to remove any premultiplied alpha *only* if the image file explicitly
// says there's premultiplied data (currently only happens in iPhone images,
// and only if iPhone convert-to-rgb processing is on).
//
// ===========================================================================
//
// HDR image support (disable by defining STBI_NO_HDR)
//
// stb_image now supports loading HDR images in general, and currently
// the Radiance .HDR file format, although the support is provided
// generically. You can still load any file through the existing interface;
// if you attempt to load an HDR file, it will be automatically remapped to
// LDR, assuming gamma 2.2 and an arbitrary scale factor defaulting to 1;
// both of these constants can be reconfigured through this interface:
//
// stbi_hdr_to_ldr_gamma(2.2f);
// stbi_hdr_to_ldr_scale(1.0f);
//
// (note, do not use _inverse_ constants; stbi_image will invert them
// appropriately).
//
// Additionally, there is a new, parallel interface for loading files as
// (linear) floats to preserve the full dynamic range:
//
// float *data = stbi_loadf(filename, &x, &y, &n, 0);
//
// If you load LDR images through this interface, those images will
// be promoted to floating point values, run through the inverse of
// constants corresponding to the above:
//
// stbi_ldr_to_hdr_scale(1.0f);
// stbi_ldr_to_hdr_gamma(2.2f);
//
// Finally, given a filename (or an open file or memory block--see header
// file for details) containing image data, you can query for the "most
// appropriate" interface to use (that is, whether the image is HDR or
// not), using:
//
// stbi_is_hdr(char *filename);
#ifndef STBI_NO_STDIO
#include <stdio.h>
#endif
#define STBI_VERSION 1
enum
{
STBI_default = 0, // only used for req_comp
STBI_grey = 1,
STBI_grey_alpha = 2,
STBI_rgb = 3,
STBI_rgb_alpha = 4,
};
typedef unsigned char stbi_uc;
#ifdef __cplusplus
extern "C" {
#endif
// PRIMARY API - works on images of any type
// load image by filename, open file, or memory buffer
extern stbi_uc *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern stbi_uc *stbi_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern stbi_uc *stbi_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
// for stbi_load_from_file, file pointer is left pointing immediately after image
#endif
#ifndef STBI_NO_HDR
extern float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern float *stbi_loadf (char const *filename, int *x, int *y, int *comp, int req_comp);
extern float *stbi_loadf_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
extern void stbi_hdr_to_ldr_gamma(float gamma);
extern void stbi_hdr_to_ldr_scale(float scale);
extern void stbi_ldr_to_hdr_gamma(float gamma);
extern void stbi_ldr_to_hdr_scale(float scale);
#endif // STBI_NO_HDR
// get a VERY brief reason for failure
// NOT THREADSAFE
extern const char *stbi_failure_reason (void);
// free the loaded image -- this is just free()
extern void stbi_image_free (void *retval_from_stbi_load);
// get image dimensions & components without fully decoding
extern int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp);
extern int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len);
#ifndef STBI_NO_STDIO
extern int stbi_info (char const *filename, int *x, int *y, int *comp);
extern int stbi_info_from_file (FILE *f, int *x, int *y, int *comp);
extern int stbi_is_hdr (char const *filename);
extern int stbi_is_hdr_from_file(FILE *f);
#endif
// for image formats that explicitly notate that they have premultiplied alpha,
// we just return the colors as stored in the file. set this flag to force
// unpremultiplication. results are undefined if the unpremultiply overflow.
extern void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply);
// indicate whether we should process iphone images back to canonical format,
// or just pass them through "as-is"
extern void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert);
// ZLIB client - used by PNG, available for other purposes
extern char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen);
extern char *stbi_zlib_decode_malloc(const char *buffer, int len, int *outlen);
extern int stbi_zlib_decode_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
extern char *stbi_zlib_decode_noheader_malloc(const char *buffer, int len, int *outlen);
extern int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
// define new loaders
typedef struct
{
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 define 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)(stbi_uc *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)(stbi_uc *output, stbi_uc const *y, stbi_uc const *cb, stbi_uc 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
// TYPE-SPECIFIC ACCESS
#ifdef STBI_TYPE_SPECIFIC_FUNCTIONS
// is it a jpeg?
extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp);
#ifndef STBI_NO_STDIO
extern stbi_uc *stbi_jpeg_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern int stbi_jpeg_test_file (FILE *f);
extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp);
extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp);
#endif
// is it a png?
extern int stbi_png_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp);
#ifndef STBI_NO_STDIO
extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern int stbi_png_info (char const *filename, int *x, int *y, int *comp);
extern int stbi_png_test_file (FILE *f);
extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp);
#endif
// is it a bmp?
extern int stbi_bmp_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern int stbi_bmp_test_file (FILE *f);
extern stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
// is it a tga?
extern int stbi_tga_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern int stbi_tga_test_file (FILE *f);
extern stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
// is it a psd?
extern int stbi_psd_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern int stbi_psd_test_file (FILE *f);
extern stbi_uc *stbi_psd_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
// is it an hdr?
extern int stbi_hdr_test_memory (stbi_uc const *buffer, int len);
extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern float * stbi_hdr_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern int stbi_hdr_test_file (FILE *f);
extern float * stbi_hdr_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
// is it a pic?
extern int stbi_pic_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_pic_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern stbi_uc *stbi_pic_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern int stbi_pic_test_file (FILE *f);
extern stbi_uc *stbi_pic_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
// is it a gif?
extern int stbi_gif_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
extern int stbi_gif_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp);
#ifndef STBI_NO_STDIO
extern int stbi_gif_test_file (FILE *f);
extern stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
extern int stbi_gif_info (char const *filename, int *x, int *y, int *comp);
extern int stbi_gif_info_from_file (FILE *f, int *x, int *y, int *comp);
#endif
#endif//STBI_TYPE_SPECIFIC_FUNCTIONS
#ifdef __cplusplus
}
#endif
//
//
//// end header file /////////////////////////////////////////////////////
#endif // STBI_INCLUDE_STB_IMAGE_H
#ifndef STBI_HEADER_FILE_ONLY
#ifndef STBI_NO_HDR
#include <math.h> // ldexp
#include <string.h> // strcmp
#endif
#ifndef STBI_NO_STDIO
#include <stdio.h>
#endif
#include <stdlib.h>
#include <string.h>
#include <malloc.h>
//#include <memory.h>
#include <assert.h>
#include <stdarg.h>
#ifndef _MSC_VER
#ifdef __cplusplus
#define __forceinline inline
#else
#define __forceinline
#endif
#endif
// implementation:
typedef unsigned char uint8;
typedef unsigned short uint16;
typedef signed short int16;
typedef unsigned int uint32;
typedef signed int int32;
typedef unsigned int uint;
// should produce compiler error if size is wrong
typedef unsigned char validate_uint32[sizeof(uint32)==4 ? 1 : -1];
#if defined(STBI_NO_STDIO) && !defined(STBI_NO_WRITE)
#define STBI_NO_WRITE
#endif
#define STBI_NOTUSED(v) v=v
#ifdef _MSC_VER
#define STBI_HAS_LRTOL
#endif
#ifdef STBI_HAS_LRTOL
#define stbi_lrot(x,y) _lrotl(x,y)
#else
#define stbi_lrot(x,y) (((x) << (y)) | ((x) >> (32 - (y))))
#endif
//////////////////////////////////////////////////////////////////////////////
//
// Generic API that works on all image types
//
// deprecated functions
// is it a jpeg?
extern int stbi_jpeg_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_jpeg_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
extern int stbi_jpeg_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp);
#ifndef STBI_NO_STDIO
extern stbi_uc *stbi_jpeg_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern int stbi_jpeg_test_file (FILE *f);
extern stbi_uc *stbi_jpeg_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
extern int stbi_jpeg_info (char const *filename, int *x, int *y, int *comp);
extern int stbi_jpeg_info_from_file (FILE *f, int *x, int *y, int *comp);
#endif
// is it a png?
extern int stbi_png_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_png_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
extern int stbi_png_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp);
#ifndef STBI_NO_STDIO
extern stbi_uc *stbi_png_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern int stbi_png_info (char const *filename, int *x, int *y, int *comp);
extern int stbi_png_test_file (FILE *f);
extern stbi_uc *stbi_png_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
extern int stbi_png_info_from_file (FILE *f, int *x, int *y, int *comp);
#endif
// is it a bmp?
extern int stbi_bmp_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_bmp_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern stbi_uc *stbi_bmp_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern int stbi_bmp_test_file (FILE *f);
extern stbi_uc *stbi_bmp_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
// is it a tga?
extern int stbi_tga_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_tga_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern stbi_uc *stbi_tga_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern int stbi_tga_test_file (FILE *f);
extern stbi_uc *stbi_tga_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
// is it a psd?
extern int stbi_psd_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_psd_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern stbi_uc *stbi_psd_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern int stbi_psd_test_file (FILE *f);
extern stbi_uc *stbi_psd_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
// is it an hdr?
extern int stbi_hdr_test_memory (stbi_uc const *buffer, int len);
extern float * stbi_hdr_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern float * stbi_hdr_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern int stbi_hdr_test_file (FILE *f);
extern float * stbi_hdr_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
// is it a pic?
extern int stbi_pic_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_pic_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern stbi_uc *stbi_pic_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
extern int stbi_pic_test_file (FILE *f);
extern stbi_uc *stbi_pic_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
// is it a gif?
extern int stbi_gif_test_memory (stbi_uc const *buffer, int len);
extern stbi_uc *stbi_gif_load (char const *filename, int *x, int *y, int *comp, int req_comp);
extern stbi_uc *stbi_gif_load_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
extern int stbi_gif_info_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp);
#ifndef STBI_NO_STDIO
extern int stbi_gif_test_file (FILE *f);
extern stbi_uc *stbi_gif_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
extern int stbi_gif_info (char const *filename, int *x, int *y, int *comp);
extern int stbi_gif_info_from_file (FILE *f, int *x, int *y, int *comp);
#endif
// this is not threadsafe
static const char *failure_reason;
const char *stbi_failure_reason(void)
{
return failure_reason;
}
static int e(const char *str)
{
failure_reason = str;
return 0;
}
#ifdef STBI_NO_FAILURE_STRINGS
#define e(x,y) 0
#elif defined(STBI_FAILURE_USERMSG)
#define e(x,y) e(y)
#else
#define e(x,y) e(x)
#endif
#define epf(x,y) ((float *) (e(x,y)?NULL:NULL))
#define epuc(x,y) ((unsigned char *) (e(x,y)?NULL:NULL))
void stbi_image_free(void *retval_from_stbi_load)
{
free(retval_from_stbi_load);
}
#define MAX_LOADERS 32
stbi_loader *loaders[MAX_LOADERS];
static int max_loaders = 0;
int stbi_register_loader(stbi_loader *loader)
{
int i;
for (i=0; i < MAX_LOADERS; ++i) {
// already present?
if (loaders[i] == loader)
return 1;
// end of the list?
if (loaders[i] == NULL) {
loaders[i] = loader;
max_loaders = i+1;
return 1;
}
}
// no room for it
return 0;
}
#ifndef STBI_NO_HDR
static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp);
static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp);
#endif
#ifndef STBI_NO_STDIO
unsigned char *stbi_load(char const *filename, int *x, int *y, int *comp, int req_comp)
{
FILE *f = fopen(filename, "rb");
unsigned char *result;
if (!f) return epuc("can't fopen", "Unable to open file");
result = stbi_load_from_file(f,x,y,comp,req_comp);
fclose(f);
return result;
}
unsigned char *stbi_load_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
{
int i;
if (stbi_jpeg_test_file(f)) return stbi_jpeg_load_from_file(f,x,y,comp,req_comp);
if (stbi_png_test_file(f)) return stbi_png_load_from_file(f,x,y,comp,req_comp);
if (stbi_bmp_test_file(f)) return stbi_bmp_load_from_file(f,x,y,comp,req_comp);
if (stbi_gif_test_file(f)) return stbi_gif_load_from_file(f,x,y,comp,req_comp);
if (stbi_psd_test_file(f)) return stbi_psd_load_from_file(f,x,y,comp,req_comp);
if (stbi_pic_test_file(f)) return stbi_pic_load_from_file(f,x,y,comp,req_comp);
#ifndef STBI_NO_HDR
if (stbi_hdr_test_file(f)) {
float *hdr = stbi_hdr_load_from_file(f, x,y,comp,req_comp);
return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp);
}
#endif
for (i=0; i < max_loaders; ++i)
if (loaders[i]->test_file(f))
return loaders[i]->load_from_file(f,x,y,comp,req_comp);
// test tga last because it's a crappy test!
if (stbi_tga_test_file(f))
return stbi_tga_load_from_file(f,x,y,comp,req_comp);
return epuc("unknown image type", "Image not of any known type, or corrupt");
}
#endif
unsigned char *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp)
{
int i;
if (stbi_jpeg_test_memory(buffer,len)) return stbi_jpeg_load_from_memory(buffer,len,x,y,comp,req_comp);
if (stbi_png_test_memory(buffer,len)) return stbi_png_load_from_memory(buffer,len,x,y,comp,req_comp);
if (stbi_bmp_test_memory(buffer,len)) return stbi_bmp_load_from_memory(buffer,len,x,y,comp,req_comp);
if (stbi_gif_test_memory(buffer,len)) return stbi_gif_load_from_memory(buffer,len,x,y,comp,req_comp);
if (stbi_psd_test_memory(buffer,len)) return stbi_psd_load_from_memory(buffer,len,x,y,comp,req_comp);
if (stbi_pic_test_memory(buffer,len)) return stbi_pic_load_from_memory(buffer,len,x,y,comp,req_comp);
#ifndef STBI_NO_HDR
if (stbi_hdr_test_memory(buffer, len)) {
float *hdr = stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp);
return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp);
}
#endif
for (i=0; i < max_loaders; ++i)
if (loaders[i]->test_memory(buffer,len))
return loaders[i]->load_from_memory(buffer,len,x,y,comp,req_comp);
// test tga last because it's a crappy test!
if (stbi_tga_test_memory(buffer,len))
return stbi_tga_load_from_memory(buffer,len,x,y,comp,req_comp);
return epuc("unknown image type", "Image not of any known type, or corrupt");
}
#ifndef STBI_NO_HDR
#ifndef STBI_NO_STDIO
float *stbi_loadf(char const *filename, int *x, int *y, int *comp, int req_comp)
{
FILE *f = fopen(filename, "rb");
float *result;
if (!f) return epf("can't fopen", "Unable to open file");
result = stbi_loadf_from_file(f,x,y,comp,req_comp);
fclose(f);
return result;
}
float *stbi_loadf_from_file(FILE *f, int *x, int *y, int *comp, int req_comp)
{
unsigned char *data;
#ifndef STBI_NO_HDR
if (stbi_hdr_test_file(f))
return stbi_hdr_load_from_file(f,x,y,comp,req_comp);
#endif
data = stbi_load_from_file(f, x, y, comp, req_comp);
if (data)
return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp);
return epf("unknown image type", "Image not of any known type, or corrupt");
}
#endif
float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp)
{
stbi_uc *data;
#ifndef STBI_NO_HDR
if (stbi_hdr_test_memory(buffer, len))
return stbi_hdr_load_from_memory(buffer, len,x,y,comp,req_comp);
#endif
data = stbi_load_from_memory(buffer, len, x, y, comp, req_comp);
if (data)
return ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp);
return epf("unknown image type", "Image not of any known type, or corrupt");
}
#endif
// these is-hdr-or-not is defined independent of whether STBI_NO_HDR is
// defined, for API simplicity; if STBI_NO_HDR is defined, it always
// reports false!
int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len)
{
#ifndef STBI_NO_HDR
return stbi_hdr_test_memory(buffer, len);
#else
return 0;
#endif
}
#ifndef STBI_NO_STDIO
extern int stbi_is_hdr (char const *filename)
{
FILE *f = fopen(filename, "rb");
int result=0;
if (f) {
result = stbi_is_hdr_from_file(f);
fclose(f);
}
return result;
}
extern int stbi_is_hdr_from_file(FILE *f)
{
#ifndef STBI_NO_HDR
return stbi_hdr_test_file(f);
#else
return 0;
#endif
}
#endif
#ifndef STBI_NO_HDR
static float h2l_gamma_i=1.0f/2.2f, h2l_scale_i=1.0f;
static float l2h_gamma=2.2f, l2h_scale=1.0f;
void stbi_hdr_to_ldr_gamma(float gamma) { h2l_gamma_i = 1/gamma; }
void stbi_hdr_to_ldr_scale(float scale) { h2l_scale_i = 1/scale; }
void stbi_ldr_to_hdr_gamma(float gamma) { l2h_gamma = gamma; }
void stbi_ldr_to_hdr_scale(float scale) { l2h_scale = scale; }
#endif
//////////////////////////////////////////////////////////////////////////////
//
// Common code used by all image loaders
//
enum
{
SCAN_load=0,
SCAN_type,
SCAN_header,
};
typedef struct
{
uint32 img_x, img_y;
int img_n, img_out_n;
#ifndef STBI_NO_STDIO
FILE *img_file;
int buflen;
uint8 buffer_start[128];
int from_file;
#endif
uint8 *img_buffer, *img_buffer_end;
} stbi;
#ifndef STBI_NO_STDIO
static void start_file(stbi *s, FILE *f)
{
s->img_file = f;
s->buflen = sizeof(s->buffer_start);
s->img_buffer_end = s->buffer_start + s->buflen;
s->img_buffer = s->img_buffer_end;
s->from_file = 1;
}
#endif
static void start_mem(stbi *s, uint8 const *buffer, int len)
{
#ifndef STBI_NO_STDIO
s->img_file = NULL;
s->from_file = 0;
#endif
s->img_buffer = (uint8 *) buffer;
s->img_buffer_end = (uint8 *) buffer+len;
}
#ifndef STBI_NO_STDIO
static void refill_buffer(stbi *s)
{
int n = fread(s->buffer_start, 1, s->buflen, s->img_file);
if (n == 0) {
s->from_file = 0;
s->img_buffer = s->img_buffer_end-1;
*s->img_buffer = 0;
} else {
s->img_buffer = s->buffer_start;
s->img_buffer_end = s->buffer_start + n;
}
}
#endif
__forceinline static int get8(stbi *s)
{
if (s->img_buffer < s->img_buffer_end)
return *s->img_buffer++;
#ifndef STBI_NO_STDIO
if (s->from_file) {
refill_buffer(s);
return *s->img_buffer++;
}
#endif
return 0;
}
__forceinline static int at_eof(stbi *s)
{
#ifndef STBI_NO_STDIO
if (s->img_file) {
if (!feof(s->img_file)) return 0;
// if feof() is true, check if buffer = end
// special case: we've only got the special 0 character at the end
if (s->from_file == 0) return 1;
}
#endif
return s->img_buffer >= s->img_buffer_end;
}
__forceinline static uint8 get8u(stbi *s)
{
return (uint8) get8(s);
}
static void skip(stbi *s, int n)
{
#ifndef STBI_NO_STDIO
if (s->img_file) {
int blen = s->img_buffer_end - s->img_buffer;
if (blen < n) {
s->img_buffer = s->img_buffer_end;
fseek(s->img_file, n - blen, SEEK_CUR);
return;
}
}
#endif
s->img_buffer += n;
}
static int getn(stbi *s, stbi_uc *buffer, int n)
{
#ifndef STBI_NO_STDIO
if (s->img_file) {
int blen = s->img_buffer_end - s->img_buffer;
if (blen < n) {
int res;
memcpy(buffer, s->img_buffer, blen);
res = ((int) fread(buffer + blen, 1, n - blen, s->img_file) == (n-blen));
s->img_buffer = s->img_buffer_end;
return res;
}
}
#endif
if (s->img_buffer+n <= s->img_buffer_end) {
memcpy(buffer, s->img_buffer, n);
s->img_buffer += n;
return 1;
} else
return 0;
}
static int get16(stbi *s)
{
int z = get8(s);
return (z << 8) + get8(s);
}
static uint32 get32(stbi *s)
{
uint32 z = get16(s);
return (z << 16) + get16(s);
}
static int get16le(stbi *s)
{
int z = get8(s);
return z + (get8(s) << 8);
}
static uint32 get32le(stbi *s)
{
uint32 z = get16le(s);
return z + (get16le(s) << 16);
}
//////////////////////////////////////////////////////////////////////////////
//
// generic converter from built-in img_n to req_comp
// individual types do this automatically as much as possible (e.g. jpeg
// does all cases internally since it needs to colorspace convert anyway,
// and it never has alpha, so very few cases ). png can automatically
// interleave an alpha=255 channel, but falls back to this for other cases
//
// assume data buffer is malloced, so malloc a new one and free that one
// only failure mode is malloc failing
static uint8 compute_y(int r, int g, int b)
{
return (uint8) (((r*77) + (g*150) + (29*b)) >> 8);
}
static unsigned char *convert_format(unsigned char *data, int img_n, int req_comp, uint x, uint y)
{
int i,j;
unsigned char *good;
if (req_comp == img_n) return data;
assert(req_comp >= 1 && req_comp <= 4);
good = (unsigned char *) malloc(req_comp * x * y);
if (good == NULL) {
free(data);
return epuc("outofmem", "Out of memory");
}
for (j=0; j < (int) y; ++j) {
unsigned char *src = data + j * x * img_n ;
unsigned char *dest = good + j * x * req_comp;
#define COMBO(a,b) ((a)*8+(b))
#define CASE(a,b) case COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b)
// convert source image with img_n components to one with req_comp components;
// avoid switch per pixel, so use switch per scanline and massive macros
switch (COMBO(img_n, req_comp)) {
CASE(1,2) dest[0]=src[0], dest[1]=255; break;
CASE(1,3) dest[0]=dest[1]=dest[2]=src[0]; break;
CASE(1,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=255; break;
CASE(2,1) dest[0]=src[0]; break;
CASE(2,3) dest[0]=dest[1]=dest[2]=src[0]; break;
CASE(2,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=src[1]; break;
CASE(3,4) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2],dest[3]=255; break;
CASE(3,1) dest[0]=compute_y(src[0],src[1],src[2]); break;
CASE(3,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = 255; break;
CASE(4,1) dest[0]=compute_y(src[0],src[1],src[2]); break;
CASE(4,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = src[3]; break;
CASE(4,3) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2]; break;
default: assert(0);
}
#undef CASE
}
free(data);
return good;
}
#ifndef STBI_NO_HDR
static float *ldr_to_hdr(stbi_uc *data, int x, int y, int comp)
{
int i,k,n;
float *output = (float *) malloc(x * y * comp * sizeof(float));
if (output == NULL) { free(data); return epf("outofmem", "Out of memory"); }
// compute number of non-alpha components
if (comp & 1) n = comp; else n = comp-1;
for (i=0; i < x*y; ++i) {
for (k=0; k < n; ++k) {
output[i*comp + k] = (float) pow(data[i*comp+k]/255.0f, l2h_gamma) * l2h_scale;
}
if (k < comp) output[i*comp + k] = data[i*comp+k]/255.0f;