diff options
Diffstat (limited to 'third_party/stb_image.c')
| -rw-r--r-- | third_party/stb_image.c | 4673 |
1 files changed, 4673 insertions, 0 deletions
diff --git a/third_party/stb_image.c b/third_party/stb_image.c new file mode 100644 index 00000000..098b91ae --- /dev/null +++ b/third_party/stb_image.c @@ -0,0 +1,4673 @@ +/* stbi-1.33 - 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-per-channel 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)
+
+ - decode from memory or through FILE (define STBI_NO_STDIO to remove code)
+ - decode from arbitrary I/O callbacks
+ - overridable dequantizing-IDCT, YCbCr-to-RGB conversion (define STBI_SIMD)
+
+ Latest revisions:
+ 1.33 (2011-07-14) minor fixes suggested by Dave Moore
+ 1.32 (2011-07-13) info support for all filetypes (SpartanJ)
+ 1.31 (2011-06-19) a few more leak fixes, bug in PNG handling (SpartanJ)
+ 1.30 (2011-06-11) added ability to load files via io callbacks (Ben Wenger)
+ 1.29 (2010-08-16) various warning fixes from Aurelien Pocheville
+ 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
+
+ See end of file for full revision history.
+
+ TODO:
+ stbi_info support for BMP,PSD,HDR,PIC
+
+
+ ============================ 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
+ Ben "Disch" Wenger (io callbacks) Aruelien Pocheville
+ Martin "SpartanJ" Golini Ryamond Barbiero
+ David Woo
+
+
+ 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
+// // ... but 'n' will always be the number that it would have been if you said 0
+// 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);
+//
+// ===========================================================================
+//
+// I/O callbacks
+//
+// I/O callbacks allow you to read from arbitrary sources, like packaged
+// files or some other source. Data read from callbacks are processed
+// through a small internal buffer (currently 128 bytes) to try to reduce
+// overhead.
+//
+// The three functions you must define are "read" (reads some bytes of data),
+// "skip" (skips some bytes of data), "eof" (reports if the stream is at the end).
+
+
+#ifndef STBI_NO_STDIO
+
+#if defined(_MSC_VER) && _MSC_VER >= 0x1400
+#define _CRT_SECURE_NO_WARNINGS // suppress bogus warnings about fopen()
+#endif
+
+#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
+
+typedef struct
+{
+ int (*read) (void *user,char *data,int size); // fill 'data' with 'size' bytes. return number of bytes actually read
+ void (*skip) (void *user,unsigned n); // skip the next 'n' bytes
+ int (*eof) (void *user); // returns nonzero if we are at end of file/data
+} stbi_io_callbacks;
+
+extern stbi_uc *stbi_load_from_callbacks (stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp, int req_comp);
+
+#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 float *stbi_loadf_from_callbacks (stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp, int req_comp);
+
+ 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
+
+// stbi_is_hdr is always defined
+extern int stbi_is_hdr_from_callbacks(stbi_io_callbacks const *clbk, void *user);
+extern int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len);
+#ifndef STBI_NO_STDIO
+extern int stbi_is_hdr (char const *filename);
+extern int stbi_is_hdr_from_file(FILE *f);
+#endif // STBI_NO_STDIO
+
+
+// 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_info_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp);
+
+#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);
+
+#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 faster low-level operations (typically SIMD support)
+#ifdef 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
+
+
+#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, strtok
+#endif
+
+#ifndef STBI_NO_STDIO
+#include <stdio.h>
+#endif
+#include <stdlib.h>
+#include <memory.h>
+#include <assert.h>
+#include <stdarg.h>
+
+#ifndef _MSC_VER
+ #ifdef __cplusplus
+ #define stbi_inline inline
+ #else
+ #define stbi_inline
+ #endif
+#else
+ #define stbi_inline __forceinline
+#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) (void)sizeof(v)
+
+#ifdef _MSC_VER
+#define STBI_HAS_LROTL
+#endif
+
+#ifdef STBI_HAS_LROTL
+ #define stbi_lrot(x,y) _lrotl(x,y)
+#else
+ #define stbi_lrot(x,y) (((x) << (y)) | ((x) >> (32 - (y))))
+#endif
+
+///////////////////////////////////////////////
+//
+// stbi struct and start_xxx functions
+
+// stbi structure is our basic context used by all images, so it
+// contains all the IO context, plus some basic image information
+typedef struct
+{
+ uint32 img_x, img_y;
+ int img_n, img_out_n;
+
+ stbi_io_callbacks io;
+ void *io_user_data;
+
+ int read_from_callbacks;
+ int buflen;
+ uint8 buffer_start[128];
+
+ uint8 *img_buffer, *img_buffer_end;
+ uint8 *img_buffer_original;
+} stbi;
+
+
+static void refill_buffer(stbi *s);
+
+// initialize a memory-decode context
+static void start_mem(stbi *s, uint8 const *buffer, int len)
+{
+ s->io.read = NULL;
+ s->read_from_callbacks = 0;
+ s->img_buffer = s->img_buffer_original = (uint8 *) buffer;
+ s->img_buffer_end = (uint8 *) buffer+len;
+}
+
+// initialize a callback-based context
+static void start_callbacks(stbi *s, stbi_io_callbacks *c, void *user)
+{
+ s->io = *c;
+ s->io_user_data = user;
+ s->buflen = sizeof(s->buffer_start);
+ s->read_from_callbacks = 1;
+ s->img_buffer_original = s->buffer_start;
+ refill_buffer(s);
+}
+
+#ifndef STBI_NO_STDIO
+
+static int stdio_read(void *user, char *data, int size)
+{
+ return (int) fread(data,1,size,(FILE*) user);
+}
+
+static void stdio_skip(void *user, unsigned n)
+{
+ fseek((FILE*) user, n, SEEK_CUR);
+}
+
+static int stdio_eof(void *user)
+{
+ return feof((FILE*) user);
+}
+
+static stbi_io_callbacks stbi_stdio_callbacks =
+{
+ stdio_read,
+ stdio_skip,
+ stdio_eof,
+};
+
+static void start_file(stbi *s, FILE *f)
+{
+ start_callbacks(s, &stbi_stdio_callbacks, (void *) f);
+}
+
+//static void stop_file(stbi *s) { }
+
+#endif // !STBI_NO_STDIO
+
+static void stbi_rewind(stbi *s)
+{
+ // conceptually rewind SHOULD rewind to the beginning of the stream,
+ // but we just rewind to the beginning of the initial buffer, because
+ // we only use it after doing 'test', which only ever looks at at most 92 bytes
+ s->img_buffer = s->img_buffer_original;
+}
+
+static int stbi_jpeg_test(stbi *s);
+static stbi_uc *stbi_jpeg_load(stbi *s, int *x, int *y, int *comp, int req_comp);
+static int stbi_jpeg_info(stbi *s, int *x, int *y, int *comp);
+static int stbi_png_test(stbi *s);
+static stbi_uc *stbi_png_load(stbi *s, int *x, int *y, int *comp, int req_comp);
+static int stbi_png_info(stbi *s, int *x, int *y, int *comp);
+static int stbi_bmp_test(stbi *s);
+static stbi_uc *stbi_bmp_load(stbi *s, int *x, int *y, int *comp, int req_comp);
+static int stbi_tga_test(stbi *s);
+static stbi_uc *stbi_tga_load(stbi *s, int *x, int *y, int *comp, int req_comp);
+static int stbi_tga_info(stbi *s, int *x, int *y, int *comp);
+static int stbi_psd_test(stbi *s);
+static stbi_uc *stbi_psd_load(stbi *s, int *x, int *y, int *comp, int req_comp);
+static int stbi_hdr_test(stbi *s);
+static float *stbi_hdr_load(stbi *s, int *x, int *y, int *comp, int req_comp);
+static int stbi_pic_test(stbi *s);
+static stbi_uc *stbi_pic_load(stbi *s, int *x, int *y, int *comp, int req_comp);
+static int stbi_gif_test(stbi *s);
+static stbi_uc *stbi_gif_load(stbi *s, int *x, int *y, int *comp, int req_comp);
+static int stbi_gif_info(stbi *s, int *x, int *y, int *comp);
+
+
+// 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;
+}
+
+// e - error
+// epf - error returning pointer to float
+// epuc - error returning pointer to unsigned char
+
+#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);
+}
+
+#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
+
+static unsigned char *stbi_load_main(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ if (stbi_jpeg_test(s)) return stbi_jpeg_load(s,x,y,comp,req_comp);
+ if (stbi_png_test(s)) return stbi_png_load(s,x,y,comp,req_comp);
+ if (stbi_bmp_test(s)) return stbi_bmp_load(s,x,y,comp,req_comp);
+ if (stbi_gif_test(s)) return stbi_gif_load(s,x,y,comp,req_comp);
+ if (stbi_psd_test(s)) return stbi_psd_load(s,x,y,comp,req_comp);
+ if (stbi_pic_test(s)) return stbi_pic_load(s,x,y,comp,req_comp);
+
+ #ifndef STBI_NO_HDR
+ if (stbi_hdr_test(s)) {
+ float *hdr = stbi_hdr_load(s, x,y,comp,req_comp);
+ return hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp);
+ }
+ #endif
+
+ // test tga last because it's a crappy test!
+ if (stbi_tga_test(s))
+ return stbi_tga_load(s,x,y,comp,req_comp);
+ return epuc("unknown image type", "Image not of any known type, or corrupt");
+}
+
+#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)
+{
+ stbi s;
+ start_file(&s,f);
+ return stbi_load_main(&s,x,y,comp,req_comp);
+}
+#endif //!STBI_NO_STDIO
+
+unsigned char *stbi_load_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ stbi s;
+ start_mem(&s,buffer,len);
+ return stbi_load_main(&s,x,y,comp,req_comp);
+}
+
+unsigned char *stbi_load_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp, int req_comp)
+{
+ stbi s;
+ start_callbacks(&s, (stbi_io_callbacks *) clbk, user);
+ return stbi_load_main(&s,x,y,comp,req_comp);
+}
+
+#ifndef STBI_NO_HDR
+
+float *stbi_loadf_main(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ unsigned char *data;
+ #ifndef STBI_NO_HDR
+ if (stbi_hdr_test(s))
+ return stbi_hdr_load(s,x,y,comp,req_comp);
+ #endif
+ data = stbi_load_main(s, 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");
+}
+
+float *stbi_loadf_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp)
+{
+ stbi s;
+ start_mem(&s,buffer,len);
+ return stbi_loadf_main(&s,x,y,comp,req_comp);
+}
+
+float *stbi_loadf_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp, int req_comp)
+{
+ stbi s;
+ start_callbacks(&s, (stbi_io_callbacks *) clbk, user);
+ return stbi_loadf_main(&s,x,y,comp,req_comp);
+}
+
+#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)
+{
+ stbi s;
+ start_file(&s,f);
+ return stbi_loadf_main(&s,x,y,comp,req_comp);
+}
+#endif // !STBI_NO_STDIO
+
+#endif // !STBI_NO_HDR
+
+// 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
+ stbi s;
+ start_mem(&s,buffer,len);
+ return stbi_hdr_test(&s);
+ #else
+ STBI_NOTUSED(buffer);
+ STBI_NOTUSED(len);
+ 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
+ stbi s;
+ start_file(&s,f);
+ return stbi_hdr_test(&s);
+ #else
+ return 0;
+ #endif
+}
+#endif // !STBI_NO_STDIO
+
+extern int stbi_is_hdr_from_callbacks(stbi_io_callbacks const *clbk, void *user)
+{
+ #ifndef STBI_NO_HDR
+ stbi s;
+ start_callbacks(&s, (stbi_io_callbacks *) clbk, user);
+ return stbi_hdr_test(&s);
+ #else
+ return 0;
+ #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
+};
+
+static void refill_buffer(stbi *s)
+{
+ int n = (s->io.read)(s->io_user_data,(char*)s->buffer_start,s->buflen);
+ if (n == 0) {
+ // at end of file, treat same as if from memory
+ s->read_from_callbacks = 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;
+ }
+}
+
+stbi_inline static int get8(stbi *s)
+{
+ if (s->img_buffer < s->img_buffer_end)
+ return *s->img_buffer++;
+ if (s->read_from_callbacks) {
+ refill_buffer(s);
+ return *s->img_buffer++;
+ }
+ return 0;
+}
+
+stbi_inline static int at_eof(stbi *s)
+{
+ if (s->io.read) {
+ if (!(s->io.eof)(s->io_user_data)) 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->read_from_callbacks == 0) return 1;
+ }
+
+ return s->img_buffer >= s->img_buffer_end;
+}
+
+stbi_inline static uint8 get8u(stbi *s)
+{
+ return (uint8) get8(s);
+}
+
+static void skip(stbi *s, int n)
+{
+ if (s->io.read) {
+ int blen = s->img_buffer_end - s->img_buffer;
+ if (blen < n) {
+ s->img_buffer = s->img_buffer_end;
+ (s->io.skip)(s->io_user_data, n - blen);
+ return;
+ }
+ }
+ s->img_buffer += n;
+}
+
+static int getn(stbi *s, stbi_uc *buffer, int n)
+{
+ if (s->io.read) {
+ int blen = s->img_buffer_end - s->img_buffer;
+ if (blen < n) {
+ int res, count;
+
+ memcpy(buffer, s->img_buffer, blen);
+
+ count = (s->io.read)(s->io_user_data, (char*) buffer + blen, n - blen);
+ res = (count == (n-blen));
+ s->img_buffer = s->img_buffer_end;
+ return res;
+ }
+ }
+
+ 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;
+ }
+ free(data);
+ return output;
+}
+
+#define float2int(x) ((int) (x))
+static stbi_uc *hdr_to_ldr(float *data, int x, int y, int comp)
+{
+ int i,k,n;
+ stbi_uc *output = (stbi_uc *) malloc(x * y * comp);
+ if (output == NULL) { free(data); return epuc("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) {
+ float z = (float) pow(data[i*comp+k]*h2l_scale_i, h2l_gamma_i) * 255 + 0.5f;
+ if (z < 0) z = 0;
+ if (z > 255) z = 255;
+ output[i*comp + k] = (uint8) float2int(z);
+ }
+ if (k < comp) {
+ float z = data[i*comp+k] * 255 + 0.5f;
+ if (z < 0) z = 0;
+ if (z > 255) z = 255;
+ output[i*comp + k] = (uint8) float2int(z);
+ }
+ }
+ free(data);
+ return output;
+}
+#endif
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// "baseline" JPEG/JFIF decoder (not actually fully baseline implementation)
+//
+// simple implementation
+// - channel subsampling of at most 2 in each dimension
+// - doesn't support delayed output of y-dimension
+// - simple interface (only one output format: 8-bit interleaved RGB)
+// - doesn't try to recover corrupt jpegs
+// - doesn't allow partial loading, loading multiple at once
+// - still fast on x86 (copying globals into locals doesn't help x86)
+// - allocates lots of intermediate memory (full size of all components)
+// - non-interleaved case requires this anyway
+// - allows good upsampling (see next)
+// high-quality
+// - upsampled channels are bilinearly interpolated, even across blocks
+// - quality integer IDCT derived from IJG's 'slow'
+// performance
+// - fast huffman; reasonable integer IDCT
+// - uses a lot of intermediate memory, could cache poorly
+// - load http://nothings.org/remote/anemones.jpg 3 times on 2.8Ghz P4
+// stb_jpeg: 1.34 seconds (MSVC6, default release build)
+// stb_jpeg: 1.06 seconds (MSVC6, processor = Pentium Pro)
+// IJL11.dll: 1.08 seconds (compiled by intel)
+// IJG 1998: 0.98 seconds (MSVC6, makefile provided by IJG)
+// IJG 1998: 0.95 seconds (MSVC6, makefile + proc=PPro)
+
+// huffman decoding acceleration
+#define FAST_BITS 9 // larger handles more cases; smaller stomps less cache
+
+typedef struct
+{
+ uint8 fast[1 << FAST_BITS];
+ // weirdly, repacking this into AoS is a 10% speed loss, instead of a win
+ uint16 code[256];
+ uint8 values[256];
+ uint8 size[257];
+ unsigned int maxcode[18];
+ int delta[17]; // old 'firstsymbol' - old 'firstcode'
+} huffman;
+
+typedef struct
+{
+ #ifdef STBI_SIMD
+ unsigned short dequant2[4][64];
+ #endif
+ stbi *s;
+ huffman huff_dc[4];
+ huffman huff_ac[4];
+ uint8 dequant[4][64];
+
+// sizes for components, interleaved MCUs
+ int img_h_max, img_v_max;
+ int img_mcu_x, img_mcu_y;
+ int img_mcu_w, img_mcu_h;
+
+// definition of jpeg image component
+ struct
+ {
+ int id;
+ int h,v;
+ int tq;
+ int hd,ha;
+ int dc_pred;
+
+ int x,y,w2,h2;
+ uint8 *data;
+ void *raw_data;
+ uint8 *linebuf;
+ } img_comp[4];
+
+ uint32 code_buffer; // jpeg entropy-coded buffer
+ int code_bits; // number of valid bits
+ unsigned char marker; // marker seen while filling entropy buffer
+ int nomore; // flag if we saw a marker so must stop
+
+ int scan_n, order[4];
+ int restart_interval, todo;
+} jpeg;
+
+static int build_huffman(huffman *h, int *count)
+{
+ int i,j,k=0,code;
+ // build size list for each symbol (from JPEG spec)
+ for (i=0; i < 16; ++i)
+ for (j=0; j < count[i]; ++j)
+ h->size[k++] = (uint8) (i+1);
+ h->size[k] = 0;
+
+ // compute actual symbols (from jpeg spec)
+ code = 0;
+ k = 0;
+ for(j=1; j <= 16; ++j) {
+ // compute delta to add to code to compute symbol id
+ h->delta[j] = k - code;
+ if (h->size[k] == j) {
+ while (h->size[k] == j)
+ h->code[k++] = (uint16) (code++);
+ if (code-1 >= (1 << j)) return e("bad code lengths","Corrupt JPEG");
+ }
+ // compute largest code + 1 for this size, preshifted as needed later
+ h->maxcode[j] = code << (16-j);
+ code <<= 1;
+ }
+ h->maxcode[j] = 0xffffffff;
+
+ // build non-spec acceleration table; 255 is flag for not-accelerated
+ memset(h->fast, 255, 1 << FAST_BITS);
+ for (i=0; i < k; ++i) {
+ int s = h->size[i];
+ if (s <= FAST_BITS) {
+ int c = h->code[i] << (FAST_BITS-s);
+ int m = 1 << (FAST_BITS-s);
+ for (j=0; j < m; ++j) {
+ h->fast[c+j] = (uint8) i;
+ }
+ }
+ }
+ return 1;
+}
+
+static void grow_buffer_unsafe(jpeg *j)
+{
+ do {
+ int b = j->nomore ? 0 : get8(j->s);
+ if (b == 0xff) {
+ int c = get8(j->s);
+ if (c != 0) {
+ j->marker |