diff options
Diffstat (limited to 'libs/dgl/src/nanovg/stb_image.c')
| -rw-r--r-- | libs/dgl/src/nanovg/stb_image.c | 4676 |
1 files changed, 4676 insertions, 0 deletions
diff --git a/libs/dgl/src/nanovg/stb_image.c b/libs/dgl/src/nanovg/stb_image.c new file mode 100644 index 0000000..1ec363b --- /dev/null +++ b/libs/dgl/src/nanovg/stb_image.c @@ -0,0 +1,4676 @@ +/* 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 = (unsigned char) c;
+ j->nomore = 1;
+ return;
+ }
+ }
+ j->code_buffer |= b << (24 - j->code_bits);
+ j->code_bits += 8;
+ } while (j->code_bits <= 24);
+}
+
+// (1 << n) - 1
+static uint32 bmask[17]={0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535};
+
+// decode a jpeg huffman value from the bitstream
+stbi_inline static int decode(jpeg *j, huffman *h)
+{
+ unsigned int temp;
+ int c,k;
+
+ if (j->code_bits < 16) grow_buffer_unsafe(j);
+
+ // look at the top FAST_BITS and determine what symbol ID it is,
+ // if the code is <= FAST_BITS
+ c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS)-1);
+ k = h->fast[c];
+ if (k < 255) {
+ int s = h->size[k];
+ if (s > j->code_bits)
+ return -1;
+ j->code_buffer <<= s;
+ j->code_bits -= s;
+ return h->values[k];
+ }
+
+ // naive test is to shift the code_buffer down so k bits are
+ // valid, then test against maxcode. To speed this up, we've
+ // preshifted maxcode left so that it has (16-k) 0s at the
+ // end; in other words, regardless of the number of bits, it
+ // wants to be compared against something shifted to have 16;
+ // that way we don't need to shift inside the loop.
+ temp = j->code_buffer >> 16;
+ for (k=FAST_BITS+1 ; ; ++k)
+ if (temp < h->maxcode[k])
+ break;
+ if (k == 17) {
+ // error! code not found
+ j->code_bits -= 16;
+ return -1;
+ }
+
+ if (k > j->code_bits)
+ return -1;
+
+ // convert the huffman code to the symbol id
+ c = ((j->code_buffer >> (32 - k)) & bmask[k]) + h->delta[k];
+ assert((((j->code_buffer) >> (32 - h->size[c])) & bmask[h->size[c]]) == h->code[c]);
+
+ // convert the id to a symbol
+ j->code_bits -= k;
+ j->code_buffer <<= k;
+ return h->values[c];
+}
+
+// combined JPEG 'receive' and JPEG 'extend', since baseline
+// always extends everything it receives.
+stbi_inline static int extend_receive(jpeg *j, int n)
+{
+ unsigned int m = 1 << (n-1);
+ unsigned int k;
+ if (j->code_bits < n) grow_buffer_unsafe(j);
+
+ #if 1
+ k = stbi_lrot(j->code_buffer, n);
+ j->code_buffer = k & ~bmask[n];
+ k &= bmask[n];
+ j->code_bits -= n;
+ #else
+ k = (j->code_buffer >> (32 - n)) & bmask[n];
+ j->code_bits -= n;
+ j->code_buffer <<= n;
+ #endif
+ // the following test is probably a random branch that won't
+ // predict well. I tried to table accelerate it but failed.
+ // maybe it's compiling as a conditional move?
+ if (k < m)
+ return (-1 << n) + k + 1;
+ else
+ return k;
+}
+
+// given a value that's at position X in the zigzag stream,
+// where does it appear in the 8x8 matrix coded as row-major?
+static uint8 dezigzag[64+15] =
+{
+ 0, 1, 8, 16, 9, 2, 3, 10,
+ 17, 24, 32, 25, 18, 11, 4, 5,
+ 12, 19, 26, 33, 40, 48, 41, 34,
+ 27, 20, 13, 6, 7, 14, 21, 28,
+ 35, 42, 49, 56, 57, 50, 43, 36,
+ 29, 22, 15, 23, 30, 37, 44, 51,
+ 58, 59, 52, 45, 38, 31, 39, 46,
+ 53, 60, 61, 54, 47, 55, 62, 63,
+ // let corrupt input sample past end
+ 63, 63, 63, 63, 63, 63, 63, 63,
+ 63, 63, 63, 63, 63, 63, 63
+};
+
+// decode one 64-entry block--
+static int decode_block(jpeg *j, short data[64], huffman *hdc, huffman *hac, int b)
+{
+ int diff,dc,k;
+ int t = decode(j, hdc);
+ if (t < 0) return e("bad huffman code","Corrupt JPEG");
+
+ // 0 all the ac values now so we can do it 32-bits at a time
+ memset(data,0,64*sizeof(data[0]));
+
+ diff = t ? extend_receive(j, t) : 0;
+ dc = j->img_comp[b].dc_pred + diff;
+ j->img_comp[b].dc_pred = dc;
+ data[0] = (short) dc;
+
+ // decode AC components, see JPEG spec
+ k = 1;
+ do {
+ int r,s;
+ int rs = decode(j, hac);
+ if (rs < 0) return e("bad huffman code","Corrupt JPEG");
+ s = rs & 15;
+ r = rs >> 4;
+ if (s == 0) {
+ if (rs != 0xf0) break; // end block
+ k += 16;
+ } else {
+ k += r;
+ // decode into unzigzag'd location
+ data[dezigzag[k++]] = (short) extend_receive(j,s);
+ }
+ } while (k < 64);
+ return 1;
+}
+
+// take a -128..127 value and clamp it and convert to 0..255
+stbi_inline static uint8 clamp(int x)
+{
+ // trick to use a single test to catch both cases
+ if ((unsigned int) x > 255) {
+ if (x < 0) return 0;
+ if (x > 255) return 255;
+ }
+ return (uint8) x;
+}
+
+#define f2f(x) (int) (((x) * 4096 + 0.5))
+#define fsh(x) ((x) << 12)
+
+// derived from jidctint -- DCT_ISLOW
+#define IDCT_1D(s0,s1,s2,s3,s4,s5,s6,s7) \
+ int t0,t1,t2,t3,p1,p2,p3,p4,p5,x0,x1,x2,x3; \
+ p2 = s2; \
+ p3 = s6; \
+ p1 = (p2+p3) * f2f(0.5411961f); \
+ t2 = p1 + p3*f2f(-1.847759065f); \
+ t3 = p1 + p2*f2f( 0.765366865f); \
+ p2 = s0; \
+ p3 = s4; \
+ t0 = fsh(p2+p3); \
+ t1 = fsh(p2-p3); \
+ x0 = t0+t3; \
+ x3 = t0-t3; \
+ x1 = t1+t2; \
+ x2 = t1-t2; \
+ t0 = s7; \
+ t1 = s5; \
+ t2 = s3; \
+ t3 = s1; \
+ p3 = t0+t2; \
+ p4 = t1+t3; \
+ p1 = t0+t3; \
+ p2 = t1+t2; \
+ p5 = (p3+p4)*f2f( 1.175875602f); \
+ t0 = t0*f2f( 0.298631336f); \
+ t1 = t1*f2f( 2.053119869f); \
+ t2 = t2*f2f( 3.072711026f); \
+ t3 = t3*f2f( 1.501321110f); \
+ p1 = p5 + p1*f2f(-0.899976223f); \
+ p2 = p5 + p2*f2f(-2.562915447f); \
+ p3 = p3*f2f(-1.961570560f); \
+ p4 = p4*f2f(-0.390180644f); \
+ t3 += p1+p4; \
+ t2 += p2+p3; \
+ t1 += p2+p4; \
+ t0 += p1+p3;
+
+#ifdef STBI_SIMD
+typedef unsigned short stbi_dequantize_t;
+#else
+typedef uint8 stbi_dequantize_t;
+#endif
+
+// .344 seconds on 3*anemones.jpg
+static void idct_block(uint8 *out, int out_stride, short data[64], stbi_dequantize_t *dequantize)
+{
+ int i,val[64],*v=val;
+ stbi_dequantize_t *dq = dequantize;
+ uint8 *o;
+ short *d = data;
+
+ // columns
+ for (i=0; i < 8; ++i,++d,++dq, ++v) {
+ // if all zeroes, shortcut -- this avoids dequantizing 0s and IDCTing
+ if (d[ 8]==0 && d[16]==0 && d[24]==0 && d[32]==0
+ && d[40]==0 && d[48]==0 && d[56]==0) {
+ // no shortcut 0 seconds
+ // (1|2|3|4|5|6|7)==0 0 seconds
+ // all separate -0.047 seconds
+ // 1 && 2|3 && 4|5 && 6|7: -0.047 seconds
+ int dcterm = d[0] * dq[0] << 2;
+ v[0] = v[8] = v[16] = v[24] = v[32] = v[40] = v[48] = v[56] = dcterm;
+ } else {
+ IDCT_1D(d[ 0]*dq[ 0],d[ 8]*dq[ 8],d[16]*dq[16],d[24]*dq[24],
+ d[32]*dq[32],d[40]*dq[40],d[48]*dq[48],d[56]*dq[56])
+ // constants scaled things up by 1<<12; let's bring them back
+ // down, but keep 2 extra bits of precision
+ x0 += 512; x1 += 512; x2 += 512; x3 += 512;
+ v[ 0] = (x0+t3) >> 10;
+ v[56] = (x0-t3) >> 10;
+ v[ 8] = (x1+t2) >> 10;
+ v[48] = (x1-t2) >> 10;
+ v[16] = (x2+t1) >> 10;
+ v[40] = (x2-t1) >> 10;
+ v[24] = (x3+t0) >> 10;
+ v[32] = (x3-t0) >> 10;
+ }
+ }
+
+ for (i=0, v=val, o=out; i < 8; ++i,v+=8,o+=out_stride) {
+ // no fast case since the first 1D IDCT spread components out
+ IDCT_1D(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7])
+ // constants scaled things up by 1<<12, plus we had 1<<2 from first
+ // loop, plus horizontal and vertical each scale by sqrt(8) so together
+ // we've got an extra 1<<3, so 1<<17 total we need to remove.
+ // so we want to round that, which means adding 0.5 * 1<<17,
+ // aka 65536. Also, we'll end up with -128 to 127 that we want
+ // to encode as 0..255 by adding 128, so we'll add that before the shift
+ x0 += 65536 + (128<<17);
+ x1 += 65536 + (128<<17);
+ x2 += 65536 + (128<<17);
+ x3 += 65536 + (128<<17);
+ // tried computing the shifts into temps, or'ing the temps to see
+ // if any were out of range, but that was slower
+ o[0] = clamp((x0+t3) >> 17);
+ o[7] = clamp((x0-t3) >> 17);
+ o[1] = clamp((x1+t2) >> 17);
+ o[6] = clamp((x1-t2) >> 17);
+ o[2] = clamp((x2+t1) >> 17);
+ o[5] = clamp((x2-t1) >> 17);
+ o[3] = clamp((x3+t0) >> 17);
+ o[4] = clamp((x3-t0) >> 17);
+ }
+}
+
+#ifdef STBI_SIMD
+static stbi_idct_8x8 stbi_idct_installed = idct_block;
+
+void stbi_install_idct(stbi_idct_8x8 func)
+{
+ stbi_idct_installed = func;
+}
+#endif
+
+#define MARKER_none 0xff
+// if there's a pending marker from the entropy stream, return that
+// otherwise, fetch from the stream and get a marker. if there's no
+// marker, return 0xff, which is never a valid marker value
+static uint8 get_marker(jpeg *j)
+{
+ uint8 x;
+ if (j->marker != MARKER_none) { x = j->marker; j->marker = MARKER_none; return x; }
+ x = get8u(j->s);
+ if (x != 0xff) return MARKER_none;
+ while (x == 0xff)
+ x = get8u(j->s);
+ return x;
+}
+
+// in each scan, we'll have scan_n components, and the order
+// of the components is specified by order[]
+#define RESTART(x) ((x) >= 0xd0 && (x) <= 0xd7)
+
+// after a restart interval, reset the entropy decoder and
+// the dc prediction
+static void reset(jpeg *j)
+{
+ j->code_bits = 0;
+ j->code_buffer = 0;
+ j->nomore = 0;
+ j->img_comp[0].dc_pred = j->img_comp[1].dc_pred = j->img_comp[2].dc_pred = 0;
+ j->marker = MARKER_none;
+ j->todo = j->restart_interval ? j->restart_interval : 0x7fffffff;
+ // no more than 1<<31 MCUs if no restart_interal? that's plenty safe,
+ // since we don't even allow 1<<30 pixels
+}
+
+static int parse_entropy_coded_data(jpeg *z)
+{
+ reset(z);
+ if (z->scan_n == 1) {
+ int i,j;
+ #ifdef STBI_SIMD
+ __declspec(align(16))
+ #endif
+ short data[64];
+ int n = z->order[0];
+ // non-interleaved data, we just need to process one block at a time,
+ // in trivial scanline order
+ // number of blocks to do just depends on how many actual "pixels" this
+ // component has, independent of interleaved MCU blocking and such
+ int w = (z->img_comp[n].x+7) >> 3;
+ int h = (z->img_comp[n].y+7) >> 3;
+ for (j=0; j < h; ++j) {
+ for (i=0; i < w; ++i) {
+ if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0;
+ #ifdef STBI_SIMD
+ stbi_idct_installed(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data, z->dequant2[z->img_comp[n].tq]);
+ #else
+ idct_block(z->img_comp[n].data+z->img_comp[n].w2*j*8+i*8, z->img_comp[n].w2, data, z->dequant[z->img_comp[n].tq]);
+ #endif
+ // every data block is an MCU, so countdown the restart interval
+ if (--z->todo <= 0) {
+ if (z->code_bits < 24) grow_buffer_unsafe(z);
+ // if it's NOT a restart, then just bail, so we get corrupt data
+ // rather than no data
+ if (!RESTART(z->marker)) return 1;
+ reset(z);
+ }
+ }
+ }
+ } else { // interleaved!
+ int i,j,k,x,y;
+ short data[64];
+ for (j=0; j < z->img_mcu_y; ++j) {
+ for (i=0; i < z->img_mcu_x; ++i) {
+ // scan an interleaved mcu... process scan_n components in order
+ for (k=0; k < z->scan_n; ++k) {
+ int n = z->order[k];
+ // scan out an mcu's worth of this component; that's just determined
+ // by the basic H and V specified for the component
+ for (y=0; y < z->img_comp[n].v; ++y) {
+ for (x=0; x < z->img_comp[n].h; ++x) {
+ int x2 = (i*z->img_comp[n].h + x)*8;
+ int y2 = (j*z->img_comp[n].v + y)*8;
+ if (!decode_block(z, data, z->huff_dc+z->img_comp[n].hd, z->huff_ac+z->img_comp[n].ha, n)) return 0;
+ #ifdef STBI_SIMD
+ stbi_idct_installed(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data, z->dequant2[z->img_comp[n].tq]);
+ #else
+ idct_block(z->img_comp[n].data+z->img_comp[n].w2*y2+x2, z->img_comp[n].w2, data, z->dequant[z->img_comp[n].tq]);
+ #endif
+ }
+ }
+ }
+ // after all interleaved components, that's an interleaved MCU,
+ // so now count down the restart interval
+ if (--z->todo <= 0) {
+ if (z->code_bits < 24) grow_buffer_unsafe(z);
+ // if it's NOT a restart, then just bail, so we get corrupt data
+ // rather than no data
+ if (!RESTART(z->marker)) return 1;
+ reset(z);
+ }
+ }
+ }
+ }
+ return 1;
+}
+
+static int process_marker(jpeg *z, int m)
+{
+ int L;
+ switch (m) {
+ case MARKER_none: // no marker found
+ return e("expected marker","Corrupt JPEG");
+
+ case 0xC2: // SOF - progressive
+ return e("progressive jpeg","JPEG format not supported (progressive)");
+
+ case 0xDD: // DRI - specify restart interval
+ if (get16(z->s) != 4) return e("bad DRI len","Corrupt JPEG");
+ z->restart_interval = get16(z->s);
+ return 1;
+
+ case 0xDB: // DQT - define quantization table
+ L = get16(z->s)-2;
+ while (L > 0) {
+ int q = get8(z->s);
+ int p = q >> 4;
+ int t = q & 15,i;
+ if (p != 0) return e("bad DQT type","Corrupt JPEG");
+ if (t > 3) return e("bad DQT table","Corrupt JPEG");
+ for (i=0; i < 64; ++i)
+ z->dequant[t][dezigzag[i]] = get8u(z->s);
+ #ifdef STBI_SIMD
+ for (i=0; i < 64; ++i)
+ z->dequant2[t][i] = z->dequant[t][i];
+ #endif
+ L -= 65;
+ }
+ return L==0;
+
+ case 0xC4: // DHT - define huffman table
+ L = get16(z->s)-2;
+ while (L > 0) {
+ uint8 *v;
+ int sizes[16],i,m=0;
+ int q = get8(z->s);
+ int tc = q >> 4;
+ int th = q & 15;
+ if (tc > 1 || th > 3) return e("bad DHT header","Corrupt JPEG");
+ for (i=0; i < 16; ++i) {
+ sizes[i] = get8(z->s);
+ m += sizes[i];
+ }
+ L -= 17;
+ if (tc == 0) {
+ if (!build_huffman(z->huff_dc+th, sizes)) return 0;
+ v = z->huff_dc[th].values;
+ } else {
+ if (!build_huffman(z->huff_ac+th, sizes)) return 0;
+ v = z->huff_ac[th].values;
+ }
+ for (i=0; i < m; ++i)
+ v[i] = get8u(z->s);
+ L -= m;
+ }
+ return L==0;
+ }
+ // check for comment block or APP blocks
+ if ((m >= 0xE0 && m <= 0xEF) || m == 0xFE) {
+ skip(z->s, get16(z->s)-2);
+ return 1;
+ }
+ return 0;
+}
+
+// after we see SOS
+static int process_scan_header(jpeg *z)
+{
+ int i;
+ int Ls = get16(z->s);
+ z->scan_n = get8(z->s);
+ if (z->scan_n < 1 || z->scan_n > 4 || z->scan_n > (int) z->s->img_n) return e("bad SOS component count","Corrupt JPEG");
+ if (Ls != 6+2*z->scan_n) return e("bad SOS len","Corrupt JPEG");
+ for (i=0; i < z->scan_n; ++i) {
+ int id = get8(z->s), which;
+ int q = get8(z->s);
+ for (which = 0; which < z->s->img_n; ++which)
+ if (z->img_comp[which].id == id)
+ break;
+ if (which == z->s->img_n) return 0;
+ z->img_comp[which].hd = q >> 4; if (z->img_comp[which].hd > 3) return e("bad DC huff","Corrupt JPEG");
+ z->img_comp[which].ha = q & 15; if (z->img_comp[which].ha > 3) return e("bad AC huff","Corrupt JPEG");
+ z->order[i] = which;
+ }
+ if (get8(z->s) != 0) return e("bad SOS","Corrupt JPEG");
+ get8(z->s); // should be 63, but might be 0
+ if (get8(z->s) != 0) return e("bad SOS","Corrupt JPEG");
+
+ return 1;
+}
+
+static int process_frame_header(jpeg *z, int scan)
+{
+ stbi *s = z->s;
+ int Lf,p,i,q, h_max=1,v_max=1,c;
+ Lf = get16(s); if (Lf < 11) return e("bad SOF len","Corrupt JPEG"); // JPEG
+ p = get8(s); if (p != 8) return e("only 8-bit","JPEG format not supported: 8-bit only"); // JPEG baseline
+ s->img_y = get16(s); if (s->img_y == 0) return e("no header height", "JPEG format not supported: delayed height"); // Legal, but we don't handle it--but neither does IJG
+ s->img_x = get16(s); if (s->img_x == 0) return e("0 width","Corrupt JPEG"); // JPEG requires
+ c = get8(s);
+ if (c != 3 && c != 1) return e("bad component count","Corrupt JPEG"); // JFIF requires
+ s->img_n = c;
+ for (i=0; i < c; ++i) {
+ z->img_comp[i].data = NULL;
+ z->img_comp[i].linebuf = NULL;
+ }
+
+ if (Lf != 8+3*s->img_n) return e("bad SOF len","Corrupt JPEG");
+
+ for (i=0; i < s->img_n; ++i) {
+ z->img_comp[i].id = get8(s);
+ if (z->img_comp[i].id != i+1) // JFIF requires
+ if (z->img_comp[i].id != i) // some version of jpegtran outputs non-JFIF-compliant files!
+ return e("bad component ID","Corrupt JPEG");
+ q = get8(s);
+ z->img_comp[i].h = (q >> 4); if (!z->img_comp[i].h || z->img_comp[i].h > 4) return e("bad H","Corrupt JPEG");
+ z->img_comp[i].v = q & 15; if (!z->img_comp[i].v || z->img_comp[i].v > 4) return e("bad V","Corrupt JPEG");
+ z->img_comp[i].tq = get8(s); if (z->img_comp[i].tq > 3) return e("bad TQ","Corrupt JPEG");
+ }
+
+ if (scan != SCAN_load) return 1;
+
+ if ((1 << 30) / s->img_x / s->img_n < s->img_y) return e("too large", "Image too large to decode");
+
+ for (i=0; i < s->img_n; ++i) {
+ if (z->img_comp[i].h > h_max) h_max = z->img_comp[i].h;
+ if (z->img_comp[i].v > v_max) v_max = z->img_comp[i].v;
+ }
+
+ // compute interleaved mcu info
+ z->img_h_max = h_max;
+ z->img_v_max = v_max;
+ z->img_mcu_w = h_max * 8;
+ z->img_mcu_h = v_max * 8;
+ z->img_mcu_x = (s->img_x + z->img_mcu_w-1) / z->img_mcu_w;
+ z->img_mcu_y = (s->img_y + z->img_mcu_h-1) / z->img_mcu_h;
+
+ for (i=0; i < s->img_n; ++i) {
+ // number of effective pixels (e.g. for non-interleaved MCU)
+ z->img_comp[i].x = (s->img_x * z->img_comp[i].h + h_max-1) / h_max;
+ z->img_comp[i].y = (s->img_y * z->img_comp[i].v + v_max-1) / v_max;
+ // to simplify generation, we'll allocate enough memory to decode
+ // the bogus oversized data from using interleaved MCUs and their
+ // big blocks (e.g. a 16x16 iMCU on an image of width 33); we won't
+ // discard the extra data until colorspace conversion
+ z->img_comp[i].w2 = z->img_mcu_x * z->img_comp[i].h * 8;
+ z->img_comp[i].h2 = z->img_mcu_y * z->img_comp[i].v * 8;
+ z->img_comp[i].raw_data = malloc(z->img_comp[i].w2 * z->img_comp[i].h2+15);
+ if (z->img_comp[i].raw_data == NULL) {
+ for(--i; i >= 0; --i) {
+ free(z->img_comp[i].raw_data);
+ z->img_comp[i].data = NULL;
+ }
+ return e("outofmem", "Out of memory");
+ }
+ // align blocks for installable-idct using mmx/sse
+ z->img_comp[i].data = (uint8*) (((size_t) z->img_comp[i].raw_data + 15) & ~15);
+ z->img_comp[i].linebuf = NULL;
+ }
+
+ return 1;
+}
+
+// use comparisons since in some cases we handle more than one case (e.g. SOF)
+#define DNL(x) ((x) == 0xdc)
+#define SOI(x) ((x) == 0xd8)
+#define EOI(x) ((x) == 0xd9)
+#define SOF(x) ((x) == 0xc0 || (x) == 0xc1)
+#define SOS(x) ((x) == 0xda)
+
+static int decode_jpeg_header(jpeg *z, int scan)
+{
+ int m;
+ z->marker = MARKER_none; // initialize cached marker to empty
+ m = get_marker(z);
+ if (!SOI(m)) return e("no SOI","Corrupt JPEG");
+ if (scan == SCAN_type) return 1;
+ m = get_marker(z);
+ while (!SOF(m)) {
+ if (!process_marker(z,m)) return 0;
+ m = get_marker(z);
+ while (m == MARKER_none) {
+ // some files have extra padding after their blocks, so ok, we'll scan
+ if (at_eof(z->s)) return e("no SOF", "Corrupt JPEG");
+ m = get_marker(z);
+ }
+ }
+ if (!process_frame_header(z, scan)) return 0;
+ return 1;
+}
+
+static int decode_jpeg_image(jpeg *j)
+{
+ int m;
+ j->restart_interval = 0;
+ if (!decode_jpeg_header(j, SCAN_load)) return 0;
+ m = get_marker(j);
+ while (!EOI(m)) {
+ if (SOS(m)) {
+ if (!process_scan_header(j)) return 0;
+ if (!parse_entropy_coded_data(j)) return 0;
+ if (j->marker == MARKER_none ) {
+ // handle 0s at the end of image data from IP Kamera 9060
+ while (!at_eof(j->s)) {
+ int x = get8(j->s);
+ if (x == 255) {
+ j->marker = get8u(j->s);
+ break;
+ } else if (x != 0) {
+ return 0;
+ }
+ }
+ // if we reach eof without hitting a marker, get_marker() below will fail and we'll eventually return 0
+ }
+ } else {
+ if (!process_marker(j, m)) return 0;
+ }
+ m = get_marker(j);
+ }
+ return 1;
+}
+
+// static jfif-centered resampling (across block boundaries)
+
+typedef uint8 *(*resample_row_func)(uint8 *out, uint8 *in0, uint8 *in1,
+ int w, int hs);
+
+#define div4(x) ((uint8) ((x) >> 2))
+
+static uint8 *resample_row_1(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs)
+{
+ STBI_NOTUSED(out);
+ STBI_NOTUSED(in_far);
+ STBI_NOTUSED(w);
+ STBI_NOTUSED(hs);
+ return in_near;
+}
+
+static uint8* resample_row_v_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs)
+{
+ // need to generate two samples vertically for every one in input
+ int i;
+ STBI_NOTUSED(hs);
+ for (i=0; i < w; ++i)
+ out[i] = div4(3*in_near[i] + in_far[i] + 2);
+ return out;
+}
+
+static uint8* resample_row_h_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs)
+{
+ // need to generate two samples horizontally for every one in input
+ int i;
+ uint8 *input = in_near;
+
+ if (w == 1) {
+ // if only one sample, can't do any interpolation
+ out[0] = out[1] = input[0];
+ return out;
+ }
+
+ out[0] = input[0];
+ out[1] = div4(input[0]*3 + input[1] + 2);
+ for (i=1; i < w-1; ++i) {
+ int n = 3*input[i]+2;
+ out[i*2+0] = div4(n+input[i-1]);
+ out[i*2+1] = div4(n+input[i+1]);
+ }
+ out[i*2+0] = div4(input[w-2]*3 + input[w-1] + 2);
+ out[i*2+1] = input[w-1];
+
+ STBI_NOTUSED(in_far);
+ STBI_NOTUSED(hs);
+
+ return out;
+}
+
+#define div16(x) ((uint8) ((x) >> 4))
+
+static uint8 *resample_row_hv_2(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs)
+{
+ // need to generate 2x2 samples for every one in input
+ int i,t0,t1;
+ if (w == 1) {
+ out[0] = out[1] = div4(3*in_near[0] + in_far[0] + 2);
+ return out;
+ }
+
+ t1 = 3*in_near[0] + in_far[0];
+ out[0] = div4(t1+2);
+ for (i=1; i < w; ++i) {
+ t0 = t1;
+ t1 = 3*in_near[i]+in_far[i];
+ out[i*2-1] = div16(3*t0 + t1 + 8);
+ out[i*2 ] = div16(3*t1 + t0 + 8);
+ }
+ out[w*2-1] = div4(t1+2);
+
+ STBI_NOTUSED(hs);
+
+ return out;
+}
+
+static uint8 *resample_row_generic(uint8 *out, uint8 *in_near, uint8 *in_far, int w, int hs)
+{
+ // resample with nearest-neighbor
+ int i,j;
+ STBI_NOTUSED(in_far);
+ for (i=0; i < w; ++i)
+ for (j=0; j < hs; ++j)
+ out[i*hs+j] = in_near[i];
+ return out;
+}
+
+#define float2fixed(x) ((int) ((x) * 65536 + 0.5))
+
+// 0.38 seconds on 3*anemones.jpg (0.25 with processor = Pro)
+// VC6 without processor=Pro is generating multiple LEAs per multiply!
+static void YCbCr_to_RGB_row(uint8 *out, const uint8 *y, const uint8 *pcb, const uint8 *pcr, int count, int step)
+{
+ int i;
+ for (i=0; i < count; ++i) {
+ int y_fixed = (y[i] << 16) + 32768; // rounding
+ int r,g,b;
+ int cr = pcr[i] - 128;
+ int cb = pcb[i] - 128;
+ r = y_fixed + cr*float2fixed(1.40200f);
+ g = y_fixed - cr*float2fixed(0.71414f) - cb*float2fixed(0.34414f);
+ b = y_fixed + cb*float2fixed(1.77200f);
+ r >>= 16;
+ g >>= 16;
+ b >>= 16;
+ if ((unsigned) r > 255) { if (r < 0) r = 0; else r = 255; }
+ if ((unsigned) g > 255) { if (g < 0) g = 0; else g = 255; }
+ if ((unsigned) b > 255) { if (b < 0) b = 0; else b = 255; }
+ out[0] = (uint8)r;
+ out[1] = (uint8)g;
+ out[2] = (uint8)b;
+ out[3] = 255;
+ out += step;
+ }
+}
+
+#ifdef STBI_SIMD
+static stbi_YCbCr_to_RGB_run stbi_YCbCr_installed = YCbCr_to_RGB_row;
+
+void stbi_install_YCbCr_to_RGB(stbi_YCbCr_to_RGB_run func)
+{
+ stbi_YCbCr_installed = func;
+}
+#endif
+
+
+// clean up the temporary component buffers
+static void cleanup_jpeg(jpeg *j)
+{
+ int i;
+ for (i=0; i < j->s->img_n; ++i) {
+ if (j->img_comp[i].data) {
+ free(j->img_comp[i].raw_data);
+ j->img_comp[i].data = NULL;
+ }
+ if (j->img_comp[i].linebuf) {
+ free(j->img_comp[i].linebuf);
+ j->img_comp[i].linebuf = NULL;
+ }
+ }
+}
+
+typedef struct
+{
+ resample_row_func resample;
+ uint8 *line0,*line1;
+ int hs,vs; // expansion factor in each axis
+ int w_lores; // horizontal pixels pre-expansion
+ int ystep; // how far through vertical expansion we are
+ int ypos; // which pre-expansion row we're on
+} stbi_resample;
+
+static uint8 *load_jpeg_image(jpeg *z, int *out_x, int *out_y, int *comp, int req_comp)
+{
+ int n, decode_n;
+ // validate req_comp
+ if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp", "Internal error");
+ z->s->img_n = 0;
+
+ // load a jpeg image from whichever source
+ if (!decode_jpeg_image(z)) { cleanup_jpeg(z); return NULL; }
+
+ // determine actual number of components to generate
+ n = req_comp ? req_comp : z->s->img_n;
+
+ if (z->s->img_n == 3 && n < 3)
+ decode_n = 1;
+ else
+ decode_n = z->s->img_n;
+
+ // resample and color-convert
+ {
+ int k;
+ uint i,j;
+ uint8 *output;
+ uint8 *coutput[4];
+
+ stbi_resample res_comp[4];
+
+ for (k=0; k < decode_n; ++k) {
+ stbi_resample *r = &res_comp[k];
+
+ // allocate line buffer big enough for upsampling off the edges
+ // with upsample factor of 4
+ z->img_comp[k].linebuf = (uint8 *) malloc(z->s->img_x + 3);
+ if (!z->img_comp[k].linebuf) { cleanup_jpeg(z); return epuc("outofmem", "Out of memory"); }
+
+ r->hs = z->img_h_max / z->img_comp[k].h;
+ r->vs = z->img_v_max / z->img_comp[k].v;
+ r->ystep = r->vs >> 1;
+ r->w_lores = (z->s->img_x + r->hs-1) / r->hs;
+ r->ypos = 0;
+ r->line0 = r->line1 = z->img_comp[k].data;
+
+ if (r->hs == 1 && r->vs == 1) r->resample = resample_row_1;
+ else if (r->hs == 1 && r->vs == 2) r->resample = resample_row_v_2;
+ else if (r->hs == 2 && r->vs == 1) r->resample = resample_row_h_2;
+ else if (r->hs == 2 && r->vs == 2) r->resample = resample_row_hv_2;
+ else r->resample = resample_row_generic;
+ }
+
+ // can't error after this so, this is safe
+ output = (uint8 *) malloc(n * z->s->img_x * z->s->img_y + 1);
+ if (!output) { cleanup_jpeg(z); return epuc("outofmem", "Out of memory"); }
+
+ // now go ahead and resample
+ for (j=0; j < z->s->img_y; ++j) {
+ uint8 *out = output + n * z->s->img_x * j;
+ for (k=0; k < decode_n; ++k) {
+ stbi_resample *r = &res_comp[k];
+ int y_bot = r->ystep >= (r->vs >> 1);
+ coutput[k] = r->resample(z->img_comp[k].linebuf,
+ y_bot ? r->line1 : r->line0,
+ y_bot ? r->line0 : r->line1,
+ r->w_lores, r->hs);
+ if (++r->ystep >= r->vs) {
+ r->ystep = 0;
+ r->line0 = r->line1;
+ if (++r->ypos < z->img_comp[k].y)
+ r->line1 += z->img_comp[k].w2;
+ }
+ }
+ if (n >= 3) {
+ uint8 *y = coutput[0];
+ if (z->s->img_n == 3) {
+ #ifdef STBI_SIMD
+ stbi_YCbCr_installed(out, y, coutput[1], coutput[2], z->s.img_x, n);
+ #else
+ YCbCr_to_RGB_row(out, y, coutput[1], coutput[2], z->s->img_x, n);
+ #endif
+ } else
+ for (i=0; i < z->s->img_x; ++i) {
+ out[0] = out[1] = out[2] = y[i];
+ out[3] = 255; // not used if n==3
+ out += n;
+ }
+ } else {
+ uint8 *y = coutput[0];
+ if (n == 1)
+ for (i=0; i < z->s->img_x; ++i) out[i] = y[i];
+ else
+ for (i=0; i < z->s->img_x; ++i) *out++ = y[i], *out++ = 255;
+ }
+ }
+ cleanup_jpeg(z);
+ *out_x = z->s->img_x;
+ *out_y = z->s->img_y;
+ if (comp) *comp = z->s->img_n; // report original components, not output
+ return output;
+ }
+}
+
+static unsigned char *stbi_jpeg_load(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ jpeg j;
+ j.s = s;
+ return load_jpeg_image(&j, x,y,comp,req_comp);
+}
+
+static int stbi_jpeg_test(stbi *s)
+{
+ int r;
+ jpeg j;
+ j.s = s;
+ r = decode_jpeg_header(&j, SCAN_type);
+ stbi_rewind(s);
+ return r;
+}
+
+static int stbi_jpeg_info_raw(jpeg *j, int *x, int *y, int *comp)
+{
+ if (!decode_jpeg_header(j, SCAN_header)) {
+ stbi_rewind( j->s );
+ return 0;
+ }
+ if (x) *x = j->s->img_x;
+ if (y) *y = j->s->img_y;
+ if (comp) *comp = j->s->img_n;
+ return 1;
+}
+
+static int stbi_jpeg_info(stbi *s, int *x, int *y, int *comp)
+{
+ jpeg j;
+ j.s = s;
+ return stbi_jpeg_info_raw(&j, x, y, comp);
+}
+
+// public domain zlib decode v0.2 Sean Barrett 2006-11-18
+// simple implementation
+// - all input must be provided in an upfront buffer
+// - all output is written to a single output buffer (can malloc/realloc)
+// performance
+// - fast huffman
+
+// fast-way is faster to check than jpeg huffman, but slow way is slower
+#define ZFAST_BITS 9 // accelerate all cases in default tables
+#define ZFAST_MASK ((1 << ZFAST_BITS) - 1)
+
+// zlib-style huffman encoding
+// (jpegs packs from left, zlib from right, so can't share code)
+typedef struct
+{
+ uint16 fast[1 << ZFAST_BITS];
+ uint16 firstcode[16];
+ int maxcode[17];
+ uint16 firstsymbol[16];
+ uint8 size[288];
+ uint16 value[288];
+} zhuffman;
+
+stbi_inline static int bitreverse16(int n)
+{
+ n = ((n & 0xAAAA) >> 1) | ((n & 0x5555) << 1);
+ n = ((n & 0xCCCC) >> 2) | ((n & 0x3333) << 2);
+ n = ((n & 0xF0F0) >> 4) | ((n & 0x0F0F) << 4);
+ n = ((n & 0xFF00) >> 8) | ((n & 0x00FF) << 8);
+ return n;
+}
+
+stbi_inline static int bit_reverse(int v, int bits)
+{
+ assert(bits <= 16);
+ // to bit reverse n bits, reverse 16 and shift
+ // e.g. 11 bits, bit reverse and shift away 5
+ return bitreverse16(v) >> (16-bits);
+}
+
+static int zbuild_huffman(zhuffman *z, uint8 *sizelist, int num)
+{
+ int i,k=0;
+ int code, next_code[16], sizes[17];
+
+ // DEFLATE spec for generating codes
+ memset(sizes, 0, sizeof(sizes));
+ memset(z->fast, 255, sizeof(z->fast));
+ for (i=0; i < num; ++i)
+ ++sizes[sizelist[i]];
+ sizes[0] = 0;
+ for (i=1; i < 16; ++i)
+ assert(sizes[i] <= (1 << i));
+ code = 0;
+ for (i=1; i < 16; ++i) {
+ next_code[i] = code;
+ z->firstcode[i] = (uint16) code;
+ z->firstsymbol[i] = (uint16) k;
+ code = (code + sizes[i]);
+ if (sizes[i])
+ if (code-1 >= (1 << i)) return e("bad codelengths","Corrupt JPEG");
+ z->maxcode[i] = code << (16-i); // preshift for inner loop
+ code <<= 1;
+ k += sizes[i];
+ }
+ z->maxcode[16] = 0x10000; // sentinel
+ for (i=0; i < num; ++i) {
+ int s = sizelist[i];
+ if (s) {
+ int c = next_code[s] - z->firstcode[s] + z->firstsymbol[s];
+ z->size[c] = (uint8)s;
+ z->value[c] = (uint16)i;
+ if (s <= ZFAST_BITS) {
+ int k = bit_reverse(next_code[s],s);
+ while (k < (1 << ZFAST_BITS)) {
+ z->fast[k] = (uint16) c;
+ k += (1 << s);
+ }
+ }
+ ++next_code[s];
+ }
+ }
+ return 1;
+}
+
+// zlib-from-memory implementation for PNG reading
+// because PNG allows splitting the zlib stream arbitrarily,
+// and it's annoying structurally to have PNG call ZLIB call PNG,
+// we require PNG read all the IDATs and combine them into a single
+// memory buffer
+
+typedef struct
+{
+ uint8 *zbuffer, *zbuffer_end;
+ int num_bits;
+ uint32 code_buffer;
+
+ char *zout;
+ char *zout_start;
+ char *zout_end;
+ int z_expandable;
+
+ zhuffman z_length, z_distance;
+} zbuf;
+
+stbi_inline static int zget8(zbuf *z)
+{
+ if (z->zbuffer >= z->zbuffer_end) return 0;
+ return *z->zbuffer++;
+}
+
+static void fill_bits(zbuf *z)
+{
+ do {
+ assert(z->code_buffer < (1U << z->num_bits));
+ z->code_buffer |= zget8(z) << z->num_bits;
+ z->num_bits += 8;
+ } while (z->num_bits <= 24);
+}
+
+stbi_inline static unsigned int zreceive(zbuf *z, int n)
+{
+ unsigned int k;
+ if (z->num_bits < n) fill_bits(z);
+ k = z->code_buffer & ((1 << n) - 1);
+ z->code_buffer >>= n;
+ z->num_bits -= n;
+ return k;
+}
+
+stbi_inline static int zhuffman_decode(zbuf *a, zhuffman *z)
+{
+ int b,s,k;
+ if (a->num_bits < 16) fill_bits(a);
+ b = z->fast[a->code_buffer & ZFAST_MASK];
+ if (b < 0xffff) {
+ s = z->size[b];
+ a->code_buffer >>= s;
+ a->num_bits -= s;
+ return z->value[b];
+ }
+
+ // not resolved by fast table, so compute it the slow way
+ // use jpeg approach, which requires MSbits at top
+ k = bit_reverse(a->code_buffer, 16);
+ for (s=ZFAST_BITS+1; ; ++s)
+ if (k < z->maxcode[s])
+ break;
+ if (s == 16) return -1; // invalid code!
+ // code size is s, so:
+ b = (k >> (16-s)) - z->firstcode[s] + z->firstsymbol[s];
+ assert(z->size[b] == s);
+ a->code_buffer >>= s;
+ a->num_bits -= s;
+ return z->value[b];
+}
+
+static int expand(zbuf *z, int n) // need to make room for n bytes
+{
+ char *q;
+ int cur, limit;
+ if (!z->z_expandable) return e("output buffer limit","Corrupt PNG");
+ cur = (int) (z->zout - z->zout_start);
+ limit = (int) (z->zout_end - z->zout_start);
+ while (cur + n > limit)
+ limit *= 2;
+ q = (char *) realloc(z->zout_start, limit);
+ if (q == NULL) return e("outofmem", "Out of memory");
+ z->zout_start = q;
+ z->zout = q + cur;
+ z->zout_end = q + limit;
+ return 1;
+}
+
+static int length_base[31] = {
+ 3,4,5,6,7,8,9,10,11,13,
+ 15,17,19,23,27,31,35,43,51,59,
+ 67,83,99,115,131,163,195,227,258,0,0 };
+
+static int length_extra[31]=
+{ 0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0,0,0 };
+
+static int dist_base[32] = { 1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,
+257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577,0,0};
+
+static int dist_extra[32] =
+{ 0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};
+
+static int parse_huffman_block(zbuf *a)
+{
+ for(;;) {
+ int z = zhuffman_decode(a, &a->z_length);
+ if (z < 256) {
+ if (z < 0) return e("bad huffman code","Corrupt PNG"); // error in huffman codes
+ if (a->zout >= a->zout_end) if (!expand(a, 1)) return 0;
+ *a->zout++ = (char) z;
+ } else {
+ uint8 *p;
+ int len,dist;
+ if (z == 256) return 1;
+ z -= 257;
+ len = length_base[z];
+ if (length_extra[z]) len += zreceive(a, length_extra[z]);
+ z = zhuffman_decode(a, &a->z_distance);
+ if (z < 0) return e("bad huffman code","Corrupt PNG");
+ dist = dist_base[z];
+ if (dist_extra[z]) dist += zreceive(a, dist_extra[z]);
+ if (a->zout - a->zout_start < dist) return e("bad dist","Corrupt PNG");
+ if (a->zout + len > a->zout_end) if (!expand(a, len)) return 0;
+ p = (uint8 *) (a->zout - dist);
+ while (len--)
+ *a->zout++ = *p++;
+ }
+ }
+}
+
+static int compute_huffman_codes(zbuf *a)
+{
+ static uint8 length_dezigzag[19] = { 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 };
+ zhuffman z_codelength;
+ uint8 lencodes[286+32+137];//padding for maximum single op
+ uint8 codelength_sizes[19];
+ int i,n;
+
+ int hlit = zreceive(a,5) + 257;
+ int hdist = zreceive(a,5) + 1;
+ int hclen = zreceive(a,4) + 4;
+
+ memset(codelength_sizes, 0, sizeof(codelength_sizes));
+ for (i=0; i < hclen; ++i) {
+ int s = zreceive(a,3);
+ codelength_sizes[length_dezigzag[i]] = (uint8) s;
+ }
+ if (!zbuild_huffman(&z_codelength, codelength_sizes, 19)) return 0;
+
+ n = 0;
+ while (n < hlit + hdist) {
+ int c = zhuffman_decode(a, &z_codelength);
+ assert(c >= 0 && c < 19);
+ if (c < 16)
+ lencodes[n++] = (uint8) c;
+ else if (c == 16) {
+ c = zreceive(a,2)+3;
+ memset(lencodes+n, lencodes[n-1], c);
+ n += c;
+ } else if (c == 17) {
+ c = zreceive(a,3)+3;
+ memset(lencodes+n, 0, c);
+ n += c;
+ } else {
+ assert(c == 18);
+ c = zreceive(a,7)+11;
+ memset(lencodes+n, 0, c);
+ n += c;
+ }
+ }
+ if (n != hlit+hdist) return e("bad codelengths","Corrupt PNG");
+ if (!zbuild_huffman(&a->z_length, lencodes, hlit)) return 0;
+ if (!zbuild_huffman(&a->z_distance, lencodes+hlit, hdist)) return 0;
+ return 1;
+}
+
+static int parse_uncompressed_block(zbuf *a)
+{
+ uint8 header[4];
+ int len,nlen,k;
+ if (a->num_bits & 7)
+ zreceive(a, a->num_bits & 7); // discard
+ // drain the bit-packed data into header
+ k = 0;
+ while (a->num_bits > 0) {
+ header[k++] = (uint8) (a->code_buffer & 255); // wtf this warns?
+ a->code_buffer >>= 8;
+ a->num_bits -= 8;
+ }
+ assert(a->num_bits == 0);
+ // now fill header the normal way
+ while (k < 4)
+ header[k++] = (uint8) zget8(a);
+ len = header[1] * 256 + header[0];
+ nlen = header[3] * 256 + header[2];
+ if (nlen != (len ^ 0xffff)) return e("zlib corrupt","Corrupt PNG");
+ if (a->zbuffer + len > a->zbuffer_end) return e("read past buffer","Corrupt PNG");
+ if (a->zout + len > a->zout_end)
+ if (!expand(a, len)) return 0;
+ memcpy(a->zout, a->zbuffer, len);
+ a->zbuffer += len;
+ a->zout += len;
+ return 1;
+}
+
+static int parse_zlib_header(zbuf *a)
+{
+ int cmf = zget8(a);
+ int cm = cmf & 15;
+ /* int cinfo = cmf >> 4; */
+ int flg = zget8(a);
+ if ((cmf*256+flg) % 31 != 0) return e("bad zlib header","Corrupt PNG"); // zlib spec
+ if (flg & 32) return e("no preset dict","Corrupt PNG"); // preset dictionary not allowed in png
+ if (cm != 8) return e("bad compression","Corrupt PNG"); // DEFLATE required for png
+ // window = 1 << (8 + cinfo)... but who cares, we fully buffer output
+ return 1;
+}
+
+// @TODO: should statically initialize these for optimal thread safety
+static uint8 default_length[288], default_distance[32];
+static void init_defaults(void)
+{
+ int i; // use <= to match clearly with spec
+ for (i=0; i <= 143; ++i) default_length[i] = 8;
+ for ( ; i <= 255; ++i) default_length[i] = 9;
+ for ( ; i <= 279; ++i) default_length[i] = 7;
+ for ( ; i <= 287; ++i) default_length[i] = 8;
+
+ for (i=0; i <= 31; ++i) default_distance[i] = 5;
+}
+
+int stbi_png_partial; // a quick hack to only allow decoding some of a PNG... I should implement real streaming support instead
+static int parse_zlib(zbuf *a, int parse_header)
+{
+ int final, type;
+ if (parse_header)
+ if (!parse_zlib_header(a)) return 0;
+ a->num_bits = 0;
+ a->code_buffer = 0;
+ do {
+ final = zreceive(a,1);
+ type = zreceive(a,2);
+ if (type == 0) {
+ if (!parse_uncompressed_block(a)) return 0;
+ } else if (type == 3) {
+ return 0;
+ } else {
+ if (type == 1) {
+ // use fixed code lengths
+ if (!default_distance[31]) init_defaults();
+ if (!zbuild_huffman(&a->z_length , default_length , 288)) return 0;
+ if (!zbuild_huffman(&a->z_distance, default_distance, 32)) return 0;
+ } else {
+ if (!compute_huffman_codes(a)) return 0;
+ }
+ if (!parse_huffman_block(a)) return 0;
+ }
+ if (stbi_png_partial && a->zout - a->zout_start > 65536)
+ break;
+ } while (!final);
+ return 1;
+}
+
+static int do_zlib(zbuf *a, char *obuf, int olen, int exp, int parse_header)
+{
+ a->zout_start = obuf;
+ a->zout = obuf;
+ a->zout_end = obuf + olen;
+ a->z_expandable = exp;
+
+ return parse_zlib(a, parse_header);
+}
+
+char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen)
+{
+ zbuf a;
+ char *p = (char *) malloc(initial_size);
+ if (p == NULL) return NULL;
+ a.zbuffer = (uint8 *) buffer;
+ a.zbuffer_end = (uint8 *) buffer + len;
+ if (do_zlib(&a, p, initial_size, 1, 1)) {
+ if (outlen) *outlen = (int) (a.zout - a.zout_start);
+ return a.zout_start;
+ } else {
+ free(a.zout_start);
+ return NULL;
+ }
+}
+
+char *stbi_zlib_decode_malloc(char const *buffer, int len, int *outlen)
+{
+ return stbi_zlib_decode_malloc_guesssize(buffer, len, 16384, outlen);
+}
+
+char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header)
+{
+ zbuf a;
+ char *p = (char *) malloc(initial_size);
+ if (p == NULL) return NULL;
+ a.zbuffer = (uint8 *) buffer;
+ a.zbuffer_end = (uint8 *) buffer + len;
+ if (do_zlib(&a, p, initial_size, 1, parse_header)) {
+ if (outlen) *outlen = (int) (a.zout - a.zout_start);
+ return a.zout_start;
+ } else {
+ free(a.zout_start);
+ return NULL;
+ }
+}
+
+int stbi_zlib_decode_buffer(char *obuffer, int olen, char const *ibuffer, int ilen)
+{
+ zbuf a;
+ a.zbuffer = (uint8 *) ibuffer;
+ a.zbuffer_end = (uint8 *) ibuffer + ilen;
+ if (do_zlib(&a, obuffer, olen, 0, 1))
+ return (int) (a.zout - a.zout_start);
+ else
+ return -1;
+}
+
+char *stbi_zlib_decode_noheader_malloc(char const *buffer, int len, int *outlen)
+{
+ zbuf a;
+ char *p = (char *) malloc(16384);
+ if (p == NULL) return NULL;
+ a.zbuffer = (uint8 *) buffer;
+ a.zbuffer_end = (uint8 *) buffer+len;
+ if (do_zlib(&a, p, 16384, 1, 0)) {
+ if (outlen) *outlen = (int) (a.zout - a.zout_start);
+ return a.zout_start;
+ } else {
+ free(a.zout_start);
+ return NULL;
+ }
+}
+
+int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen)
+{
+ zbuf a;
+ a.zbuffer = (uint8 *) ibuffer;
+ a.zbuffer_end = (uint8 *) ibuffer + ilen;
+ if (do_zlib(&a, obuffer, olen, 0, 0))
+ return (int) (a.zout - a.zout_start);
+ else
+ return -1;
+}
+
+// public domain "baseline" PNG decoder v0.10 Sean Barrett 2006-11-18
+// simple implementation
+// - only 8-bit samples
+// - no CRC checking
+// - allocates lots of intermediate memory
+// - avoids problem of streaming data between subsystems
+// - avoids explicit window management
+// performance
+// - uses stb_zlib, a PD zlib implementation with fast huffman decoding
+
+
+typedef struct
+{
+ uint32 length;
+ uint32 type;
+} chunk;
+
+#define PNG_TYPE(a,b,c,d) (((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
+
+static chunk get_chunk_header(stbi *s)
+{
+ chunk c;
+ c.length = get32(s);
+ c.type = get32(s);
+ return c;
+}
+
+static int check_png_header(stbi *s)
+{
+ static uint8 png_sig[8] = { 137,80,78,71,13,10,26,10 };
+ int i;
+ for (i=0; i < 8; ++i)
+ if (get8u(s) != png_sig[i]) return e("bad png sig","Not a PNG");
+ return 1;
+}
+
+typedef struct
+{
+ stbi *s;
+ uint8 *idata, *expanded, *out;
+} png;
+
+
+enum {
+ F_none=0, F_sub=1, F_up=2, F_avg=3, F_paeth=4,
+ F_avg_first, F_paeth_first
+};
+
+static uint8 first_row_filter[5] =
+{
+ F_none, F_sub, F_none, F_avg_first, F_paeth_first
+};
+
+static int paeth(int a, int b, int c)
+{
+ int p = a + b - c;
+ int pa = abs(p-a);
+ int pb = abs(p-b);
+ int pc = abs(p-c);
+ if (pa <= pb && pa <= pc) return a;
+ if (pb <= pc) return b;
+ return c;
+}
+
+// create the png data from post-deflated data
+static int create_png_image_raw(png *a, uint8 *raw, uint32 raw_len, int out_n, uint32 x, uint32 y)
+{
+ stbi *s = a->s;
+ uint32 i,j,stride = x*out_n;
+ int k;
+ int img_n = s->img_n; // copy it into a local for later
+ assert(out_n == s->img_n || out_n == s->img_n+1);
+ if (stbi_png_partial) y = 1;
+ a->out = (uint8 *) malloc(x * y * out_n);
+ if (!a->out) return e("outofmem", "Out of memory");
+ if (!stbi_png_partial) {
+ if (s->img_x == x && s->img_y == y) {
+ if (raw_len != (img_n * x + 1) * y) return e("not enough pixels","Corrupt PNG");
+ } else { // interlaced:
+ if (raw_len < (img_n * x + 1) * y) return e("not enough pixels","Corrupt PNG");
+ }
+ }
+ for (j=0; j < y; ++j) {
+ uint8 *cur = a->out + stride*j;
+ uint8 *prior = cur - stride;
+ int filter = *raw++;
+ if (filter > 4) return e("invalid filter","Corrupt PNG");
+ // if first row, use special filter that doesn't sample previous row
+ if (j == 0) filter = first_row_filter[filter];
+ // handle first pixel explicitly
+ for (k=0; k < img_n; ++k) {
+ switch (filter) {
+ case F_none : cur[k] = raw[k]; break;
+ case F_sub : cur[k] = raw[k]; break;
+ case F_up : cur[k] = raw[k] + prior[k]; break;
+ case F_avg : cur[k] = raw[k] + (prior[k]>>1); break;
+ case F_paeth : cur[k] = (uint8) (raw[k] + paeth(0,prior[k],0)); break;
+ case F_avg_first : cur[k] = raw[k]; break;
+ case F_paeth_first: cur[k] = raw[k]; break;
+ }
+ }
+ if (img_n != out_n) cur[img_n] = 255;
+ raw += img_n;
+ cur += out_n;
+ prior += out_n;
+ // this is a little gross, so that we don't switch per-pixel or per-component
+ if (img_n == out_n) {
+ #define CASE(f) \
+ case f: \
+ for (i=x-1; i >= 1; --i, raw+=img_n,cur+=img_n,prior+=img_n) \
+ for (k=0; k < img_n; ++k)
+ switch (filter) {
+ CASE(F_none) cur[k] = raw[k]; break;
+ CASE(F_sub) cur[k] = raw[k] + cur[k-img_n]; break;
+ CASE(F_up) cur[k] = raw[k] + prior[k]; break;
+ CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-img_n])>>1); break;
+ CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],prior[k],prior[k-img_n])); break;
+ CASE(F_avg_first) cur[k] = raw[k] + (cur[k-img_n] >> 1); break;
+ CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],0,0)); break;
+ }
+ #undef CASE
+ } else {
+ assert(img_n+1 == out_n);
+ #define CASE(f) \
+ case f: \
+ for (i=x-1; i >= 1; --i, cur[img_n]=255,raw+=img_n,cur+=out_n,prior+=out_n) \
+ for (k=0; k < img_n; ++k)
+ switch (filter) {
+ CASE(F_none) cur[k] = raw[k]; break;
+ CASE(F_sub) cur[k] = raw[k] + cur[k-out_n]; break;
+ CASE(F_up) cur[k] = raw[k] + prior[k]; break;
+ CASE(F_avg) cur[k] = raw[k] + ((prior[k] + cur[k-out_n])>>1); break;
+ CASE(F_paeth) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],prior[k],prior[k-out_n])); break;
+ CASE(F_avg_first) cur[k] = raw[k] + (cur[k-out_n] >> 1); break;
+ CASE(F_paeth_first) cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],0,0)); break;
+ }
+ #undef CASE
+ }
+ }
+ return 1;
+}
+
+static int create_png_image(png *a, uint8 *raw, uint32 raw_len, int out_n, int interlaced)
+{
+ uint8 *final;
+ int p;
+ int save;
+ if (!interlaced)
+ return create_png_image_raw(a, raw, raw_len, out_n, a->s->img_x, a->s->img_y);
+ save = stbi_png_partial;
+ stbi_png_partial = 0;
+
+ // de-interlacing
+ final = (uint8 *) malloc(a->s->img_x * a->s->img_y * out_n);
+ for (p=0; p < 7; ++p) {
+ int xorig[] = { 0,4,0,2,0,1,0 };
+ int yorig[] = { 0,0,4,0,2,0,1 };
+ int xspc[] = { 8,8,4,4,2,2,1 };
+ int yspc[] = { 8,8,8,4,4,2,2 };
+ int i,j,x,y;
+ // pass1_x[4] = 0, pass1_x[5] = 1, pass1_x[12] = 1
+ x = (a->s->img_x - xorig[p] + xspc[p]-1) / xspc[p];
+ y = (a->s->img_y - yorig[p] + yspc[p]-1) / yspc[p];
+ if (x && y) {
+ if (!create_png_image_raw(a, raw, raw_len, out_n, x, y)) {
+ free(final);
+ return 0;
+ }
+ for (j=0; j < y; ++j)
+ for (i=0; i < x; ++i)
+ memcpy(final + (j*yspc[p]+yorig[p])*a->s->img_x*out_n + (i*xspc[p]+xorig[p])*out_n,
+ a->out + (j*x+i)*out_n, out_n);
+ free(a->out);
+ raw += (x*out_n+1)*y;
+ raw_len -= (x*out_n+1)*y;
+ }
+ }
+ a->out = final;
+
+ stbi_png_partial = save;
+ return 1;
+}
+
+static int compute_transparency(png *z, uint8 tc[3], int out_n)
+{
+ stbi *s = z->s;
+ uint32 i, pixel_count = s->img_x * s->img_y;
+ uint8 *p = z->out;
+
+ // compute color-based transparency, assuming we've
+ // already got 255 as the alpha value in the output
+ assert(out_n == 2 || out_n == 4);
+
+ if (out_n == 2) {
+ for (i=0; i < pixel_count; ++i) {
+ p[1] = (p[0] == tc[0] ? 0 : 255);
+ p += 2;
+ }
+ } else {
+ for (i=0; i < pixel_count; ++i) {
+ if (p[0] == tc[0] && p[1] == tc[1] && p[2] == tc[2])
+ p[3] = 0;
+ p += 4;
+ }
+ }
+ return 1;
+}
+
+static int expand_palette(png *a, uint8 *palette, int len, int pal_img_n)
+{
+ uint32 i, pixel_count = a->s->img_x * a->s->img_y;
+ uint8 *p, *temp_out, *orig = a->out;
+
+ p = (uint8 *) malloc(pixel_count * pal_img_n);
+ if (p == NULL) return e("outofmem", "Out of memory");
+
+ // between here and free(out) below, exitting would leak
+ temp_out = p;
+
+ if (pal_img_n == 3) {
+ for (i=0; i < pixel_count; ++i) {
+ int n = orig[i]*4;
+ p[0] = palette[n ];
+ p[1] = palette[n+1];
+ p[2] = palette[n+2];
+ p += 3;
+ }
+ } else {
+ for (i=0; i < pixel_count; ++i) {
+ int n = orig[i]*4;
+ p[0] = palette[n ];
+ p[1] = palette[n+1];
+ p[2] = palette[n+2];
+ p[3] = palette[n+3];
+ p += 4;
+ }
+ }
+ free(a->out);
+ a->out = temp_out;
+
+ STBI_NOTUSED(len);
+
+ return 1;
+}
+
+static int stbi_unpremultiply_on_load = 0;
+static int stbi_de_iphone_flag = 0;
+
+void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply)
+{
+ stbi_unpremultiply_on_load = flag_true_if_should_unpremultiply;
+}
+void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert)
+{
+ stbi_de_iphone_flag = flag_true_if_should_convert;
+}
+
+static void stbi_de_iphone(png *z)
+{
+ stbi *s = z->s;
+ uint32 i, pixel_count = s->img_x * s->img_y;
+ uint8 *p = z->out;
+
+ if (s->img_out_n == 3) { // convert bgr to rgb
+ for (i=0; i < pixel_count; ++i) {
+ uint8 t = p[0];
+ p[0] = p[2];
+ p[2] = t;
+ p += 3;
+ }
+ } else {
+ assert(s->img_out_n == 4);
+ if (stbi_unpremultiply_on_load) {
+ // convert bgr to rgb and unpremultiply
+ for (i=0; i < pixel_count; ++i) {
+ uint8 a = p[3];
+ uint8 t = p[0];
+ if (a) {
+ p[0] = p[2] * 255 / a;
+ p[1] = p[1] * 255 / a;
+ p[2] = t * 255 / a;
+ } else {
+ p[0] = p[2];
+ p[2] = t;
+ }
+ p += 4;
+ }
+ } else {
+ // convert bgr to rgb
+ for (i=0; i < pixel_count; ++i) {
+ uint8 t = p[0];
+ p[0] = p[2];
+ p[2] = t;
+ p += 4;
+ }
+ }
+ }
+}
+
+static int parse_png_file(png *z, int scan, int req_comp)
+{
+ uint8 palette[1024], pal_img_n=0;
+ uint8 has_trans=0, tc[3];
+ uint32 ioff=0, idata_limit=0, i, pal_len=0;
+ int first=1,k,interlace=0, iphone=0;
+ stbi *s = z->s;
+
+ z->expanded = NULL;
+ z->idata = NULL;
+ z->out = NULL;
+
+ if (!check_png_header(s)) return 0;
+
+ if (scan == SCAN_type) return 1;
+
+ for (;;) {
+ chunk c = get_chunk_header(s);
+ switch (c.type) {
+ case PNG_TYPE('C','g','B','I'):
+ iphone = stbi_de_iphone_flag;
+ skip(s, c.length);
+ break;
+ case PNG_TYPE('I','H','D','R'): {
+ int depth,color,comp,filter;
+ if (!first) return e("multiple IHDR","Corrupt PNG");
+ first = 0;
+ if (c.length != 13) return e("bad IHDR len","Corrupt PNG");
+ s->img_x = get32(s); if (s->img_x > (1 << 24)) return e("too large","Very large image (corrupt?)");
+ s->img_y = get32(s); if (s->img_y > (1 << 24)) return e("too large","Very large image (corrupt?)");
+ depth = get8(s); if (depth != 8) return e("8bit only","PNG not supported: 8-bit only");
+ color = get8(s); if (color > 6) return e("bad ctype","Corrupt PNG");
+ if (color == 3) pal_img_n = 3; else if (color & 1) return e("bad ctype","Corrupt PNG");
+ comp = get8(s); if (comp) return e("bad comp method","Corrupt PNG");
+ filter= get8(s); if (filter) return e("bad filter method","Corrupt PNG");
+ interlace = get8(s); if (interlace>1) return e("bad interlace method","Corrupt PNG");
+ if (!s->img_x || !s->img_y) return e("0-pixel image","Corrupt PNG");
+ if (!pal_img_n) {
+ s->img_n = (color & 2 ? 3 : 1) + (color & 4 ? 1 : 0);
+ if ((1 << 30) / s->img_x / s->img_n < s->img_y) return e("too large", "Image too large to decode");
+ if (scan == SCAN_header) return 1;
+ } else {
+ // if paletted, then pal_n is our final components, and
+ // img_n is # components to decompress/filter.
+ s->img_n = 1;
+ if ((1 << 30) / s->img_x / 4 < s->img_y) return e("too large","Corrupt PNG");
+ // if SCAN_header, have to scan to see if we have a tRNS
+ }
+ break;
+ }
+
+ case PNG_TYPE('P','L','T','E'): {
+ if (first) return e("first not IHDR", "Corrupt PNG");
+ if (c.length > 256*3) return e("invalid PLTE","Corrupt PNG");
+ pal_len = c.length / 3;
+ if (pal_len * 3 != c.length) return e("invalid PLTE","Corrupt PNG");
+ for (i=0; i < pal_len; ++i) {
+ palette[i*4+0] = get8u(s);
+ palette[i*4+1] = get8u(s);
+ palette[i*4+2] = get8u(s);
+ palette[i*4+3] = 255;
+ }
+ break;
+ }
+
+ case PNG_TYPE('t','R','N','S'): {
+ if (first) return e("first not IHDR", "Corrupt PNG");
+ if (z->idata) return e("tRNS after IDAT","Corrupt PNG");
+ if (pal_img_n) {
+ if (scan == SCAN_header) { s->img_n = 4; return 1; }
+ if (pal_len == 0) return e("tRNS before PLTE","Corrupt PNG");
+ if (c.length > pal_len) return e("bad tRNS len","Corrupt PNG");
+ pal_img_n = 4;
+ for (i=0; i < c.length; ++i)
+ palette[i*4+3] = get8u(s);
+ } else {
+ if (!(s->img_n & 1)) return e("tRNS with alpha","Corrupt PNG");
+ if (c.length != (uint32) s->img_n*2) return e("bad tRNS len","Corrupt PNG");
+ has_trans = 1;
+ for (k=0; k < s->img_n; ++k)
+ tc[k] = (uint8) get16(s); // non 8-bit images will be larger
+ }
+ break;
+ }
+
+ case PNG_TYPE('I','D','A','T'): {
+ if (first) return e("first not IHDR", "Corrupt PNG");
+ if (pal_img_n && !pal_len) return e("no PLTE","Corrupt PNG");
+ if (scan == SCAN_header) { s->img_n = pal_img_n; return 1; }
+ if (ioff + c.length > idata_limit) {
+ uint8 *p;
+ if (idata_limit == 0) idata_limit = c.length > 4096 ? c.length : 4096;
+ while (ioff + c.length > idata_limit)
+ idata_limit *= 2;
+ p = (uint8 *) realloc(z->idata, idata_limit); if (p == NULL) return e("outofmem", "Out of memory");
+ z->idata = p;
+ }
+ if (!getn(s, z->idata+ioff,c.length)) return e("outofdata","Corrupt PNG");
+ ioff += c.length;
+ break;
+ }
+
+ case PNG_TYPE('I','E','N','D'): {
+ uint32 raw_len;
+ if (first) return e("first not IHDR", "Corrupt PNG");
+ if (scan != SCAN_load) return 1;
+ if (z->idata == NULL) return e("no IDAT","Corrupt PNG");
+ z->expanded = (uint8 *) stbi_zlib_decode_malloc_guesssize_headerflag((char *) z->idata, ioff, 16384, (int *) &raw_len, !iphone);
+ if (z->expanded == NULL) return 0; // zlib should set error
+ free(z->idata); z->idata = NULL;
+ if ((req_comp == s->img_n+1 && req_comp != 3 && !pal_img_n) || has_trans)
+ s->img_out_n = s->img_n+1;
+ else
+ s->img_out_n = s->img_n;
+ if (!create_png_image(z, z->expanded, raw_len, s->img_out_n, interlace)) return 0;
+ if (has_trans)
+ if (!compute_transparency(z, tc, s->img_out_n)) return 0;
+ if (iphone && s->img_out_n > 2)
+ stbi_de_iphone(z);
+ if (pal_img_n) {
+ // pal_img_n == 3 or 4
+ s->img_n = pal_img_n; // record the actual colors we had
+ s->img_out_n = pal_img_n;
+ if (req_comp >= 3) s->img_out_n = req_comp;
+ if (!expand_palette(z, palette, pal_len, s->img_out_n))
+ return 0;
+ }
+ free(z->expanded); z->expanded = NULL;
+ return 1;
+ }
+
+ default:
+ // if critical, fail
+ if (first) return e("first not IHDR", "Corrupt PNG");
+ if ((c.type & (1 << 29)) == 0) {
+ #ifndef STBI_NO_FAILURE_STRINGS
+ // not threadsafe
+ static char invalid_chunk[] = "XXXX chunk not known";
+ invalid_chunk[0] = (uint8) (c.type >> 24);
+ invalid_chunk[1] = (uint8) (c.type >> 16);
+ invalid_chunk[2] = (uint8) (c.type >> 8);
+ invalid_chunk[3] = (uint8) (c.type >> 0);
+ #endif
+ return e(invalid_chunk, "PNG not supported: unknown chunk type");
+ }
+ skip(s, c.length);
+ break;
+ }
+ // end of chunk, read and skip CRC
+ get32(s);
+ }
+}
+
+static unsigned char *do_png(png *p, int *x, int *y, int *n, int req_comp)
+{
+ unsigned char *result=NULL;
+ if (req_comp < 0 || req_comp > 4) return epuc("bad req_comp", "Internal error");
+ if (parse_png_file(p, SCAN_load, req_comp)) {
+ result = p->out;
+ p->out = NULL;
+ if (req_comp && req_comp != p->s->img_out_n) {
+ result = convert_format(result, p->s->img_out_n, req_comp, p->s->img_x, p->s->img_y);
+ p->s->img_out_n = req_comp;
+ if (result == NULL) return result;
+ }
+ *x = p->s->img_x;
+ *y = p->s->img_y;
+ if (n) *n = p->s->img_n;
+ }
+ free(p->out); p->out = NULL;
+ free(p->expanded); p->expanded = NULL;
+ free(p->idata); p->idata = NULL;
+
+ return result;
+}
+
+static unsigned char *stbi_png_load(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ png p;
+ p.s = s;
+ return do_png(&p, x,y,comp,req_comp);
+}
+
+static int stbi_png_test(stbi *s)
+{
+ int r;
+ r = check_png_header(s);
+ stbi_rewind(s);
+ return r;
+}
+
+static int stbi_png_info_raw(png *p, int *x, int *y, int *comp)
+{
+ if (!parse_png_file(p, SCAN_header, 0)) {
+ stbi_rewind( p->s );
+ return 0;
+ }
+ if (x) *x = p->s->img_x;
+ if (y) *y = p->s->img_y;
+ if (comp) *comp = p->s->img_n;
+ return 1;
+}
+
+static int stbi_png_info(stbi *s, int *x, int *y, int *comp)
+{
+ png p;
+ p.s = s;
+ return stbi_png_info_raw(&p, x, y, comp);
+}
+
+// Microsoft/Windows BMP image
+
+static int bmp_test(stbi *s)
+{
+ int sz;
+ if (get8(s) != 'B') return 0;
+ if (get8(s) != 'M') return 0;
+ get32le(s); // discard filesize
+ get16le(s); // discard reserved
+ get16le(s); // discard reserved
+ get32le(s); // discard data offset
+ sz = get32le(s);
+ if (sz == 12 || sz == 40 || sz == 56 || sz == 108) return 1;
+ return 0;
+}
+
+static int stbi_bmp_test(stbi *s)
+{
+ int r = bmp_test(s);
+ stbi_rewind(s);
+ return r;
+}
+
+
+// returns 0..31 for the highest set bit
+static int high_bit(unsigned int z)
+{
+ int n=0;
+ if (z == 0) return -1;
+ if (z >= 0x10000) n += 16, z >>= 16;
+ if (z >= 0x00100) n += 8, z >>= 8;
+ if (z >= 0x00010) n += 4, z >>= 4;
+ if (z >= 0x00004) n += 2, z >>= 2;
+ if (z >= 0x00002) n += 1, z >>= 1;
+ return n;
+}
+
+static int bitcount(unsigned int a)
+{
+ a = (a & 0x55555555) + ((a >> 1) & 0x55555555); // max 2
+ a = (a & 0x33333333) + ((a >> 2) & 0x33333333); // max 4
+ a = (a + (a >> 4)) & 0x0f0f0f0f; // max 8 per 4, now 8 bits
+ a = (a + (a >> 8)); // max 16 per 8 bits
+ a = (a + (a >> 16)); // max 32 per 8 bits
+ return a & 0xff;
+}
+
+static int shiftsigned(int v, int shift, int bits)
+{
+ int result;
+ int z=0;
+
+ if (shift < 0) v <<= -shift;
+ else v >>= shift;
+ result = v;
+
+ z = bits;
+ while (z < 8) {
+ result += v >> z;
+ z += bits;
+ }
+ return result;
+}
+
+static stbi_uc *bmp_load(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ uint8 *out;
+ unsigned int mr=0,mg=0,mb=0,ma=0, fake_a=0;
+ stbi_uc pal[256][4];
+ int psize=0,i,j,compress=0,width;
+ int bpp, flip_vertically, pad, target, offset, hsz;
+ if (get8(s) != 'B' || get8(s) != 'M') return epuc("not BMP", "Corrupt BMP");
+ get32le(s); // discard filesize
+ get16le(s); // discard reserved
+ get16le(s); // discard reserved
+ offset = get32le(s);
+ hsz = get32le(s);
+ if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108) return epuc("unknown BMP", "BMP type not supported: unknown");
+ if (hsz == 12) {
+ s->img_x = get16le(s);
+ s->img_y = get16le(s);
+ } else {
+ s->img_x = get32le(s);
+ s->img_y = get32le(s);
+ }
+ if (get16le(s) != 1) return epuc("bad BMP", "bad BMP");
+ bpp = get16le(s);
+ if (bpp == 1) return epuc("monochrome", "BMP type not supported: 1-bit");
+ flip_vertically = ((int) s->img_y) > 0;
+ s->img_y = abs((int) s->img_y);
+ if (hsz == 12) {
+ if (bpp < 24)
+ psize = (offset - 14 - 24) / 3;
+ } else {
+ compress = get32le(s);
+ if (compress == 1 || compress == 2) return epuc("BMP RLE", "BMP type not supported: RLE");
+ get32le(s); // discard sizeof
+ get32le(s); // discard hres
+ get32le(s); // discard vres
+ get32le(s); // discard colorsused
+ get32le(s); // discard max important
+ if (hsz == 40 || hsz == 56) {
+ if (hsz == 56) {
+ get32le(s);
+ get32le(s);
+ get32le(s);
+ get32le(s);
+ }
+ if (bpp == 16 || bpp == 32) {
+ mr = mg = mb = 0;
+ if (compress == 0) {
+ if (bpp == 32) {
+ mr = 0xffu << 16;
+ mg = 0xffu << 8;
+ mb = 0xffu << 0;
+ ma = 0xffu << 24;
+ fake_a = 1; // @TODO: check for cases like alpha value is all 0 and switch it to 255
+ } else {
+ mr = 31u << 10;
+ mg = 31u << 5;
+ mb = 31u << 0;
+ }
+ } else if (compress == 3) {
+ mr = get32le(s);
+ mg = get32le(s);
+ mb = get32le(s);
+ // not documented, but generated by photoshop and handled by mspaint
+ if (mr == mg && mg == mb) {
+ // ?!?!?
+ return epuc("bad BMP", "bad BMP");
+ }
+ } else
+ return epuc("bad BMP", "bad BMP");
+ }
+ } else {
+ assert(hsz == 108);
+ mr = get32le(s);
+ mg = get32le(s);
+ mb = get32le(s);
+ ma = get32le(s);
+ get32le(s); // discard color space
+ for (i=0; i < 12; ++i)
+ get32le(s); // discard color space parameters
+ }
+ if (bpp < 16)
+ psize = (offset - 14 - hsz) >> 2;
+ }
+ s->img_n = ma ? 4 : 3;
+ if (req_comp && req_comp >= 3) // we can directly decode 3 or 4
+ target = req_comp;
+ else
+ target = s->img_n; // if they want monochrome, we'll post-convert
+ out = (stbi_uc *) malloc(target * s->img_x * s->img_y);
+ if (!out) return epuc("outofmem", "Out of memory");
+ if (bpp < 16) {
+ int z=0;
+ if (psize == 0 || psize > 256) { free(out); return epuc("invalid", "Corrupt BMP"); }
+ for (i=0; i < psize; ++i) {
+ pal[i][2] = get8u(s);
+ pal[i][1] = get8u(s);
+ pal[i][0] = get8u(s);
+ if (hsz != 12) get8(s);
+ pal[i][3] = 255;
+ }
+ skip(s, offset - 14 - hsz - psize * (hsz == 12 ? 3 : 4));
+ if (bpp == 4) width = (s->img_x + 1) >> 1;
+ else if (bpp == 8) width = s->img_x;
+ else { free(out); return epuc("bad bpp", "Corrupt BMP"); }
+ pad = (-width)&3;
+ for (j=0; j < (int) s->img_y; ++j) {
+ for (i=0; i < (int) s->img_x; i += 2) {
+ int v=get8(s),v2=0;
+ if (bpp == 4) {
+ v2 = v & 15;
+ v >>= 4;
+ }
+ out[z++] = pal[v][0];
+ out[z++] = pal[v][1];
+ out[z++] = pal[v][2];
+ if (target == 4) out[z++] = 255;
+ if (i+1 == (int) s->img_x) break;
+ v = (bpp == 8) ? get8(s) : v2;
+ out[z++] = pal[v][0];
+ out[z++] = pal[v][1];
+ out[z++] = pal[v][2];
+ if (target == 4) out[z++] = 255;
+ }
+ skip(s, pad);
+ }
+ } else {
+ int rshift=0,gshift=0,bshift=0,ashift=0,rcount=0,gcount=0,bcount=0,acount=0;
+ int z = 0;
+ int easy=0;
+ skip(s, offset - 14 - hsz);
+ if (bpp == 24) width = 3 * s->img_x;
+ else if (bpp == 16) width = 2*s->img_x;
+ else /* bpp = 32 and pad = 0 */ width=0;
+ pad = (-width) & 3;
+ if (bpp == 24) {
+ easy = 1;
+ } else if (bpp == 32) {
+ if (mb == 0xff && mg == 0xff00 && mr == 0x00ff0000 && ma == 0xff000000)
+ easy = 2;
+ }
+ if (!easy) {
+ if (!mr || !mg || !mb) { free(out); return epuc("bad masks", "Corrupt BMP"); }
+ // right shift amt to put high bit in position #7
+ rshift = high_bit(mr)-7; rcount = bitcount(mr);
+ gshift = high_bit(mg)-7; gcount = bitcount(mr);
+ bshift = high_bit(mb)-7; bcount = bitcount(mr);
+ ashift = high_bit(ma)-7; acount = bitcount(mr);
+ }
+ for (j=0; j < (int) s->img_y; ++j) {
+ if (easy) {
+ for (i=0; i < (int) s->img_x; ++i) {
+ int a;
+ out[z+2] = get8u(s);
+ out[z+1] = get8u(s);
+ out[z+0] = get8u(s);
+ z += 3;
+ a = (easy == 2 ? get8(s) : 255);
+ if (target == 4) out[z++] = (uint8) a;
+ }
+ } else {
+ for (i=0; i < (int) s->img_x; ++i) {
+ uint32 v = (bpp == 16 ? get16le(s) : get32le(s));
+ int a;
+ out[z++] = (uint8) shiftsigned(v & mr, rshift, rcount);
+ out[z++] = (uint8) shiftsigned(v & mg, gshift, gcount);
+ out[z++] = (uint8) shiftsigned(v & mb, bshift, bcount);
+ a = (ma ? shiftsigned(v & ma, ashift, acount) : 255);
+ if (target == 4) out[z++] = (uint8) a;
+ }
+ }
+ skip(s, pad);
+ }
+ }
+ if (flip_vertically) {
+ stbi_uc t;
+ for (j=0; j < (int) s->img_y>>1; ++j) {
+ stbi_uc *p1 = out + j *s->img_x*target;
+ stbi_uc *p2 = out + (s->img_y-1-j)*s->img_x*target;
+ for (i=0; i < (int) s->img_x*target; ++i) {
+ t = p1[i], p1[i] = p2[i], p2[i] = t;
+ }
+ }
+ }
+
+ if (req_comp && req_comp != target) {
+ out = convert_format(out, target, req_comp, s->img_x, s->img_y);
+ if (out == NULL) return out; // convert_format frees input on failure
+ }
+
+ *x = s->img_x;
+ *y = s->img_y;
+ if (comp) *comp = s->img_n;
+ return out;
+
+ NVG_NOTUSED(fake_a);
+}
+
+static stbi_uc *stbi_bmp_load(stbi *s,int *x, int *y, int *comp, int req_comp)
+{
+ return bmp_load(s, x,y,comp,req_comp);
+}
+
+
+// Targa Truevision - TGA
+// by Jonathan Dummer
+
+static int tga_info(stbi *s, int *x, int *y, int *comp)
+{
+ int tga_w, tga_h, tga_comp;
+ int sz;
+ get8u(s); // discard Offset
+ sz = get8u(s); // color type
+ if( sz > 1 ) {
+ stbi_rewind(s);
+ return 0; // only RGB or indexed allowed
+ }
+ sz = get8u(s); // image type
+ // only RGB or grey allowed, +/- RLE
+ if ((sz != 1) && (sz != 2) && (sz != 3) && (sz != 9) && (sz != 10) && (sz != 11)) return 0;
+ skip(s,9);
+ tga_w = get16le(s);
+ if( tga_w < 1 ) {
+ stbi_rewind(s);
+ return 0; // test width
+ }
+ tga_h = get16le(s);
+ if( tga_h < 1 ) {
+ stbi_rewind(s);
+ return 0; // test height
+ }
+ sz = get8(s); // bits per pixel
+ // only RGB or RGBA or grey allowed
+ if ((sz != 8) && (sz != 16) && (sz != 24) && (sz != 32)) {
+ stbi_rewind(s);
+ return 0;
+ }
+ tga_comp = sz;
+ if (x) *x = tga_w;
+ if (y) *y = tga_h;
+ if (comp) *comp = tga_comp / 8;
+ return 1; // seems to have passed everything
+}
+
+int stbi_tga_info(stbi *s, int *x, int *y, int *comp)
+{
+ return tga_info(s, x, y, comp);
+}
+
+static int tga_test(stbi *s)
+{
+ int sz;
+ get8u(s); // discard Offset
+ sz = get8u(s); // color type
+ if ( sz > 1 ) return 0; // only RGB or indexed allowed
+ sz = get8u(s); // image type
+ if ( (sz != 1) && (sz != 2) && (sz != 3) && (sz != 9) && (sz != 10) && (sz != 11) ) return 0; // only RGB or grey allowed, +/- RLE
+ get16(s); // discard palette start
+ get16(s); // discard palette length
+ get8(s); // discard bits per palette color entry
+ get16(s); // discard x origin
+ get16(s); // discard y origin
+ if ( get16(s) < 1 ) return 0; // test width
+ if ( get16(s) < 1 ) return 0; // test height
+ sz = get8(s); // bits per pixel
+ if ( (sz != 8) && (sz != 16) && (sz != 24) && (sz != 32) ) return 0; // only RGB or RGBA or grey allowed
+ return 1; // seems to have passed everything
+}
+
+static int stbi_tga_test(stbi *s)
+{
+ int res = tga_test(s);
+ stbi_rewind(s);
+ return res;
+}
+
+static stbi_uc *tga_load(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ // read in the TGA header stuff
+ int tga_offset = get8u(s);
+ int tga_indexed = get8u(s);
+ int tga_image_type = get8u(s);
+ int tga_is_RLE = 0;
+ int tga_palette_start = get16le(s);
+ int tga_palette_len = get16le(s);
+ int tga_palette_bits = get8u(s);
+ int tga_x_origin = get16le(s);
+ int tga_y_origin = get16le(s);
+ int tga_width = get16le(s);
+ int tga_height = get16le(s);
+ int tga_bits_per_pixel = get8u(s);
+ int tga_inverted = get8u(s);
+ // image data
+ unsigned char *tga_data;
+ unsigned char *tga_palette = NULL;
+ int i, j;
+ unsigned char raw_data[4];
+ unsigned char trans_data[4];
+ int RLE_count = 0;
+ int RLE_repeating = 0;
+ int read_next_pixel = 1;
+
+ // do a tiny bit of precessing
+ if ( tga_image_type >= 8 )
+ {
+ tga_image_type -= 8;
+ tga_is_RLE = 1;
+ }
+ /* int tga_alpha_bits = tga_inverted & 15; */
+ tga_inverted = 1 - ((tga_inverted >> 5) & 1);
+
+ // error check
+ if ( //(tga_indexed) ||
+ (tga_width < 1) || (tga_height < 1) ||
+ (tga_image_type < 1) || (tga_image_type > 3) ||
+ ((tga_bits_per_pixel != 8) && (tga_bits_per_pixel != 16) &&
+ (tga_bits_per_pixel != 24) && (tga_bits_per_pixel != 32))
+ )
+ {
+ return NULL; // we don't report this as a bad TGA because we don't even know if it's TGA
+ }
+
+ // If I'm paletted, then I'll use the number of bits from the palette
+ if ( tga_indexed )
+ {
+ tga_bits_per_pixel = tga_palette_bits;
+ }
+
+ // tga info
+ *x = tga_width;
+ *y = tga_height;
+ if ( (req_comp < 1) || (req_comp > 4) )
+ {
+ // just use whatever the file was
+ req_comp = tga_bits_per_pixel / 8;
+ *comp = req_comp;
+ } else
+ {
+ // force a new number of components
+ *comp = tga_bits_per_pixel/8;
+ }
+ tga_data = (unsigned char*)malloc( tga_width * tga_height * req_comp );
+ if (!tga_data) return epuc("outofmem", "Out of memory");
+
+ // skip to the data's starting position (offset usually = 0)
+ skip(s, tga_offset );
+ // do I need to load a palette?
+ if ( tga_indexed )
+ {
+ // any data to skip? (offset usually = 0)
+ skip(s, tga_palette_start );
+ // load the palette
+ tga_palette = (unsigned char*)malloc( tga_palette_len * tga_palette_bits / 8 );
+ if (!tga_palette) return epuc("outofmem", "Out of memory");
+ if (!getn(s, tga_palette, tga_palette_len * tga_palette_bits / 8 )) {
+ free(tga_data);
+ free(tga_palette);
+ return epuc("bad palette", "Corrupt TGA");
+ }
+ }
+ // load the data
+ trans_data[0] = trans_data[1] = trans_data[2] = trans_data[3] = 0;
+ for (i=0; i < tga_width * tga_height; ++i)
+ {
+ // if I'm in RLE mode, do I need to get a RLE chunk?
+ if ( tga_is_RLE )
+ {
+ if ( RLE_count == 0 )
+ {
+ // yep, get the next byte as a RLE command
+ int RLE_cmd = get8u(s);
+ RLE_count = 1 + (RLE_cmd & 127);
+ RLE_repeating = RLE_cmd >> 7;
+ read_next_pixel = 1;
+ } else if ( !RLE_repeating )
+ {
+ read_next_pixel = 1;
+ }
+ } else
+ {
+ read_next_pixel = 1;
+ }
+ // OK, if I need to read a pixel, do it now
+ if ( read_next_pixel )
+ {
+ // load however much data we did have
+ if ( tga_indexed )
+ {
+ // read in 1 byte, then perform the lookup
+ int pal_idx = get8u(s);
+ if ( pal_idx >= tga_palette_len )
+ {
+ // invalid index
+ pal_idx = 0;
+ }
+ pal_idx *= tga_bits_per_pixel / 8;
+ for (j = 0; j*8 < tga_bits_per_pixel; ++j)
+ {
+ raw_data[j] = tga_palette[pal_idx+j];
+ }
+ } else
+ {
+ // read in the data raw
+ for (j = 0; j*8 < tga_bits_per_pixel; ++j)
+ {
+ raw_data[j] = get8u(s);
+ }
+ }
+ // convert raw to the intermediate format
+ switch (tga_bits_per_pixel)
+ {
+ case 8:
+ // Luminous => RGBA
+ trans_data[0] = raw_data[0];
+ trans_data[1] = raw_data[0];
+ trans_data[2] = raw_data[0];
+ trans_data[3] = 255;
+ break;
+ case 16:
+ // Luminous,Alpha => RGBA
+ trans_data[0] = raw_data[0];
+ trans_data[1] = raw_data[0];
+ trans_data[2] = raw_data[0];
+ trans_data[3] = raw_data[1];
+ break;
+ case 24:
+ // BGR => RGBA
+ trans_data[0] = raw_data[2];
+ trans_data[1] = raw_data[1];
+ trans_data[2] = raw_data[0];
+ trans_data[3] = 255;
+ break;
+ case 32:
+ // BGRA => RGBA
+ trans_data[0] = raw_data[2];
+ trans_data[1] = raw_data[1];
+ trans_data[2] = raw_data[0];
+ trans_data[3] = raw_data[3];
+ break;
+ }
+ // clear the reading flag for the next pixel
+ read_next_pixel = 0;
+ } // end of reading a pixel
+ // convert to final format
+ switch (req_comp)
+ {
+ case 1:
+ // RGBA => Luminance
+ tga_data[i*req_comp+0] = compute_y(trans_data[0],trans_data[1],trans_data[2]);
+ break;
+ case 2:
+ // RGBA => Luminance,Alpha
+ tga_data[i*req_comp+0] = compute_y(trans_data[0],trans_data[1],trans_data[2]);
+ tga_data[i*req_comp+1] = trans_data[3];
+ break;
+ case 3:
+ // RGBA => RGB
+ tga_data[i*req_comp+0] = trans_data[0];
+ tga_data[i*req_comp+1] = trans_data[1];
+ tga_data[i*req_comp+2] = trans_data[2];
+ break;
+ case 4:
+ // RGBA => RGBA
+ tga_data[i*req_comp+0] = trans_data[0];
+ tga_data[i*req_comp+1] = trans_data[1];
+ tga_data[i*req_comp+2] = trans_data[2];
+ tga_data[i*req_comp+3] = trans_data[3];
+ break;
+ }
+ // in case we're in RLE mode, keep counting down
+ --RLE_count;
+ }
+ // do I need to invert the image?
+ if ( tga_inverted )
+ {
+ for (j = 0; j*2 < tga_height; ++j)
+ {
+ int index1 = j * tga_width * req_comp;
+ int index2 = (tga_height - 1 - j) * tga_width * req_comp;
+ for (i = tga_width * req_comp; i > 0; --i)
+ {
+ unsigned char temp = tga_data[index1];
+ tga_data[index1] = tga_data[index2];
+ tga_data[index2] = temp;
+ ++index1;
+ ++index2;
+ }
+ }
+ }
+ // clear my palette, if I had one
+ if ( tga_palette != NULL )
+ {
+ free( tga_palette );
+ }
+ // the things I do to get rid of an error message, and yet keep
+ // Microsoft's C compilers happy... [8^(
+ tga_palette_start = tga_palette_len = tga_palette_bits =
+ tga_x_origin = tga_y_origin = 0;
+ // OK, done
+ return tga_data;
+}
+
+static stbi_uc *stbi_tga_load(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ return tga_load(s,x,y,comp,req_comp);
+}
+
+
+// *************************************************************************************************
+// Photoshop PSD loader -- PD by Thatcher Ulrich, integration by Nicolas Schulz, tweaked by STB
+
+static int psd_test(stbi *s)
+{
+ if (get32(s) != 0x38425053) return 0; // "8BPS"
+ else return 1;
+}
+
+static int stbi_psd_test(stbi *s)
+{
+ int r = psd_test(s);
+ stbi_rewind(s);
+ return r;
+}
+
+static stbi_uc *psd_load(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ int pixelCount;
+ int channelCount, compression;
+ int channel, i, count, len;
+ int w,h;
+ uint8 *out;
+
+ // Check identifier
+ if (get32(s) != 0x38425053) // "8BPS"
+ return epuc("not PSD", "Corrupt PSD image");
+
+ // Check file type version.
+ if (get16(s) != 1)
+ return epuc("wrong version", "Unsupported version of PSD image");
+
+ // Skip 6 reserved bytes.
+ skip(s, 6 );
+
+ // Read the number of channels (R, G, B, A, etc).
+ channelCount = get16(s);
+ if (channelCount < 0 || channelCount > 16)
+ return epuc("wrong channel count", "Unsupported number of channels in PSD image");
+
+ // Read the rows and columns of the image.
+ h = get32(s);
+ w = get32(s);
+
+ // Make sure the depth is 8 bits.
+ if (get16(s) != 8)
+ return epuc("unsupported bit depth", "PSD bit depth is not 8 bit");
+
+ // Make sure the color mode is RGB.
+ // Valid options are:
+ // 0: Bitmap
+ // 1: Grayscale
+ // 2: Indexed color
+ // 3: RGB color
+ // 4: CMYK color
+ // 7: Multichannel
+ // 8: Duotone
+ // 9: Lab color
+ if (get16(s) != 3)
+ return epuc("wrong color format", "PSD is not in RGB color format");
+
+ // Skip the Mode Data. (It's the palette for indexed color; other info for other modes.)
+ skip(s,get32(s) );
+
+ // Skip the image resources. (resolution, pen tool paths, etc)
+ skip(s, get32(s) );
+
+ // Skip the reserved data.
+ skip(s, get32(s) );
+
+ // Find out if the data is compressed.
+ // Known values:
+ // 0: no compression
+ // 1: RLE compressed
+ compression = get16(s);
+ if (compression > 1)
+ return epuc("bad compression", "PSD has an unknown compression format");
+
+ // Create the destination image.
+ out = (stbi_uc *) malloc(4 * w*h);
+ if (!out) return epuc("outofmem", "Out of memory");
+ pixelCount = w*h;
+
+ // Initialize the data to zero.
+ //memset( out, 0, pixelCount * 4 );
+
+ // Finally, the image data.
+ if (compression) {
+ // RLE as used by .PSD and .TIFF
+ // Loop until you get the number of unpacked bytes you are expecting:
+ // Read the next source byte into n.
+ // If n is between 0 and 127 inclusive, copy the next n+1 bytes literally.
+ // Else if n is between -127 and -1 inclusive, copy the next byte -n+1 times.
+ // Else if n is 128, noop.
+ // Endloop
+
+ // The RLE-compressed data is preceeded by a 2-byte data count for each row in the data,
+ // which we're going to just skip.
+ skip(s, h * channelCount * 2 );
+
+ // Read the RLE data by channel.
+ for (channel = 0; channel < 4; channel++) {
+ uint8 *p;
+
+ p = out+channel;
+ if (channel >= channelCount) {
+ // Fill this channel with default data.
+ for (i = 0; i < pixelCount; i++) *p = (channel == 3 ? 255 : 0), p += 4;
+ } else {
+ // Read the RLE data.
+ count = 0;
+ while (count < pixelCount) {
+ len = get8(s);
+ if (len == 128) {
+ // No-op.
+ } else if (len < 128) {
+ // Copy next len+1 bytes literally.
+ len++;
+ count += len;
+ while (len) {
+ *p = get8u(s);
+ p += 4;
+ len--;
+ }
+ } else if (len > 128) {
+ uint8 val;
+ // Next -len+1 bytes in the dest are replicated from next source byte.
+ // (Interpret len as a negative 8-bit int.)
+ len ^= 0x0FF;
+ len += 2;
+ val = get8u(s);
+ count += len;
+ while (len) {
+ *p = val;
+ p += 4;
+ len--;
+ }
+ }
+ }
+ }
+ }
+
+ } else {
+ // We're at the raw image data. It's each channel in order (Red, Green, Blue, Alpha, ...)
+ // where each channel consists of an 8-bit value for each pixel in the image.
+
+ // Read the data by channel.
+ for (channel = 0; channel < 4; channel++) {
+ uint8 *p;
+
+ p = out + channel;
+ if (channel > channelCount) {
+ // Fill this channel with default data.
+ for (i = 0; i < pixelCount; i++) *p = channel == 3 ? 255 : 0, p += 4;
+ } else {
+ // Read the data.
+ for (i = 0; i < pixelCount; i++)
+ *p = get8u(s), p += 4;
+ }
+ }
+ }
+
+ if (req_comp && req_comp != 4) {
+ out = convert_format(out, 4, req_comp, w, h);
+ if (out == NULL) return out; // convert_format frees input on failure
+ }
+
+ if (comp) *comp = channelCount;
+ *y = h;
+ *x = w;
+
+ return out;
+}
+
+static stbi_uc *stbi_psd_load(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ return psd_load(s,x,y,comp,req_comp);
+}
+
+// *************************************************************************************************
+// Softimage PIC loader
+// by Tom Seddon
+//
+// See http://softimage.wiki.softimage.com/index.php/INFO:_PIC_file_format
+// See http://ozviz.wasp.uwa.edu.au/~pbourke/dataformats/softimagepic/
+
+static int pic_is4(stbi *s,const char *str)
+{
+ int i;
+ for (i=0; i<4; ++i)
+ if (get8(s) != (stbi_uc)str[i])
+ return 0;
+
+ return 1;
+}
+
+static int pic_test(stbi *s)
+{
+ int i;
+
+ if (!pic_is4(s,"\x53\x80\xF6\x34"))
+ return 0;
+
+ for(i=0;i<84;++i)
+ get8(s);
+
+ if (!pic_is4(s,"PICT"))
+ return 0;
+
+ return 1;
+}
+
+typedef struct
+{
+ stbi_uc size,type,channel;
+} pic_packet_t;
+
+static stbi_uc *pic_readval(stbi *s, int channel, stbi_uc *dest)
+{
+ int mask=0x80, i;
+
+ for (i=0; i<4; ++i, mask>>=1) {
+ if (channel & mask) {
+ if (at_eof(s)) return epuc("bad file","PIC file too short");
+ dest[i]=get8u(s);
+ }
+ }
+
+ return dest;
+}
+
+static void pic_copyval(int channel,stbi_uc *dest,const stbi_uc *src)
+{
+ int mask=0x80,i;
+
+ for (i=0;i<4; ++i, mask>>=1)
+ if (channel&mask)
+ dest[i]=src[i];
+}
+
+static stbi_uc *pic_load2(stbi *s,int width,int height,int *comp, stbi_uc *result)
+{
+ int act_comp=0,num_packets=0,y,chained;
+ pic_packet_t packets[10];
+
+ // this will (should...) cater for even some bizarre stuff like having data
+ // for the same channel in multiple packets.
+ do {
+ pic_packet_t *packet;
+
+ if (num_packets==sizeof(packets)/sizeof(packets[0]))
+ return epuc("bad format","too many packets");
+
+ packet = &packets[num_packets++];
+
+ chained = get8(s);
+ packet->size = get8u(s);
+ packet->type = get8u(s);
+ packet->channel = get8u(s);
+
+ act_comp |= packet->channel;
+
+ if (at_eof(s)) return epuc("bad file","file too short (reading packets)");
+ if (packet->size != 8) return epuc("bad format","packet isn't 8bpp");
+ } while (chained);
+
+ *comp = (act_comp & 0x10 ? 4 : 3); // has alpha channel?
+
+ for(y=0; y<height; ++y) {
+ int packet_idx;
+
+ for(packet_idx=0; packet_idx < num_packets; ++packet_idx) {
+ pic_packet_t *packet = &packets[packet_idx];
+ stbi_uc *dest = result+y*width*4;
+
+ switch (packet->type) {
+ default:
+ return epuc("bad format","packet has bad compression type");
+
+ case 0: {//uncompressed
+ int x;
+
+ for(x=0;x<width;++x, dest+=4)
+ if (!pic_readval(s,packet->channel,dest))
+ return 0;
+ break;
+ }
+
+ case 1://Pure RLE
+ {
+ int left=width, i;
+
+ while (left>0) {
+ stbi_uc count,value[4];
+
+ count=get8u(s);
+ if (at_eof(s)) return epuc("bad file","file too short (pure read count)");
+
+ if (count > left)
+ count = (uint8) left;
+
+ if (!pic_readval(s,packet->channel,value)) return 0;
+
+ for(i=0; i<count; ++i,dest+=4)
+ pic_copyval(packet->channel,dest,value);
+ left -= count;
+ }
+ }
+ break;
+
+ case 2: {//Mixed RLE
+ int left=width;
+ while (left>0) {
+ int count = get8(s), i;
+ if (at_eof(s)) return epuc("bad file","file too short (mixed read count)");
+
+ if (count >= 128) { // Repeated
+ stbi_uc value[4];
+ int i;
+
+ if (count==128)
+ count = get16(s);
+ else
+ count -= 127;
+ if (count > left)
+ return epuc("bad file","scanline overrun");
+
+ if (!pic_readval(s,packet->channel,value))
+ return 0;
+
+ for(i=0;i<count;++i, dest += 4)
+ pic_copyval(packet->channel,dest,value);
+ } else { // Raw
+ ++count;
+ if (count>left) return epuc("bad file","scanline overrun");
+
+ for(i=0;i<count;++i, dest+=4)
+ if (!pic_readval(s,packet->channel,dest))
+ return 0;
+ }
+ left-=count;
+ }
+ break;
+ }
+ }
+ }
+ }
+
+ return result;
+}
+
+static stbi_uc *pic_load(stbi *s,int *px,int *py,int *comp,int req_comp)
+{
+ stbi_uc *result;
+ int i, x,y;
+
+ for (i=0; i<92; ++i)
+ get8(s);
+
+ x = get16(s);
+ y = get16(s);
+ if (at_eof(s)) return epuc("bad file","file too short (pic header)");
+ if ((1 << 28) / x < y) return epuc("too large", "Image too large to decode");
+
+ get32(s); //skip `ratio'
+ get16(s); //skip `fields'
+ get16(s); //skip `pad'
+
+ // intermediate buffer is RGBA
+ result = (stbi_uc *) malloc(x*y*4);
+ memset(result, 0xff, x*y*4);
+
+ if (!pic_load2(s,x,y,comp, result)) {
+ free(result);
+ result=0;
+ }
+ *px = x;
+ *py = y;
+ if (req_comp == 0) req_comp = *comp;
+ result=convert_format(result,4,req_comp,x,y);
+
+ return result;
+}
+
+static int stbi_pic_test(stbi *s)
+{
+ int r = pic_test(s);
+ stbi_rewind(s);
+ return r;
+}
+
+static stbi_uc *stbi_pic_load(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ return pic_load(s,x,y,comp,req_comp);
+}
+
+// *************************************************************************************************
+// GIF loader -- public domain by Jean-Marc Lienher -- simplified/shrunk by stb
+typedef struct stbi_gif_lzw_struct {
+ int16 prefix;
+ uint8 first;
+ uint8 suffix;
+} stbi_gif_lzw;
+
+typedef struct stbi_gif_struct
+{
+ int w,h;
+ stbi_uc *out; // output buffer (always 4 components)
+ int flags, bgindex, ratio, transparent, eflags;
+ uint8 pal[256][4];
+ uint8 lpal[256][4];
+ stbi_gif_lzw codes[4096];
+ uint8 *color_table;
+ int parse, step;
+ int lflags;
+ int start_x, start_y;
+ int max_x, max_y;
+ int cur_x, cur_y;
+ int line_size;
+} stbi_gif;
+
+static int gif_test(stbi *s)
+{
+ int sz;
+ if (get8(s) != 'G' || get8(s) != 'I' || get8(s) != 'F' || get8(s) != '8') return 0;
+ sz = get8(s);
+ if (sz != '9' && sz != '7') return 0;
+ if (get8(s) != 'a') return 0;
+ return 1;
+}
+
+static int stbi_gif_test(stbi *s)
+{
+ int r = gif_test(s);
+ stbi_rewind(s);
+ return r;
+}
+
+static void stbi_gif_parse_colortable(stbi *s, uint8 pal[256][4], int num_entries, int transp)
+{
+ int i;
+ for (i=0; i < num_entries; ++i) {
+ pal[i][2] = get8u(s);
+ pal[i][1] = get8u(s);
+ pal[i][0] = get8u(s);
+ pal[i][3] = transp ? 0 : 255;
+ }
+}
+
+static int stbi_gif_header(stbi *s, stbi_gif *g, int *comp, int is_info)
+{
+ uint8 version;
+ if (get8(s) != 'G' || get8(s) != 'I' || get8(s) != 'F' || get8(s) != '8')
+ return e("not GIF", "Corrupt GIF");
+
+ version = get8u(s);
+ if (version != '7' && version != '9') return e("not GIF", "Corrupt GIF");
+ if (get8(s) != 'a') return e("not GIF", "Corrupt GIF");
+
+ failure_reason = "";
+ g->w = get16le(s);
+ g->h = get16le(s);
+ g->flags = get8(s);
+ g->bgindex = get8(s);
+ g->ratio = get8(s);
+ g->transparent = -1;
+
+ if (comp != 0) *comp = 4; // can't actually tell whether it's 3 or 4 until we parse the comments
+
+ if (is_info) return 1;
+
+ if (g->flags & 0x80)
+ stbi_gif_parse_colortable(s,g->pal, 2 << (g->flags & 7), -1);
+
+ return 1;
+}
+
+static int stbi_gif_info_raw(stbi *s, int *x, int *y, int *comp)
+{
+ stbi_gif g;
+ if (!stbi_gif_header(s, &g, comp, 1)) {
+ stbi_rewind( s );
+ return 0;
+ }
+ if (x) *x = g.w;
+ if (y) *y = g.h;
+ return 1;
+}
+
+static void stbi_out_gif_code(stbi_gif *g, uint16 code)
+{
+ uint8 *p, *c;
+
+ // recurse to decode the prefixes, since the linked-list is backwards,
+ // and working backwards through an interleaved image would be nasty
+ if (g->codes[code].prefix >= 0)
+ stbi_out_gif_code(g, g->codes[code].prefix);
+
+ if (g->cur_y >= g->max_y) return;
+
+ p = &g->out[g->cur_x + g->cur_y];
+ c = &g->color_table[g->codes[code].suffix * 4];
+
+ if (c[3] >= 128) {
+ p[0] = c[2];
+ p[1] = c[1];
+ p[2] = c[0];
+ p[3] = c[3];
+ }
+ g->cur_x += 4;
+
+ if (g->cur_x >= g->max_x) {
+ g->cur_x = g->start_x;
+ g->cur_y += g->step;
+
+ while (g->cur_y >= g->max_y && g->parse > 0) {
+ g->step = (1 << g->parse) * g->line_size;
+ g->cur_y = g->start_y + (g->step >> 1);
+ --g->parse;
+ }
+ }
+}
+
+static uint8 *stbi_process_gif_raster(stbi *s, stbi_gif *g)
+{
+ uint8 lzw_cs;
+ int32 len, code;
+ uint32 first;
+ int32 codesize, codemask, avail, oldcode, bits, valid_bits, clear;
+ stbi_gif_lzw *p;
+
+ lzw_cs = get8u(s);
+ clear = 1 << lzw_cs;
+ first = 1;
+ codesize = lzw_cs + 1;
+ codemask = (1 << codesize) - 1;
+ bits = 0;
+ valid_bits = 0;
+ for (code = 0; code < clear; code++) {
+ g->codes[code].prefix = -1;
+ g->codes[code].first = (uint8) code;
+ g->codes[code].suffix = (uint8) code;
+ }
+
+ // support no starting clear code
+ avail = clear+2;
+ oldcode = -1;
+
+ len = 0;
+ for(;;) {
+ if (valid_bits < codesize) {
+ if (len == 0) {
+ len = get8(s); // start new block
+ if (len == 0)
+ return g->out;
+ }
+ --len;
+ bits |= (int32) get8(s) << valid_bits;
+ valid_bits += 8;
+ } else {
+ int32 code = bits & codemask;
+ bits >>= codesize;
+ valid_bits -= codesize;
+ // @OPTIMIZE: is there some way we can accelerate the non-clear path?
+ if (code == clear) { // clear code
+ codesize = lzw_cs + 1;
+ codemask = (1 << codesize) - 1;
+ avail = clear + 2;
+ oldcode = -1;
+ first = 0;
+ } else if (code == clear + 1) { // end of stream code
+ skip(s, len);
+ while ((len = get8(s)) > 0)
+ skip(s,len);
+ return g->out;
+ } else if (code <= avail) {
+ if (first) return epuc("no clear code", "Corrupt GIF");
+
+ if (oldcode >= 0) {
+ p = &g->codes[avail++];
+ if (avail > 4096) return epuc("too many codes", "Corrupt GIF");
+ p->prefix = (int16) oldcode;
+ p->first = g->codes[oldcode].first;
+ p->suffix = (code == avail) ? p->first : g->codes[code].first;
+ } else if (code == avail)
+ return epuc("illegal code in raster", "Corrupt GIF");
+
+ stbi_out_gif_code(g, (uint16) code);
+
+ if ((avail & codemask) == 0 && avail <= 0x0FFF) {
+ codesize++;
+ codemask = (1 << codesize) - 1;
+ }
+
+ oldcode = code;
+ } else {
+ return epuc("illegal code in raster", "Corrupt GIF");
+ }
+ }
+ }
+}
+
+static void stbi_fill_gif_background(stbi_gif *g)
+{
+ int i;
+ uint8 *c = g->pal[g->bgindex];
+ // @OPTIMIZE: write a dword at a time
+ for (i = 0; i < g->w * g->h * 4; i += 4) {
+ uint8 *p = &g->out[i];
+ p[0] = c[2];
+ p[1] = c[1];
+ p[2] = c[0];
+ p[3] = c[3];
+ }
+}
+
+// this function is designed to support animated gifs, although stb_image doesn't support it
+static uint8 *stbi_gif_load_next(stbi *s, stbi_gif *g, int *comp, int req_comp)
+{
+ int i;
+ uint8 *old_out = 0;
+
+ if (g->out == 0) {
+ if (!stbi_gif_header(s, g, comp,0)) return 0; // failure_reason set by stbi_gif_header
+ g->out = (uint8 *) malloc(4 * g->w * g->h);
+ if (g->out == 0) return epuc("outofmem", "Out of memory");
+ stbi_fill_gif_background(g);
+ } else {
+ // animated-gif-only path
+ if (((g->eflags & 0x1C) >> 2) == 3) {
+ old_out = g->out;
+ g->out = (uint8 *) malloc(4 * g->w * g->h);
+ if (g->out == 0) return epuc("outofmem", "Out of memory");
+ memcpy(g->out, old_out, g->w*g->h*4);
+ }
+ }
+
+ for (;;) {
+ switch (get8(s)) {
+ case 0x2C: /* Image Descriptor */
+ {
+ int32 x, y, w, h;
+ uint8 *o;
+
+ x = get16le(s);
+ y = get16le(s);
+ w = get16le(s);
+ h = get16le(s);
+ if (((x + w) > (g->w)) || ((y + h) > (g->h)))
+ return epuc("bad Image Descriptor", "Corrupt GIF");
+
+ g->line_size = g->w * 4;
+ g->start_x = x * 4;
+ g->start_y = y * g->line_size;
+ g->max_x = g->start_x + w * 4;
+ g->max_y = g->start_y + h * g->line_size;
+ g->cur_x = g->start_x;
+ g->cur_y = g->start_y;
+
+ g->lflags = get8(s);
+
+ if (g->lflags & 0x40) {
+ g->step = 8 * g->line_size; // first interlaced spacing
+ g->parse = 3;
+ } else {
+ g->step = g->line_size;
+ g->parse = 0;
+ }
+
+ if (g->lflags & 0x80) {
+ stbi_gif_parse_colortable(s,g->lpal, 2 << (g->lflags & 7), g->eflags & 0x01 ? g->transparent : -1);
+ g->color_table = (uint8 *) g->lpal;
+ } else if (g->flags & 0x80) {
+ for (i=0; i < 256; ++i) // @OPTIMIZE: reset only the previous transparent
+ g->pal[i][3] = 255;
+ if (g->transparent >= 0 && (g->eflags & 0x01))
+ g->pal[g->transparent][3] = 0;
+ g->color_table = (uint8 *) g->pal;
+ } else
+ return epuc("missing color table", "Corrupt GIF");
+
+ o = stbi_process_gif_raster(s, g);
+ if (o == NULL) return NULL;
+
+ if (req_comp && req_comp != 4)
+ o = convert_format(o, 4, req_comp, g->w, g->h);
+ return o;
+ }
+
+ case 0x21: // Comment Extension.
+ {
+ int len;
+ if (get8(s) == 0xF9) { // Graphic Control Extension.
+ len = get8(s);
+ if (len == 4) {
+ g->eflags = get8(s);
+ get16le(s); // delay
+ g->transparent = get8(s);
+ } else {
+ skip(s, len);
+ break;
+ }
+ }
+ while ((len = get8(s)) != 0)
+ skip(s, len);
+ break;
+ }
+
+ case 0x3B: // gif stream termination code
+ return (uint8 *) 1;
+
+ default:
+ return epuc("unknown code", "Corrupt GIF");
+ }
+ }
+}
+
+static stbi_uc *stbi_gif_load(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ uint8 *u = 0;
+ stbi_gif g;
+ memset(&g, 0, sizeof(stbi_gif));
+
+ u = stbi_gif_load_next(s, &g, comp, req_comp);
+ if (u == (void *) 1) u = 0; // end of animated gif marker
+ if (u) {
+ *x = g.w;
+ *y = g.h;
+ }
+
+ return u;
+}
+
+static int stbi_gif_info(stbi *s, int *x, int *y, int *comp)
+{
+ return stbi_gif_info_raw(s,x,y,comp);
+}
+
+
+// *************************************************************************************************
+// Radiance RGBE HDR loader
+// originally by Nicolas Schulz
+#ifndef STBI_NO_HDR
+static int hdr_test(stbi *s)
+{
+ const char *signature = "#?RADIANCE\n";
+ int i;
+ for (i=0; signature[i]; ++i)
+ if (get8(s) != signature[i])
+ return 0;
+ return 1;
+}
+
+static int stbi_hdr_test(stbi* s)
+{
+ int r = hdr_test(s);
+ stbi_rewind(s);
+ return r;
+}
+
+#define HDR_BUFLEN 1024
+static char *hdr_gettoken(stbi *z, char *buffer)
+{
+ int len=0;
+ char c = '\0';
+
+ c = (char) get8(z);
+
+ while (!at_eof(z) && c != '\n') {
+ buffer[len++] = c;
+ if (len == HDR_BUFLEN-1) {
+ // flush to end of line
+ while (!at_eof(z) && get8(z) != '\n')
+ ;
+ break;
+ }
+ c = (char) get8(z);
+ }
+
+ buffer[len] = 0;
+ return buffer;
+}
+
+static void hdr_convert(float *output, stbi_uc *input, int req_comp)
+{
+ if ( input[3] != 0 ) {
+ float f1;
+ // Exponent
+ f1 = (float) ldexp(1.0f, input[3] - (int)(128 + 8));
+ if (req_comp <= 2)
+ output[0] = (input[0] + input[1] + input[2]) * f1 / 3;
+ else {
+ output[0] = input[0] * f1;
+ output[1] = input[1] * f1;
+ output[2] = input[2] * f1;
+ }
+ if (req_comp == 2) output[1] = 1;
+ if (req_comp == 4) output[3] = 1;
+ } else {
+ switch (req_comp) {
+ case 4: output[3] = 1; /* fallthrough */
+ case 3: output[0] = output[1] = output[2] = 0;
+ break;
+ case 2: output[1] = 1; /* fallthrough */
+ case 1: output[0] = 0;
+ break;
+ }
+ }
+}
+
+static float *hdr_load(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ char buffer[HDR_BUFLEN];
+ char *token;
+ int valid = 0;
+ int width, height;
+ stbi_uc *scanline;
+ float *hdr_data;
+ int len;
+ unsigned char count, value;
+ int i, j, k, c1,c2, z;
+
+
+ // Check identifier
+ if (strcmp(hdr_gettoken(s,buffer), "#?RADIANCE") != 0)
+ return epf("not HDR", "Corrupt HDR image");
+
+ // Parse header
+ for(;;) {
+ token = hdr_gettoken(s,buffer);
+ if (token[0] == 0) break;
+ if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1;
+ }
+
+ if (!valid) return epf("unsupported format", "Unsupported HDR format");
+
+ // Parse width and height
+ // can't use sscanf() if we're not using stdio!
+ token = hdr_gettoken(s,buffer);
+ if (strncmp(token, "-Y ", 3)) return epf("unsupported data layout", "Unsupported HDR format");
+ token += 3;
+ height = strtol(token, &token, 10);
+ while (*token == ' ') ++token;
+ if (strncmp(token, "+X ", 3)) return epf("unsupported data layout", "Unsupported HDR format");
+ token += 3;
+ width = strtol(token, NULL, 10);
+
+ *x = width;
+ *y = height;
+
+ *comp = 3;
+ if (req_comp == 0) req_comp = 3;
+
+ // Read data
+ hdr_data = (float *) malloc(height * width * req_comp * sizeof(float));
+
+ // Load image data
+ // image data is stored as some number of sca
+ if ( width < 8 || width >= 32768) {
+ // Read flat data
+ for (j=0; j < height; ++j) {
+ for (i=0; i < width; ++i) {
+ stbi_uc rgbe[4];
+ main_decode_loop:
+ getn(s, rgbe, 4);
+ hdr_convert(hdr_data + j * width * req_comp + i * req_comp, rgbe, req_comp);
+ }
+ }
+ } else {
+ // Read RLE-encoded data
+ scanline = NULL;
+
+ for (j = 0; j < height; ++j) {
+ c1 = get8(s);
+ c2 = get8(s);
+ len = get8(s);
+ if (c1 != 2 || c2 != 2 || (len & 0x80)) {
+ // not run-length encoded, so we have to actually use THIS data as a decoded
+ // pixel (note this can't be a valid pixel--one of RGB must be >= 128)
+ uint8 rgbe[4];
+ rgbe[0] = (uint8) c1;
+ rgbe[1] = (uint8) c2;
+ rgbe[2] = (uint8) len;
+ rgbe[3] = (uint8) get8u(s);
+ hdr_convert(hdr_data, rgbe, req_comp);
+ i = 1;
+ j = 0;
+ free(scanline);
+ goto main_decode_loop; // yes, this makes no sense
+ }
+ len <<= 8;
+ len |= get8(s);
+ if (len != width) { free(hdr_data); free(scanline); return epf("invalid decoded scanline length", "corrupt HDR"); }
+ if (scanline == NULL) scanline = (stbi_uc *) malloc(width * 4);
+
+ for (k = 0; k < 4; ++k) {
+ i = 0;
+ while (i < width) {
+ count = get8u(s);
+ if (count > 128) {
+ // Run
+ value = get8u(s);
+ count -= 128;
+ for (z = 0; z < count; ++z)
+ scanline[i++ * 4 + k] = value;
+ } else {
+ // Dump
+ for (z = 0; z < count; ++z)
+ scanline[i++ * 4 + k] = get8u(s);
+ }
+ }
+ }
+ for (i=0; i < width; ++i)
+ hdr_convert(hdr_data+(j*width + i)*req_comp, scanline + i*4, req_comp);
+ }
+ free(scanline);
+ }
+
+ return hdr_data;
+}
+
+static float *stbi_hdr_load(stbi *s, int *x, int *y, int *comp, int req_comp)
+{
+ return hdr_load(s,x,y,comp,req_comp);
+}
+
+static int stbi_hdr_info(stbi *s, int *x, int *y, int *comp)
+{
+ char buffer[HDR_BUFLEN];
+ char *token;
+ int valid = 0;
+
+ if (strcmp(hdr_gettoken(s,buffer), "#?RADIANCE") != 0) {
+ stbi_rewind( s );
+ return 0;
+ }
+
+ for(;;) {
+ token = hdr_gettoken(s,buffer);
+ if (token[0] == 0) break;
+ if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1;
+ }
+
+ if (!valid) {
+ stbi_rewind( s );
+ return 0;
+ }
+ token = hdr_gettoken(s,buffer);
+ if (strncmp(token, "-Y ", 3)) {
+ stbi_rewind( s );
+ return 0;
+ }
+ token += 3;
+ *y = strtol(token, &token, 10);
+ while (*token == ' ') ++token;
+ if (strncmp(token, "+X ", 3)) {
+ stbi_rewind( s );
+ return 0;
+ }
+ token += 3;
+ *x = strtol(token, NULL, 10);
+ *comp = 3;
+ return 1;
+}
+#endif // STBI_NO_HDR
+
+static int stbi_bmp_info(stbi *s, int *x, int *y, int *comp)
+{
+ int hsz;
+ if (get8(s) != 'B' || get8(s) != 'M') {
+ stbi_rewind( s );
+ return 0;
+ }
+ skip(s,12);
+ hsz = get32le(s);
+ if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108) {
+ stbi_rewind( s );
+ return 0;
+ }
+ if (hsz == 12) {
+ *x = get16le(s);
+ *y = get16le(s);
+ } else {
+ *x = get32le(s);
+ *y = get32le(s);
+ }
+ if (get16le(s) != 1) {
+ stbi_rewind( s );
+ return 0;
+ }
+ *comp = get16le(s) / 8;
+ return 1;
+}
+
+static int stbi_psd_info(stbi *s, int *x, int *y, int *comp)
+{
+ int channelCount;
+ if (get32(s) != 0x38425053) {
+ stbi_rewind( s );
+ return 0;
+ }
+ if (get16(s) != 1) {
+ stbi_rewind( s );
+ return 0;
+ }
+ skip(s, 6);
+ channelCount = get16(s);
+ if (channelCount < 0 || channelCount > 16) {
+ stbi_rewind( s );
+ return 0;
+ }
+ *y = get32(s);
+ *x = get32(s);
+ if (get16(s) != 8) {
+ stbi_rewind( s );
+ return 0;
+ }
+ if (get16(s) != 3) {
+ stbi_rewind( s );
+ return 0;
+ }
+ *comp = 4;
+ return 1;
+}
+
+static int stbi_pic_info(stbi *s, int *x, int *y, int *comp)
+{
+ int act_comp=0,num_packets=0,chained;
+ pic_packet_t packets[10];
+
+ skip(s, 92);
+
+ *x = get16(s);
+ *y = get16(s);
+ if (at_eof(s)) return 0;
+ if ( (*x) != 0 && (1 << 28) / (*x) < (*y)) {
+ stbi_rewind( s );
+ return 0;
+ }
+
+ skip(s, 8);
+
+ do {
+ pic_packet_t *packet;
+
+ if (num_packets==sizeof(packets)/sizeof(packets[0]))
+ return 0;
+
+ packet = &packets[num_packets++];
+ chained = get8(s);
+ packet->size = get8u(s);
+ packet->type = get8u(s);
+ packet->channel = get8u(s);
+ act_comp |= packet->channel;
+
+ if (at_eof(s)) {
+ stbi_rewind( s );
+ return 0;
+ }
+ if (packet->size != 8) {
+ stbi_rewind( s );
+ return 0;
+ }
+ } while (chained);
+
+ *comp = (act_comp & 0x10 ? 4 : 3);
+
+ return 1;
+}
+
+static int stbi_info_main(stbi *s, int *x, int *y, int *comp)
+{
+ if (stbi_jpeg_info(s, x, y, comp))
+ return 1;
+ if (stbi_png_info(s, x, y, comp))
+ return 1;
+ if (stbi_gif_info(s, x, y, comp))
+ return 1;
+ if (stbi_bmp_info(s, x, y, comp))
+ return 1;
+ if (stbi_psd_info(s, x, y, comp))
+ return 1;
+ if (stbi_pic_info(s, x, y, comp))
+ return 1;
+ #ifndef STBI_NO_HDR
+ if (stbi_hdr_info(s, x, y, comp))
+ return 1;
+ #endif
+ // test tga last because it's a crappy test!
+ if (stbi_tga_info(s, x, y, comp))
+ return 1;
+ return e("unknown image type", "Image not of any known type, or corrupt");
+}
+
+#ifndef STBI_NO_STDIO
+int stbi_info(char const *filename, int *x, int *y, int *comp)
+{
+ FILE *f = fopen(filename, "rb");
+ int result;
+ if (!f) return e("can't fopen", "Unable to open file");
+ result = stbi_info_from_file(f, x, y, comp);
+ fclose(f);
+ return result;
+}
+
+int stbi_info_from_file(FILE *f, int *x, int *y, int *comp)
+{
+ int r;
+ stbi s;
+ long pos = ftell(f);
+ start_file(&s, f);
+ r = stbi_info_main(&s,x,y,comp);
+ fseek(f,pos,SEEK_SET);
+ return r;
+}
+#endif // !STBI_NO_STDIO
+
+int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp)
+{
+ stbi s;
+ start_mem(&s,buffer,len);
+ return stbi_info_main(&s,x,y,comp);
+}
+
+int stbi_info_from_callbacks(stbi_io_callbacks const *c, void *user, int *x, int *y, int *comp)
+{
+ stbi s;
+ start_callbacks(&s, (stbi_io_callbacks *) c, user);
+ return stbi_info_main(&s,x,y,comp);
+}
+
+#endif // STBI_HEADER_FILE_ONLY
+
+/*
+ revision history:
+ 1.33 (2011-07-14)
+ make stbi_is_hdr work in STBI_NO_HDR (as specified), minor compiler-friendly improvements
+ 1.32 (2011-07-13)
+ support for "info" function for all supported filetypes (SpartanJ)
+ 1.31 (2011-06-20)
+ a few more leak fixes, bug in PNG handling (SpartanJ)
+ 1.30 (2011-06-11)
+ added ability to load files via callbacks to accomidate custom input streams (Ben Wenger)
+ removed deprecated format-specific test/load functions
+ removed support for installable file formats (stbi_loader) -- would have been broken for IO callbacks anyway
+ error cases in bmp and tga give messages and don't leak (Raymond Barbiero, grisha)
+ fix inefficiency in decoding 32-bit BMP (David Woo)
+ 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
+ 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 on platforms with lock-heavy fgetc()
+ minor perf improvements for jpeg
+ deprecated type-specific functions so we'll get feedback if they're needed
+ attempt to fix trans_data warning (Won Chun)
+ 1.23 fixed bug in iPhone support
+ 1.22 (2010-07-10)
+ removed image *writing* support
+ 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 (i.e. Janez (U+017D)emva)
+ 1.21 fix use of 'uint8' in header (reported by jon blow)
+ 1.20 added support for Softimage PIC, by Tom Seddon
+ 1.19 bug in interlaced PNG corruption check (found by ryg)
+ 1.18 2008-08-02
+ fix a threading bug (local mutable static)
+ 1.17 support interlaced PNG
+ 1.16 major bugfix - convert_format converted one too many pixels
+ 1.15 initialize some fields for thread safety
+ 1.14 fix threadsafe conversion bug
+ header-file-only version (#define STBI_HEADER_FILE_ONLY before including)
+ 1.13 threadsafe
+ 1.12 const qualifiers in the API
+ 1.11 Support installable IDCT, colorspace conversion routines
+ 1.10 Fixes for 64-bit (don't use "unsigned long")
+ optimized upsampling by Fabian "ryg" Giesen
+ 1.09 Fix format-conversion for PSD code (bad global variables!)
+ 1.08 Thatcher Ulrich's PSD code integrated by Nicolas Schulz
+ 1.07 attempt to fix C++ warning/errors again
+ 1.06 attempt to fix C++ warning/errors again
+ 1.05 fix TGA loading to return correct *comp and use good luminance calc
+ 1.04 default float alpha is 1, not 255; use 'void *' for stbi_image_free
+ 1.03 bugfixes to STBI_NO_STDIO, STBI_NO_HDR
+ 1.02 support for (subset of) HDR files, float interface for preferred access to them
+ 1.01 fix bug: possible bug in handling right-side up bmps... not sure
+ fix bug: the stbi_bmp_load() and stbi_tga_load() functions didn't work at all
+ 1.00 interface to zlib that skips zlib header
+ 0.99 correct handling of alpha in palette
+ 0.98 TGA loader by lonesock; dynamically add loaders (untested)
+ 0.97 jpeg errors on too large a file; also catch another malloc failure
+ 0.96 fix detection of invalid v value - particleman@mollyrocket forum
+ 0.95 during header scan, seek to markers in case of padding
+ 0.94 STBI_NO_STDIO to disable stdio usage; rename all #defines the same
+ 0.93 handle jpegtran output; verbose errors
+ 0.92 read 4,8,16,24,32-bit BMP files of several formats
+ 0.91 output 24-bit Windows 3.0 BMP files
+ 0.90 fix a few more warnings; bump version number to approach 1.0
+ 0.61 bugfixes due to Marc LeBlanc, Christopher Lloyd
+ 0.60 fix compiling as c++
+ 0.59 fix warnings: merge Dave Moore's -Wall fixes
+ 0.58 fix bug: zlib uncompressed mode len/nlen was wrong endian
+ 0.57 fix bug: jpg last huffman symbol before marker was >9 bits but less than 16 available
+ 0.56 fix bug: zlib uncompressed mode len vs. nlen
+ 0.55 fix bug: restart_interval not initialized to 0
+ 0.54 allow NULL for 'int *comp'
+ 0.53 fix bug in png 3->4; speedup png decoding
+ 0.52 png handles req_comp=3,4 directly; minor cleanup; jpeg comments
+ 0.51 obey req_comp requests, 1-component jpegs return as 1-component,
+ on 'test' only check type, not whether we support this variant
+ 0.50 first released version
+*/
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