一個讀取圖片的程式碼
阿新 • • 發佈:2019-01-19
摘自
單標頭檔案 不用新增多餘依賴 比較方便使用
/* stb_image - v2.12 - public domain image loader - http://nothings.org/stb_image.h
no warranty implied; use at your own risk
Do this:
#define STB_IMAGE_IMPLEMENTATION
before you include this file in *one* C or C++ file to create the implementation.
// i.e. it should look like this:
#include ...
#include ...
#include ...
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
You can #define STBI_ASSERT(x) before the #include to avoid using assert.h.
And #define STBI_MALLOC, STBI_REALLOC, and STBI_FREE to avoid using malloc,realloc,free
QUICK NOTES:
Primarily of interest to game developers and other people who can
avoid problematic images and only need the trivial interface
JPEG baseline & progressive (12 bpc/arithmetic not supported, same as stock IJG lib)
PNG 1/2/4/8-bit-per-channel (16 bpc not supported)
TGA (not sure what subset, if a subset)
BMP non-1bpp, non-RLE
PSD (composited view only, no extra channels, 8/16 bit-per-channel)
GIF (*comp always reports as 4-channel)
HDR (radiance rgbE format)
PIC (Softimage PIC)
PNM (PPM and PGM binary only)
Animated GIF still needs a proper API, but here's one way to do it:
http://gist.github.com/urraka/685d9a6340b26b830d49
- decode from memory or through FILE (define STBI_NO_STDIO to remove code)
- decode from arbitrary I/O callbacks
- SIMD acceleration on x86/x64 (SSE2) and ARM (NEON)
Full documentation under "DOCUMENTATION" below.
Revision 2.00 release notes:
- Progressive JPEG is now supported.
- PPM and PGM binary formats are now supported, thanks to Ken Miller.
- x86 platforms now make use of SSE2 SIMD instructions for
JPEG decoding, and ARM platforms can use NEON SIMD if requested.
This work was done by Fabian "ryg" Giesen. SSE2 is used by
default, but NEON must be enabled explicitly; see docs.
With other JPEG optimizations included in this version, we see
2x speedup on a JPEG on an x86 machine, and a 1.5x speedup
on a JPEG on an ARM machine, relative to previous versions of this
library. The same results will not obtain for all JPGs and for all
x86/ARM machines. (Note that progressive JPEGs are significantly
slower to decode than regular JPEGs.) This doesn't mean that this
is the fastest JPEG decoder in the land; rather, it brings it
closer to parity with standard libraries. If you want the fastest
decode, look elsewhere. (See "Philosophy" section of docs below.)
See final bullet items below for more info on SIMD.
- Added STBI_MALLOC, STBI_REALLOC, and STBI_FREE macros for replacing
the memory allocator. Unlike other STBI libraries, these macros don't
support a context parameter, so if you need to pass a context in to
the allocator, you'll have to store it in a global or a thread-local
variable.
- Split existing STBI_NO_HDR flag into two flags, STBI_NO_HDR and
STBI_NO_LINEAR.
STBI_NO_HDR: suppress implementation of .hdr reader format
STBI_NO_LINEAR: suppress high-dynamic-range light-linear float API
- You can suppress implementation of any of the decoders to reduce
your code footprint by #defining one or more of the following
symbols before creating the implementation.
STBI_NO_JPEG
STBI_NO_PNG
STBI_NO_BMP
STBI_NO_PSD
STBI_NO_TGA
STBI_NO_GIF
STBI_NO_HDR
STBI_NO_PIC
STBI_NO_PNM (.ppm and .pgm)
- You can request *only* certain decoders and suppress all other ones
(this will be more forward-compatible, as addition of new decoders
doesn't require you to disable them explicitly):
STBI_ONLY_JPEG
STBI_ONLY_PNG
STBI_ONLY_BMP
STBI_ONLY_PSD
STBI_ONLY_TGA
STBI_ONLY_GIF
STBI_ONLY_HDR
STBI_ONLY_PIC
STBI_ONLY_PNM (.ppm and .pgm)
Note that you can define multiples of these, and you will get all
of them ("only x" and "only y" is interpreted to mean "only x&y").
- If you use STBI_NO_PNG (or _ONLY_ without PNG), and you still
want the zlib decoder to be available, #define STBI_SUPPORT_ZLIB
- Compilation of all SIMD code can be suppressed with
#define STBI_NO_SIMD
It should not be necessary to disable SIMD unless you have issues
compiling (e.g. using an x86 compiler which doesn't support SSE
intrinsics or that doesn't support the method used to detect
SSE2 support at run-time), and even those can be reported as
bugs so I can refine the built-in compile-time checking to be
smarter.
- The old STBI_SIMD system which allowed installing a user-defined
IDCT etc. has been removed. If you need this, don't upgrade. My
assumption is that almost nobody was doing this, and those who
were will find the built-in SIMD more satisfactory anyway.
- RGB values computed for JPEG images are slightly different from
previous versions of stb_image. (This is due to using less
integer precision in SIMD.) The C code has been adjusted so
that the same RGB values will be computed regardless of whether
SIMD support is available, so your app should always produce
consistent results. But these results are slightly different from
previous versions. (Specifically, about 3% of available YCbCr values
will compute different RGB results from pre-1.49 versions by +-1;
most of the deviating values are one smaller in the G channel.)
- If you must produce consistent results with previous versions of
stb_image, #define STBI_JPEG_OLD and you will get the same results
you used to; however, you will not get the SIMD speedups for
the YCbCr-to-RGB conversion step (although you should still see
significant JPEG speedup from the other changes).
Please note that STBI_JPEG_OLD is a temporary feature; it will be
removed in future versions of the library. It is only intended for
near-term back-compatibility use.
Latest revision history:
2.12 (2016-04-02) fix typo in 2.11 PSD fix that caused crashes
2.11 (2016-04-02) 16-bit PNGS; enable SSE2 in non-gcc x64
RGB-format JPEG; remove white matting in PSD;
allocate large structures on the stack;
correct channel count for PNG & BMP
2.10 (2016-01-22) avoid warning introduced in 2.09
2.09 (2016-01-16) 16-bit TGA; comments in PNM files; STBI_REALLOC_SIZED
2.08 (2015-09-13) fix to 2.07 cleanup, reading RGB PSD as RGBA
2.07 (2015-09-13) partial animated GIF support
limited 16-bit PSD support
minor bugs, code cleanup, and compiler warnings
2.06 (2015-04-19) fix bug where PSD returns wrong '*comp' value
2.05 (2015-04-19) fix bug in progressive JPEG handling, fix warning
2.04 (2015-04-15) try to re-enable SIMD on MinGW 64-bit
2.03 (2015-04-12) additional corruption checking
stbi_set_flip_vertically_on_load
fix NEON support; fix mingw support
2.02 (2015-01-19) fix incorrect assert, fix warning
2.01 (2015-01-17) fix various warnings
2.00b (2014-12-25) fix STBI_MALLOC in progressive JPEG
2.00 (2014-12-25) optimize JPEG, including x86 SSE2 & ARM NEON SIMD
progressive JPEG
PGM/PPM support
STBI_MALLOC,STBI_REALLOC,STBI_FREE
STBI_NO_*, STBI_ONLY_*
GIF bugfix
See end of file for full revision history.
============================ Contributors =========================
Image formats Extensions, features
Sean Barrett (jpeg, png, bmp) Jetro Lauha (stbi_info)
Nicolas Schulz (hdr, psd) Martin "SpartanJ" Golini (stbi_info)
Jonathan Dummer (tga) James "moose2000" Brown (iPhone PNG)
Jean-Marc Lienher (gif) Ben "Disch" Wenger (io callbacks)
Tom Seddon (pic) Omar Cornut (1/2/4-bit PNG)
Thatcher Ulrich (psd) Nicolas Guillemot (vertical flip)
Ken Miller (pgm, ppm) Richard Mitton (16-bit PSD)
[email protected] (animated gif) Junggon Kim (PNM comments)
Daniel Gibson (16-bit TGA)
Optimizations & bugfixes
Fabian "ryg" Giesen
Arseny Kapoulkine
Bug & warning fixes
Marc LeBlanc David Woo Guillaume George Martins Mozeiko
Christpher Lloyd Martin Golini Jerry Jansson Joseph Thomson
Dave Moore Roy Eltham Hayaki Saito Phil Jordan
Won Chun Luke Graham Johan Duparc Nathan Reed
the Horde3D community Thomas Ruf Ronny Chevalier Nick Verigakis
Janez Zemva John Bartholomew Michal Cichon [email protected]
Jonathan Blow Ken Hamada Tero Hanninen Baldur Karlsson
Laurent Gomila Cort Stratton Sergio Gonzalez [email protected]
Aruelien Pocheville Thibault Reuille Cass Everitt Matthew Gregan
Ryamond Barbiero Paul Du Bois Engin Manap [email protected]
[email protected] Oriol Ferrer Mesia socks-the-fox
Blazej Dariusz Roszkowski
LICENSE
This software is dual-licensed to the public domain and under the following
license: you are granted a perpetual, irrevocable license to copy, modify,
publish, and distribute this file as you see fit.
*/
#ifndef STBI_INCLUDE_STB_IMAGE_H
#define STBI_INCLUDE_STB_IMAGE_H
// DOCUMENTATION
//
// Limitations:
// - no 16-bit-per-channel PNG
// - no 12-bit-per-channel JPEG
// - no JPEGs with arithmetic coding
// - no 1-bit BMP
// - GIF always returns *comp=4
//
// Basic usage (see HDR discussion below for HDR usage):
// 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, or NULL on an allocation failure or if the image is
// corrupt or invalid. 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 see if it's trivially opaque
// because e.g. there were only 3 channels in the source image.
//
// 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.
//
// ===========================================================================
//
// Philosophy
//
// stb libraries are designed with the following priorities:
//
// 1. easy to use
// 2. easy to maintain
// 3. good performance
//
// Sometimes I let "good performance" creep up in priority over "easy to maintain",
// and for best performance I may provide less-easy-to-use APIs that give higher
// performance, in addition to the easy to use ones. Nevertheless, it's important
// to keep in mind that from the standpoint of you, a client of this library,
// all you care about is #1 and #3, and stb libraries do not emphasize #3 above all.
//
// Some secondary priorities arise directly from the first two, some of which
// make more explicit reasons why performance can't be emphasized.
//
// - Portable ("ease of use")
// - Small footprint ("easy to maintain")
// - No dependencies ("ease of use")
//
// ===========================================================================
//
// 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).
//
// ===========================================================================
//
// SIMD support
//
// The JPEG decoder will try to automatically use SIMD kernels on x86 when
// supported by the compiler. For ARM Neon support, you must explicitly
// request it.
//
// (The old do-it-yourself SIMD API is no longer supported in the current
// code.)
//
// On x86, SSE2 will automatically be used when available based on a run-time
// test; if not, the generic C versions are used as a fall-back. On ARM targets,
// the typical path is to have separate builds for NEON and non-NEON devices
// (at least this is true for iOS and Android). Therefore, the NEON support is
// toggled by a build flag: define STBI_NEON to get NEON loops.
//
// The output of the JPEG decoder is slightly different from versions where
// SIMD support was introduced (that is, for versions before 1.49). The
// difference is only +-1 in the 8-bit RGB channels, and only on a small
// fraction of pixels. You can force the pre-1.49 behavior by defining
// STBI_JPEG_OLD, but this will disable some of the SIMD decoding path
// and hence cost some performance.
//
// If for some reason you do not want to use any of SIMD code, or if
// you have issues compiling it, you can disable it entirely by
// defining STBI_NO_SIMD.
//
// ===========================================================================
//
// 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);
//
// ===========================================================================
//
// iPhone PNG support:
//
// By default we convert iphone-formatted PNGs back to RGB, even though
// they are internally encoded differently. 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 (which
// is BGR stored in RGB).
//
// 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).
//
#ifndef STBI_NO_STDIO
#include <stdio.h>
#endif // STBI_NO_STDIO
#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
#ifdef STB_IMAGE_STATIC
#define STBIDEF static
#else
#define STBIDEF extern
#endif
//////////////////////////////////////////////////////////////////////////////
//
// PRIMARY API - works on images of any type
//
//
// load image by filename, open file, or memory buffer
//
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,int n); // skip the next 'n' bytes, or 'unget' the last -n bytes if negative
int (*eof) (void *user); // returns nonzero if we are at end of file/data
} stbi_io_callbacks;
STBIDEF stbi_uc *stbi_load (char const *filename, int *x, int *y, int *comp, int req_comp);
STBIDEF stbi_uc *stbi_load_from_memory (stbi_uc const *buffer, int len , int *x, int *y, int *comp, int req_comp);
STBIDEF 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_STDIO
STBIDEF stbi_uc *stbi_load_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
// for stbi_load_from_file, file pointer is left pointing immediately after image
#endif
#ifndef STBI_NO_LINEAR
STBIDEF float *stbi_loadf (char const *filename, int *x, int *y, int *comp, int req_comp);
STBIDEF float *stbi_loadf_from_memory (stbi_uc const *buffer, int len, int *x, int *y, int *comp, int req_comp);
STBIDEF float *stbi_loadf_from_callbacks (stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp, int req_comp);
#ifndef STBI_NO_STDIO
STBIDEF float *stbi_loadf_from_file (FILE *f, int *x, int *y, int *comp, int req_comp);
#endif
#endif
#ifndef STBI_NO_HDR
STBIDEF void stbi_hdr_to_ldr_gamma(float gamma);
STBIDEF void stbi_hdr_to_ldr_scale(float scale);
#endif // STBI_NO_HDR
#ifndef STBI_NO_LINEAR
STBIDEF void stbi_ldr_to_hdr_gamma(float gamma);
STBIDEF void stbi_ldr_to_hdr_scale(float scale);
#endif // STBI_NO_LINEAR
// stbi_is_hdr is always defined, but always returns false if STBI_NO_HDR
STBIDEF int stbi_is_hdr_from_callbacks(stbi_io_callbacks const *clbk, void *user);
STBIDEF int stbi_is_hdr_from_memory(stbi_uc const *buffer, int len);
#ifndef STBI_NO_STDIO
STBIDEF int stbi_is_hdr (char const *filename);
STBIDEF int stbi_is_hdr_from_file(FILE *f);
#endif // STBI_NO_STDIO
// get a VERY brief reason for failure
// NOT THREADSAFE
STBIDEF const char *stbi_failure_reason (void);
// free the loaded image -- this is just free()
STBIDEF void stbi_image_free (void *retval_from_stbi_load);
// get image dimensions & components without fully decoding
STBIDEF int stbi_info_from_memory(stbi_uc const *buffer, int len, int *x, int *y, int *comp);
STBIDEF int stbi_info_from_callbacks(stbi_io_callbacks const *clbk, void *user, int *x, int *y, int *comp);
#ifndef STBI_NO_STDIO
STBIDEF int stbi_info (char const *filename, int *x, int *y, int *comp);
STBIDEF 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.
STBIDEF 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"
STBIDEF void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert);
// flip the image vertically, so the first pixel in the output array is the bottom left
STBIDEF void stbi_set_flip_vertically_on_load(int flag_true_if_should_flip);
// ZLIB client - used by PNG, available for other purposes
STBIDEF char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int initial_size, int *outlen);
STBIDEF char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, int len, int initial_size, int *outlen, int parse_header);
STBIDEF char *stbi_zlib_decode_malloc(const char *buffer, int len, int *outlen);
STBIDEF int stbi_zlib_decode_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
STBIDEF char *stbi_zlib_decode_noheader_malloc(const char *buffer, int len, int *outlen);
STBIDEF int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char *ibuffer, int ilen);
#ifdef __cplusplus
}
#endif
//
//
//// end header file /////////////////////////////////////////////////////
#endif // STBI_INCLUDE_STB_IMAGE_H
#ifdef STB_IMAGE_IMPLEMENTATION
#if defined(STBI_ONLY_JPEG) || defined(STBI_ONLY_PNG) || defined(STBI_ONLY_BMP) \
|| defined(STBI_ONLY_TGA) || defined(STBI_ONLY_GIF) || defined(STBI_ONLY_PSD) \
|| defined(STBI_ONLY_HDR) || defined(STBI_ONLY_PIC) || defined(STBI_ONLY_PNM) \
|| defined(STBI_ONLY_ZLIB)
#ifndef STBI_ONLY_JPEG
#define STBI_NO_JPEG
#endif
#ifndef STBI_ONLY_PNG
#define STBI_NO_PNG
#endif
#ifndef STBI_ONLY_BMP
#define STBI_NO_BMP
#endif
#ifndef STBI_ONLY_PSD
#define STBI_NO_PSD
#endif
#ifndef STBI_ONLY_TGA
#define STBI_NO_TGA
#endif
#ifndef STBI_ONLY_GIF
#define STBI_NO_GIF
#endif
#ifndef STBI_ONLY_HDR
#define STBI_NO_HDR
#endif
#ifndef STBI_ONLY_PIC
#define STBI_NO_PIC
#endif
#ifndef STBI_ONLY_PNM
#define STBI_NO_PNM
#endif
#endif
#if defined(STBI_NO_PNG) && !defined(STBI_SUPPORT_ZLIB) && !defined(STBI_NO_ZLIB)
#define STBI_NO_ZLIB
#endif
#include <stdarg.h>
#include <stddef.h> // ptrdiff_t on osx
#include <stdlib.h>
#include <string.h>
#if !defined(STBI_NO_LINEAR) || !defined(STBI_NO_HDR)
#include <math.h> // ldexp
#endif
#ifndef STBI_NO_STDIO
#include <stdio.h>
#endif
#ifndef STBI_ASSERT
#include <assert.h>
#define STBI_ASSERT(x) assert(x)
#endif
#ifndef _MSC_VER
#ifdef __cplusplus
#define stbi_inline inline
#else
#define stbi_inline
#endif
#else
#define stbi_inline __forceinline
#endif
#ifdef _MSC_VER
typedef unsigned short stbi__uint16;
typedef signed short stbi__int16;
typedef unsigned int stbi__uint32;
typedef signed int stbi__int32;
#else
#include <stdint.h>
typedef uint16_t stbi__uint16;
typedef int16_t stbi__int16;
typedef uint32_t stbi__uint32;
typedef int32_t stbi__int32;
#endif
// should produce compiler error if size is wrong
typedef unsigned char validate_uint32[sizeof(stbi__uint32)==4 ? 1 : -1];
#ifdef _MSC_VER
#define STBI_NOTUSED(v) (void)(v)
#else
#define STBI_NOTUSED(v) (void)sizeof(v)
#endif
#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
#if defined(STBI_MALLOC) && defined(STBI_FREE) && (defined(STBI_REALLOC) || defined(STBI_REALLOC_SIZED))
// ok
#elif !defined(STBI_MALLOC) && !defined(STBI_FREE) && !defined(STBI_REALLOC) && !defined(STBI_REALLOC_SIZED)
// ok
#else
#error "Must define all or none of STBI_MALLOC, STBI_FREE, and STBI_REALLOC (or STBI_REALLOC_SIZED)."
#endif
#ifndef STBI_MALLOC
#define STBI_MALLOC(sz) malloc(sz)
#define STBI_REALLOC(p,newsz) realloc(p,newsz)
#define STBI_FREE(p) free(p)
#endif
#ifndef STBI_REALLOC_SIZED
#define STBI_REALLOC_SIZED(p,oldsz,newsz) STBI_REALLOC(p,newsz)
#endif
// x86/x64 detection
#if defined(__x86_64__) || defined(_M_X64)
#define STBI__X64_TARGET
#elif defined(__i386) || defined(_M_IX86)
#define STBI__X86_TARGET
#endif
#if defined(__GNUC__) && (defined(STBI__X86_TARGET) || defined(STBI__X64_TARGET)) && !defined(__SSE2__) && !defined(STBI_NO_SIMD)
// NOTE: not clear do we actually need this for the 64-bit path?
// gcc doesn't support sse2 intrinsics unless you compile with -msse2,
// (but compiling with -msse2 allows the compiler to use SSE2 everywhere;
// this is just broken and gcc are jerks for not fixing it properly
// http://www.virtualdub.org/blog/pivot/entry.php?id=363 )
#define STBI_NO_SIMD
#endif
#if defined(__MINGW32__) && defined(STBI__X86_TARGET) && !defined(STBI_MINGW_ENABLE_SSE2) && !defined(STBI_NO_SIMD)
// Note that __MINGW32__ doesn't actually mean 32-bit, so we have to avoid STBI__X64_TARGET
//
// 32-bit MinGW wants ESP to be 16-byte aligned, but this is not in the
// Windows ABI and VC++ as well as Windows DLLs don't maintain that invariant.
// As a result, enabling SSE2 on 32-bit MinGW is dangerous when not
// simultaneously enabling "-mstackrealign".
//
// See https://github.com/nothings/stb/issues/81 for more information.
//
// So default to no SSE2 on 32-bit MinGW. If you've read this far and added
// -mstackrealign to your build settings, feel free to #define STBI_MINGW_ENABLE_SSE2.
#define STBI_NO_SIMD
#endif
#if !defined(STBI_NO_SIMD) && (defined(STBI__X86_TARGET) || defined(STBI__X64_TARGET))
#define STBI_SSE2
#include <emmintrin.h>
#ifdef _MSC_VER
#if _MSC_VER >= 1400 // not VC6
#include <intrin.h> // __cpuid
static int stbi__cpuid3(void)
{
int info[4];
__cpuid(info,1);
return info[3];
}
#else
static int stbi__cpuid3(void)
{
int res;
__asm {
mov eax,1
cpuid
mov res,edx
}
return res;
}
#endif
#define STBI_SIMD_ALIGN(type, name) __declspec(align(16)) type name
static int stbi__sse2_available()
{
int info3 = stbi__cpuid3();
return ((info3 >> 26) & 1) != 0;
}
#else // assume GCC-style if not VC++
#define STBI_SIMD_ALIGN(type, name) type name __attribute__((aligned(16)))
static int stbi__sse2_available()
{
#if defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__) >= 408 // GCC 4.8 or later
// GCC 4.8+ has a nice way to do this
return __builtin_cpu_supports("sse2");
#else
// portable way to do this, preferably without using GCC inline ASM?
// just bail for now.
return 0;
#endif
}
#endif
#endif
// ARM NEON
#if defined(STBI_NO_SIMD) && defined(STBI_NEON)
#undef STBI_NEON
#endif
#ifdef STBI_NEON
#include <arm_neon.h>
// assume GCC or Clang on ARM targets
#define STBI_SIMD_ALIGN(type, name) type name __attribute__((aligned(16)))
#endif
#ifndef STBI_SIMD_ALIGN
#define STBI_SIMD_ALIGN(type, name) type name
#endif
///////////////////////////////////////////////
//
// stbi__context struct and start_xxx functions
// stbi__context structure is our basic context used by all images, so it
// contains all the IO context, plus some basic image information
typedef struct
{
stbi__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;
stbi_uc buffer_start[128];
stbi_uc *img_buffer, *img_buffer_end;
stbi_uc *img_buffer_original, *img_buffer_original_end;
} stbi__context;
static void stbi__refill_buffer(stbi__context *s);
// initialize a memory-decode context
static void stbi__start_mem(stbi__context *s, stbi_uc const *buffer, int len)
{
s->io.read = NULL;
s->read_from_callbacks = 0;
s->img_buffer = s->img_buffer_original = (stbi_uc *) buffer;
s->img_buffer_end = s->img_buffer_original_end = (stbi_uc *) buffer+len;
}
// initialize a callback-based context
static void stbi__start_callbacks(stbi__context *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;
stbi__refill_buffer(s);
s->img_buffer_original_end = s->img_buffer_end;
}
#ifndef STBI_NO_STDIO
static int stbi__stdio_read(void *user, char *data, int size)
{
return (int) fread(data,1,size,(FILE*) user);
}
static void stbi__stdio_skip(void *user, int n)
{
fseek((FILE*) user, n, SEEK_CUR);
}
static int stbi__stdio_eof(void *user)
{
return feof((FILE*) user);
}
static stbi_io_callbacks stbi__stdio_callbacks =
{
stbi__stdio_read,
stbi__stdio_skip,
stbi__stdio_eof,
};
static void stbi__start_file(stbi__context *s, FILE *f)
{
stbi__start_callbacks(s, &stbi__stdio_callbacks, (void *) f);
}
//static void stop_file(stbi__context *s) { }
#endif // !STBI_NO_STDIO
static void stbi__rewind(stbi__context *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;
s->img_buffer_end = s->img_buffer_original_end;
}
#ifndef STBI_NO_JPEG
static int stbi__jpeg_test(stbi__context *s);
static stbi_uc *stbi__jpeg_load(stbi__context *s, int *x, int *y, int *comp, int req_comp);
static int stbi__jpeg_info(stbi__context *s, int *x, int *y, int *comp);
#endif
#ifndef STBI_NO_PNG
static int stbi__png_test(stbi__context *s);
static stbi_uc *stbi__png_load(stbi__context *s, int *x, int *y, int *comp, int req_comp);
static int stbi__png_info(stbi__context *s, int *x, int *y, int *comp);
#endif
#ifndef STBI_NO_BMP
static int stbi__bmp_test(stbi__context *s);
static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int req_comp);
static int stbi__bmp_info(stbi__context *s, int *x, int *y, int *comp);
#endif
#ifndef STBI_NO_TGA
static int stbi__tga_test(stbi__context *s);
static stbi_uc *stbi__tga_load(stbi__context *s, int *x, int *y, int *comp, int req_comp);
static int stbi__tga_info(stbi__context *s, int *x, int *y, int *comp);
#endif
#ifndef STBI_NO_PSD
static int stbi__psd_test(stbi__context *s);
static stbi_uc *stbi__psd_load(stbi__context *s, int *x, int *y, int *comp, int req_comp);
static int stbi__psd_info(stbi__context *s, int *x, int *y, int *comp);
#endif
#ifndef STBI_NO_HDR
static int stbi__hdr_test(stbi__context *s);
static float *stbi__hdr_load(stbi__context *s, int *x, int *y, int *comp, int req_comp);
static int stbi__hdr_info(stbi__context *s, int *x, int *y, int *comp);
#endif
#ifndef STBI_NO_PIC
static int stbi__pic_test(stbi__context *s);
static stbi_uc *stbi__pic_load(stbi__context *s, int *x, int *y, int *comp, int req_comp);
static int stbi__pic_info(stbi__context *s, int *x, int *y, int *comp);
#endif
#ifndef STBI_NO_GIF
static int stbi__gif_test(stbi__context *s);
static stbi_uc *stbi__gif_load(stbi__context *s, int *x, int *y, int *comp, int req_comp);
static int stbi__gif_info(stbi__context *s, int *x, int *y, int *comp);
#endif
#ifndef STBI_NO_PNM
static int stbi__pnm_test(stbi__context *s);