duilib库的增强拓展版，库修复了大量用户在使用中反馈的Bug，新增了用户需求的功能

#define STBI_NO_STDIO #define STBI_NO_WRITE #define STBI_NO_HDR /* 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 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); // // ========================