/* BMP File Reader/Writer Implementation Anton Gerdelan Version: 3.1 18 March 2020. Licence: see bottom of file. C89 ( Implementation is C99 ) Contributors: - Anton Gerdelan - Initial code. - Saija Sorsa - Fuzz testing. Instructions: - Just drop this header, and the matching .c file into your project. - To get debug printouts during parsing define APG_BMP_DEBUG_OUTPUT. Advantages: - The implementation is fast, simple, and supports more formats than most BMP reader libraries. - The reader function is fuzzed with AFL https://lcamtuf.coredump.cx/afl/. - The reader is robust to large files and malformed files, and will return any valid partial data in an image. - Reader supports 32bpp (with alpha channel), 24bpp, 8bpp, 4bpp, and 1bpp monochrome BMP images. - Reader handles indexed BMP images using a colour palette. - Writer supports 32bpp RGBA and 24bpp uncompressed RGB images. Current Limitations: - 16-bit images not supported (don't have any samples to test on). - No support for interleaved channel bit layouts eg RGB101010 RGB555 RGB565. - No support for compressed BMP images, although in practice these are not used. - Output images with alpha channel are written in BITMAPINFOHEADER format. For better alpha support in other apps the 124-bit v5 header could be used instead, at the cost of some backward compatibility and bloat. To Do: - FUZZING - create a unique fuzz test set for (8,4,1 BPP). - (maybe) FEATURE Flipping the image based on negative width and height in header, and/or function arguments. - (maybe) PERF ifdef intrinsics/asm for bitscan. Platform-specific code so won't include unless necessary. - (maybe) FEATURE Add parameter for padding output memory to eg 4-byte alignment or n channels. - (maybe) FEATURE Improved apps support in alpha channel writing (using v5 header). */ #ifndef APG_BMP_H_ #define APG_BMP_H_ #ifdef __cplusplus extern "C" { #endif /* CPP */ /* Reads a bitmap from a file, allocates memory for the raw image data, and returns it. PARAMS * w,h, - Retrieves the width and height of the BMP in pixels. * n_chans - Retrieves the number of channels in the BMP. RETURNS * Tightly-packed pixel memory in RGBA order. The caller must call free() on the memory. * NULL on any error. Any allocated memory is freed before returning NULL. */ unsigned char* apg_bmp_read( const char* filename, int* w, int* h, unsigned int* n_chans ); /* Calls free() on memory created by apg_bmp_read */ void apg_bmp_free( unsigned char* pixels_ptr ); /* Writes a bitmap to a file. PARAMS * filename - e.g."my_bitmap.bmp". Must not be NULL. * pixels_ptr - Pointer to tightly-packed pixel memory in RGBA order. Must not be NULL. There must be abs(w)*abs(h)*n_chans bytes in the memory pointed to. * w,h, - Width and height of the image in pixels. * n_chans - The number of channels in the BMP. 3 or 4 supported for writing, which means RGB or RGBA memory, respectively. RETURNS * Zero on any error, non zero on success. */ unsigned int apg_bmp_write( const char* filename, unsigned char* pixels_ptr, int w, int h, unsigned int n_chans ); #ifdef __cplusplus } #endif /* CPP */ #endif /*_APG_BMP_H_ */ /* ------------------------------------------------------------------------------------- This software is available under two licences - you may use it under either licence. ------------------------------------------------------------------------------------- FIRST LICENCE OPTION > Apache License > Version 2.0, January 2004 > http://www.apache.org/licenses/ > Copyright 2019 Anton Gerdelan. > Licensed under the Apache License, Version 2.0 (the "License"); > you may not use this file except in compliance with the License. > You may obtain a copy of the License at > http://www.apache.org/licenses/LICENSE-2.0 > Unless required by applicable law or agreed to in writing, software > distributed under the License is distributed on an "AS IS" BASIS, > WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. > See the License for the specific language governing permissions and > limitations under the License. ------------------------------------------------------------------------------------- SECOND LICENCE OPTION > This is free and unencumbered software released into the public domain. > > Anyone is free to copy, modify, publish, use, compile, sell, or > distribute this software, either in source code form or as a compiled > binary, for any purpose, commercial or non-commercial, and by any > means. > > In jurisdictions that recognize copyright laws, the author or authors > of this software dedicate any and all copyright interest in the > software to the public domain. We make this dedication for the benefit > of the public at large and to the detriment of our heirs and > successors. We intend this dedication to be an overt act of > relinquishment in perpetuity of all present and future rights to this > software under copyright law. > > THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, > EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF > MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. > IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR > OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, > ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR > OTHER DEALINGS IN THE SOFTWARE. > > For more information, please refer to ------------------------------------------------------------------------------------- */