app_lcdboard_demo_picture - Example for the LPC4088 QSB Base Board

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EmbeddedArtists AB / Mbed 2 deprecated app_lcdboard_demo_picture

Example for the LPC4088 QSB Base Board

lodepng.h@3:33a36d79ab7d, 2014-04-09 (annotated)

Committer:: embeddedartists
Date:: Wed Apr 09 10:26:13 2014 +0000
Revision:: 3:33a36d79ab7d
Parent:: 0:83b8ee8e8d4b

Updated to latest version of EALib

Who changed what in which revision?

User	Revision	Line number	New contents of line
embeddedartists	0:83b8ee8e8d4b	1	/*
embeddedartists	0:83b8ee8e8d4b	2	LodePNG version 20131222
embeddedartists	0:83b8ee8e8d4b	3
embeddedartists	0:83b8ee8e8d4b	4	Copyright (c) 2005-2013 Lode Vandevenne
embeddedartists	0:83b8ee8e8d4b	5
embeddedartists	0:83b8ee8e8d4b	6	This software is provided 'as-is', without any express or implied
embeddedartists	0:83b8ee8e8d4b	7	warranty. In no event will the authors be held liable for any damages
embeddedartists	0:83b8ee8e8d4b	8	arising from the use of this software.
embeddedartists	0:83b8ee8e8d4b	9
embeddedartists	0:83b8ee8e8d4b	10	Permission is granted to anyone to use this software for any purpose,
embeddedartists	0:83b8ee8e8d4b	11	including commercial applications, and to alter it and redistribute it
embeddedartists	0:83b8ee8e8d4b	12	freely, subject to the following restrictions:
embeddedartists	0:83b8ee8e8d4b	13
embeddedartists	0:83b8ee8e8d4b	14	1. The origin of this software must not be misrepresented; you must not
embeddedartists	0:83b8ee8e8d4b	15	claim that you wrote the original software. If you use this software
embeddedartists	0:83b8ee8e8d4b	16	in a product, an acknowledgment in the product documentation would be
embeddedartists	0:83b8ee8e8d4b	17	appreciated but is not required.
embeddedartists	0:83b8ee8e8d4b	18
embeddedartists	0:83b8ee8e8d4b	19	2. Altered source versions must be plainly marked as such, and must not be
embeddedartists	0:83b8ee8e8d4b	20	misrepresented as being the original software.
embeddedartists	0:83b8ee8e8d4b	21
embeddedartists	0:83b8ee8e8d4b	22	3. This notice may not be removed or altered from any source
embeddedartists	0:83b8ee8e8d4b	23	distribution.
embeddedartists	0:83b8ee8e8d4b	24	*/
embeddedartists	0:83b8ee8e8d4b	25
embeddedartists	0:83b8ee8e8d4b	26	#ifndef LODEPNG_H
embeddedartists	0:83b8ee8e8d4b	27	#define LODEPNG_H
embeddedartists	0:83b8ee8e8d4b	28
embeddedartists	0:83b8ee8e8d4b	29	#include <string.h> /for size_t/
embeddedartists	0:83b8ee8e8d4b	30
embeddedartists	0:83b8ee8e8d4b	31	#ifdef __cplusplus
embeddedartists	0:83b8ee8e8d4b	32	#include <vector>
embeddedartists	0:83b8ee8e8d4b	33	#include <string>
embeddedartists	0:83b8ee8e8d4b	34	#endif /__cplusplus/
embeddedartists	0:83b8ee8e8d4b	35
embeddedartists	0:83b8ee8e8d4b	36
embeddedartists	0:83b8ee8e8d4b	37	// Settings modified by Embedded Artists
embeddedartists	0:83b8ee8e8d4b	38	#define LODEPNG_NO_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	39	#define LODEPNG_NO_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	40	#define LODEPNG_NO_COMPILE_ANCILLARY_CHUNKS
embeddedartists	0:83b8ee8e8d4b	41	#define LODEPNG_NO_COMPILE_ERROR_TEXT
embeddedartists	0:83b8ee8e8d4b	42	#define LODEPNG_NO_COMPILE_CPP
embeddedartists	0:83b8ee8e8d4b	43
embeddedartists	0:83b8ee8e8d4b	44
embeddedartists	0:83b8ee8e8d4b	45	/*
embeddedartists	0:83b8ee8e8d4b	46	The following #defines are used to create code sections. They can be disabled
embeddedartists	0:83b8ee8e8d4b	47	to disable code sections, which can give faster compile time and smaller binary.
embeddedartists	0:83b8ee8e8d4b	48	The "NO_COMPILE" defines are designed to be used to pass as defines to the
embeddedartists	0:83b8ee8e8d4b	49	compiler command to disable them without modifying this header, e.g.
embeddedartists	0:83b8ee8e8d4b	50	-DLODEPNG_NO_COMPILE_ZLIB for gcc.
embeddedartists	0:83b8ee8e8d4b	51	*/
embeddedartists	0:83b8ee8e8d4b	52	/*deflate & zlib. If disabled, you must specify alternative zlib functions in
embeddedartists	0:83b8ee8e8d4b	53	the custom_zlib field of the compress and decompress settings*/
embeddedartists	0:83b8ee8e8d4b	54	#ifndef LODEPNG_NO_COMPILE_ZLIB
embeddedartists	0:83b8ee8e8d4b	55	#define LODEPNG_COMPILE_ZLIB
embeddedartists	0:83b8ee8e8d4b	56	#endif
embeddedartists	0:83b8ee8e8d4b	57	/png encoder and png decoder/
embeddedartists	0:83b8ee8e8d4b	58	#ifndef LODEPNG_NO_COMPILE_PNG
embeddedartists	0:83b8ee8e8d4b	59	#define LODEPNG_COMPILE_PNG
embeddedartists	0:83b8ee8e8d4b	60	#endif
embeddedartists	0:83b8ee8e8d4b	61	/deflate&zlib decoder and png decoder/
embeddedartists	0:83b8ee8e8d4b	62	#ifndef LODEPNG_NO_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	63	#define LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	64	#endif
embeddedartists	0:83b8ee8e8d4b	65	/deflate&zlib encoder and png encoder/
embeddedartists	0:83b8ee8e8d4b	66	#ifndef LODEPNG_NO_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	67	#define LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	68	#endif
embeddedartists	0:83b8ee8e8d4b	69	/the optional built in harddisk file loading and saving functions/
embeddedartists	0:83b8ee8e8d4b	70	#ifndef LODEPNG_NO_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	71	#define LODEPNG_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	72	#endif
embeddedartists	0:83b8ee8e8d4b	73	/support for chunks other than IHDR, IDAT, PLTE, tRNS, IEND: ancillary and unknown chunks/
embeddedartists	0:83b8ee8e8d4b	74	#ifndef LODEPNG_NO_COMPILE_ANCILLARY_CHUNKS
embeddedartists	0:83b8ee8e8d4b	75	#define LODEPNG_COMPILE_ANCILLARY_CHUNKS
embeddedartists	0:83b8ee8e8d4b	76	#endif
embeddedartists	0:83b8ee8e8d4b	77	/ability to convert error numerical codes to English text string/
embeddedartists	0:83b8ee8e8d4b	78	#ifndef LODEPNG_NO_COMPILE_ERROR_TEXT
embeddedartists	0:83b8ee8e8d4b	79	#define LODEPNG_COMPILE_ERROR_TEXT
embeddedartists	0:83b8ee8e8d4b	80	#endif
embeddedartists	0:83b8ee8e8d4b	81	/*Compile the default allocators (C's free, malloc and realloc). If you disable this,
embeddedartists	0:83b8ee8e8d4b	82	you can define the functions lodepng_free, lodepng_malloc and lodepng_realloc in your
embeddedartists	0:83b8ee8e8d4b	83	source files with custom allocators.*/
embeddedartists	0:83b8ee8e8d4b	84	#ifndef LODEPNG_NO_COMPILE_ALLOCATORS
embeddedartists	0:83b8ee8e8d4b	85	#define LODEPNG_COMPILE_ALLOCATORS
embeddedartists	0:83b8ee8e8d4b	86	#endif
embeddedartists	0:83b8ee8e8d4b	87	/compile the C++ version (you can disable the C++ wrapper here even when compiling for C++)/
embeddedartists	0:83b8ee8e8d4b	88	#ifdef __cplusplus
embeddedartists	0:83b8ee8e8d4b	89	#ifndef LODEPNG_NO_COMPILE_CPP
embeddedartists	0:83b8ee8e8d4b	90	#define LODEPNG_COMPILE_CPP
embeddedartists	0:83b8ee8e8d4b	91	#endif
embeddedartists	0:83b8ee8e8d4b	92	#endif
embeddedartists	0:83b8ee8e8d4b	93
embeddedartists	0:83b8ee8e8d4b	94	#ifdef LODEPNG_COMPILE_PNG
embeddedartists	0:83b8ee8e8d4b	95	/The PNG color types (also used for raw)./
embeddedartists	0:83b8ee8e8d4b	96	typedef enum LodePNGColorType
embeddedartists	0:83b8ee8e8d4b	97	{
embeddedartists	0:83b8ee8e8d4b	98	LCT_GREY = 0, /greyscale: 1,2,4,8,16 bit/
embeddedartists	0:83b8ee8e8d4b	99	LCT_RGB = 2, /RGB: 8,16 bit/
embeddedartists	0:83b8ee8e8d4b	100	LCT_PALETTE = 3, /palette: 1,2,4,8 bit/
embeddedartists	0:83b8ee8e8d4b	101	LCT_GREY_ALPHA = 4, /greyscale with alpha: 8,16 bit/
embeddedartists	0:83b8ee8e8d4b	102	LCT_RGBA = 6 /RGB with alpha: 8,16 bit/
embeddedartists	0:83b8ee8e8d4b	103	} LodePNGColorType;
embeddedartists	0:83b8ee8e8d4b	104
embeddedartists	0:83b8ee8e8d4b	105	#ifdef LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	106	/*
embeddedartists	0:83b8ee8e8d4b	107	Converts PNG data in memory to raw pixel data.
embeddedartists	0:83b8ee8e8d4b	108	out: Output parameter. Pointer to buffer that will contain the raw pixel data.
embeddedartists	0:83b8ee8e8d4b	109	After decoding, its size is w * h * (bytes per pixel) bytes larger than
embeddedartists	0:83b8ee8e8d4b	110	initially. Bytes per pixel depends on colortype and bitdepth.
embeddedartists	0:83b8ee8e8d4b	111	Must be freed after usage with free(*out).
embeddedartists	0:83b8ee8e8d4b	112	Note: for 16-bit per channel colors, uses big endian format like PNG does.
embeddedartists	0:83b8ee8e8d4b	113	w: Output parameter. Pointer to width of pixel data.
embeddedartists	0:83b8ee8e8d4b	114	h: Output parameter. Pointer to height of pixel data.
embeddedartists	0:83b8ee8e8d4b	115	in: Memory buffer with the PNG file.
embeddedartists	0:83b8ee8e8d4b	116	insize: size of the in buffer.
embeddedartists	0:83b8ee8e8d4b	117	colortype: the desired color type for the raw output image. See explanation on PNG color types.
embeddedartists	0:83b8ee8e8d4b	118	bitdepth: the desired bit depth for the raw output image. See explanation on PNG color types.
embeddedartists	0:83b8ee8e8d4b	119	Return value: LodePNG error code (0 means no error).
embeddedartists	0:83b8ee8e8d4b	120	*/
embeddedartists	0:83b8ee8e8d4b	121	unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h,
embeddedartists	0:83b8ee8e8d4b	122	const unsigned char* in, size_t insize,
embeddedartists	0:83b8ee8e8d4b	123	LodePNGColorType colortype, unsigned bitdepth);
embeddedartists	0:83b8ee8e8d4b	124
embeddedartists	0:83b8ee8e8d4b	125	/Same as lodepng_decode_memory, but always decodes to 32-bit RGBA raw image/
embeddedartists	0:83b8ee8e8d4b	126	unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h,
embeddedartists	0:83b8ee8e8d4b	127	const unsigned char* in, size_t insize);
embeddedartists	0:83b8ee8e8d4b	128
embeddedartists	0:83b8ee8e8d4b	129	/Same as lodepng_decode_memory, but always decodes to 24-bit RGB raw image/
embeddedartists	0:83b8ee8e8d4b	130	unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h,
embeddedartists	0:83b8ee8e8d4b	131	const unsigned char* in, size_t insize);
embeddedartists	0:83b8ee8e8d4b	132
embeddedartists	0:83b8ee8e8d4b	133	#ifdef LODEPNG_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	134	/*
embeddedartists	0:83b8ee8e8d4b	135	Load PNG from disk, from file with given name.
embeddedartists	0:83b8ee8e8d4b	136	Same as the other decode functions, but instead takes a filename as input.
embeddedartists	0:83b8ee8e8d4b	137	*/
embeddedartists	0:83b8ee8e8d4b	138	unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h,
embeddedartists	0:83b8ee8e8d4b	139	const char* filename,
embeddedartists	0:83b8ee8e8d4b	140	LodePNGColorType colortype, unsigned bitdepth);
embeddedartists	0:83b8ee8e8d4b	141
embeddedartists	0:83b8ee8e8d4b	142	/Same as lodepng_decode_file, but always decodes to 32-bit RGBA raw image./
embeddedartists	0:83b8ee8e8d4b	143	unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h,
embeddedartists	0:83b8ee8e8d4b	144	const char* filename);
embeddedartists	0:83b8ee8e8d4b	145
embeddedartists	0:83b8ee8e8d4b	146	/Same as lodepng_decode_file, but always decodes to 24-bit RGB raw image./
embeddedartists	0:83b8ee8e8d4b	147	unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h,
embeddedartists	0:83b8ee8e8d4b	148	const char* filename);
embeddedartists	0:83b8ee8e8d4b	149	#endif /LODEPNG_COMPILE_DISK/
embeddedartists	0:83b8ee8e8d4b	150	#endif /LODEPNG_COMPILE_DECODER/
embeddedartists	0:83b8ee8e8d4b	151
embeddedartists	0:83b8ee8e8d4b	152
embeddedartists	0:83b8ee8e8d4b	153	#ifdef LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	154	/*
embeddedartists	0:83b8ee8e8d4b	155	Converts raw pixel data into a PNG image in memory. The colortype and bitdepth
embeddedartists	0:83b8ee8e8d4b	156	of the output PNG image cannot be chosen, they are automatically determined
embeddedartists	0:83b8ee8e8d4b	157	by the colortype, bitdepth and content of the input pixel data.
embeddedartists	0:83b8ee8e8d4b	158	Note: for 16-bit per channel colors, needs big endian format like PNG does.
embeddedartists	0:83b8ee8e8d4b	159	out: Output parameter. Pointer to buffer that will contain the PNG image data.
embeddedartists	0:83b8ee8e8d4b	160	Must be freed after usage with free(*out).
embeddedartists	0:83b8ee8e8d4b	161	outsize: Output parameter. Pointer to the size in bytes of the out buffer.
embeddedartists	0:83b8ee8e8d4b	162	image: The raw pixel data to encode. The size of this buffer should be
embeddedartists	0:83b8ee8e8d4b	163	w * h * (bytes per pixel), bytes per pixel depends on colortype and bitdepth.
embeddedartists	0:83b8ee8e8d4b	164	w: width of the raw pixel data in pixels.
embeddedartists	0:83b8ee8e8d4b	165	h: height of the raw pixel data in pixels.
embeddedartists	0:83b8ee8e8d4b	166	colortype: the color type of the raw input image. See explanation on PNG color types.
embeddedartists	0:83b8ee8e8d4b	167	bitdepth: the bit depth of the raw input image. See explanation on PNG color types.
embeddedartists	0:83b8ee8e8d4b	168	Return value: LodePNG error code (0 means no error).
embeddedartists	0:83b8ee8e8d4b	169	*/
embeddedartists	0:83b8ee8e8d4b	170	unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize,
embeddedartists	0:83b8ee8e8d4b	171	const unsigned char* image, unsigned w, unsigned h,
embeddedartists	0:83b8ee8e8d4b	172	LodePNGColorType colortype, unsigned bitdepth);
embeddedartists	0:83b8ee8e8d4b	173
embeddedartists	0:83b8ee8e8d4b	174	/Same as lodepng_encode_memory, but always encodes from 32-bit RGBA raw image./
embeddedartists	0:83b8ee8e8d4b	175	unsigned lodepng_encode32(unsigned char** out, size_t* outsize,
embeddedartists	0:83b8ee8e8d4b	176	const unsigned char* image, unsigned w, unsigned h);
embeddedartists	0:83b8ee8e8d4b	177
embeddedartists	0:83b8ee8e8d4b	178	/Same as lodepng_encode_memory, but always encodes from 24-bit RGB raw image./
embeddedartists	0:83b8ee8e8d4b	179	unsigned lodepng_encode24(unsigned char** out, size_t* outsize,
embeddedartists	0:83b8ee8e8d4b	180	const unsigned char* image, unsigned w, unsigned h);
embeddedartists	0:83b8ee8e8d4b	181
embeddedartists	0:83b8ee8e8d4b	182	#ifdef LODEPNG_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	183	/*
embeddedartists	0:83b8ee8e8d4b	184	Converts raw pixel data into a PNG file on disk.
embeddedartists	0:83b8ee8e8d4b	185	Same as the other encode functions, but instead takes a filename as output.
embeddedartists	0:83b8ee8e8d4b	186	NOTE: This overwrites existing files without warning!
embeddedartists	0:83b8ee8e8d4b	187	*/
embeddedartists	0:83b8ee8e8d4b	188	unsigned lodepng_encode_file(const char* filename,
embeddedartists	0:83b8ee8e8d4b	189	const unsigned char* image, unsigned w, unsigned h,
embeddedartists	0:83b8ee8e8d4b	190	LodePNGColorType colortype, unsigned bitdepth);
embeddedartists	0:83b8ee8e8d4b	191
embeddedartists	0:83b8ee8e8d4b	192	/Same as lodepng_encode_file, but always encodes from 32-bit RGBA raw image./
embeddedartists	0:83b8ee8e8d4b	193	unsigned lodepng_encode32_file(const char* filename,
embeddedartists	0:83b8ee8e8d4b	194	const unsigned char* image, unsigned w, unsigned h);
embeddedartists	0:83b8ee8e8d4b	195
embeddedartists	0:83b8ee8e8d4b	196	/Same as lodepng_encode_file, but always encodes from 24-bit RGB raw image./
embeddedartists	0:83b8ee8e8d4b	197	unsigned lodepng_encode24_file(const char* filename,
embeddedartists	0:83b8ee8e8d4b	198	const unsigned char* image, unsigned w, unsigned h);
embeddedartists	0:83b8ee8e8d4b	199	#endif /LODEPNG_COMPILE_DISK/
embeddedartists	0:83b8ee8e8d4b	200	#endif /LODEPNG_COMPILE_ENCODER/
embeddedartists	0:83b8ee8e8d4b	201
embeddedartists	0:83b8ee8e8d4b	202
embeddedartists	0:83b8ee8e8d4b	203	#ifdef LODEPNG_COMPILE_CPP
embeddedartists	0:83b8ee8e8d4b	204	namespace lodepng
embeddedartists	0:83b8ee8e8d4b	205	{
embeddedartists	0:83b8ee8e8d4b	206	#ifdef LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	207	/Same as lodepng_decode_memory, but decodes to an std::vector./
embeddedartists	0:83b8ee8e8d4b	208	unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
embeddedartists	0:83b8ee8e8d4b	209	const unsigned char* in, size_t insize,
embeddedartists	0:83b8ee8e8d4b	210	LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
embeddedartists	0:83b8ee8e8d4b	211	unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
embeddedartists	0:83b8ee8e8d4b	212	const std::vector<unsigned char>& in,
embeddedartists	0:83b8ee8e8d4b	213	LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
embeddedartists	0:83b8ee8e8d4b	214	#ifdef LODEPNG_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	215	/*
embeddedartists	0:83b8ee8e8d4b	216	Converts PNG file from disk to raw pixel data in memory.
embeddedartists	0:83b8ee8e8d4b	217	Same as the other decode functions, but instead takes a filename as input.
embeddedartists	0:83b8ee8e8d4b	218	*/
embeddedartists	0:83b8ee8e8d4b	219	unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
embeddedartists	0:83b8ee8e8d4b	220	const std::string& filename,
embeddedartists	0:83b8ee8e8d4b	221	LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
embeddedartists	0:83b8ee8e8d4b	222	#endif //LODEPNG_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	223	#endif //LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	224
embeddedartists	0:83b8ee8e8d4b	225	#ifdef LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	226	/Same as lodepng_encode_memory, but encodes to an std::vector./
embeddedartists	0:83b8ee8e8d4b	227	unsigned encode(std::vector<unsigned char>& out,
embeddedartists	0:83b8ee8e8d4b	228	const unsigned char* in, unsigned w, unsigned h,
embeddedartists	0:83b8ee8e8d4b	229	LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
embeddedartists	0:83b8ee8e8d4b	230	unsigned encode(std::vector<unsigned char>& out,
embeddedartists	0:83b8ee8e8d4b	231	const std::vector<unsigned char>& in, unsigned w, unsigned h,
embeddedartists	0:83b8ee8e8d4b	232	LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
embeddedartists	0:83b8ee8e8d4b	233	#ifdef LODEPNG_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	234	/*
embeddedartists	0:83b8ee8e8d4b	235	Converts 32-bit RGBA raw pixel data into a PNG file on disk.
embeddedartists	0:83b8ee8e8d4b	236	Same as the other encode functions, but instead takes a filename as output.
embeddedartists	0:83b8ee8e8d4b	237	NOTE: This overwrites existing files without warning!
embeddedartists	0:83b8ee8e8d4b	238	*/
embeddedartists	0:83b8ee8e8d4b	239	unsigned encode(const std::string& filename,
embeddedartists	0:83b8ee8e8d4b	240	const unsigned char* in, unsigned w, unsigned h,
embeddedartists	0:83b8ee8e8d4b	241	LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
embeddedartists	0:83b8ee8e8d4b	242	unsigned encode(const std::string& filename,
embeddedartists	0:83b8ee8e8d4b	243	const std::vector<unsigned char>& in, unsigned w, unsigned h,
embeddedartists	0:83b8ee8e8d4b	244	LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
embeddedartists	0:83b8ee8e8d4b	245	#endif //LODEPNG_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	246	#endif //LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	247	} //namespace lodepng
embeddedartists	0:83b8ee8e8d4b	248	#endif /LODEPNG_COMPILE_CPP/
embeddedartists	0:83b8ee8e8d4b	249	#endif /LODEPNG_COMPILE_PNG/
embeddedartists	0:83b8ee8e8d4b	250
embeddedartists	0:83b8ee8e8d4b	251	#ifdef LODEPNG_COMPILE_ERROR_TEXT
embeddedartists	0:83b8ee8e8d4b	252	/Returns an English description of the numerical error code./
embeddedartists	0:83b8ee8e8d4b	253	const char* lodepng_error_text(unsigned code);
embeddedartists	0:83b8ee8e8d4b	254	#endif /LODEPNG_COMPILE_ERROR_TEXT/
embeddedartists	0:83b8ee8e8d4b	255
embeddedartists	0:83b8ee8e8d4b	256	#ifdef LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	257	/Settings for zlib decompression/
embeddedartists	0:83b8ee8e8d4b	258	typedef struct LodePNGDecompressSettings LodePNGDecompressSettings;
embeddedartists	0:83b8ee8e8d4b	259	struct LodePNGDecompressSettings
embeddedartists	0:83b8ee8e8d4b	260	{
embeddedartists	0:83b8ee8e8d4b	261	unsigned ignore_adler32; /if 1, continue and don't give an error message if the Adler32 checksum is corrupted/
embeddedartists	0:83b8ee8e8d4b	262
embeddedartists	0:83b8ee8e8d4b	263	/use custom zlib decoder instead of built in one (default: null)/
embeddedartists	0:83b8ee8e8d4b	264	unsigned (custom_zlib)(unsigned char, size_t,
embeddedartists	0:83b8ee8e8d4b	265	const unsigned char*, size_t,
embeddedartists	0:83b8ee8e8d4b	266	const LodePNGDecompressSettings*);
embeddedartists	0:83b8ee8e8d4b	267	/*use custom deflate decoder instead of built in one (default: null)
embeddedartists	0:83b8ee8e8d4b	268	if custom_zlib is used, custom_deflate is ignored since only the built in
embeddedartists	0:83b8ee8e8d4b	269	zlib function will call custom_deflate*/
embeddedartists	0:83b8ee8e8d4b	270	unsigned (custom_inflate)(unsigned char, size_t,
embeddedartists	0:83b8ee8e8d4b	271	const unsigned char*, size_t,
embeddedartists	0:83b8ee8e8d4b	272	const LodePNGDecompressSettings*);
embeddedartists	0:83b8ee8e8d4b	273
embeddedartists	0:83b8ee8e8d4b	274	const void* custom_context; /optional custom settings for custom functions/
embeddedartists	0:83b8ee8e8d4b	275	};
embeddedartists	0:83b8ee8e8d4b	276
embeddedartists	0:83b8ee8e8d4b	277	extern const LodePNGDecompressSettings lodepng_default_decompress_settings;
embeddedartists	0:83b8ee8e8d4b	278	void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings);
embeddedartists	0:83b8ee8e8d4b	279	#endif /LODEPNG_COMPILE_DECODER/
embeddedartists	0:83b8ee8e8d4b	280
embeddedartists	0:83b8ee8e8d4b	281	#ifdef LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	282	/*
embeddedartists	0:83b8ee8e8d4b	283	Settings for zlib compression. Tweaking these settings tweaks the balance
embeddedartists	0:83b8ee8e8d4b	284	between speed and compression ratio.
embeddedartists	0:83b8ee8e8d4b	285	*/
embeddedartists	0:83b8ee8e8d4b	286	typedef struct LodePNGCompressSettings LodePNGCompressSettings;
embeddedartists	0:83b8ee8e8d4b	287	struct LodePNGCompressSettings /deflate = compress/
embeddedartists	0:83b8ee8e8d4b	288	{
embeddedartists	0:83b8ee8e8d4b	289	/LZ77 related settings/
embeddedartists	0:83b8ee8e8d4b	290	unsigned btype; /the block type for LZ (0, 1, 2 or 3, see zlib standard). Should be 2 for proper compression./
embeddedartists	0:83b8ee8e8d4b	291	unsigned use_lz77; /whether or not to use LZ77. Should be 1 for proper compression./
embeddedartists	0:83b8ee8e8d4b	292	unsigned windowsize; /must be a power of two <= 32768. higher compresses more but is slower. Typical value: 2048./
embeddedartists	0:83b8ee8e8d4b	293	unsigned minmatch; /mininum lz77 length. 3 is normally best, 6 can be better for some PNGs. Default: 0/
embeddedartists	0:83b8ee8e8d4b	294	unsigned nicematch; /stop searching if >= this length found. Set to 258 for best compression. Default: 128/
embeddedartists	0:83b8ee8e8d4b	295	unsigned lazymatching; /use lazy matching: better compression but a bit slower. Default: true/
embeddedartists	0:83b8ee8e8d4b	296
embeddedartists	0:83b8ee8e8d4b	297	/use custom zlib encoder instead of built in one (default: null)/
embeddedartists	0:83b8ee8e8d4b	298	unsigned (custom_zlib)(unsigned char, size_t,
embeddedartists	0:83b8ee8e8d4b	299	const unsigned char*, size_t,
embeddedartists	0:83b8ee8e8d4b	300	const LodePNGCompressSettings*);
embeddedartists	0:83b8ee8e8d4b	301	/*use custom deflate encoder instead of built in one (default: null)
embeddedartists	0:83b8ee8e8d4b	302	if custom_zlib is used, custom_deflate is ignored since only the built in
embeddedartists	0:83b8ee8e8d4b	303	zlib function will call custom_deflate*/
embeddedartists	0:83b8ee8e8d4b	304	unsigned (custom_deflate)(unsigned char, size_t,
embeddedartists	0:83b8ee8e8d4b	305	const unsigned char*, size_t,
embeddedartists	0:83b8ee8e8d4b	306	const LodePNGCompressSettings*);
embeddedartists	0:83b8ee8e8d4b	307
embeddedartists	0:83b8ee8e8d4b	308	const void* custom_context; /optional custom settings for custom functions/
embeddedartists	0:83b8ee8e8d4b	309	};
embeddedartists	0:83b8ee8e8d4b	310
embeddedartists	0:83b8ee8e8d4b	311	extern const LodePNGCompressSettings lodepng_default_compress_settings;
embeddedartists	0:83b8ee8e8d4b	312	void lodepng_compress_settings_init(LodePNGCompressSettings* settings);
embeddedartists	0:83b8ee8e8d4b	313	#endif /LODEPNG_COMPILE_ENCODER/
embeddedartists	0:83b8ee8e8d4b	314
embeddedartists	0:83b8ee8e8d4b	315	#ifdef LODEPNG_COMPILE_PNG
embeddedartists	0:83b8ee8e8d4b	316	/*
embeddedartists	0:83b8ee8e8d4b	317	Color mode of an image. Contains all information required to decode the pixel
embeddedartists	0:83b8ee8e8d4b	318	bits to RGBA colors. This information is the same as used in the PNG file
embeddedartists	0:83b8ee8e8d4b	319	format, and is used both for PNG and raw image data in LodePNG.
embeddedartists	0:83b8ee8e8d4b	320	*/
embeddedartists	0:83b8ee8e8d4b	321	typedef struct LodePNGColorMode
embeddedartists	0:83b8ee8e8d4b	322	{
embeddedartists	0:83b8ee8e8d4b	323	/header (IHDR)/
embeddedartists	0:83b8ee8e8d4b	324	LodePNGColorType colortype; /color type, see PNG standard or documentation further in this header file/
embeddedartists	0:83b8ee8e8d4b	325	unsigned bitdepth; /bits per sample, see PNG standard or documentation further in this header file/
embeddedartists	0:83b8ee8e8d4b	326
embeddedartists	0:83b8ee8e8d4b	327	/*
embeddedartists	0:83b8ee8e8d4b	328	palette (PLTE and tRNS)
embeddedartists	0:83b8ee8e8d4b	329
embeddedartists	0:83b8ee8e8d4b	330	Dynamically allocated with the colors of the palette, including alpha.
embeddedartists	0:83b8ee8e8d4b	331	When encoding a PNG, to store your colors in the palette of the LodePNGColorMode, first use
embeddedartists	0:83b8ee8e8d4b	332	lodepng_palette_clear, then for each color use lodepng_palette_add.
embeddedartists	0:83b8ee8e8d4b	333	If you encode an image without alpha with palette, don't forget to put value 255 in each A byte of the palette.
embeddedartists	0:83b8ee8e8d4b	334
embeddedartists	0:83b8ee8e8d4b	335	When decoding, by default you can ignore this palette, since LodePNG already
embeddedartists	0:83b8ee8e8d4b	336	fills the palette colors in the pixels of the raw RGBA output.
embeddedartists	0:83b8ee8e8d4b	337
embeddedartists	0:83b8ee8e8d4b	338	The palette is only supported for color type 3.
embeddedartists	0:83b8ee8e8d4b	339	*/
embeddedartists	0:83b8ee8e8d4b	340	unsigned char* palette; /palette in RGBARGBA... order. When allocated, must be either 0, or have size 1024/
embeddedartists	0:83b8ee8e8d4b	341	size_t palettesize; /palette size in number of colors (amount of bytes is 4 palettesize)*/
embeddedartists	0:83b8ee8e8d4b	342
embeddedartists	0:83b8ee8e8d4b	343	/*
embeddedartists	0:83b8ee8e8d4b	344	transparent color key (tRNS)
embeddedartists	0:83b8ee8e8d4b	345
embeddedartists	0:83b8ee8e8d4b	346	This color uses the same bit depth as the bitdepth value in this struct, which can be 1-bit to 16-bit.
embeddedartists	0:83b8ee8e8d4b	347	For greyscale PNGs, r, g and b will all 3 be set to the same.
embeddedartists	0:83b8ee8e8d4b	348
embeddedartists	0:83b8ee8e8d4b	349	When decoding, by default you can ignore this information, since LodePNG sets
embeddedartists	0:83b8ee8e8d4b	350	pixels with this key to transparent already in the raw RGBA output.
embeddedartists	0:83b8ee8e8d4b	351
embeddedartists	0:83b8ee8e8d4b	352	The color key is only supported for color types 0 and 2.
embeddedartists	0:83b8ee8e8d4b	353	*/
embeddedartists	0:83b8ee8e8d4b	354	unsigned key_defined; /is a transparent color key given? 0 = false, 1 = true/
embeddedartists	0:83b8ee8e8d4b	355	unsigned key_r; /red/greyscale component of color key/
embeddedartists	0:83b8ee8e8d4b	356	unsigned key_g; /green component of color key/
embeddedartists	0:83b8ee8e8d4b	357	unsigned key_b; /blue component of color key/
embeddedartists	0:83b8ee8e8d4b	358	} LodePNGColorMode;
embeddedartists	0:83b8ee8e8d4b	359
embeddedartists	0:83b8ee8e8d4b	360	/init, cleanup and copy functions to use with this struct/
embeddedartists	0:83b8ee8e8d4b	361	void lodepng_color_mode_init(LodePNGColorMode* info);
embeddedartists	0:83b8ee8e8d4b	362	void lodepng_color_mode_cleanup(LodePNGColorMode* info);
embeddedartists	0:83b8ee8e8d4b	363	/return value is error code (0 means no error)/
embeddedartists	0:83b8ee8e8d4b	364	unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source);
embeddedartists	0:83b8ee8e8d4b	365
embeddedartists	0:83b8ee8e8d4b	366	void lodepng_palette_clear(LodePNGColorMode* info);
embeddedartists	0:83b8ee8e8d4b	367	/add 1 color to the palette/
embeddedartists	0:83b8ee8e8d4b	368	unsigned lodepng_palette_add(LodePNGColorMode* info,
embeddedartists	0:83b8ee8e8d4b	369	unsigned char r, unsigned char g, unsigned char b, unsigned char a);
embeddedartists	0:83b8ee8e8d4b	370
embeddedartists	0:83b8ee8e8d4b	371	/get the total amount of bits per pixel, based on colortype and bitdepth in the struct/
embeddedartists	0:83b8ee8e8d4b	372	unsigned lodepng_get_bpp(const LodePNGColorMode* info);
embeddedartists	0:83b8ee8e8d4b	373	/*get the amount of color channels used, based on colortype in the struct.
embeddedartists	0:83b8ee8e8d4b	374	If a palette is used, it counts as 1 channel.*/
embeddedartists	0:83b8ee8e8d4b	375	unsigned lodepng_get_channels(const LodePNGColorMode* info);
embeddedartists	0:83b8ee8e8d4b	376	/is it a greyscale type? (only colortype 0 or 4)/
embeddedartists	0:83b8ee8e8d4b	377	unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info);
embeddedartists	0:83b8ee8e8d4b	378	/has it got an alpha channel? (only colortype 2 or 6)/
embeddedartists	0:83b8ee8e8d4b	379	unsigned lodepng_is_alpha_type(const LodePNGColorMode* info);
embeddedartists	0:83b8ee8e8d4b	380	/has it got a palette? (only colortype 3)/
embeddedartists	0:83b8ee8e8d4b	381	unsigned lodepng_is_palette_type(const LodePNGColorMode* info);
embeddedartists	0:83b8ee8e8d4b	382	/*only returns true if there is a palette and there is a value in the palette with alpha < 255.
embeddedartists	0:83b8ee8e8d4b	383	Loops through the palette to check this.*/
embeddedartists	0:83b8ee8e8d4b	384	unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info);
embeddedartists	0:83b8ee8e8d4b	385	/*
embeddedartists	0:83b8ee8e8d4b	386	Check if the given color info indicates the possibility of having non-opaque pixels in the PNG image.
embeddedartists	0:83b8ee8e8d4b	387	Returns true if the image can have translucent or invisible pixels (it still be opaque if it doesn't use such pixels).
embeddedartists	0:83b8ee8e8d4b	388	Returns false if the image can only have opaque pixels.
embeddedartists	0:83b8ee8e8d4b	389	In detail, it returns true only if it's a color type with alpha, or has a palette with non-opaque values,
embeddedartists	0:83b8ee8e8d4b	390	or if "key_defined" is true.
embeddedartists	0:83b8ee8e8d4b	391	*/
embeddedartists	0:83b8ee8e8d4b	392	unsigned lodepng_can_have_alpha(const LodePNGColorMode* info);
embeddedartists	0:83b8ee8e8d4b	393	/Returns the byte size of a raw image buffer with given width, height and color mode/
embeddedartists	0:83b8ee8e8d4b	394	size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color);
embeddedartists	0:83b8ee8e8d4b	395
embeddedartists	0:83b8ee8e8d4b	396	#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
embeddedartists	0:83b8ee8e8d4b	397	/The information of a Time chunk in PNG./
embeddedartists	0:83b8ee8e8d4b	398	typedef struct LodePNGTime
embeddedartists	0:83b8ee8e8d4b	399	{
embeddedartists	0:83b8ee8e8d4b	400	unsigned year; /2 bytes used (0-65535)/
embeddedartists	0:83b8ee8e8d4b	401	unsigned month; /1-12/
embeddedartists	0:83b8ee8e8d4b	402	unsigned day; /1-31/
embeddedartists	0:83b8ee8e8d4b	403	unsigned hour; /0-23/
embeddedartists	0:83b8ee8e8d4b	404	unsigned minute; /0-59/
embeddedartists	0:83b8ee8e8d4b	405	unsigned second; /0-60 (to allow for leap seconds)/
embeddedartists	0:83b8ee8e8d4b	406	} LodePNGTime;
embeddedartists	0:83b8ee8e8d4b	407	#endif /LODEPNG_COMPILE_ANCILLARY_CHUNKS/
embeddedartists	0:83b8ee8e8d4b	408
embeddedartists	0:83b8ee8e8d4b	409	/Information about the PNG image, except pixels, width and height./
embeddedartists	0:83b8ee8e8d4b	410	typedef struct LodePNGInfo
embeddedartists	0:83b8ee8e8d4b	411	{
embeddedartists	0:83b8ee8e8d4b	412	/header (IHDR), palette (PLTE) and transparency (tRNS) chunks/
embeddedartists	0:83b8ee8e8d4b	413	unsigned compression_method;/compression method of the original file. Always 0./
embeddedartists	0:83b8ee8e8d4b	414	unsigned filter_method; /filter method of the original file/
embeddedartists	0:83b8ee8e8d4b	415	unsigned interlace_method; /interlace method of the original file/
embeddedartists	0:83b8ee8e8d4b	416	LodePNGColorMode color; /color type and bits, palette and transparency of the PNG file/
embeddedartists	0:83b8ee8e8d4b	417
embeddedartists	0:83b8ee8e8d4b	418	#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
embeddedartists	0:83b8ee8e8d4b	419	/*
embeddedartists	0:83b8ee8e8d4b	420	suggested background color chunk (bKGD)
embeddedartists	0:83b8ee8e8d4b	421	This color uses the same color mode as the PNG (except alpha channel), which can be 1-bit to 16-bit.
embeddedartists	0:83b8ee8e8d4b	422
embeddedartists	0:83b8ee8e8d4b	423	For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding
embeddedartists	0:83b8ee8e8d4b	424	the encoder writes the red one. For palette PNGs: When decoding, the RGB value
embeddedartists	0:83b8ee8e8d4b	425	will be stored, not a palette index. But when encoding, specify the index of
embeddedartists	0:83b8ee8e8d4b	426	the palette in background_r, the other two are then ignored.
embeddedartists	0:83b8ee8e8d4b	427
embeddedartists	0:83b8ee8e8d4b	428	The decoder does not use this background color to edit the color of pixels.
embeddedartists	0:83b8ee8e8d4b	429	*/
embeddedartists	0:83b8ee8e8d4b	430	unsigned background_defined; /is a suggested background color given?/
embeddedartists	0:83b8ee8e8d4b	431	unsigned background_r; /red component of suggested background color/
embeddedartists	0:83b8ee8e8d4b	432	unsigned background_g; /green component of suggested background color/
embeddedartists	0:83b8ee8e8d4b	433	unsigned background_b; /blue component of suggested background color/
embeddedartists	0:83b8ee8e8d4b	434
embeddedartists	0:83b8ee8e8d4b	435	/*
embeddedartists	0:83b8ee8e8d4b	436	non-international text chunks (tEXt and zTXt)
embeddedartists	0:83b8ee8e8d4b	437
embeddedartists	0:83b8ee8e8d4b	438	The char** arrays each contain num strings. The actual messages are in
embeddedartists	0:83b8ee8e8d4b	439	text_strings, while text_keys are keywords that give a short description what
embeddedartists	0:83b8ee8e8d4b	440	the actual text represents, e.g. Title, Author, Description, or anything else.
embeddedartists	0:83b8ee8e8d4b	441
embeddedartists	0:83b8ee8e8d4b	442	A keyword is minimum 1 character and maximum 79 characters long. It's
embeddedartists	0:83b8ee8e8d4b	443	discouraged to use a single line length longer than 79 characters for texts.
embeddedartists	0:83b8ee8e8d4b	444
embeddedartists	0:83b8ee8e8d4b	445	Don't allocate these text buffers yourself. Use the init/cleanup functions
embeddedartists	0:83b8ee8e8d4b	446	correctly and use lodepng_add_text and lodepng_clear_text.
embeddedartists	0:83b8ee8e8d4b	447	*/
embeddedartists	0:83b8ee8e8d4b	448	size_t text_num; /the amount of texts in these char* buffers (there may be more texts in itext)*/
embeddedartists	0:83b8ee8e8d4b	449	char** text_keys; /the keyword of a text chunk (e.g. "Comment")/
embeddedartists	0:83b8ee8e8d4b	450	char** text_strings; /the actual text/
embeddedartists	0:83b8ee8e8d4b	451
embeddedartists	0:83b8ee8e8d4b	452	/*
embeddedartists	0:83b8ee8e8d4b	453	international text chunks (iTXt)
embeddedartists	0:83b8ee8e8d4b	454	Similar to the non-international text chunks, but with additional strings
embeddedartists	0:83b8ee8e8d4b	455	"langtags" and "transkeys".
embeddedartists	0:83b8ee8e8d4b	456	*/
embeddedartists	0:83b8ee8e8d4b	457	size_t itext_num; /the amount of international texts in this PNG/
embeddedartists	0:83b8ee8e8d4b	458	char** itext_keys; /the English keyword of the text chunk (e.g. "Comment")/
embeddedartists	0:83b8ee8e8d4b	459	char** itext_langtags; /language tag for this text's language, ISO/IEC 646 string, e.g. ISO 639 language tag/
embeddedartists	0:83b8ee8e8d4b	460	char** itext_transkeys; /keyword translated to the international language - UTF-8 string/
embeddedartists	0:83b8ee8e8d4b	461	char** itext_strings; /the actual international text - UTF-8 string/
embeddedartists	0:83b8ee8e8d4b	462
embeddedartists	0:83b8ee8e8d4b	463	/time chunk (tIME)/
embeddedartists	0:83b8ee8e8d4b	464	unsigned time_defined; /set to 1 to make the encoder generate a tIME chunk/
embeddedartists	0:83b8ee8e8d4b	465	LodePNGTime time;
embeddedartists	0:83b8ee8e8d4b	466
embeddedartists	0:83b8ee8e8d4b	467	/phys chunk (pHYs)/
embeddedartists	0:83b8ee8e8d4b	468	unsigned phys_defined; /if 0, there is no pHYs chunk and the values below are undefined, if 1 else there is one/
embeddedartists	0:83b8ee8e8d4b	469	unsigned phys_x; /pixels per unit in x direction/
embeddedartists	0:83b8ee8e8d4b	470	unsigned phys_y; /pixels per unit in y direction/
embeddedartists	0:83b8ee8e8d4b	471	unsigned phys_unit; /may be 0 (unknown unit) or 1 (metre)/
embeddedartists	0:83b8ee8e8d4b	472
embeddedartists	0:83b8ee8e8d4b	473	/*
embeddedartists	0:83b8ee8e8d4b	474	unknown chunks
embeddedartists	0:83b8ee8e8d4b	475	There are 3 buffers, one for each position in the PNG where unknown chunks can appear
embeddedartists	0:83b8ee8e8d4b	476	each buffer contains all unknown chunks for that position consecutively
embeddedartists	0:83b8ee8e8d4b	477	The 3 buffers are the unknown chunks between certain critical chunks:
embeddedartists	0:83b8ee8e8d4b	478	0: IHDR-PLTE, 1: PLTE-IDAT, 2: IDAT-IEND
embeddedartists	0:83b8ee8e8d4b	479	Do not allocate or traverse this data yourself. Use the chunk traversing functions declared
embeddedartists	0:83b8ee8e8d4b	480	later, such as lodepng_chunk_next and lodepng_chunk_append, to read/write this struct.
embeddedartists	0:83b8ee8e8d4b	481	*/
embeddedartists	0:83b8ee8e8d4b	482	unsigned char* unknown_chunks_data[3];
embeddedartists	0:83b8ee8e8d4b	483	size_t unknown_chunks_size[3]; /size in bytes of the unknown chunks, given for protection/
embeddedartists	0:83b8ee8e8d4b	484	#endif /LODEPNG_COMPILE_ANCILLARY_CHUNKS/
embeddedartists	0:83b8ee8e8d4b	485	} LodePNGInfo;
embeddedartists	0:83b8ee8e8d4b	486
embeddedartists	0:83b8ee8e8d4b	487	/init, cleanup and copy functions to use with this struct/
embeddedartists	0:83b8ee8e8d4b	488	void lodepng_info_init(LodePNGInfo* info);
embeddedartists	0:83b8ee8e8d4b	489	void lodepng_info_cleanup(LodePNGInfo* info);
embeddedartists	0:83b8ee8e8d4b	490	/return value is error code (0 means no error)/
embeddedartists	0:83b8ee8e8d4b	491	unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source);
embeddedartists	0:83b8ee8e8d4b	492
embeddedartists	0:83b8ee8e8d4b	493	#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
embeddedartists	0:83b8ee8e8d4b	494	void lodepng_clear_text(LodePNGInfo* info); /use this to clear the texts again after you filled them in/
embeddedartists	0:83b8ee8e8d4b	495	unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str); /push back both texts at once/
embeddedartists	0:83b8ee8e8d4b	496
embeddedartists	0:83b8ee8e8d4b	497	void lodepng_clear_itext(LodePNGInfo* info); /use this to clear the itexts again after you filled them in/
embeddedartists	0:83b8ee8e8d4b	498	unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
embeddedartists	0:83b8ee8e8d4b	499	const char* transkey, const char* str); /push back the 4 texts of 1 chunk at once/
embeddedartists	0:83b8ee8e8d4b	500	#endif /LODEPNG_COMPILE_ANCILLARY_CHUNKS/
embeddedartists	0:83b8ee8e8d4b	501
embeddedartists	0:83b8ee8e8d4b	502	/*
embeddedartists	0:83b8ee8e8d4b	503	Converts raw buffer from one color type to another color type, based on
embeddedartists	0:83b8ee8e8d4b	504	LodePNGColorMode structs to describe the input and output color type.
embeddedartists	0:83b8ee8e8d4b	505	See the reference manual at the end of this header file to see which color conversions are supported.
embeddedartists	0:83b8ee8e8d4b	506	return value = LodePNG error code (0 if all went ok, an error if the conversion isn't supported)
embeddedartists	0:83b8ee8e8d4b	507	The out buffer must have size (w * h * bpp + 7) / 8, where bpp is the bits per pixel
embeddedartists	0:83b8ee8e8d4b	508	of the output color type (lodepng_get_bpp)
embeddedartists	0:83b8ee8e8d4b	509	The fix_png value works as described in struct LodePNGDecoderSettings.
embeddedartists	0:83b8ee8e8d4b	510	Note: for 16-bit per channel colors, uses big endian format like PNG does.
embeddedartists	0:83b8ee8e8d4b	511	*/
embeddedartists	0:83b8ee8e8d4b	512	unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
embeddedartists	0:83b8ee8e8d4b	513	LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
embeddedartists	0:83b8ee8e8d4b	514	unsigned w, unsigned h, unsigned fix_png);
embeddedartists	0:83b8ee8e8d4b	515
embeddedartists	0:83b8ee8e8d4b	516	#ifdef LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	517	/*
embeddedartists	0:83b8ee8e8d4b	518	Settings for the decoder. This contains settings for the PNG and the Zlib
embeddedartists	0:83b8ee8e8d4b	519	decoder, but not the Info settings from the Info structs.
embeddedartists	0:83b8ee8e8d4b	520	*/
embeddedartists	0:83b8ee8e8d4b	521	typedef struct LodePNGDecoderSettings
embeddedartists	0:83b8ee8e8d4b	522	{
embeddedartists	0:83b8ee8e8d4b	523	LodePNGDecompressSettings zlibsettings; /in here is the setting to ignore Adler32 checksums/
embeddedartists	0:83b8ee8e8d4b	524
embeddedartists	0:83b8ee8e8d4b	525	unsigned ignore_crc; /ignore CRC checksums/
embeddedartists	0:83b8ee8e8d4b	526	/*
embeddedartists	0:83b8ee8e8d4b	527	The fix_png setting, if 1, makes the decoder tolerant towards some PNG images
embeddedartists	0:83b8ee8e8d4b	528	that do not correctly follow the PNG specification. This only supports errors
embeddedartists	0:83b8ee8e8d4b	529	that are fixable, were found in images that are actually used on the web, and
embeddedartists	0:83b8ee8e8d4b	530	are silently tolerated by other decoders as well. Currently only one such fix
embeddedartists	0:83b8ee8e8d4b	531	is implemented: if a palette index is out of bounds given the palette size,
embeddedartists	0:83b8ee8e8d4b	532	interpret it as opaque black.
embeddedartists	0:83b8ee8e8d4b	533	By default this value is 0, which makes it stop with an error on such images.
embeddedartists	0:83b8ee8e8d4b	534	*/
embeddedartists	0:83b8ee8e8d4b	535	unsigned fix_png;
embeddedartists	0:83b8ee8e8d4b	536	unsigned color_convert; /whether to convert the PNG to the color type you want. Default: yes/
embeddedartists	0:83b8ee8e8d4b	537
embeddedartists	0:83b8ee8e8d4b	538	#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
embeddedartists	0:83b8ee8e8d4b	539	unsigned read_text_chunks; /if false but remember_unknown_chunks is true, they're stored in the unknown chunks/
embeddedartists	0:83b8ee8e8d4b	540	/store all bytes from unknown chunks in the LodePNGInfo (off by default, useful for a png editor)/
embeddedartists	0:83b8ee8e8d4b	541	unsigned remember_unknown_chunks;
embeddedartists	0:83b8ee8e8d4b	542	#endif /LODEPNG_COMPILE_ANCILLARY_CHUNKS/
embeddedartists	0:83b8ee8e8d4b	543	} LodePNGDecoderSettings;
embeddedartists	0:83b8ee8e8d4b	544
embeddedartists	0:83b8ee8e8d4b	545	void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings);
embeddedartists	0:83b8ee8e8d4b	546	#endif /LODEPNG_COMPILE_DECODER/
embeddedartists	0:83b8ee8e8d4b	547
embeddedartists	0:83b8ee8e8d4b	548	#ifdef LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	549	/automatically use color type with less bits per pixel if losslessly possible. Default: AUTO/
embeddedartists	0:83b8ee8e8d4b	550	typedef enum LodePNGFilterStrategy
embeddedartists	0:83b8ee8e8d4b	551	{
embeddedartists	0:83b8ee8e8d4b	552	/every filter at zero/
embeddedartists	0:83b8ee8e8d4b	553	LFS_ZERO,
embeddedartists	0:83b8ee8e8d4b	554	/Use filter that gives minumum sum, as described in the official PNG filter heuristic./
embeddedartists	0:83b8ee8e8d4b	555	LFS_MINSUM,
embeddedartists	0:83b8ee8e8d4b	556	/*Use the filter type that gives smallest Shannon entropy for this scanline. Depending
embeddedartists	0:83b8ee8e8d4b	557	on the image, this is better or worse than minsum.*/
embeddedartists	0:83b8ee8e8d4b	558	LFS_ENTROPY,
embeddedartists	0:83b8ee8e8d4b	559	/*
embeddedartists	0:83b8ee8e8d4b	560	Brute-force-search PNG filters by compressing each filter for each scanline.
embeddedartists	0:83b8ee8e8d4b	561	Experimental, very slow, and only rarely gives better compression than MINSUM.
embeddedartists	0:83b8ee8e8d4b	562	*/
embeddedartists	0:83b8ee8e8d4b	563	LFS_BRUTE_FORCE,
embeddedartists	0:83b8ee8e8d4b	564	/use predefined_filters buffer: you specify the filter type for each scanline/
embeddedartists	0:83b8ee8e8d4b	565	LFS_PREDEFINED
embeddedartists	0:83b8ee8e8d4b	566	} LodePNGFilterStrategy;
embeddedartists	0:83b8ee8e8d4b	567
embeddedartists	0:83b8ee8e8d4b	568	/automatically use color type with less bits per pixel if losslessly possible. Default: LAC_AUTO/
embeddedartists	0:83b8ee8e8d4b	569	typedef enum LodePNGAutoConvert
embeddedartists	0:83b8ee8e8d4b	570	{
embeddedartists	0:83b8ee8e8d4b	571	LAC_NO, /use color type user requested/
embeddedartists	0:83b8ee8e8d4b	572	LAC_ALPHA, /use color type user requested, but if only opaque pixels and RGBA or grey+alpha, use RGB or grey/
embeddedartists	0:83b8ee8e8d4b	573	LAC_AUTO, /use PNG color type that can losslessly represent the uncompressed image the smallest possible/
embeddedartists	0:83b8ee8e8d4b	574	/*
embeddedartists	0:83b8ee8e8d4b	575	like AUTO, but do not choose 1, 2 or 4 bit per pixel types.
embeddedartists	0:83b8ee8e8d4b	576	sometimes a PNG image compresses worse if less than 8 bits per pixels.
embeddedartists	0:83b8ee8e8d4b	577	*/
embeddedartists	0:83b8ee8e8d4b	578	LAC_AUTO_NO_NIBBLES,
embeddedartists	0:83b8ee8e8d4b	579	/*
embeddedartists	0:83b8ee8e8d4b	580	like AUTO, but never choose palette color type. For small images, encoding
embeddedartists	0:83b8ee8e8d4b	581	the palette may take more bytes than what is gained. Note that AUTO also
embeddedartists	0:83b8ee8e8d4b	582	already prevents encoding the palette for extremely small images, but that may
embeddedartists	0:83b8ee8e8d4b	583	not be sufficient because due to the compression it cannot predict when to
embeddedartists	0:83b8ee8e8d4b	584	switch.
embeddedartists	0:83b8ee8e8d4b	585	*/
embeddedartists	0:83b8ee8e8d4b	586	LAC_AUTO_NO_PALETTE,
embeddedartists	0:83b8ee8e8d4b	587	LAC_AUTO_NO_NIBBLES_NO_PALETTE
embeddedartists	0:83b8ee8e8d4b	588	} LodePNGAutoConvert;
embeddedartists	0:83b8ee8e8d4b	589
embeddedartists	0:83b8ee8e8d4b	590
embeddedartists	0:83b8ee8e8d4b	591	/*
embeddedartists	0:83b8ee8e8d4b	592	Automatically chooses color type that gives smallest amount of bits in the
embeddedartists	0:83b8ee8e8d4b	593	output image, e.g. grey if there are only greyscale pixels, palette if there
embeddedartists	0:83b8ee8e8d4b	594	are less than 256 colors, ...
embeddedartists	0:83b8ee8e8d4b	595	The auto_convert parameter allows limiting it to not use palette, ...
embeddedartists	0:83b8ee8e8d4b	596	*/
embeddedartists	0:83b8ee8e8d4b	597	unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out,
embeddedartists	0:83b8ee8e8d4b	598	const unsigned char* image, unsigned w, unsigned h,
embeddedartists	0:83b8ee8e8d4b	599	const LodePNGColorMode* mode_in,
embeddedartists	0:83b8ee8e8d4b	600	LodePNGAutoConvert auto_convert);
embeddedartists	0:83b8ee8e8d4b	601
embeddedartists	0:83b8ee8e8d4b	602	/Settings for the encoder./
embeddedartists	0:83b8ee8e8d4b	603	typedef struct LodePNGEncoderSettings
embeddedartists	0:83b8ee8e8d4b	604	{
embeddedartists	0:83b8ee8e8d4b	605	LodePNGCompressSettings zlibsettings; /settings for the zlib encoder, such as window size, .../
embeddedartists	0:83b8ee8e8d4b	606
embeddedartists	0:83b8ee8e8d4b	607	LodePNGAutoConvert auto_convert; /how to automatically choose output PNG color type, if at all/
embeddedartists	0:83b8ee8e8d4b	608
embeddedartists	0:83b8ee8e8d4b	609	/*If true, follows the official PNG heuristic: if the PNG uses a palette or lower than
embeddedartists	0:83b8ee8e8d4b	610	8 bit depth, set all filters to zero. Otherwise use the filter_strategy. Note that to
embeddedartists	0:83b8ee8e8d4b	611	completely follow the official PNG heuristic, filter_palette_zero must be true and
embeddedartists	0:83b8ee8e8d4b	612	filter_strategy must be LFS_MINSUM*/
embeddedartists	0:83b8ee8e8d4b	613	unsigned filter_palette_zero;
embeddedartists	0:83b8ee8e8d4b	614	/*Which filter strategy to use when not using zeroes due to filter_palette_zero.
embeddedartists	0:83b8ee8e8d4b	615	Set filter_palette_zero to 0 to ensure always using your chosen strategy. Default: LFS_MINSUM*/
embeddedartists	0:83b8ee8e8d4b	616	LodePNGFilterStrategy filter_strategy;
embeddedartists	0:83b8ee8e8d4b	617	/*used if filter_strategy is LFS_PREDEFINED. In that case, this must point to a buffer with
embeddedartists	0:83b8ee8e8d4b	618	the same length as the amount of scanlines in the image, and each value must <= 5. You
embeddedartists	0:83b8ee8e8d4b	619	have to cleanup this buffer, LodePNG will never free it. Don't forget that filter_palette_zero
embeddedartists	0:83b8ee8e8d4b	620	must be set to 0 to ensure this is also used on palette or low bitdepth images.*/
embeddedartists	0:83b8ee8e8d4b	621	const unsigned char* predefined_filters;
embeddedartists	0:83b8ee8e8d4b	622
embeddedartists	0:83b8ee8e8d4b	623	/*force creating a PLTE chunk if colortype is 2 or 6 (= a suggested palette).
embeddedartists	0:83b8ee8e8d4b	624	If colortype is 3, PLTE is _always_ created.*/
embeddedartists	0:83b8ee8e8d4b	625	unsigned force_palette;
embeddedartists	0:83b8ee8e8d4b	626	#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
embeddedartists	0:83b8ee8e8d4b	627	/add LodePNG identifier and version as a text chunk, for debugging/
embeddedartists	0:83b8ee8e8d4b	628	unsigned add_id;
embeddedartists	0:83b8ee8e8d4b	629	/encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks/
embeddedartists	0:83b8ee8e8d4b	630	unsigned text_compression;
embeddedartists	0:83b8ee8e8d4b	631	#endif /LODEPNG_COMPILE_ANCILLARY_CHUNKS/
embeddedartists	0:83b8ee8e8d4b	632	} LodePNGEncoderSettings;
embeddedartists	0:83b8ee8e8d4b	633
embeddedartists	0:83b8ee8e8d4b	634	void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings);
embeddedartists	0:83b8ee8e8d4b	635	#endif /LODEPNG_COMPILE_ENCODER/
embeddedartists	0:83b8ee8e8d4b	636
embeddedartists	0:83b8ee8e8d4b	637
embeddedartists	0:83b8ee8e8d4b	638	#if defined(LODEPNG_COMPILE_DECODER) \|\| defined(LODEPNG_COMPILE_ENCODER)
embeddedartists	0:83b8ee8e8d4b	639	/The settings, state and information for extended encoding and decoding./
embeddedartists	0:83b8ee8e8d4b	640	typedef struct LodePNGState
embeddedartists	0:83b8ee8e8d4b	641	{
embeddedartists	0:83b8ee8e8d4b	642	#ifdef LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	643	LodePNGDecoderSettings decoder; /the decoding settings/
embeddedartists	0:83b8ee8e8d4b	644	#endif /LODEPNG_COMPILE_DECODER/
embeddedartists	0:83b8ee8e8d4b	645	#ifdef LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	646	LodePNGEncoderSettings encoder; /the encoding settings/
embeddedartists	0:83b8ee8e8d4b	647	#endif /LODEPNG_COMPILE_ENCODER/
embeddedartists	0:83b8ee8e8d4b	648	LodePNGColorMode info_raw; /specifies the format in which you would like to get the raw pixel buffer/
embeddedartists	0:83b8ee8e8d4b	649	LodePNGInfo info_png; /info of the PNG image obtained after decoding/
embeddedartists	0:83b8ee8e8d4b	650	unsigned error;
embeddedartists	0:83b8ee8e8d4b	651	#ifdef LODEPNG_COMPILE_CPP
embeddedartists	0:83b8ee8e8d4b	652	//For the lodepng::State subclass.
embeddedartists	0:83b8ee8e8d4b	653	virtual ~LodePNGState(){}
embeddedartists	0:83b8ee8e8d4b	654	#endif
embeddedartists	0:83b8ee8e8d4b	655	} LodePNGState;
embeddedartists	0:83b8ee8e8d4b	656
embeddedartists	0:83b8ee8e8d4b	657	/init, cleanup and copy functions to use with this struct/
embeddedartists	0:83b8ee8e8d4b	658	void lodepng_state_init(LodePNGState* state);
embeddedartists	0:83b8ee8e8d4b	659	void lodepng_state_cleanup(LodePNGState* state);
embeddedartists	0:83b8ee8e8d4b	660	void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source);
embeddedartists	0:83b8ee8e8d4b	661	#endif /* defined(LODEPNG_COMPILE_DECODER) \|\| defined(LODEPNG_COMPILE_ENCODER) */
embeddedartists	0:83b8ee8e8d4b	662
embeddedartists	0:83b8ee8e8d4b	663	#ifdef LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	664	/*
embeddedartists	0:83b8ee8e8d4b	665	Same as lodepng_decode_memory, but uses a LodePNGState to allow custom settings and
embeddedartists	0:83b8ee8e8d4b	666	getting much more information about the PNG image and color mode.
embeddedartists	0:83b8ee8e8d4b	667	*/
embeddedartists	0:83b8ee8e8d4b	668	unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h,
embeddedartists	0:83b8ee8e8d4b	669	LodePNGState* state,
embeddedartists	0:83b8ee8e8d4b	670	const unsigned char* in, size_t insize);
embeddedartists	0:83b8ee8e8d4b	671
embeddedartists	0:83b8ee8e8d4b	672	/*
embeddedartists	0:83b8ee8e8d4b	673	Read the PNG header, but not the actual data. This returns only the information
embeddedartists	0:83b8ee8e8d4b	674	that is in the header chunk of the PNG, such as width, height and color type. The
embeddedartists	0:83b8ee8e8d4b	675	information is placed in the info_png field of the LodePNGState.
embeddedartists	0:83b8ee8e8d4b	676	*/
embeddedartists	0:83b8ee8e8d4b	677	unsigned lodepng_inspect(unsigned* w, unsigned* h,
embeddedartists	0:83b8ee8e8d4b	678	LodePNGState* state,
embeddedartists	0:83b8ee8e8d4b	679	const unsigned char* in, size_t insize);
embeddedartists	0:83b8ee8e8d4b	680	#endif /LODEPNG_COMPILE_DECODER/
embeddedartists	0:83b8ee8e8d4b	681
embeddedartists	0:83b8ee8e8d4b	682
embeddedartists	0:83b8ee8e8d4b	683	#ifdef LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	684	/This function allocates the out buffer with standard malloc and stores the size in outsize.*/
embeddedartists	0:83b8ee8e8d4b	685	unsigned lodepng_encode(unsigned char** out, size_t* outsize,
embeddedartists	0:83b8ee8e8d4b	686	const unsigned char* image, unsigned w, unsigned h,
embeddedartists	0:83b8ee8e8d4b	687	LodePNGState* state);
embeddedartists	0:83b8ee8e8d4b	688	#endif /LODEPNG_COMPILE_ENCODER/
embeddedartists	0:83b8ee8e8d4b	689
embeddedartists	0:83b8ee8e8d4b	690	/*
embeddedartists	0:83b8ee8e8d4b	691	The lodepng_chunk functions are normally not needed, except to traverse the
embeddedartists	0:83b8ee8e8d4b	692	unknown chunks stored in the LodePNGInfo struct, or add new ones to it.
embeddedartists	0:83b8ee8e8d4b	693	It also allows traversing the chunks of an encoded PNG file yourself.
embeddedartists	0:83b8ee8e8d4b	694
embeddedartists	0:83b8ee8e8d4b	695	PNG standard chunk naming conventions:
embeddedartists	0:83b8ee8e8d4b	696	First byte: uppercase = critical, lowercase = ancillary
embeddedartists	0:83b8ee8e8d4b	697	Second byte: uppercase = public, lowercase = private
embeddedartists	0:83b8ee8e8d4b	698	Third byte: must be uppercase
embeddedartists	0:83b8ee8e8d4b	699	Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy
embeddedartists	0:83b8ee8e8d4b	700	*/
embeddedartists	0:83b8ee8e8d4b	701
embeddedartists	0:83b8ee8e8d4b	702	/get the length of the data of the chunk. Total chunk length has 12 bytes more./
embeddedartists	0:83b8ee8e8d4b	703	unsigned lodepng_chunk_length(const unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	704
embeddedartists	0:83b8ee8e8d4b	705	/puts the 4-byte type in null terminated string/
embeddedartists	0:83b8ee8e8d4b	706	void lodepng_chunk_type(char type[5], const unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	707
embeddedartists	0:83b8ee8e8d4b	708	/check if the type is the given type/
embeddedartists	0:83b8ee8e8d4b	709	unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type);
embeddedartists	0:83b8ee8e8d4b	710
embeddedartists	0:83b8ee8e8d4b	711	/0: it's one of the critical chunk types, 1: it's an ancillary chunk (see PNG standard)/
embeddedartists	0:83b8ee8e8d4b	712	unsigned char lodepng_chunk_ancillary(const unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	713
embeddedartists	0:83b8ee8e8d4b	714	/0: public, 1: private (see PNG standard)/
embeddedartists	0:83b8ee8e8d4b	715	unsigned char lodepng_chunk_private(const unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	716
embeddedartists	0:83b8ee8e8d4b	717	/0: the chunk is unsafe to copy, 1: the chunk is safe to copy (see PNG standard)/
embeddedartists	0:83b8ee8e8d4b	718	unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	719
embeddedartists	0:83b8ee8e8d4b	720	/get pointer to the data of the chunk, where the input points to the header of the chunk/
embeddedartists	0:83b8ee8e8d4b	721	unsigned char* lodepng_chunk_data(unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	722	const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	723
embeddedartists	0:83b8ee8e8d4b	724	/returns 0 if the crc is correct, 1 if it's incorrect (0 for OK as usual!)/
embeddedartists	0:83b8ee8e8d4b	725	unsigned lodepng_chunk_check_crc(const unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	726
embeddedartists	0:83b8ee8e8d4b	727	/generates the correct CRC from the data and puts it in the last 4 bytes of the chunk/
embeddedartists	0:83b8ee8e8d4b	728	void lodepng_chunk_generate_crc(unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	729
embeddedartists	0:83b8ee8e8d4b	730	/iterate to next chunks. don't use on IEND chunk, as there is no next chunk then/
embeddedartists	0:83b8ee8e8d4b	731	unsigned char* lodepng_chunk_next(unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	732	const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	733
embeddedartists	0:83b8ee8e8d4b	734	/*
embeddedartists	0:83b8ee8e8d4b	735	Appends chunk to the data in out. The given chunk should already have its chunk header.
embeddedartists	0:83b8ee8e8d4b	736	The out variable and outlength are updated to reflect the new reallocated buffer.
embeddedartists	0:83b8ee8e8d4b	737	Returns error code (0 if it went ok)
embeddedartists	0:83b8ee8e8d4b	738	*/
embeddedartists	0:83b8ee8e8d4b	739	unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk);
embeddedartists	0:83b8ee8e8d4b	740
embeddedartists	0:83b8ee8e8d4b	741	/*
embeddedartists	0:83b8ee8e8d4b	742	Appends new chunk to out. The chunk to append is given by giving its length, type
embeddedartists	0:83b8ee8e8d4b	743	and data separately. The type is a 4-letter string.
embeddedartists	0:83b8ee8e8d4b	744	The out variable and outlength are updated to reflect the new reallocated buffer.
embeddedartists	0:83b8ee8e8d4b	745	Returne error code (0 if it went ok)
embeddedartists	0:83b8ee8e8d4b	746	*/
embeddedartists	0:83b8ee8e8d4b	747	unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length,
embeddedartists	0:83b8ee8e8d4b	748	const char* type, const unsigned char* data);
embeddedartists	0:83b8ee8e8d4b	749
embeddedartists	0:83b8ee8e8d4b	750
embeddedartists	0:83b8ee8e8d4b	751	/Calculate CRC32 of buffer/
embeddedartists	0:83b8ee8e8d4b	752	unsigned lodepng_crc32(const unsigned char* buf, size_t len);
embeddedartists	0:83b8ee8e8d4b	753	#endif /LODEPNG_COMPILE_PNG/
embeddedartists	0:83b8ee8e8d4b	754
embeddedartists	0:83b8ee8e8d4b	755
embeddedartists	0:83b8ee8e8d4b	756	#ifdef LODEPNG_COMPILE_ZLIB
embeddedartists	0:83b8ee8e8d4b	757	/*
embeddedartists	0:83b8ee8e8d4b	758	This zlib part can be used independently to zlib compress and decompress a
embeddedartists	0:83b8ee8e8d4b	759	buffer. It cannot be used to create gzip files however, and it only supports the
embeddedartists	0:83b8ee8e8d4b	760	part of zlib that is required for PNG, it does not support dictionaries.
embeddedartists	0:83b8ee8e8d4b	761	*/
embeddedartists	0:83b8ee8e8d4b	762
embeddedartists	0:83b8ee8e8d4b	763	#ifdef LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	764	/Inflate a buffer. Inflate is the decompression step of deflate. Out buffer must be freed after use./
embeddedartists	0:83b8ee8e8d4b	765	unsigned lodepng_inflate(unsigned char** out, size_t* outsize,
embeddedartists	0:83b8ee8e8d4b	766	const unsigned char* in, size_t insize,
embeddedartists	0:83b8ee8e8d4b	767	const LodePNGDecompressSettings* settings);
embeddedartists	0:83b8ee8e8d4b	768
embeddedartists	0:83b8ee8e8d4b	769	/*
embeddedartists	0:83b8ee8e8d4b	770	Decompresses Zlib data. Reallocates the out buffer and appends the data. The
embeddedartists	0:83b8ee8e8d4b	771	data must be according to the zlib specification.
embeddedartists	0:83b8ee8e8d4b	772	Either, out must be NULL and outsize must be 0, or, *out must be a valid
embeddedartists	0:83b8ee8e8d4b	773	buffer and *outsize its size in bytes. out must be freed by user after usage.
embeddedartists	0:83b8ee8e8d4b	774	*/
embeddedartists	0:83b8ee8e8d4b	775	unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize,
embeddedartists	0:83b8ee8e8d4b	776	const unsigned char* in, size_t insize,
embeddedartists	0:83b8ee8e8d4b	777	const LodePNGDecompressSettings* settings);
embeddedartists	0:83b8ee8e8d4b	778	#endif /LODEPNG_COMPILE_DECODER/
embeddedartists	0:83b8ee8e8d4b	779
embeddedartists	0:83b8ee8e8d4b	780	#ifdef LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	781	/*
embeddedartists	0:83b8ee8e8d4b	782	Compresses data with Zlib. Reallocates the out buffer and appends the data.
embeddedartists	0:83b8ee8e8d4b	783	Zlib adds a small header and trailer around the deflate data.
embeddedartists	0:83b8ee8e8d4b	784	The data is output in the format of the zlib specification.
embeddedartists	0:83b8ee8e8d4b	785	Either, out must be NULL and outsize must be 0, or, *out must be a valid
embeddedartists	0:83b8ee8e8d4b	786	buffer and *outsize its size in bytes. out must be freed by user after usage.
embeddedartists	0:83b8ee8e8d4b	787	*/
embeddedartists	0:83b8ee8e8d4b	788	unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize,
embeddedartists	0:83b8ee8e8d4b	789	const unsigned char* in, size_t insize,
embeddedartists	0:83b8ee8e8d4b	790	const LodePNGCompressSettings* settings);
embeddedartists	0:83b8ee8e8d4b	791
embeddedartists	0:83b8ee8e8d4b	792	/*
embeddedartists	0:83b8ee8e8d4b	793	Find length-limited Huffman code for given frequencies. This function is in the
embeddedartists	0:83b8ee8e8d4b	794	public interface only for tests, it's used internally by lodepng_deflate.
embeddedartists	0:83b8ee8e8d4b	795	*/
embeddedartists	0:83b8ee8e8d4b	796	unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies,
embeddedartists	0:83b8ee8e8d4b	797	size_t numcodes, unsigned maxbitlen);
embeddedartists	0:83b8ee8e8d4b	798
embeddedartists	0:83b8ee8e8d4b	799	/Compress a buffer with deflate. See RFC 1951. Out buffer must be freed after use./
embeddedartists	0:83b8ee8e8d4b	800	unsigned lodepng_deflate(unsigned char** out, size_t* outsize,
embeddedartists	0:83b8ee8e8d4b	801	const unsigned char* in, size_t insize,
embeddedartists	0:83b8ee8e8d4b	802	const LodePNGCompressSettings* settings);
embeddedartists	0:83b8ee8e8d4b	803
embeddedartists	0:83b8ee8e8d4b	804	#endif /LODEPNG_COMPILE_ENCODER/
embeddedartists	0:83b8ee8e8d4b	805	#endif /LODEPNG_COMPILE_ZLIB/
embeddedartists	0:83b8ee8e8d4b	806
embeddedartists	0:83b8ee8e8d4b	807	#ifdef LODEPNG_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	808	/*
embeddedartists	0:83b8ee8e8d4b	809	Load a file from disk into buffer. The function allocates the out buffer, and
embeddedartists	0:83b8ee8e8d4b	810	after usage you should free it.
embeddedartists	0:83b8ee8e8d4b	811	out: output parameter, contains pointer to loaded buffer.
embeddedartists	0:83b8ee8e8d4b	812	outsize: output parameter, size of the allocated out buffer
embeddedartists	0:83b8ee8e8d4b	813	filename: the path to the file to load
embeddedartists	0:83b8ee8e8d4b	814	return value: error code (0 means ok)
embeddedartists	0:83b8ee8e8d4b	815	*/
embeddedartists	0:83b8ee8e8d4b	816	unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename);
embeddedartists	0:83b8ee8e8d4b	817
embeddedartists	0:83b8ee8e8d4b	818	/*
embeddedartists	0:83b8ee8e8d4b	819	Save a file from buffer to disk. Warning, if it exists, this function overwrites
embeddedartists	0:83b8ee8e8d4b	820	the file without warning!
embeddedartists	0:83b8ee8e8d4b	821	buffer: the buffer to write
embeddedartists	0:83b8ee8e8d4b	822	buffersize: size of the buffer to write
embeddedartists	0:83b8ee8e8d4b	823	filename: the path to the file to save to
embeddedartists	0:83b8ee8e8d4b	824	return value: error code (0 means ok)
embeddedartists	0:83b8ee8e8d4b	825	*/
embeddedartists	0:83b8ee8e8d4b	826	unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename);
embeddedartists	0:83b8ee8e8d4b	827	#endif /LODEPNG_COMPILE_DISK/
embeddedartists	0:83b8ee8e8d4b	828
embeddedartists	0:83b8ee8e8d4b	829	#ifdef LODEPNG_COMPILE_CPP
embeddedartists	0:83b8ee8e8d4b	830	//The LodePNG C++ wrapper uses std::vectors instead of manually allocated memory buffers.
embeddedartists	0:83b8ee8e8d4b	831	namespace lodepng
embeddedartists	0:83b8ee8e8d4b	832	{
embeddedartists	0:83b8ee8e8d4b	833	#ifdef LODEPNG_COMPILE_PNG
embeddedartists	0:83b8ee8e8d4b	834	class State : public LodePNGState
embeddedartists	0:83b8ee8e8d4b	835	{
embeddedartists	0:83b8ee8e8d4b	836	public:
embeddedartists	0:83b8ee8e8d4b	837	State();
embeddedartists	0:83b8ee8e8d4b	838	State(const State& other);
embeddedartists	0:83b8ee8e8d4b	839	virtual ~State();
embeddedartists	0:83b8ee8e8d4b	840	State& operator=(const State& other);
embeddedartists	0:83b8ee8e8d4b	841	};
embeddedartists	0:83b8ee8e8d4b	842
embeddedartists	0:83b8ee8e8d4b	843	#ifdef LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	844	//Same as other lodepng::decode, but using a State for more settings and information.
embeddedartists	0:83b8ee8e8d4b	845	unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
embeddedartists	0:83b8ee8e8d4b	846	State& state,
embeddedartists	0:83b8ee8e8d4b	847	const unsigned char* in, size_t insize);
embeddedartists	0:83b8ee8e8d4b	848	unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
embeddedartists	0:83b8ee8e8d4b	849	State& state,
embeddedartists	0:83b8ee8e8d4b	850	const std::vector<unsigned char>& in);
embeddedartists	0:83b8ee8e8d4b	851	#endif /LODEPNG_COMPILE_DECODER/
embeddedartists	0:83b8ee8e8d4b	852
embeddedartists	0:83b8ee8e8d4b	853	#ifdef LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	854	//Same as other lodepng::encode, but using a State for more settings and information.
embeddedartists	0:83b8ee8e8d4b	855	unsigned encode(std::vector<unsigned char>& out,
embeddedartists	0:83b8ee8e8d4b	856	const unsigned char* in, unsigned w, unsigned h,
embeddedartists	0:83b8ee8e8d4b	857	State& state);
embeddedartists	0:83b8ee8e8d4b	858	unsigned encode(std::vector<unsigned char>& out,
embeddedartists	0:83b8ee8e8d4b	859	const std::vector<unsigned char>& in, unsigned w, unsigned h,
embeddedartists	0:83b8ee8e8d4b	860	State& state);
embeddedartists	0:83b8ee8e8d4b	861	#endif /LODEPNG_COMPILE_ENCODER/
embeddedartists	0:83b8ee8e8d4b	862
embeddedartists	0:83b8ee8e8d4b	863	#ifdef LODEPNG_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	864	/*
embeddedartists	0:83b8ee8e8d4b	865	Load a file from disk into an std::vector. If the vector is empty, then either
embeddedartists	0:83b8ee8e8d4b	866	the file doesn't exist or is an empty file.
embeddedartists	0:83b8ee8e8d4b	867	*/
embeddedartists	0:83b8ee8e8d4b	868	void load_file(std::vector<unsigned char>& buffer, const std::string& filename);
embeddedartists	0:83b8ee8e8d4b	869
embeddedartists	0:83b8ee8e8d4b	870	/*
embeddedartists	0:83b8ee8e8d4b	871	Save the binary data in an std::vector to a file on disk. The file is overwritten
embeddedartists	0:83b8ee8e8d4b	872	without warning.
embeddedartists	0:83b8ee8e8d4b	873	*/
embeddedartists	0:83b8ee8e8d4b	874	void save_file(const std::vector<unsigned char>& buffer, const std::string& filename);
embeddedartists	0:83b8ee8e8d4b	875	#endif //LODEPNG_COMPILE_DISK
embeddedartists	0:83b8ee8e8d4b	876	#endif //LODEPNG_COMPILE_PNG
embeddedartists	0:83b8ee8e8d4b	877
embeddedartists	0:83b8ee8e8d4b	878	#ifdef LODEPNG_COMPILE_ZLIB
embeddedartists	0:83b8ee8e8d4b	879	#ifdef LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	880	//Zlib-decompress an unsigned char buffer
embeddedartists	0:83b8ee8e8d4b	881	unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
embeddedartists	0:83b8ee8e8d4b	882	const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings);
embeddedartists	0:83b8ee8e8d4b	883
embeddedartists	0:83b8ee8e8d4b	884	//Zlib-decompress an std::vector
embeddedartists	0:83b8ee8e8d4b	885	unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
embeddedartists	0:83b8ee8e8d4b	886	const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings);
embeddedartists	0:83b8ee8e8d4b	887	#endif //LODEPNG_COMPILE_DECODER
embeddedartists	0:83b8ee8e8d4b	888
embeddedartists	0:83b8ee8e8d4b	889	#ifdef LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	890	//Zlib-compress an unsigned char buffer
embeddedartists	0:83b8ee8e8d4b	891	unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
embeddedartists	0:83b8ee8e8d4b	892	const LodePNGCompressSettings& settings = lodepng_default_compress_settings);
embeddedartists	0:83b8ee8e8d4b	893
embeddedartists	0:83b8ee8e8d4b	894	//Zlib-compress an std::vector
embeddedartists	0:83b8ee8e8d4b	895	unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
embeddedartists	0:83b8ee8e8d4b	896	const LodePNGCompressSettings& settings = lodepng_default_compress_settings);
embeddedartists	0:83b8ee8e8d4b	897	#endif //LODEPNG_COMPILE_ENCODER
embeddedartists	0:83b8ee8e8d4b	898	#endif //LODEPNG_COMPILE_ZLIB
embeddedartists	0:83b8ee8e8d4b	899	} //namespace lodepng
embeddedartists	0:83b8ee8e8d4b	900	#endif /LODEPNG_COMPILE_CPP/
embeddedartists	0:83b8ee8e8d4b	901
embeddedartists	0:83b8ee8e8d4b	902	/*
embeddedartists	0:83b8ee8e8d4b	903	TODO:
embeddedartists	0:83b8ee8e8d4b	904	[.] test if there are no memory leaks or security exploits - done a lot but needs to be checked often
embeddedartists	0:83b8ee8e8d4b	905	[.] check compatibility with vareous compilers - done but needs to be redone for every newer version
embeddedartists	0:83b8ee8e8d4b	906	[X] converting color to 16-bit per channel types
embeddedartists	0:83b8ee8e8d4b	907	[ ] read all public PNG chunk types (but never let the color profile and gamma ones touch RGB values)
embeddedartists	0:83b8ee8e8d4b	908	[ ] make sure encoder generates no chunks with size > (2^31)-1
embeddedartists	0:83b8ee8e8d4b	909	[ ] partial decoding (stream processing)
embeddedartists	0:83b8ee8e8d4b	910	[X] let the "isFullyOpaque" function check color keys and transparent palettes too
embeddedartists	0:83b8ee8e8d4b	911	[X] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl"
embeddedartists	0:83b8ee8e8d4b	912	[ ] don't stop decoding on errors like 69, 57, 58 (make warnings)
embeddedartists	0:83b8ee8e8d4b	913	[ ] make option to choose if the raw image with non multiple of 8 bits per scanline should have padding bits or not
embeddedartists	0:83b8ee8e8d4b	914	[ ] let the C++ wrapper catch exceptions coming from the standard library and return LodePNG error codes
embeddedartists	0:83b8ee8e8d4b	915	*/
embeddedartists	0:83b8ee8e8d4b	916
embeddedartists	0:83b8ee8e8d4b	917	#endif /LODEPNG_H inclusion guard/
embeddedartists	0:83b8ee8e8d4b	918
embeddedartists	0:83b8ee8e8d4b	919	/*
embeddedartists	0:83b8ee8e8d4b	920	LodePNG Documentation
embeddedartists	0:83b8ee8e8d4b	921	---------------------
embeddedartists	0:83b8ee8e8d4b	922
embeddedartists	0:83b8ee8e8d4b	923	0. table of contents
embeddedartists	0:83b8ee8e8d4b	924	--------------------
embeddedartists	0:83b8ee8e8d4b	925
embeddedartists	0:83b8ee8e8d4b	926	1. about
embeddedartists	0:83b8ee8e8d4b	927	1.1. supported features
embeddedartists	0:83b8ee8e8d4b	928	1.2. features not supported
embeddedartists	0:83b8ee8e8d4b	929	2. C and C++ version
embeddedartists	0:83b8ee8e8d4b	930	3. security
embeddedartists	0:83b8ee8e8d4b	931	4. decoding
embeddedartists	0:83b8ee8e8d4b	932	5. encoding
embeddedartists	0:83b8ee8e8d4b	933	6. color conversions
embeddedartists	0:83b8ee8e8d4b	934	6.1. PNG color types
embeddedartists	0:83b8ee8e8d4b	935	6.2. color conversions
embeddedartists	0:83b8ee8e8d4b	936	6.3. padding bits
embeddedartists	0:83b8ee8e8d4b	937	6.4. A note about 16-bits per channel and endianness
embeddedartists	0:83b8ee8e8d4b	938	7. error values
embeddedartists	0:83b8ee8e8d4b	939	8. chunks and PNG editing
embeddedartists	0:83b8ee8e8d4b	940	9. compiler support
embeddedartists	0:83b8ee8e8d4b	941	10. examples
embeddedartists	0:83b8ee8e8d4b	942	10.1. decoder C++ example
embeddedartists	0:83b8ee8e8d4b	943	10.2. decoder C example
embeddedartists	0:83b8ee8e8d4b	944	11. changes
embeddedartists	0:83b8ee8e8d4b	945	12. contact information
embeddedartists	0:83b8ee8e8d4b	946
embeddedartists	0:83b8ee8e8d4b	947
embeddedartists	0:83b8ee8e8d4b	948	1. about
embeddedartists	0:83b8ee8e8d4b	949	--------
embeddedartists	0:83b8ee8e8d4b	950
embeddedartists	0:83b8ee8e8d4b	951	PNG is a file format to store raster images losslessly with good compression,
embeddedartists	0:83b8ee8e8d4b	952	supporting different color types and alpha channel.
embeddedartists	0:83b8ee8e8d4b	953
embeddedartists	0:83b8ee8e8d4b	954	LodePNG is a PNG codec according to the Portable Network Graphics (PNG)
embeddedartists	0:83b8ee8e8d4b	955	Specification (Second Edition) - W3C Recommendation 10 November 2003.
embeddedartists	0:83b8ee8e8d4b	956
embeddedartists	0:83b8ee8e8d4b	957	The specifications used are:
embeddedartists	0:83b8ee8e8d4b	958
embeddedartists	0:83b8ee8e8d4b	959	*) Portable Network Graphics (PNG) Specification (Second Edition):
embeddedartists	0:83b8ee8e8d4b	960	http://www.w3.org/TR/2003/REC-PNG-20031110
embeddedartists	0:83b8ee8e8d4b	961	*) RFC 1950 ZLIB Compressed Data Format version 3.3:
embeddedartists	0:83b8ee8e8d4b	962	http://www.gzip.org/zlib/rfc-zlib.html
embeddedartists	0:83b8ee8e8d4b	963	*) RFC 1951 DEFLATE Compressed Data Format Specification ver 1.3:
embeddedartists	0:83b8ee8e8d4b	964	http://www.gzip.org/zlib/rfc-deflate.html
embeddedartists	0:83b8ee8e8d4b	965
embeddedartists	0:83b8ee8e8d4b	966	The most recent version of LodePNG can currently be found at
embeddedartists	0:83b8ee8e8d4b	967	http://lodev.org/lodepng/
embeddedartists	0:83b8ee8e8d4b	968
embeddedartists	0:83b8ee8e8d4b	969	LodePNG works both in C (ISO C90) and C++, with a C++ wrapper that adds
embeddedartists	0:83b8ee8e8d4b	970	extra functionality.
embeddedartists	0:83b8ee8e8d4b	971
embeddedartists	0:83b8ee8e8d4b	972	LodePNG exists out of two files:
embeddedartists	0:83b8ee8e8d4b	973	-lodepng.h: the header file for both C and C++
embeddedartists	0:83b8ee8e8d4b	974	-lodepng.c(pp): give it the name lodepng.c or lodepng.cpp (or .cc) depending on your usage
embeddedartists	0:83b8ee8e8d4b	975
embeddedartists	0:83b8ee8e8d4b	976	If you want to start using LodePNG right away without reading this doc, get the
embeddedartists	0:83b8ee8e8d4b	977	examples from the LodePNG website to see how to use it in code, or check the
embeddedartists	0:83b8ee8e8d4b	978	smaller examples in chapter 13 here.
embeddedartists	0:83b8ee8e8d4b	979
embeddedartists	0:83b8ee8e8d4b	980	LodePNG is simple but only supports the basic requirements. To achieve
embeddedartists	0:83b8ee8e8d4b	981	simplicity, the following design choices were made: There are no dependencies
embeddedartists	0:83b8ee8e8d4b	982	on any external library. There are functions to decode and encode a PNG with
embeddedartists	0:83b8ee8e8d4b	983	a single function call, and extended versions of these functions taking a
embeddedartists	0:83b8ee8e8d4b	984	LodePNGState struct allowing to specify or get more information. By default
embeddedartists	0:83b8ee8e8d4b	985	the colors of the raw image are always RGB or RGBA, no matter what color type
embeddedartists	0:83b8ee8e8d4b	986	the PNG file uses. To read and write files, there are simple functions to
embeddedartists	0:83b8ee8e8d4b	987	convert the files to/from buffers in memory.
embeddedartists	0:83b8ee8e8d4b	988
embeddedartists	0:83b8ee8e8d4b	989	This all makes LodePNG suitable for loading textures in games, demos and small
embeddedartists	0:83b8ee8e8d4b	990	programs, ... It's less suitable for full fledged image editors, loading PNGs
embeddedartists	0:83b8ee8e8d4b	991	over network (it requires all the image data to be available before decoding can
embeddedartists	0:83b8ee8e8d4b	992	begin), life-critical systems, ...
embeddedartists	0:83b8ee8e8d4b	993
embeddedartists	0:83b8ee8e8d4b	994	1.1. supported features
embeddedartists	0:83b8ee8e8d4b	995	-----------------------
embeddedartists	0:83b8ee8e8d4b	996
embeddedartists	0:83b8ee8e8d4b	997	The following features are supported by the decoder:
embeddedartists	0:83b8ee8e8d4b	998
embeddedartists	0:83b8ee8e8d4b	999	*) decoding of PNGs with any color type, bit depth and interlace mode, to a 24- or 32-bit color raw image,
embeddedartists	0:83b8ee8e8d4b	1000	or the same color type as the PNG
embeddedartists	0:83b8ee8e8d4b	1001	*) encoding of PNGs, from any raw image to 24- or 32-bit color, or the same color type as the raw image
embeddedartists	0:83b8ee8e8d4b	1002	*) Adam7 interlace and deinterlace for any color type
embeddedartists	0:83b8ee8e8d4b	1003	*) loading the image from harddisk or decoding it from a buffer from other sources than harddisk
embeddedartists	0:83b8ee8e8d4b	1004	*) support for alpha channels, including RGBA color model, translucent palettes and color keying
embeddedartists	0:83b8ee8e8d4b	1005	*) zlib decompression (inflate)
embeddedartists	0:83b8ee8e8d4b	1006	*) zlib compression (deflate)
embeddedartists	0:83b8ee8e8d4b	1007	*) CRC32 and ADLER32 checksums
embeddedartists	0:83b8ee8e8d4b	1008	*) handling of unknown chunks, allowing making a PNG editor that stores custom and unknown chunks.
embeddedartists	0:83b8ee8e8d4b	1009	*) the following chunks are supported (generated/interpreted) by both encoder and decoder:
embeddedartists	0:83b8ee8e8d4b	1010	IHDR: header information
embeddedartists	0:83b8ee8e8d4b	1011	PLTE: color palette
embeddedartists	0:83b8ee8e8d4b	1012	IDAT: pixel data
embeddedartists	0:83b8ee8e8d4b	1013	IEND: the final chunk
embeddedartists	0:83b8ee8e8d4b	1014	tRNS: transparency for palettized images
embeddedartists	0:83b8ee8e8d4b	1015	tEXt: textual information
embeddedartists	0:83b8ee8e8d4b	1016	zTXt: compressed textual information
embeddedartists	0:83b8ee8e8d4b	1017	iTXt: international textual information
embeddedartists	0:83b8ee8e8d4b	1018	bKGD: suggested background color
embeddedartists	0:83b8ee8e8d4b	1019	pHYs: physical dimensions
embeddedartists	0:83b8ee8e8d4b	1020	tIME: modification time
embeddedartists	0:83b8ee8e8d4b	1021
embeddedartists	0:83b8ee8e8d4b	1022	1.2. features not supported
embeddedartists	0:83b8ee8e8d4b	1023	---------------------------
embeddedartists	0:83b8ee8e8d4b	1024
embeddedartists	0:83b8ee8e8d4b	1025	The following features are _not_ supported:
embeddedartists	0:83b8ee8e8d4b	1026
embeddedartists	0:83b8ee8e8d4b	1027	*) some features needed to make a conformant PNG-Editor might be still missing.
embeddedartists	0:83b8ee8e8d4b	1028	*) partial loading/stream processing. All data must be available and is processed in one call.
embeddedartists	0:83b8ee8e8d4b	1029	*) The following public chunks are not supported but treated as unknown chunks by LodePNG
embeddedartists	0:83b8ee8e8d4b	1030	cHRM, gAMA, iCCP, sRGB, sBIT, hIST, sPLT
embeddedartists	0:83b8ee8e8d4b	1031	Some of these are not supported on purpose: LodePNG wants to provide the RGB values
embeddedartists	0:83b8ee8e8d4b	1032	stored in the pixels, not values modified by system dependent gamma or color models.
embeddedartists	0:83b8ee8e8d4b	1033
embeddedartists	0:83b8ee8e8d4b	1034
embeddedartists	0:83b8ee8e8d4b	1035	2. C and C++ version
embeddedartists	0:83b8ee8e8d4b	1036	--------------------
embeddedartists	0:83b8ee8e8d4b	1037
embeddedartists	0:83b8ee8e8d4b	1038	The C version uses buffers allocated with alloc that you need to free()
embeddedartists	0:83b8ee8e8d4b	1039	yourself. You need to use init and cleanup functions for each struct whenever
embeddedartists	0:83b8ee8e8d4b	1040	using a struct from the C version to avoid exploits and memory leaks.
embeddedartists	0:83b8ee8e8d4b	1041
embeddedartists	0:83b8ee8e8d4b	1042	The C++ version has extra functions with std::vectors in the interface and the
embeddedartists	0:83b8ee8e8d4b	1043	lodepng::State class which is a LodePNGState with constructor and destructor.
embeddedartists	0:83b8ee8e8d4b	1044
embeddedartists	0:83b8ee8e8d4b	1045	These files work without modification for both C and C++ compilers because all
embeddedartists	0:83b8ee8e8d4b	1046	the additional C++ code is in "#ifdef __cplusplus" blocks that make C-compilers
embeddedartists	0:83b8ee8e8d4b	1047	ignore it, and the C code is made to compile both with strict ISO C90 and C++.
embeddedartists	0:83b8ee8e8d4b	1048
embeddedartists	0:83b8ee8e8d4b	1049	To use the C++ version, you need to rename the source file to lodepng.cpp
embeddedartists	0:83b8ee8e8d4b	1050	(instead of lodepng.c), and compile it with a C++ compiler.
embeddedartists	0:83b8ee8e8d4b	1051
embeddedartists	0:83b8ee8e8d4b	1052	To use the C version, you need to rename the source file to lodepng.c (instead
embeddedartists	0:83b8ee8e8d4b	1053	of lodepng.cpp), and compile it with a C compiler.
embeddedartists	0:83b8ee8e8d4b	1054
embeddedartists	0:83b8ee8e8d4b	1055
embeddedartists	0:83b8ee8e8d4b	1056	3. Security
embeddedartists	0:83b8ee8e8d4b	1057	-----------
embeddedartists	0:83b8ee8e8d4b	1058
embeddedartists	0:83b8ee8e8d4b	1059	Even if carefully designed, it's always possible that LodePNG contains possible
embeddedartists	0:83b8ee8e8d4b	1060	exploits. If you discover one, please let me know, and it will be fixed.
embeddedartists	0:83b8ee8e8d4b	1061
embeddedartists	0:83b8ee8e8d4b	1062	When using LodePNG, care has to be taken with the C version of LodePNG, as well
embeddedartists	0:83b8ee8e8d4b	1063	as the C-style structs when working with C++. The following conventions are used
embeddedartists	0:83b8ee8e8d4b	1064	for all C-style structs:
embeddedartists	0:83b8ee8e8d4b	1065
embeddedartists	0:83b8ee8e8d4b	1066	-if a struct has a corresponding init function, always call the init function when making a new one
embeddedartists	0:83b8ee8e8d4b	1067	-if a struct has a corresponding cleanup function, call it before the struct disappears to avoid memory leaks
embeddedartists	0:83b8ee8e8d4b	1068	-if a struct has a corresponding copy function, use the copy function instead of "=".
embeddedartists	0:83b8ee8e8d4b	1069	The destination must also be inited already.
embeddedartists	0:83b8ee8e8d4b	1070
embeddedartists	0:83b8ee8e8d4b	1071
embeddedartists	0:83b8ee8e8d4b	1072	4. Decoding
embeddedartists	0:83b8ee8e8d4b	1073	-----------
embeddedartists	0:83b8ee8e8d4b	1074
embeddedartists	0:83b8ee8e8d4b	1075	Decoding converts a PNG compressed image to a raw pixel buffer.
embeddedartists	0:83b8ee8e8d4b	1076
embeddedartists	0:83b8ee8e8d4b	1077	Most documentation on using the decoder is at its declarations in the header
embeddedartists	0:83b8ee8e8d4b	1078	above. For C, simple decoding can be done with functions such as
embeddedartists	0:83b8ee8e8d4b	1079	lodepng_decode32, and more advanced decoding can be done with the struct
embeddedartists	0:83b8ee8e8d4b	1080	LodePNGState and lodepng_decode. For C++, all decoding can be done with the
embeddedartists	0:83b8ee8e8d4b	1081	various lodepng::decode functions, and lodepng::State can be used for advanced
embeddedartists	0:83b8ee8e8d4b	1082	features.
embeddedartists	0:83b8ee8e8d4b	1083
embeddedartists	0:83b8ee8e8d4b	1084	When using the LodePNGState, it uses the following fields for decoding:
embeddedartists	0:83b8ee8e8d4b	1085	*) LodePNGInfo info_png: it stores extra information about the PNG (the input) in here
embeddedartists	0:83b8ee8e8d4b	1086	*) LodePNGColorMode info_raw: here you can say what color mode of the raw image (the output) you want to get
embeddedartists	0:83b8ee8e8d4b	1087	*) LodePNGDecoderSettings decoder: you can specify a few extra settings for the decoder to use
embeddedartists	0:83b8ee8e8d4b	1088
embeddedartists	0:83b8ee8e8d4b	1089	LodePNGInfo info_png
embeddedartists	0:83b8ee8e8d4b	1090	--------------------
embeddedartists	0:83b8ee8e8d4b	1091
embeddedartists	0:83b8ee8e8d4b	1092	After decoding, this contains extra information of the PNG image, except the actual
embeddedartists	0:83b8ee8e8d4b	1093	pixels, width and height because these are already gotten directly from the decoder
embeddedartists	0:83b8ee8e8d4b	1094	functions.
embeddedartists	0:83b8ee8e8d4b	1095
embeddedartists	0:83b8ee8e8d4b	1096	It contains for example the original color type of the PNG image, text comments,
embeddedartists	0:83b8ee8e8d4b	1097	suggested background color, etc... More details about the LodePNGInfo struct are
embeddedartists	0:83b8ee8e8d4b	1098	at its declaration documentation.
embeddedartists	0:83b8ee8e8d4b	1099
embeddedartists	0:83b8ee8e8d4b	1100	LodePNGColorMode info_raw
embeddedartists	0:83b8ee8e8d4b	1101	-------------------------
embeddedartists	0:83b8ee8e8d4b	1102
embeddedartists	0:83b8ee8e8d4b	1103	When decoding, here you can specify which color type you want
embeddedartists	0:83b8ee8e8d4b	1104	the resulting raw image to be. If this is different from the colortype of the
embeddedartists	0:83b8ee8e8d4b	1105	PNG, then the decoder will automatically convert the result. This conversion
embeddedartists	0:83b8ee8e8d4b	1106	always works, except if you want it to convert a color PNG to greyscale or to
embeddedartists	0:83b8ee8e8d4b	1107	a palette with missing colors.
embeddedartists	0:83b8ee8e8d4b	1108
embeddedartists	0:83b8ee8e8d4b	1109	By default, 32-bit color is used for the result.
embeddedartists	0:83b8ee8e8d4b	1110
embeddedartists	0:83b8ee8e8d4b	1111	LodePNGDecoderSettings decoder
embeddedartists	0:83b8ee8e8d4b	1112	------------------------------
embeddedartists	0:83b8ee8e8d4b	1113
embeddedartists	0:83b8ee8e8d4b	1114	The settings can be used to ignore the errors created by invalid CRC and Adler32
embeddedartists	0:83b8ee8e8d4b	1115	chunks, and to disable the decoding of tEXt chunks.
embeddedartists	0:83b8ee8e8d4b	1116
embeddedartists	0:83b8ee8e8d4b	1117	There's also a setting color_convert, true by default. If false, no conversion
embeddedartists	0:83b8ee8e8d4b	1118	is done, the resulting data will be as it was in the PNG (after decompression)
embeddedartists	0:83b8ee8e8d4b	1119	and you'll have to puzzle the colors of the pixels together yourself using the
embeddedartists	0:83b8ee8e8d4b	1120	color type information in the LodePNGInfo.
embeddedartists	0:83b8ee8e8d4b	1121
embeddedartists	0:83b8ee8e8d4b	1122
embeddedartists	0:83b8ee8e8d4b	1123	5. Encoding
embeddedartists	0:83b8ee8e8d4b	1124	-----------
embeddedartists	0:83b8ee8e8d4b	1125
embeddedartists	0:83b8ee8e8d4b	1126	Encoding converts a raw pixel buffer to a PNG compressed image.
embeddedartists	0:83b8ee8e8d4b	1127
embeddedartists	0:83b8ee8e8d4b	1128	Most documentation on using the encoder is at its declarations in the header
embeddedartists	0:83b8ee8e8d4b	1129	above. For C, simple encoding can be done with functions such as
embeddedartists	0:83b8ee8e8d4b	1130	lodepng_encode32, and more advanced decoding can be done with the struct
embeddedartists	0:83b8ee8e8d4b	1131	LodePNGState and lodepng_encode. For C++, all encoding can be done with the
embeddedartists	0:83b8ee8e8d4b	1132	various lodepng::encode functions, and lodepng::State can be used for advanced
embeddedartists	0:83b8ee8e8d4b	1133	features.
embeddedartists	0:83b8ee8e8d4b	1134
embeddedartists	0:83b8ee8e8d4b	1135	Like the decoder, the encoder can also give errors. However it gives less errors
embeddedartists	0:83b8ee8e8d4b	1136	since the encoder input is trusted, the decoder input (a PNG image that could
embeddedartists	0:83b8ee8e8d4b	1137	be forged by anyone) is not trusted.
embeddedartists	0:83b8ee8e8d4b	1138
embeddedartists	0:83b8ee8e8d4b	1139	When using the LodePNGState, it uses the following fields for encoding:
embeddedartists	0:83b8ee8e8d4b	1140	*) LodePNGInfo info_png: here you specify how you want the PNG (the output) to be.
embeddedartists	0:83b8ee8e8d4b	1141	*) LodePNGColorMode info_raw: here you say what color type of the raw image (the input) has
embeddedartists	0:83b8ee8e8d4b	1142	*) LodePNGEncoderSettings encoder: you can specify a few settings for the encoder to use
embeddedartists	0:83b8ee8e8d4b	1143
embeddedartists	0:83b8ee8e8d4b	1144	LodePNGInfo info_png
embeddedartists	0:83b8ee8e8d4b	1145	--------------------
embeddedartists	0:83b8ee8e8d4b	1146
embeddedartists	0:83b8ee8e8d4b	1147	When encoding, you use this the opposite way as when decoding: for encoding,
embeddedartists	0:83b8ee8e8d4b	1148	you fill in the values you want the PNG to have before encoding. By default it's
embeddedartists	0:83b8ee8e8d4b	1149	not needed to specify a color type for the PNG since it's automatically chosen,
embeddedartists	0:83b8ee8e8d4b	1150	but it's possible to choose it yourself given the right settings.
embeddedartists	0:83b8ee8e8d4b	1151
embeddedartists	0:83b8ee8e8d4b	1152	The encoder will not always exactly match the LodePNGInfo struct you give,
embeddedartists	0:83b8ee8e8d4b	1153	it tries as close as possible. Some things are ignored by the encoder. The
embeddedartists	0:83b8ee8e8d4b	1154	encoder uses, for example, the following settings from it when applicable:
embeddedartists	0:83b8ee8e8d4b	1155	colortype and bitdepth, text chunks, time chunk, the color key, the palette, the
embeddedartists	0:83b8ee8e8d4b	1156	background color, the interlace method, unknown chunks, ...
embeddedartists	0:83b8ee8e8d4b	1157
embeddedartists	0:83b8ee8e8d4b	1158	When encoding to a PNG with colortype 3, the encoder will generate a PLTE chunk.
embeddedartists	0:83b8ee8e8d4b	1159	If the palette contains any colors for which the alpha channel is not 255 (so
embeddedartists	0:83b8ee8e8d4b	1160	there are translucent colors in the palette), it'll add a tRNS chunk.
embeddedartists	0:83b8ee8e8d4b	1161
embeddedartists	0:83b8ee8e8d4b	1162	LodePNGColorMode info_raw
embeddedartists	0:83b8ee8e8d4b	1163	-------------------------
embeddedartists	0:83b8ee8e8d4b	1164
embeddedartists	0:83b8ee8e8d4b	1165	You specify the color type of the raw image that you give to the input here,
embeddedartists	0:83b8ee8e8d4b	1166	including a possible transparent color key and palette you happen to be using in
embeddedartists	0:83b8ee8e8d4b	1167	your raw image data.
embeddedartists	0:83b8ee8e8d4b	1168
embeddedartists	0:83b8ee8e8d4b	1169	By default, 32-bit color is assumed, meaning your input has to be in RGBA
embeddedartists	0:83b8ee8e8d4b	1170	format with 4 bytes (unsigned chars) per pixel.
embeddedartists	0:83b8ee8e8d4b	1171
embeddedartists	0:83b8ee8e8d4b	1172	LodePNGEncoderSettings encoder
embeddedartists	0:83b8ee8e8d4b	1173	------------------------------
embeddedartists	0:83b8ee8e8d4b	1174
embeddedartists	0:83b8ee8e8d4b	1175	The following settings are supported (some are in sub-structs):
embeddedartists	0:83b8ee8e8d4b	1176	*) auto_convert: when this option is enabled, the encoder will
embeddedartists	0:83b8ee8e8d4b	1177	automatically choose the smallest possible color mode (including color key) that
embeddedartists	0:83b8ee8e8d4b	1178	can encode the colors of all pixels without information loss.
embeddedartists	0:83b8ee8e8d4b	1179	*) btype: the block type for LZ77. 0 = uncompressed, 1 = fixed huffman tree,
embeddedartists	0:83b8ee8e8d4b	1180	2 = dynamic huffman tree (best compression). Should be 2 for proper
embeddedartists	0:83b8ee8e8d4b	1181	compression.
embeddedartists	0:83b8ee8e8d4b	1182	*) use_lz77: whether or not to use LZ77 for compressed block types. Should be
embeddedartists	0:83b8ee8e8d4b	1183	true for proper compression.
embeddedartists	0:83b8ee8e8d4b	1184	*) windowsize: the window size used by the LZ77 encoder (1 - 32768). Has value
embeddedartists	0:83b8ee8e8d4b	1185	2048 by default, but can be set to 32768 for better, but slow, compression.
embeddedartists	0:83b8ee8e8d4b	1186	*) force_palette: if colortype is 2 or 6, you can make the encoder write a PLTE
embeddedartists	0:83b8ee8e8d4b	1187	chunk if force_palette is true. This can used as suggested palette to convert
embeddedartists	0:83b8ee8e8d4b	1188	to by viewers that don't support more than 256 colors (if those still exist)
embeddedartists	0:83b8ee8e8d4b	1189	*) add_id: add text chunk "Encoder: LodePNG <version>" to the image.
embeddedartists	0:83b8ee8e8d4b	1190	*) text_compression: default 1. If 1, it'll store texts as zTXt instead of tEXt chunks.
embeddedartists	0:83b8ee8e8d4b	1191	zTXt chunks use zlib compression on the text. This gives a smaller result on
embeddedartists	0:83b8ee8e8d4b	1192	large texts but a larger result on small texts (such as a single program name).
embeddedartists	0:83b8ee8e8d4b	1193	It's all tEXt or all zTXt though, there's no separate setting per text yet.
embeddedartists	0:83b8ee8e8d4b	1194
embeddedartists	0:83b8ee8e8d4b	1195
embeddedartists	0:83b8ee8e8d4b	1196	6. color conversions
embeddedartists	0:83b8ee8e8d4b	1197	--------------------
embeddedartists	0:83b8ee8e8d4b	1198
embeddedartists	0:83b8ee8e8d4b	1199	An important thing to note about LodePNG, is that the color type of the PNG, and
embeddedartists	0:83b8ee8e8d4b	1200	the color type of the raw image, are completely independent. By default, when
embeddedartists	0:83b8ee8e8d4b	1201	you decode a PNG, you get the result as a raw image in the color type you want,
embeddedartists	0:83b8ee8e8d4b	1202	no matter whether the PNG was encoded with a palette, greyscale or RGBA color.
embeddedartists	0:83b8ee8e8d4b	1203	And if you encode an image, by default LodePNG will automatically choose the PNG
embeddedartists	0:83b8ee8e8d4b	1204	color type that gives good compression based on the values of colors and amount
embeddedartists	0:83b8ee8e8d4b	1205	of colors in the image. It can be configured to let you control it instead as
embeddedartists	0:83b8ee8e8d4b	1206	well, though.
embeddedartists	0:83b8ee8e8d4b	1207
embeddedartists	0:83b8ee8e8d4b	1208	To be able to do this, LodePNG does conversions from one color mode to another.
embeddedartists	0:83b8ee8e8d4b	1209	It can convert from almost any color type to any other color type, except the
embeddedartists	0:83b8ee8e8d4b	1210	following conversions: RGB to greyscale is not supported, and converting to a
embeddedartists	0:83b8ee8e8d4b	1211	palette when the palette doesn't have a required color is not supported. This is
embeddedartists	0:83b8ee8e8d4b	1212	not supported on purpose: this is information loss which requires a color
embeddedartists	0:83b8ee8e8d4b	1213	reduction algorithm that is beyong the scope of a PNG encoder (yes, RGB to grey
embeddedartists	0:83b8ee8e8d4b	1214	is easy, but there are multiple ways if you want to give some channels more
embeddedartists	0:83b8ee8e8d4b	1215	weight).
embeddedartists	0:83b8ee8e8d4b	1216
embeddedartists	0:83b8ee8e8d4b	1217	By default, when decoding, you get the raw image in 32-bit RGBA or 24-bit RGB
embeddedartists	0:83b8ee8e8d4b	1218	color, no matter what color type the PNG has. And by default when encoding,
embeddedartists	0:83b8ee8e8d4b	1219	LodePNG automatically picks the best color model for the output PNG, and expects
embeddedartists	0:83b8ee8e8d4b	1220	the input image to be 32-bit RGBA or 24-bit RGB. So, unless you want to control
embeddedartists	0:83b8ee8e8d4b	1221	the color format of the images yourself, you can skip this chapter.
embeddedartists	0:83b8ee8e8d4b	1222
embeddedartists	0:83b8ee8e8d4b	1223	6.1. PNG color types
embeddedartists	0:83b8ee8e8d4b	1224	--------------------
embeddedartists	0:83b8ee8e8d4b	1225
embeddedartists	0:83b8ee8e8d4b	1226	A PNG image can have many color types, ranging from 1-bit color to 64-bit color,
embeddedartists	0:83b8ee8e8d4b	1227	as well as palettized color modes. After the zlib decompression and unfiltering
embeddedartists	0:83b8ee8e8d4b	1228	in the PNG image is done, the raw pixel data will have that color type and thus
embeddedartists	0:83b8ee8e8d4b	1229	a certain amount of bits per pixel. If you want the output raw image after
embeddedartists	0:83b8ee8e8d4b	1230	decoding to have another color type, a conversion is done by LodePNG.
embeddedartists	0:83b8ee8e8d4b	1231
embeddedartists	0:83b8ee8e8d4b	1232	The PNG specification gives the following color types:
embeddedartists	0:83b8ee8e8d4b	1233
embeddedartists	0:83b8ee8e8d4b	1234	0: greyscale, bit depths 1, 2, 4, 8, 16
embeddedartists	0:83b8ee8e8d4b	1235	2: RGB, bit depths 8 and 16
embeddedartists	0:83b8ee8e8d4b	1236	3: palette, bit depths 1, 2, 4 and 8
embeddedartists	0:83b8ee8e8d4b	1237	4: greyscale with alpha, bit depths 8 and 16
embeddedartists	0:83b8ee8e8d4b	1238	6: RGBA, bit depths 8 and 16
embeddedartists	0:83b8ee8e8d4b	1239
embeddedartists	0:83b8ee8e8d4b	1240	Bit depth is the amount of bits per pixel per color channel. So the total amount
embeddedartists	0:83b8ee8e8d4b	1241	of bits per pixel is: amount of channels * bitdepth.
embeddedartists	0:83b8ee8e8d4b	1242
embeddedartists	0:83b8ee8e8d4b	1243	6.2. color conversions
embeddedartists	0:83b8ee8e8d4b	1244	----------------------
embeddedartists	0:83b8ee8e8d4b	1245
embeddedartists	0:83b8ee8e8d4b	1246	As explained in the sections about the encoder and decoder, you can specify
embeddedartists	0:83b8ee8e8d4b	1247	color types and bit depths in info_png and info_raw to change the default
embeddedartists	0:83b8ee8e8d4b	1248	behaviour.
embeddedartists	0:83b8ee8e8d4b	1249
embeddedartists	0:83b8ee8e8d4b	1250	If, when decoding, you want the raw image to be something else than the default,
embeddedartists	0:83b8ee8e8d4b	1251	you need to set the color type and bit depth you want in the LodePNGColorMode,
embeddedartists	0:83b8ee8e8d4b	1252	or the parameters of the simple function of LodePNG you're using.
embeddedartists	0:83b8ee8e8d4b	1253
embeddedartists	0:83b8ee8e8d4b	1254	If, when encoding, you use another color type than the default in the input
embeddedartists	0:83b8ee8e8d4b	1255	image, you need to specify its color type and bit depth in the LodePNGColorMode
embeddedartists	0:83b8ee8e8d4b	1256	of the raw image, or use the parameters of the simplefunction of LodePNG you're
embeddedartists	0:83b8ee8e8d4b	1257	using.
embeddedartists	0:83b8ee8e8d4b	1258
embeddedartists	0:83b8ee8e8d4b	1259	If, when encoding, you don't want LodePNG to choose the output PNG color type
embeddedartists	0:83b8ee8e8d4b	1260	but control it yourself, you need to set auto_convert in the encoder settings
embeddedartists	0:83b8ee8e8d4b	1261	to LAC_NONE, and specify the color type you want in the LodePNGInfo of the
embeddedartists	0:83b8ee8e8d4b	1262	encoder.
embeddedartists	0:83b8ee8e8d4b	1263
embeddedartists	0:83b8ee8e8d4b	1264	If you do any of the above, LodePNG may need to do a color conversion, which
embeddedartists	0:83b8ee8e8d4b	1265	follows the rules below, and may sometimes not be allowed.
embeddedartists	0:83b8ee8e8d4b	1266
embeddedartists	0:83b8ee8e8d4b	1267	To avoid some confusion:
embeddedartists	0:83b8ee8e8d4b	1268	-the decoder converts from PNG to raw image
embeddedartists	0:83b8ee8e8d4b	1269	-the encoder converts from raw image to PNG
embeddedartists	0:83b8ee8e8d4b	1270	-the colortype and bitdepth in LodePNGColorMode info_raw, are those of the raw image
embeddedartists	0:83b8ee8e8d4b	1271	-the colortype and bitdepth in the color field of LodePNGInfo info_png, are those of the PNG
embeddedartists	0:83b8ee8e8d4b	1272	-when encoding, the color type in LodePNGInfo is ignored if auto_convert
embeddedartists	0:83b8ee8e8d4b	1273	is enabled, it is automatically generated instead
embeddedartists	0:83b8ee8e8d4b	1274	-when decoding, the color type in LodePNGInfo is set by the decoder to that of the original
embeddedartists	0:83b8ee8e8d4b	1275	PNG image, but it can be ignored since the raw image has the color type you requested instead
embeddedartists	0:83b8ee8e8d4b	1276	-if the color type of the LodePNGColorMode and PNG image aren't the same, a conversion
embeddedartists	0:83b8ee8e8d4b	1277	between the color types is done if the color types are supported. If it is not
embeddedartists	0:83b8ee8e8d4b	1278	supported, an error is returned. If the types are the same, no conversion is done.
embeddedartists	0:83b8ee8e8d4b	1279	-even though some conversions aren't supported, LodePNG supports loading PNGs from any
embeddedartists	0:83b8ee8e8d4b	1280	colortype and saving PNGs to any colortype, sometimes it just requires preparing
embeddedartists	0:83b8ee8e8d4b	1281	the raw image correctly before encoding.
embeddedartists	0:83b8ee8e8d4b	1282	-both encoder and decoder use the same color converter.
embeddedartists	0:83b8ee8e8d4b	1283
embeddedartists	0:83b8ee8e8d4b	1284	Non supported color conversions:
embeddedartists	0:83b8ee8e8d4b	1285	-color to greyscale: no error is thrown, but the result will look ugly because
embeddedartists	0:83b8ee8e8d4b	1286	only the red channel is taken
embeddedartists	0:83b8ee8e8d4b	1287	-anything, to palette when that palette does not have that color in it: in this
embeddedartists	0:83b8ee8e8d4b	1288	case an error is thrown
embeddedartists	0:83b8ee8e8d4b	1289
embeddedartists	0:83b8ee8e8d4b	1290	Supported color conversions:
embeddedartists	0:83b8ee8e8d4b	1291	-anything to 8-bit RGB, 8-bit RGBA, 16-bit RGB, 16-bit RGBA
embeddedartists	0:83b8ee8e8d4b	1292	-any grey or grey+alpha, to grey or grey+alpha
embeddedartists	0:83b8ee8e8d4b	1293	-anything to a palette, as long as the palette has the requested colors in it
embeddedartists	0:83b8ee8e8d4b	1294	-removing alpha channel
embeddedartists	0:83b8ee8e8d4b	1295	-higher to smaller bitdepth, and vice versa
embeddedartists	0:83b8ee8e8d4b	1296
embeddedartists	0:83b8ee8e8d4b	1297	If you want no color conversion to be done:
embeddedartists	0:83b8ee8e8d4b	1298	-In the encoder, you can make it save a PNG with any color type by giving the
embeddedartists	0:83b8ee8e8d4b	1299	raw color mode and LodePNGInfo the same color mode, and setting auto_convert to
embeddedartists	0:83b8ee8e8d4b	1300	LAC_NO.
embeddedartists	0:83b8ee8e8d4b	1301	-In the decoder, you can make it store the pixel data in the same color type
embeddedartists	0:83b8ee8e8d4b	1302	as the PNG has, by setting the color_convert setting to false. Settings in
embeddedartists	0:83b8ee8e8d4b	1303	info_raw are then ignored.
embeddedartists	0:83b8ee8e8d4b	1304
embeddedartists	0:83b8ee8e8d4b	1305	The function lodepng_convert does the color conversion. It is available in the
embeddedartists	0:83b8ee8e8d4b	1306	interface but normally isn't needed since the encoder and decoder already call
embeddedartists	0:83b8ee8e8d4b	1307	it.
embeddedartists	0:83b8ee8e8d4b	1308
embeddedartists	0:83b8ee8e8d4b	1309	6.3. padding bits
embeddedartists	0:83b8ee8e8d4b	1310	-----------------
embeddedartists	0:83b8ee8e8d4b	1311
embeddedartists	0:83b8ee8e8d4b	1312	In the PNG file format, if a less than 8-bit per pixel color type is used and the scanlines
embeddedartists	0:83b8ee8e8d4b	1313	have a bit amount that isn't a multiple of 8, then padding bits are used so that each
embeddedartists	0:83b8ee8e8d4b	1314	scanline starts at a fresh byte. But that is NOT true for the LodePNG raw input and output.
embeddedartists	0:83b8ee8e8d4b	1315	The raw input image you give to the encoder, and the raw output image you get from the decoder
embeddedartists	0:83b8ee8e8d4b	1316	will NOT have these padding bits, e.g. in the case of a 1-bit image with a width
embeddedartists	0:83b8ee8e8d4b	1317	of 7 pixels, the first pixel of the second scanline will the the 8th bit of the first byte,
embeddedartists	0:83b8ee8e8d4b	1318	not the first bit of a new byte.
embeddedartists	0:83b8ee8e8d4b	1319
embeddedartists	0:83b8ee8e8d4b	1320	6.4. A note about 16-bits per channel and endianness
embeddedartists	0:83b8ee8e8d4b	1321	----------------------------------------------------
embeddedartists	0:83b8ee8e8d4b	1322
embeddedartists	0:83b8ee8e8d4b	1323	LodePNG uses unsigned char arrays for 16-bit per channel colors too, just like
embeddedartists	0:83b8ee8e8d4b	1324	for any other color format. The 16-bit values are stored in big endian (most
embeddedartists	0:83b8ee8e8d4b	1325	significant byte first) in these arrays. This is the opposite order of the
embeddedartists	0:83b8ee8e8d4b	1326	little endian used by x86 CPU's.
embeddedartists	0:83b8ee8e8d4b	1327
embeddedartists	0:83b8ee8e8d4b	1328	LodePNG always uses big endian because the PNG file format does so internally.
embeddedartists	0:83b8ee8e8d4b	1329	Conversions to other formats than PNG uses internally are not supported by
embeddedartists	0:83b8ee8e8d4b	1330	LodePNG on purpose, there are myriads of formats, including endianness of 16-bit
embeddedartists	0:83b8ee8e8d4b	1331	colors, the order in which you store R, G, B and A, and so on. Supporting and
embeddedartists	0:83b8ee8e8d4b	1332	converting to/from all that is outside the scope of LodePNG.
embeddedartists	0:83b8ee8e8d4b	1333
embeddedartists	0:83b8ee8e8d4b	1334	This may mean that, depending on your use case, you may want to convert the big
embeddedartists	0:83b8ee8e8d4b	1335	endian output of LodePNG to little endian with a for loop. This is certainly not
embeddedartists	0:83b8ee8e8d4b	1336	always needed, many applications and libraries support big endian 16-bit colors
embeddedartists	0:83b8ee8e8d4b	1337	anyway, but it means you cannot simply cast the unsigned char* buffer to an
embeddedartists	0:83b8ee8e8d4b	1338	unsigned short* buffer on x86 CPUs.
embeddedartists	0:83b8ee8e8d4b	1339
embeddedartists	0:83b8ee8e8d4b	1340
embeddedartists	0:83b8ee8e8d4b	1341	7. error values
embeddedartists	0:83b8ee8e8d4b	1342	---------------
embeddedartists	0:83b8ee8e8d4b	1343
embeddedartists	0:83b8ee8e8d4b	1344	All functions in LodePNG that return an error code, return 0 if everything went
embeddedartists	0:83b8ee8e8d4b	1345	OK, or a non-zero code if there was an error.
embeddedartists	0:83b8ee8e8d4b	1346
embeddedartists	0:83b8ee8e8d4b	1347	The meaning of the LodePNG error values can be retrieved with the function
embeddedartists	0:83b8ee8e8d4b	1348	lodepng_error_text: given the numerical error code, it returns a description
embeddedartists	0:83b8ee8e8d4b	1349	of the error in English as a string.
embeddedartists	0:83b8ee8e8d4b	1350
embeddedartists	0:83b8ee8e8d4b	1351	Check the implementation of lodepng_error_text to see the meaning of each code.
embeddedartists	0:83b8ee8e8d4b	1352
embeddedartists	0:83b8ee8e8d4b	1353
embeddedartists	0:83b8ee8e8d4b	1354	8. chunks and PNG editing
embeddedartists	0:83b8ee8e8d4b	1355	-------------------------
embeddedartists	0:83b8ee8e8d4b	1356
embeddedartists	0:83b8ee8e8d4b	1357	If you want to add extra chunks to a PNG you encode, or use LodePNG for a PNG
embeddedartists	0:83b8ee8e8d4b	1358	editor that should follow the rules about handling of unknown chunks, or if your
embeddedartists	0:83b8ee8e8d4b	1359	program is able to read other types of chunks than the ones handled by LodePNG,
embeddedartists	0:83b8ee8e8d4b	1360	then that's possible with the chunk functions of LodePNG.
embeddedartists	0:83b8ee8e8d4b	1361
embeddedartists	0:83b8ee8e8d4b	1362	A PNG chunk has the following layout:
embeddedartists	0:83b8ee8e8d4b	1363
embeddedartists	0:83b8ee8e8d4b	1364	4 bytes length
embeddedartists	0:83b8ee8e8d4b	1365	4 bytes type name
embeddedartists	0:83b8ee8e8d4b	1366	length bytes data
embeddedartists	0:83b8ee8e8d4b	1367	4 bytes CRC
embeddedartists	0:83b8ee8e8d4b	1368
embeddedartists	0:83b8ee8e8d4b	1369	8.1. iterating through chunks
embeddedartists	0:83b8ee8e8d4b	1370	-----------------------------
embeddedartists	0:83b8ee8e8d4b	1371
embeddedartists	0:83b8ee8e8d4b	1372	If you have a buffer containing the PNG image data, then the first chunk (the
embeddedartists	0:83b8ee8e8d4b	1373	IHDR chunk) starts at byte number 8 of that buffer. The first 8 bytes are the
embeddedartists	0:83b8ee8e8d4b	1374	signature of the PNG and are not part of a chunk. But if you start at byte 8
embeddedartists	0:83b8ee8e8d4b	1375	then you have a chunk, and can check the following things of it.
embeddedartists	0:83b8ee8e8d4b	1376
embeddedartists	0:83b8ee8e8d4b	1377	NOTE: none of these functions check for memory buffer boundaries. To avoid
embeddedartists	0:83b8ee8e8d4b	1378	exploits, always make sure the buffer contains all the data of the chunks.
embeddedartists	0:83b8ee8e8d4b	1379	When using lodepng_chunk_next, make sure the returned value is within the
embeddedartists	0:83b8ee8e8d4b	1380	allocated memory.
embeddedartists	0:83b8ee8e8d4b	1381
embeddedartists	0:83b8ee8e8d4b	1382	unsigned lodepng_chunk_length(const unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1383
embeddedartists	0:83b8ee8e8d4b	1384	Get the length of the chunk's data. The total chunk length is this length + 12.
embeddedartists	0:83b8ee8e8d4b	1385
embeddedartists	0:83b8ee8e8d4b	1386	void lodepng_chunk_type(char type[5], const unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1387	unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type):
embeddedartists	0:83b8ee8e8d4b	1388
embeddedartists	0:83b8ee8e8d4b	1389	Get the type of the chunk or compare if it's a certain type
embeddedartists	0:83b8ee8e8d4b	1390
embeddedartists	0:83b8ee8e8d4b	1391	unsigned char lodepng_chunk_critical(const unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1392	unsigned char lodepng_chunk_private(const unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1393	unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1394
embeddedartists	0:83b8ee8e8d4b	1395	Check if the chunk is critical in the PNG standard (only IHDR, PLTE, IDAT and IEND are).
embeddedartists	0:83b8ee8e8d4b	1396	Check if the chunk is private (public chunks are part of the standard, private ones not).
embeddedartists	0:83b8ee8e8d4b	1397	Check if the chunk is safe to copy. If it's not, then, when modifying data in a critical
embeddedartists	0:83b8ee8e8d4b	1398	chunk, unsafe to copy chunks of the old image may NOT be saved in the new one if your
embeddedartists	0:83b8ee8e8d4b	1399	program doesn't handle that type of unknown chunk.
embeddedartists	0:83b8ee8e8d4b	1400
embeddedartists	0:83b8ee8e8d4b	1401	unsigned char* lodepng_chunk_data(unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1402	const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1403
embeddedartists	0:83b8ee8e8d4b	1404	Get a pointer to the start of the data of the chunk.
embeddedartists	0:83b8ee8e8d4b	1405
embeddedartists	0:83b8ee8e8d4b	1406	unsigned lodepng_chunk_check_crc(const unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1407	void lodepng_chunk_generate_crc(unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1408
embeddedartists	0:83b8ee8e8d4b	1409	Check if the crc is correct or generate a correct one.
embeddedartists	0:83b8ee8e8d4b	1410
embeddedartists	0:83b8ee8e8d4b	1411	unsigned char* lodepng_chunk_next(unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1412	const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1413
embeddedartists	0:83b8ee8e8d4b	1414	Iterate to the next chunk. This works if you have a buffer with consecutive chunks. Note that these
embeddedartists	0:83b8ee8e8d4b	1415	functions do no boundary checking of the allocated data whatsoever, so make sure there is enough
embeddedartists	0:83b8ee8e8d4b	1416	data available in the buffer to be able to go to the next chunk.
embeddedartists	0:83b8ee8e8d4b	1417
embeddedartists	0:83b8ee8e8d4b	1418	unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk):
embeddedartists	0:83b8ee8e8d4b	1419	unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length,
embeddedartists	0:83b8ee8e8d4b	1420	const char* type, const unsigned char* data):
embeddedartists	0:83b8ee8e8d4b	1421
embeddedartists	0:83b8ee8e8d4b	1422	These functions are used to create new chunks that are appended to the data in *out that has
embeddedartists	0:83b8ee8e8d4b	1423	length *outlength. The append function appends an existing chunk to the new data. The create
embeddedartists	0:83b8ee8e8d4b	1424	function creates a new chunk with the given parameters and appends it. Type is the 4-letter
embeddedartists	0:83b8ee8e8d4b	1425	name of the chunk.
embeddedartists	0:83b8ee8e8d4b	1426
embeddedartists	0:83b8ee8e8d4b	1427	8.2. chunks in info_png
embeddedartists	0:83b8ee8e8d4b	1428	-----------------------
embeddedartists	0:83b8ee8e8d4b	1429
embeddedartists	0:83b8ee8e8d4b	1430	The LodePNGInfo struct contains fields with the unknown chunk in it. It has 3
embeddedartists	0:83b8ee8e8d4b	1431	buffers (each with size) to contain 3 types of unknown chunks:
embeddedartists	0:83b8ee8e8d4b	1432	the ones that come before the PLTE chunk, the ones that come between the PLTE
embeddedartists	0:83b8ee8e8d4b	1433	and the IDAT chunks, and the ones that come after the IDAT chunks.
embeddedartists	0:83b8ee8e8d4b	1434	It's necessary to make the distionction between these 3 cases because the PNG
embeddedartists	0:83b8ee8e8d4b	1435	standard forces to keep the ordering of unknown chunks compared to the critical
embeddedartists	0:83b8ee8e8d4b	1436	chunks, but does not force any other ordering rules.
embeddedartists	0:83b8ee8e8d4b	1437
embeddedartists	0:83b8ee8e8d4b	1438	info_png.unknown_chunks_data[0] is the chunks before PLTE
embeddedartists	0:83b8ee8e8d4b	1439	info_png.unknown_chunks_data[1] is the chunks after PLTE, before IDAT
embeddedartists	0:83b8ee8e8d4b	1440	info_png.unknown_chunks_data[2] is the chunks after IDAT
embeddedartists	0:83b8ee8e8d4b	1441
embeddedartists	0:83b8ee8e8d4b	1442	The chunks in these 3 buffers can be iterated through and read by using the same
embeddedartists	0:83b8ee8e8d4b	1443	way described in the previous subchapter.
embeddedartists	0:83b8ee8e8d4b	1444
embeddedartists	0:83b8ee8e8d4b	1445	When using the decoder to decode a PNG, you can make it store all unknown chunks
embeddedartists	0:83b8ee8e8d4b	1446	if you set the option settings.remember_unknown_chunks to 1. By default, this
embeddedartists	0:83b8ee8e8d4b	1447	option is off (0).
embeddedartists	0:83b8ee8e8d4b	1448
embeddedartists	0:83b8ee8e8d4b	1449	The encoder will always encode unknown chunks that are stored in the info_png.
embeddedartists	0:83b8ee8e8d4b	1450	If you need it to add a particular chunk that isn't known by LodePNG, you can
embeddedartists	0:83b8ee8e8d4b	1451	use lodepng_chunk_append or lodepng_chunk_create to the chunk data in
embeddedartists	0:83b8ee8e8d4b	1452	info_png.unknown_chunks_data[x].
embeddedartists	0:83b8ee8e8d4b	1453
embeddedartists	0:83b8ee8e8d4b	1454	Chunks that are known by LodePNG should not be added in that way. E.g. to make
embeddedartists	0:83b8ee8e8d4b	1455	LodePNG add a bKGD chunk, set background_defined to true and add the correct
embeddedartists	0:83b8ee8e8d4b	1456	parameters there instead.
embeddedartists	0:83b8ee8e8d4b	1457
embeddedartists	0:83b8ee8e8d4b	1458
embeddedartists	0:83b8ee8e8d4b	1459	9. compiler support
embeddedartists	0:83b8ee8e8d4b	1460	-------------------
embeddedartists	0:83b8ee8e8d4b	1461
embeddedartists	0:83b8ee8e8d4b	1462	No libraries other than the current standard C library are needed to compile
embeddedartists	0:83b8ee8e8d4b	1463	LodePNG. For the C++ version, only the standard C++ library is needed on top.
embeddedartists	0:83b8ee8e8d4b	1464	Add the files lodepng.c(pp) and lodepng.h to your project, include
embeddedartists	0:83b8ee8e8d4b	1465	lodepng.h where needed, and your program can read/write PNG files.
embeddedartists	0:83b8ee8e8d4b	1466
embeddedartists	0:83b8ee8e8d4b	1467	If performance is important, use optimization when compiling! For both the
embeddedartists	0:83b8ee8e8d4b	1468	encoder and decoder, this makes a large difference.
embeddedartists	0:83b8ee8e8d4b	1469
embeddedartists	0:83b8ee8e8d4b	1470	Make sure that LodePNG is compiled with the same compiler of the same version
embeddedartists	0:83b8ee8e8d4b	1471	and with the same settings as the rest of the program, or the interfaces with
embeddedartists	0:83b8ee8e8d4b	1472	std::vectors and std::strings in C++ can be incompatible.
embeddedartists	0:83b8ee8e8d4b	1473
embeddedartists	0:83b8ee8e8d4b	1474	CHAR_BITS must be 8 or higher, because LodePNG uses unsigned chars for octets.
embeddedartists	0:83b8ee8e8d4b	1475
embeddedartists	0:83b8ee8e8d4b	1476	*) gcc and g++
embeddedartists	0:83b8ee8e8d4b	1477
embeddedartists	0:83b8ee8e8d4b	1478	LodePNG is developed in gcc so this compiler is natively supported. It gives no
embeddedartists	0:83b8ee8e8d4b	1479	warnings with compiler options "-Wall -Wextra -pedantic -ansi", with gcc and g++
embeddedartists	0:83b8ee8e8d4b	1480	version 4.7.1 on Linux, 32-bit and 64-bit.
embeddedartists	0:83b8ee8e8d4b	1481
embeddedartists	0:83b8ee8e8d4b	1482	*) Mingw
embeddedartists	0:83b8ee8e8d4b	1483
embeddedartists	0:83b8ee8e8d4b	1484	The Mingw compiler (a port of gcc) for Windows is fully supported by LodePNG.
embeddedartists	0:83b8ee8e8d4b	1485
embeddedartists	0:83b8ee8e8d4b	1486	*) Visual Studio 2005 and up, Visual C++ Express Edition 2005 and up
embeddedartists	0:83b8ee8e8d4b	1487
embeddedartists	0:83b8ee8e8d4b	1488	Visual Studio may give warnings about 'fopen' being deprecated. A multiplatform library
embeddedartists	0:83b8ee8e8d4b	1489	can't support the proposed Visual Studio alternative however, so LodePNG keeps using
embeddedartists	0:83b8ee8e8d4b	1490	fopen. If you don't want to see the deprecated warnings, put this on top of lodepng.h
embeddedartists	0:83b8ee8e8d4b	1491	before the inclusions:
embeddedartists	0:83b8ee8e8d4b	1492	#define _CRT_SECURE_NO_DEPRECATE
embeddedartists	0:83b8ee8e8d4b	1493
embeddedartists	0:83b8ee8e8d4b	1494	Other than the above warnings, LodePNG should be warning-free with warning
embeddedartists	0:83b8ee8e8d4b	1495	level 3 (W3). Warning level 4 (W4) will give warnings about integer conversions.
embeddedartists	0:83b8ee8e8d4b	1496	I'm not planning to resolve these warnings. To get rid of them, let Visual
embeddedartists	0:83b8ee8e8d4b	1497	Studio use warning level W3 for lodepng.cpp only: right click lodepng.cpp,
embeddedartists	0:83b8ee8e8d4b	1498	Properties, C/C++, General, Warning Level: Level 3 (/W3).
embeddedartists	0:83b8ee8e8d4b	1499
embeddedartists	0:83b8ee8e8d4b	1500	Visual Studio may want "stdafx.h" files to be included in each source file and
embeddedartists	0:83b8ee8e8d4b	1501	give an error "unexpected end of file while looking for precompiled header".
embeddedartists	0:83b8ee8e8d4b	1502	That is not standard C++ and will not be added to the stock LodePNG. You can
embeddedartists	0:83b8ee8e8d4b	1503	disable it for lodepng.cpp only by right clicking it, Properties, C/C++,
embeddedartists	0:83b8ee8e8d4b	1504	Precompiled Headers, and set it to Not Using Precompiled Headers there.
embeddedartists	0:83b8ee8e8d4b	1505
embeddedartists	0:83b8ee8e8d4b	1506	*) Visual Studio 6.0
embeddedartists	0:83b8ee8e8d4b	1507
embeddedartists	0:83b8ee8e8d4b	1508	LodePNG support for Visual Studio 6.0 is not guaranteed because VS6 doesn't
embeddedartists	0:83b8ee8e8d4b	1509	follow the C++ standard correctly.
embeddedartists	0:83b8ee8e8d4b	1510
embeddedartists	0:83b8ee8e8d4b	1511	*) Comeau C/C++
embeddedartists	0:83b8ee8e8d4b	1512
embeddedartists	0:83b8ee8e8d4b	1513	Vesion 20070107 compiles without problems on the Comeau C/C++ Online Test Drive
embeddedartists	0:83b8ee8e8d4b	1514	at http://www.comeaucomputing.com/tryitout in both C90 and C++ mode.
embeddedartists	0:83b8ee8e8d4b	1515
embeddedartists	0:83b8ee8e8d4b	1516	*) Compilers on Macintosh
embeddedartists	0:83b8ee8e8d4b	1517
embeddedartists	0:83b8ee8e8d4b	1518	LodePNG has been reported to work both with the gcc and LLVM for Macintosh, both
embeddedartists	0:83b8ee8e8d4b	1519	for C and C++.
embeddedartists	0:83b8ee8e8d4b	1520
embeddedartists	0:83b8ee8e8d4b	1521	*) Other Compilers
embeddedartists	0:83b8ee8e8d4b	1522
embeddedartists	0:83b8ee8e8d4b	1523	If you encounter problems on other compilers, feel free to let me know and I may
embeddedartists	0:83b8ee8e8d4b	1524	try to fix it if the compiler is modern standards complient.
embeddedartists	0:83b8ee8e8d4b	1525
embeddedartists	0:83b8ee8e8d4b	1526
embeddedartists	0:83b8ee8e8d4b	1527	10. examples
embeddedartists	0:83b8ee8e8d4b	1528	------------
embeddedartists	0:83b8ee8e8d4b	1529
embeddedartists	0:83b8ee8e8d4b	1530	This decoder example shows the most basic usage of LodePNG. More complex
embeddedartists	0:83b8ee8e8d4b	1531	examples can be found on the LodePNG website.
embeddedartists	0:83b8ee8e8d4b	1532
embeddedartists	0:83b8ee8e8d4b	1533	10.1. decoder C++ example
embeddedartists	0:83b8ee8e8d4b	1534	-------------------------
embeddedartists	0:83b8ee8e8d4b	1535
embeddedartists	0:83b8ee8e8d4b	1536	#include "lodepng.h"
embeddedartists	0:83b8ee8e8d4b	1537	#include <iostream>
embeddedartists	0:83b8ee8e8d4b	1538
embeddedartists	0:83b8ee8e8d4b	1539	int main(int argc, char *argv[])
embeddedartists	0:83b8ee8e8d4b	1540	{
embeddedartists	0:83b8ee8e8d4b	1541	const char* filename = argc > 1 ? argv[1] : "test.png";
embeddedartists	0:83b8ee8e8d4b	1542
embeddedartists	0:83b8ee8e8d4b	1543	//load and decode
embeddedartists	0:83b8ee8e8d4b	1544	std::vector<unsigned char> image;
embeddedartists	0:83b8ee8e8d4b	1545	unsigned width, height;
embeddedartists	0:83b8ee8e8d4b	1546	unsigned error = lodepng::decode(image, width, height, filename);
embeddedartists	0:83b8ee8e8d4b	1547
embeddedartists	0:83b8ee8e8d4b	1548	//if there's an error, display it
embeddedartists	0:83b8ee8e8d4b	1549	if(error) std::cout << "decoder error " << error << ": " << lodepng_error_text(error) << std::endl;
embeddedartists	0:83b8ee8e8d4b	1550
embeddedartists	0:83b8ee8e8d4b	1551	//the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ...
embeddedartists	0:83b8ee8e8d4b	1552	}
embeddedartists	0:83b8ee8e8d4b	1553
embeddedartists	0:83b8ee8e8d4b	1554	10.2. decoder C example
embeddedartists	0:83b8ee8e8d4b	1555	-----------------------
embeddedartists	0:83b8ee8e8d4b	1556
embeddedartists	0:83b8ee8e8d4b	1557	#include "lodepng.h"
embeddedartists	0:83b8ee8e8d4b	1558
embeddedartists	0:83b8ee8e8d4b	1559	int main(int argc, char *argv[])
embeddedartists	0:83b8ee8e8d4b	1560	{
embeddedartists	0:83b8ee8e8d4b	1561	unsigned error;
embeddedartists	0:83b8ee8e8d4b	1562	unsigned char* image;
embeddedartists	0:83b8ee8e8d4b	1563	size_t width, height;
embeddedartists	0:83b8ee8e8d4b	1564	const char* filename = argc > 1 ? argv[1] : "test.png";
embeddedartists	0:83b8ee8e8d4b	1565
embeddedartists	0:83b8ee8e8d4b	1566	error = lodepng_decode32_file(&image, &width, &height, filename);
embeddedartists	0:83b8ee8e8d4b	1567
embeddedartists	0:83b8ee8e8d4b	1568	if(error) printf("decoder error %u: %s\n", error, lodepng_error_text(error));
embeddedartists	0:83b8ee8e8d4b	1569
embeddedartists	0:83b8ee8e8d4b	1570	/ * use image here * /
embeddedartists	0:83b8ee8e8d4b	1571
embeddedartists	0:83b8ee8e8d4b	1572	free(image);
embeddedartists	0:83b8ee8e8d4b	1573	return 0;
embeddedartists	0:83b8ee8e8d4b	1574	}
embeddedartists	0:83b8ee8e8d4b	1575
embeddedartists	0:83b8ee8e8d4b	1576
embeddedartists	0:83b8ee8e8d4b	1577	11. changes
embeddedartists	0:83b8ee8e8d4b	1578	-----------
embeddedartists	0:83b8ee8e8d4b	1579
embeddedartists	0:83b8ee8e8d4b	1580	The version number of LodePNG is the date of the change given in the format
embeddedartists	0:83b8ee8e8d4b	1581	yyyymmdd.
embeddedartists	0:83b8ee8e8d4b	1582
embeddedartists	0:83b8ee8e8d4b	1583	Some changes aren't backwards compatible. Those are indicated with a (!)
embeddedartists	0:83b8ee8e8d4b	1584	symbol.
embeddedartists	0:83b8ee8e8d4b	1585
embeddedartists	0:83b8ee8e8d4b	1586	*) 22 dec 2013: Power of two windowsize required for optimization.
embeddedartists	0:83b8ee8e8d4b	1587	*) 15 apr 2013: Fixed bug with LAC_ALPHA and color key.
embeddedartists	0:83b8ee8e8d4b	1588	*) 25 mar 2013: Added an optional feature to ignore some PNG errors (fix_png).
embeddedartists	0:83b8ee8e8d4b	1589	*) 11 mar 2013 (!): Bugfix with custom free. Changed from "my" to "lodepng_"
embeddedartists	0:83b8ee8e8d4b	1590	prefix for the custom allocators and made it possible with a new #define to
embeddedartists	0:83b8ee8e8d4b	1591	use custom ones in your project without needing to change lodepng's code.
embeddedartists	0:83b8ee8e8d4b	1592	*) 28 jan 2013: Bugfix with color key.
embeddedartists	0:83b8ee8e8d4b	1593	*) 27 okt 2012: Tweaks in text chunk keyword length error handling.
embeddedartists	0:83b8ee8e8d4b	1594	*) 8 okt 2012 (!): Added new filter strategy (entropy) and new auto color mode.
embeddedartists	0:83b8ee8e8d4b	1595	(no palette). Better deflate tree encoding. New compression tweak settings.
embeddedartists	0:83b8ee8e8d4b	1596	Faster color conversions while decoding. Some internal cleanups.
embeddedartists	0:83b8ee8e8d4b	1597	*) 23 sep 2012: Reduced warnings in Visual Studio a little bit.
embeddedartists	0:83b8ee8e8d4b	1598	*) 1 sep 2012 (!): Removed #define's for giving custom (de)compression functions
embeddedartists	0:83b8ee8e8d4b	1599	and made it work with function pointers instead.
embeddedartists	0:83b8ee8e8d4b	1600	*) 23 jun 2012: Added more filter strategies. Made it easier to use custom alloc
embeddedartists	0:83b8ee8e8d4b	1601	and free functions and toggle #defines from compiler flags. Small fixes.
embeddedartists	0:83b8ee8e8d4b	1602	*) 6 may 2012 (!): Made plugging in custom zlib/deflate functions more flexible.
embeddedartists	0:83b8ee8e8d4b	1603	*) 22 apr 2012 (!): Made interface more consistent, renaming a lot. Removed
embeddedartists	0:83b8ee8e8d4b	1604	redundant C++ codec classes. Reduced amount of structs. Everything changed,
embeddedartists	0:83b8ee8e8d4b	1605	but it is cleaner now imho and functionality remains the same. Also fixed
embeddedartists	0:83b8ee8e8d4b	1606	several bugs and shrinked the implementation code. Made new samples.
embeddedartists	0:83b8ee8e8d4b	1607	*) 6 nov 2011 (!): By default, the encoder now automatically chooses the best
embeddedartists	0:83b8ee8e8d4b	1608	PNG color model and bit depth, based on the amount and type of colors of the
embeddedartists	0:83b8ee8e8d4b	1609	raw image. For this, autoLeaveOutAlphaChannel replaced by auto_choose_color.
embeddedartists	0:83b8ee8e8d4b	1610	*) 9 okt 2011: simpler hash chain implementation for the encoder.
embeddedartists	0:83b8ee8e8d4b	1611	*) 8 sep 2011: lz77 encoder lazy matching instead of greedy matching.
embeddedartists	0:83b8ee8e8d4b	1612	*) 23 aug 2011: tweaked the zlib compression parameters after benchmarking.
embeddedartists	0:83b8ee8e8d4b	1613	A bug with the PNG filtertype heuristic was fixed, so that it chooses much
embeddedartists	0:83b8ee8e8d4b	1614	better ones (it's quite significant). A setting to do an experimental, slow,
embeddedartists	0:83b8ee8e8d4b	1615	brute force search for PNG filter types is added.
embeddedartists	0:83b8ee8e8d4b	1616	*) 17 aug 2011 (!): changed some C zlib related function names.
embeddedartists	0:83b8ee8e8d4b	1617	*) 16 aug 2011: made the code less wide (max 120 characters per line).
embeddedartists	0:83b8ee8e8d4b	1618	*) 17 apr 2011: code cleanup. Bugfixes. Convert low to 16-bit per sample colors.
embeddedartists	0:83b8ee8e8d4b	1619	*) 21 feb 2011: fixed compiling for C90. Fixed compiling with sections disabled.
embeddedartists	0:83b8ee8e8d4b	1620	*) 11 dec 2010: encoding is made faster, based on suggestion by Peter Eastman
embeddedartists	0:83b8ee8e8d4b	1621	to optimize long sequences of zeros.
embeddedartists	0:83b8ee8e8d4b	1622	*) 13 nov 2010: added LodePNG_InfoColor_hasPaletteAlpha and
embeddedartists	0:83b8ee8e8d4b	1623	LodePNG_InfoColor_canHaveAlpha functions for convenience.
embeddedartists	0:83b8ee8e8d4b	1624	*) 7 nov 2010: added LodePNG_error_text function to get error code description.
embeddedartists	0:83b8ee8e8d4b	1625	*) 30 okt 2010: made decoding slightly faster
embeddedartists	0:83b8ee8e8d4b	1626	*) 26 okt 2010: (!) changed some C function and struct names (more consistent).
embeddedartists	0:83b8ee8e8d4b	1627	Reorganized the documentation and the declaration order in the header.
embeddedartists	0:83b8ee8e8d4b	1628	*) 08 aug 2010: only changed some comments and external samples.
embeddedartists	0:83b8ee8e8d4b	1629	*) 05 jul 2010: fixed bug thanks to warnings in the new gcc version.
embeddedartists	0:83b8ee8e8d4b	1630	*) 14 mar 2010: fixed bug where too much memory was allocated for char buffers.
embeddedartists	0:83b8ee8e8d4b	1631	*) 02 sep 2008: fixed bug where it could create empty tree that linux apps could
embeddedartists	0:83b8ee8e8d4b	1632	read by ignoring the problem but windows apps couldn't.
embeddedartists	0:83b8ee8e8d4b	1633	*) 06 jun 2008: added more error checks for out of memory cases.
embeddedartists	0:83b8ee8e8d4b	1634	*) 26 apr 2008: added a few more checks here and there to ensure more safety.
embeddedartists	0:83b8ee8e8d4b	1635	*) 06 mar 2008: crash with encoding of strings fixed
embeddedartists	0:83b8ee8e8d4b	1636	*) 02 feb 2008: support for international text chunks added (iTXt)
embeddedartists	0:83b8ee8e8d4b	1637	*) 23 jan 2008: small cleanups, and #defines to divide code in sections
embeddedartists	0:83b8ee8e8d4b	1638	*) 20 jan 2008: support for unknown chunks allowing using LodePNG for an editor.
embeddedartists	0:83b8ee8e8d4b	1639	*) 18 jan 2008: support for tIME and pHYs chunks added to encoder and decoder.
embeddedartists	0:83b8ee8e8d4b	1640	*) 17 jan 2008: ability to encode and decode compressed zTXt chunks added
embeddedartists	0:83b8ee8e8d4b	1641	Also vareous fixes, such as in the deflate and the padding bits code.
embeddedartists	0:83b8ee8e8d4b	1642	*) 13 jan 2008: Added ability to encode Adam7-interlaced images. Improved
embeddedartists	0:83b8ee8e8d4b	1643	filtering code of encoder.
embeddedartists	0:83b8ee8e8d4b	1644	*) 07 jan 2008: (!) changed LodePNG to use ISO C90 instead of C++. A
embeddedartists	0:83b8ee8e8d4b	1645	C++ wrapper around this provides an interface almost identical to before.
embeddedartists	0:83b8ee8e8d4b	1646	Having LodePNG be pure ISO C90 makes it more portable. The C and C++ code
embeddedartists	0:83b8ee8e8d4b	1647	are together in these files but it works both for C and C++ compilers.
embeddedartists	0:83b8ee8e8d4b	1648	*) 29 dec 2007: (!) changed most integer types to unsigned int + other tweaks
embeddedartists	0:83b8ee8e8d4b	1649	*) 30 aug 2007: bug fixed which makes this Borland C++ compatible
embeddedartists	0:83b8ee8e8d4b	1650	*) 09 aug 2007: some VS2005 warnings removed again
embeddedartists	0:83b8ee8e8d4b	1651	*) 21 jul 2007: deflate code placed in new namespace separate from zlib code
embeddedartists	0:83b8ee8e8d4b	1652	*) 08 jun 2007: fixed bug with 2- and 4-bit color, and small interlaced images
embeddedartists	0:83b8ee8e8d4b	1653	*) 04 jun 2007: improved support for Visual Studio 2005: crash with accessing
embeddedartists	0:83b8ee8e8d4b	1654	invalid std::vector element [0] fixed, and level 3 and 4 warnings removed
embeddedartists	0:83b8ee8e8d4b	1655	*) 02 jun 2007: made the encoder add a tag with version by default
embeddedartists	0:83b8ee8e8d4b	1656	*) 27 may 2007: zlib and png code separated (but still in the same file),
embeddedartists	0:83b8ee8e8d4b	1657	simple encoder/decoder functions added for more simple usage cases
embeddedartists	0:83b8ee8e8d4b	1658	*) 19 may 2007: minor fixes, some code cleaning, new error added (error 69),
embeddedartists	0:83b8ee8e8d4b	1659	moved some examples from here to lodepng_examples.cpp
embeddedartists	0:83b8ee8e8d4b	1660	*) 12 may 2007: palette decoding bug fixed
embeddedartists	0:83b8ee8e8d4b	1661	*) 24 apr 2007: changed the license from BSD to the zlib license
embeddedartists	0:83b8ee8e8d4b	1662	*) 11 mar 2007: very simple addition: ability to encode bKGD chunks.
embeddedartists	0:83b8ee8e8d4b	1663	*) 04 mar 2007: (!) tEXt chunk related fixes, and support for encoding
embeddedartists	0:83b8ee8e8d4b	1664	palettized PNG images. Plus little interface change with palette and texts.
embeddedartists	0:83b8ee8e8d4b	1665	*) 03 mar 2007: Made it encode dynamic Huffman shorter with repeat codes.
embeddedartists	0:83b8ee8e8d4b	1666	Fixed a bug where the end code of a block had length 0 in the Huffman tree.
embeddedartists	0:83b8ee8e8d4b	1667	*) 26 feb 2007: Huffman compression with dynamic trees (BTYPE 2) now implemented
embeddedartists	0:83b8ee8e8d4b	1668	and supported by the encoder, resulting in smaller PNGs at the output.
embeddedartists	0:83b8ee8e8d4b	1669	*) 27 jan 2007: Made the Adler-32 test faster so that a timewaste is gone.
embeddedartists	0:83b8ee8e8d4b	1670	*) 24 jan 2007: gave encoder an error interface. Added color conversion from any
embeddedartists	0:83b8ee8e8d4b	1671	greyscale type to 8-bit greyscale with or without alpha.
embeddedartists	0:83b8ee8e8d4b	1672	*) 21 jan 2007: (!) Totally changed the interface. It allows more color types
embeddedartists	0:83b8ee8e8d4b	1673	to convert to and is more uniform. See the manual for how it works now.
embeddedartists	0:83b8ee8e8d4b	1674	*) 07 jan 2007: Some cleanup & fixes, and a few changes over the last days:
embeddedartists	0:83b8ee8e8d4b	1675	encode/decode custom tEXt chunks, separate classes for zlib & deflate, and
embeddedartists	0:83b8ee8e8d4b	1676	at last made the decoder give errors for incorrect Adler32 or Crc.
embeddedartists	0:83b8ee8e8d4b	1677	*) 01 jan 2007: Fixed bug with encoding PNGs with less than 8 bits per channel.
embeddedartists	0:83b8ee8e8d4b	1678	*) 29 dec 2006: Added support for encoding images without alpha channel, and
embeddedartists	0:83b8ee8e8d4b	1679	cleaned out code as well as making certain parts faster.
embeddedartists	0:83b8ee8e8d4b	1680	*) 28 dec 2006: Added "Settings" to the encoder.
embeddedartists	0:83b8ee8e8d4b	1681	*) 26 dec 2006: The encoder now does LZ77 encoding and produces much smaller files now.
embeddedartists	0:83b8ee8e8d4b	1682	Removed some code duplication in the decoder. Fixed little bug in an example.
embeddedartists	0:83b8ee8e8d4b	1683	*) 09 dec 2006: (!) Placed output parameters of public functions as first parameter.
embeddedartists	0:83b8ee8e8d4b	1684	Fixed a bug of the decoder with 16-bit per color.
embeddedartists	0:83b8ee8e8d4b	1685	*) 15 okt 2006: Changed documentation structure
embeddedartists	0:83b8ee8e8d4b	1686	*) 09 okt 2006: Encoder class added. It encodes a valid PNG image from the
embeddedartists	0:83b8ee8e8d4b	1687	given image buffer, however for now it's not compressed.
embeddedartists	0:83b8ee8e8d4b	1688	*) 08 sep 2006: (!) Changed to interface with a Decoder class
embeddedartists	0:83b8ee8e8d4b	1689	*) 30 jul 2006: (!) LodePNG_InfoPng , width and height are now retrieved in different
embeddedartists	0:83b8ee8e8d4b	1690	way. Renamed decodePNG to decodePNGGeneric.
embeddedartists	0:83b8ee8e8d4b	1691	*) 29 jul 2006: (!) Changed the interface: image info is now returned as a
embeddedartists	0:83b8ee8e8d4b	1692	struct of type LodePNG::LodePNG_Info, instead of a vector, which was a bit clumsy.
embeddedartists	0:83b8ee8e8d4b	1693	*) 28 jul 2006: Cleaned the code and added new error checks.
embeddedartists	0:83b8ee8e8d4b	1694	Corrected terminology "deflate" into "inflate".
embeddedartists	0:83b8ee8e8d4b	1695	*) 23 jun 2006: Added SDL example in the documentation in the header, this
embeddedartists	0:83b8ee8e8d4b	1696	example allows easy debugging by displaying the PNG and its transparency.
embeddedartists	0:83b8ee8e8d4b	1697	*) 22 jun 2006: (!) Changed way to obtain error value. Added
embeddedartists	0:83b8ee8e8d4b	1698	loadFile function for convenience. Made decodePNG32 faster.
embeddedartists	0:83b8ee8e8d4b	1699	*) 21 jun 2006: (!) Changed type of info vector to unsigned.
embeddedartists	0:83b8ee8e8d4b	1700	Changed position of palette in info vector. Fixed an important bug that
embeddedartists	0:83b8ee8e8d4b	1701	happened on PNGs with an uncompressed block.
embeddedartists	0:83b8ee8e8d4b	1702	*) 16 jun 2006: Internally changed unsigned into unsigned where
embeddedartists	0:83b8ee8e8d4b	1703	needed, and performed some optimizations.
embeddedartists	0:83b8ee8e8d4b	1704	*) 07 jun 2006: (!) Renamed functions to decodePNG and placed them
embeddedartists	0:83b8ee8e8d4b	1705	in LodePNG namespace. Changed the order of the parameters. Rewrote the
embeddedartists	0:83b8ee8e8d4b	1706	documentation in the header. Renamed files to lodepng.cpp and lodepng.h
embeddedartists	0:83b8ee8e8d4b	1707	*) 22 apr 2006: Optimized and improved some code
embeddedartists	0:83b8ee8e8d4b	1708	*) 07 sep 2005: (!) Changed to std::vector interface
embeddedartists	0:83b8ee8e8d4b	1709	*) 12 aug 2005: Initial release (C++, decoder only)
embeddedartists	0:83b8ee8e8d4b	1710
embeddedartists	0:83b8ee8e8d4b	1711
embeddedartists	0:83b8ee8e8d4b	1712	12. contact information
embeddedartists	0:83b8ee8e8d4b	1713	-----------------------
embeddedartists	0:83b8ee8e8d4b	1714
embeddedartists	0:83b8ee8e8d4b	1715	Feel free to contact me with suggestions, problems, comments, ... concerning
embeddedartists	0:83b8ee8e8d4b	1716	LodePNG. If you encounter a PNG image that doesn't work properly with this
embeddedartists	0:83b8ee8e8d4b	1717	decoder, feel free to send it and I'll use it to find and fix the problem.
embeddedartists	0:83b8ee8e8d4b	1718
embeddedartists	0:83b8ee8e8d4b	1719	My email address is (puzzle the account and domain together with an @ symbol):
embeddedartists	0:83b8ee8e8d4b	1720	Domain: gmail dot com.
embeddedartists	0:83b8ee8e8d4b	1721	Account: lode dot vandevenne.
embeddedartists	0:83b8ee8e8d4b	1722
embeddedartists	0:83b8ee8e8d4b	1723
embeddedartists	0:83b8ee8e8d4b	1724	Copyright (c) 2005-2013 Lode Vandevenne
embeddedartists	0:83b8ee8e8d4b	1725	*/

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	08 Jan 2014
Imports:	64
Forks:	0
Commits:	4
Dependents:	0
Dependencies:	2
Followers:	4

lodepng.h@3:33a36d79ab7d, 2014-04-09 (annotated)

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