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diff --git a/tests/lodepng.h b/tests/lodepng.h deleted file mode 100644 index a0a654f..0000000 --- a/tests/lodepng.h +++ /dev/null @@ -1,1899 +0,0 @@ -#ifndef LODEPNG_H_ -#define LODEPNG_H_ - -/* -LodePNG version 20110908 - -Copyright (c) 2005-2011 Lode Vandevenne - -This software is provided 'as-is', without any express or implied -warranty. In no event will the authors be held liable for any damages -arising from the use of this software. - -Permission is granted to anyone to use this software for any purpose, -including commercial applications, and to alter it and redistribute it -freely, subject to the following restrictions: - - 1. The origin of this software must not be misrepresented; you must not - claim that you wrote the original software. If you use this software - in a product, an acknowledgment in the product documentation would be - appreciated but is not required. - - 2. Altered source versions must be plainly marked as such, and must not be - misrepresented as being the original software. - - 3. This notice may not be removed or altered from any source - distribution. -*/ - -#ifndef LODEPNG_H -#define LODEPNG_H - -#include <string.h> /*for size_t*/ - -#ifdef __cplusplus -#include <vector> -#include <string> -#endif /*__cplusplus*/ - -/* ////////////////////////////////////////////////////////////////////////// */ -/* Code Sections */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/* -The following #defines are used to create code sections. They can be disabled -to disable code sections, which can give faster compile time and smaller binary. -*/ - -/*deflate&zlib encoder and deflate&zlib decoder. -If this is disabled, you need to implement the dummy LodePNG_zlib_compress and -LodePNG_zlib_decompress functions in the #else belonging to this #define in the -source file.*/ -#define LODEPNG_COMPILE_ZLIB -/*png encoder and png decoder*/ -#define LODEPNG_COMPILE_PNG -/*deflate&zlib decoder and png decoder*/ -#define LODEPNG_COMPILE_DECODER -/*deflate&zlib encoder and png encoder*/ -#define LODEPNG_COMPILE_ENCODER -/*the optional built in harddisk file loading and saving functions*/ -#define LODEPNG_COMPILE_DISK -/*any code or struct datamember related to chunks other than IHDR, IDAT, PLTE, tRNS, IEND*/ -#define LODEPNG_COMPILE_ANCILLARY_CHUNKS -/*handling of unknown chunks*/ -#define LODEPNG_COMPILE_UNKNOWN_CHUNKS -/*ability to convert error numerical codes to English text string*/ -#define LODEPNG_COMPILE_ERROR_TEXT - -/* ////////////////////////////////////////////////////////////////////////// */ -/* Simple Functions */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/* -This are the simple C and C++ functions, which cover basic usage. -Further on in the header file are the more advanced functions allowing custom behaviour. -*/ - -#ifdef LODEPNG_COMPILE_PNG - -/*constants for the PNG color types. "LCT" = "LodePNG Color Type"*/ -#define LCT_GREY 0 /*PNG color type greyscale*/ -#define LCT_RGB 2 /*PNG color type RGB*/ -#define LCT_PALETTE 3 /*PNG color type palette*/ -#define LCT_GREY_ALPHA 4 /*PNG color type greyscale with alpha*/ -#define LCT_RGBA 6 /*PNG color type RGB with alpha*/ - -#ifdef LODEPNG_COMPILE_DECODER -/* -Converts PNG data in memory to raw pixel data. -out: Output parameter. Pointer to buffer that will contain the raw pixel data. - Its size is w * h * (bytes per pixel), bytes per pixel depends on colorType and bitDepth. - Must be freed after usage with free(*out). -w: Output parameter. Pointer to width of pixel data. -h: Output parameter. Pointer to height of pixel data. -in: Memory buffer with the PNG file. -insize: size of the in buffer. -colorType: the desired color type for the raw output image. See explanation on PNG color types. -bitDepth: the desired bit depth for the raw output image. See explanation on PNG color types. -Return value: LodePNG error code (0 means no error). -*/ -unsigned LodePNG_decode(unsigned char** out, unsigned* w, unsigned* h, - const unsigned char* in, size_t insize, unsigned colorType, unsigned bitDepth); - -/*Same as LodePNG_decode, but uses colorType = 6 and bitDepth = 8 by default (32-bit RGBA)*/ -unsigned LodePNG_decode32(unsigned char** out, unsigned* w, unsigned* h, - const unsigned char* in, size_t insize); - -/*Same as LodePNG_decode, but uses colorType = 2 and bitDepth = 8 by default (24-bit RGB)*/ -unsigned LodePNG_decode24(unsigned char** out, unsigned* w, unsigned* h, - const unsigned char* in, size_t insize); - -#ifdef LODEPNG_COMPILE_DISK -/* -Load PNG from disk, from file with given name. -out: Output parameter. Pointer to buffer that will contain the raw pixel data. - Its size is w * h * (bytes per pixel), bytes per pixel depends on colorType and bitDepth. - Must be freed after usage with free(*out). -w: Output parameter. Pointer to width of pixel data. -h: Output parameter. Pointer to height of pixel data. -filename: Path on disk of the PNG file. -colorType: the desired color type for the raw output image. See explanation on PNG color types. -bitDepth: the desired bit depth for the raw output image. See explanation on PNG color types. -Return value: LodePNG error code (0 means no error). -*/ -unsigned LodePNG_decode_file(unsigned char** out, unsigned* w, unsigned* h, - const char* filename, unsigned colorType, unsigned bitDepth); - -/*Same as LodePNG_decode_file, but uses colorType = 6 and bitDepth = 8 by default (32-bit RGBA)*/ -unsigned LodePNG_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename); - -/*Same as LodePNG_decode_file, but uses colorType = 2 and bitDepth = 8 by default (24-bit RGB)*/ -unsigned LodePNG_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename); - - -#endif /*LODEPNG_COMPILE_DISK*/ -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER -/* -Converts raw pixel data into a PNG image in memory. The colorType and bitDepth - of the output PNG image cannot be chosen, they are automatically determined - by the colorType, bitDepth and content of the input pixel data. -out: Output parameter. Pointer to buffer that will contain the raw pixel data. - Must be freed after usage with free(*out). -outsize: Output parameter. Pointer to the size in bytes of the out buffer. -image: The raw pixel data to encode. The size of this buffer should be - w * h * (bytes per pixel), bytes per pixel depends on colorType and bitDepth. -w: width of the raw pixel data in pixels. -h: height of the raw pixel data in pixels. -colorType: the color type of the raw input image. See explanation on PNG color types. -bitDepth: the bit depth of the raw input image. See explanation on PNG color types. -Return value: LodePNG error code (0 means no error). -*/ -unsigned LodePNG_encode(unsigned char** out, size_t* outsize, - const unsigned char* image, unsigned w, unsigned h, unsigned colorType, unsigned bitDepth); - -/*Same as LodePNG_encode, but uses colorType = 6 and bitDepth = 8 by default (32-bit RGBA).*/ -unsigned LodePNG_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h); - -/*Same as LodePNG_encode, but uses colorType = 2 and bitDepth = 8 by default (24-bit RGB).*/ -unsigned LodePNG_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h); - -#ifdef LODEPNG_COMPILE_DISK - -/* -Converts raw pixel data into a PNG file on disk. Same as LodePNG_encode, but -outputs to disk instead of memory buffer. -filename: path to file on disk to write the PNG image to. -image: The raw pixel data to encode. The size of this buffer should be - w * h * (bytes per pixel), bytes per pixel depends on colorType and bitDepth. -w: width of the raw pixel data in pixels. -h: height of the raw pixel data in pixels. -colorType: the color type of the raw input image. See explanation on PNG color types. -bitDepth: the bit depth of the raw input image. See explanation on PNG color types. -Return value: LodePNG error code (0 means no error). -*/ -unsigned LodePNG_encode_file(const char* filename, const unsigned char* image, - unsigned w, unsigned h, unsigned colorType, unsigned bitDepth); - -/*Same as LodePNG_encode_file, but uses colorType = 6 and bitDepth = 8 by default (32-bit RGBS).*/ -unsigned LodePNG_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h); - -/*Same as LodePNG_encode_file, but uses colorType = 2 and bitDepth = 8 by default (24-bit RGB).*/ -unsigned LodePNG_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h); -#endif /*LODEPNG_COMPILE_DISK*/ -#endif /*LODEPNG_COMPILE_ENCODER*/ - -#ifdef __cplusplus -namespace LodePNG -{ - -#ifdef LODEPNG_COMPILE_DECODER - /* - Converts PNG data in memory to raw pixel data. - out: Output parameter, std::vector containing the raw pixel data. Its size - will be w * h * (bytes per pixel), where bytes per pixel is 4 if the default - colorType=6 and bitDepth=8 is used. The pixels are 32-bit RGBA bit in that case. - w: Output parameter, width of the image in pixels. - h: Output parameter, height of the image in pixels. - in: Memory buffer with the PNG file. - insize: size of the in buffer. - colorType: the desired color type for the raw output image. See explanation on PNG color types. - bitDepth: the desired bit depth for the raw output image. See explanation on PNG color types. - Return value: LodePNG error code (0 means no error). - */ - unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - const unsigned char* in, size_t insize, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8); - - /* - Same as the decode function that takes a unsigned char buffer, but instead of giving - a pointer and a size, this takes the input buffer as an std::vector. - */ - unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - const std::vector<unsigned char>& in, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8); -#ifdef LODEPNG_COMPILE_DISK - /* - Converts PNG file from disk to raw pixel data in memory. - out: Output parameter, std::vector containing the raw pixel data. Its size - will be w * h * (bytes per pixel), where bytes per pixel is 4 if the default - colorType=6 and bitDepth=8 is used. The pixels are 32-bit RGBA bit in that case. - w: Output parameter, width of the image in pixels. - h: Output parameter, height of the image in pixels. - filename: Path to PNG file on disk. - colorType: the desired color type for the raw output image. See explanation on PNG color types. - bitDepth: the desired bit depth for the raw output image. See explanation on PNG color types. - Return value: LodePNG error code (0 means no error). - */ - unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - const std::string& filename, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8); -#endif //LODEPNG_COMPILE_DISK -#endif //LODEPNG_COMPILE_DECODER - -#ifdef LODEPNG_COMPILE_ENCODER - /* - Converts 32-bit RGBA raw pixel data into a PNG image in memory. - out: Output parameter, std::vector containing the PNG image data. - in: Memory buffer with raw pixel data. The size of this buffer should be - w * h * (bytes per pixel), With the default colorType=6 and bitDepth=8, bytes - per pixel should be 4 and the data is a 32-bit RGBA pixel buffer. - w: Width of the image in pixels. - h: Height of the image in pixels. - colorType: the color type of the raw input image. See explanation on PNG color types. - bitDepth: the bit depth of the raw input image. See explanation on PNG color types. - Return value: LodePNG error code (0 means no error). - */ - unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, - unsigned w, unsigned h, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8); - - /* - Same as the encode function that takes a unsigned char buffer, but instead of giving - a pointer and a size, this takes the input buffer as an std::vector. - */ - unsigned encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, - unsigned w, unsigned h, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8); -#ifdef LODEPNG_COMPILE_DISK - /* - Converts 32-bit RGBA raw pixel data into a PNG file on disk. - filename: Path to the file to write the PNG image to. - in: Memory buffer with raw pixel data. The size of this buffer should be - w * h * (bytes per pixel), With the default colorType=6 and bitDepth=8, bytes - per pixel should be 4 and the data is a 32-bit RGBA pixel buffer. - w: Width of the image in pixels. - h: Height of the image in pixels. - colorType: the color type of the raw input image. See explanation on PNG color types. - bitDepth: the bit depth of the raw input image. See explanation on PNG color types. - Return value: LodePNG error code (0 means no error). - */ - unsigned encode(const std::string& filename, const unsigned char* in, - unsigned w, unsigned h, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8); - - /* - Same as the encode function that takes a unsigned char buffer, but instead of giving - a pointer and a size, this takes the input buffer as an std::vector. - */ - unsigned encode(const std::string& filename, const std::vector<unsigned char>& in, - unsigned w, unsigned h, unsigned colorType = LCT_RGBA, unsigned bitDepth = 8); -#endif //LODEPNG_COMPILE_DISK -#endif //LODEPNG_COMPILE_ENCODER -} //namespace LodePNG -#endif /*__cplusplus*/ -#endif /*LODEPNG_COMPILE_PNG*/ - -#ifdef LODEPNG_COMPILE_ERROR_TEXT -/* -Returns a textual description of the error code, in English. The -numerical value of the code itself is not included in this description. -*/ -const char* LodePNG_error_text(unsigned code); -#endif /*LODEPNG_COMPILE_ERROR_TEXT*/ - -/* ////////////////////////////////////////////////////////////////////////// */ -/* Inflate & Deflate Setting Structs */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/* -These structs contain settings for the decompression and compression of the -PNG files. Typically you won't need these directly. -*/ - -#ifdef LODEPNG_COMPILE_DECODER -typedef struct LodePNG_DecompressSettings -{ - unsigned ignoreAdler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/ -} LodePNG_DecompressSettings; - -extern const LodePNG_DecompressSettings LodePNG_defaultDecompressSettings; -void LodePNG_DecompressSettings_init(LodePNG_DecompressSettings* settings); -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER -/* -Compression settings. Tweaking these settings tweaks the balance between -speed and compression ratio. -*/ -typedef struct LodePNG_CompressSettings /*deflate = compress*/ -{ - /*LZ77 related settings*/ - unsigned btype; /*the block type for LZ (0, 1, 2 or 3, see zlib standard). Should be 2 for proper compression.*/ - unsigned useLZ77; /*whether or not to use LZ77. Should be 1 for proper compression.*/ - unsigned windowSize; /*the maximum is 32768, higher gives more compression but is slower. Typical value: 2048.*/ -} LodePNG_CompressSettings; - -extern const LodePNG_CompressSettings LodePNG_defaultCompressSettings; -void LodePNG_CompressSettings_init(LodePNG_CompressSettings* settings); -#endif /*LODEPNG_COMPILE_ENCODER*/ - -#ifdef LODEPNG_COMPILE_PNG -/* ////////////////////////////////////////////////////////////////////////// */ -/* PNG and Raw Image Information Structs */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/* -Info about the color type of an image. -The same LodePNG_InfoColor struct is used for both the PNG and raw image type, -even though they are two totally different things. -*/ -typedef struct LodePNG_InfoColor -{ - /*header (IHDR)*/ - unsigned colorType; /*color type, see PNG standard or documentation further in this header file*/ - unsigned bitDepth; /*bits per sample, see PNG standard or documentation further in this header file*/ - - /* - palette (PLTE and tRNS) - - This is a dynamically allocated unsigned char array with the colors of the palette, including alpha. - The value palettesize indicates the amount of colors in the palette. - The allocated size of the buffer is 4 * palettesize bytes, in order RGBARGBARGBA... - - When encoding a PNG, to store your colors in the palette of the LodePNG_InfoRaw, first use - LodePNG_InfoColor_clearPalette, then for each color use LodePNG_InfoColor_addPalette. - - If you encode an image without alpha with palette, don't forget to put value 255 in each A byte of the palette. - - When decoding, by default you can ignore this palette, since LodePNG already - fills the palette colors in the pixels of the raw RGBA output. - */ - unsigned char* palette; /*palette in RGBARGBA... order*/ - size_t palettesize; /*palette size in number of colors (amount of bytes is 4 * palettesize)*/ - - /* - transparent color key (tRNS) - This color uses the same bit depth as the bitDepth value in this struct, which can be 1-bit to 16-bit. - For greyscale PNGs, r, g and b will all 3 be set to the same. - - When decoding, by default you can ignore this information, since LodePNG sets - pixels with this key to transparent already in the raw RGBA output. - */ - unsigned key_defined; /*is a transparent color key given? 0 = false, 1 = true*/ - unsigned key_r; /*red/greyscale component of color key*/ - unsigned key_g; /*green component of color key*/ - unsigned key_b; /*blue component of color key*/ -} LodePNG_InfoColor; - -/*init, cleanup and copy functions to use with this struct*/ -void LodePNG_InfoColor_init(LodePNG_InfoColor* info); -void LodePNG_InfoColor_cleanup(LodePNG_InfoColor* info); -/*return value is error code (0 means no error)*/ -unsigned LodePNG_InfoColor_copy(LodePNG_InfoColor* dest, const LodePNG_InfoColor* source); - -void LodePNG_InfoColor_clearPalette(LodePNG_InfoColor* info); -/*add 1 color to the palette*/ -unsigned LodePNG_InfoColor_addPalette(LodePNG_InfoColor* info, unsigned char r, - unsigned char g, unsigned char b, unsigned char a); - -/*additional color info*/ - -/*get the total amount of bits per pixel, based on colorType and bitDepth in the struct*/ -unsigned LodePNG_InfoColor_getBpp(const LodePNG_InfoColor* info); -/*get the amount of color channels used, based on colorType in the struct. -If a palette is used, it counts as 1 channel.*/ -unsigned LodePNG_InfoColor_getChannels(const LodePNG_InfoColor* info); -/*is it a greyscale type? (only colorType 0 or 4)*/ -unsigned LodePNG_InfoColor_isGreyscaleType(const LodePNG_InfoColor* info); -/*has it got an alpha channel? (only colorType 2 or 6)*/ -unsigned LodePNG_InfoColor_isAlphaType(const LodePNG_InfoColor* info); -/*has it got a palette? (only colorType 3)*/ -unsigned LodePNG_InfoColor_isPaletteType(const LodePNG_InfoColor* info); -/*only returns true if there is a palette and there is a value in the palette with alpha < 255. -Loops through the palette to check this.*/ -unsigned LodePNG_InfoColor_hasPaletteAlpha(const LodePNG_InfoColor* info); - -/* -Check if the given color info indicates the possibility of having non-opaque pixels in the PNG image. -Returns true if the image can have translucent or invisible pixels (it still be opaque if it doesn't use such pixels). -Returns false if the image can only have opaque pixels. -In detail, it returns true only if it's a color type with alpha, or has a palette with non-opaque values, -or if "key_defined" is true. -*/ -unsigned LodePNG_InfoColor_canHaveAlpha(const LodePNG_InfoColor* info); - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -/* -The information of a Time chunk in PNG. -To make the encoder add a time chunk, set time_defined to 1 and fill in -the correct values in all the time parameters. LodePNG will not fill the current -time in these values itself, all it does is copy them over into the chunk bytes. -*/ -typedef struct LodePNG_Time -{ - unsigned year; /*2 bytes used (0-65535)*/ - unsigned char month; /*1-12*/ - unsigned char day; /*1-31*/ - unsigned char hour; /*0-23*/ - unsigned char minute; /*0-59*/ - unsigned char second; /*0-60 (to allow for leap seconds)*/ -} LodePNG_Time; - -/* -Info about text chunks in a PNG file. The arrays can contain multiple keys -and strings. The amount of keys and strings is the same. The amount of strings -ends when the pointer to the string is a null pointer. - -They keyword of text chunks gives a short description what the actual text -represents. There are a few standard standard keywords recognised -by many programs: Title, Author, Description, Copyright, Creation Time, -Software, Disclaimer, Warning, Source, Comment. It's allowed to use other keys. - -A keyword is minimum 1 character and maximum 79 characters long. It's -discouraged to use a single line length longer than 79 characters for texts. -*/ -typedef struct LodePNG_Text /*non-international text*/ -{ - /*Don't allocate these text buffers yourself. Use the init/cleanup functions - correctly and use LodePNG_Text_add and LodePNG_Text_clear.*/ - size_t num; /*the amount of texts in these char** buffers (there may be more texts in itext)*/ - char** keys; /*the keyword of a text chunk (e.g. "Comment")*/ - char** strings; /*the actual text*/ -} LodePNG_Text; - -/*init, cleanup and copy functions to use with this struct*/ -void LodePNG_Text_init(LodePNG_Text* text); -void LodePNG_Text_cleanup(LodePNG_Text* text); -/*return value is error code (0 means no error)*/ -unsigned LodePNG_Text_copy(LodePNG_Text* dest, const LodePNG_Text* source); - -/*Use these functions instead of allocating the char**s manually*/ -void LodePNG_Text_clear(LodePNG_Text* text); /*use this to clear the texts again after you filled them in*/ -unsigned LodePNG_Text_add(LodePNG_Text* text, const char* key, const char* str); /*push back both texts at once*/ - -/* -Info about international text chunks in a PNG file. The arrays can contain multiple keys -and strings. The amount of keys, lengtags, transkeys and strings is the same. -The amount of strings ends when the pointer to the string is a null pointer. - -A keyword is minimum 1 character and maximum 79 characters long. It's -discouraged to use a single line length longer than 79 characters for texts. -*/ -typedef struct LodePNG_IText /*international text*/ -{ - /*Don't allocate these text buffers yourself. Use the init/cleanup functions - correctly and use LodePNG_IText_add and LodePNG_IText_clear.*/ - - /*the amount of international texts in this PNG*/ - size_t num; - /*the English keyword of the text chunk (e.g. "Comment")*/ - char** keys; - /*the language tag for this text's international language, ISO/IEC 646 string, e.g. ISO 639 language tag*/ - char** langtags; - /*keyword translated to the international language - UTF-8 string*/ - char** transkeys; - /*the actual international text - UTF-8 string*/ - char** strings; -} LodePNG_IText; - -/*init, cleanup and copy functions to use with this struct*/ -void LodePNG_IText_init(LodePNG_IText* text); -void LodePNG_IText_cleanup(LodePNG_IText* text); -/*return value is error code (0 means no error)*/ -unsigned LodePNG_IText_copy(LodePNG_IText* dest, const LodePNG_IText* source); - -/*Use these functions instead of allocating the char**s manually*/ -void LodePNG_IText_clear(LodePNG_IText* text); /*use this to clear the itexts again after you filled them in*/ -unsigned LodePNG_IText_add(LodePNG_IText* text, const char* key, const char* langtag, - const char* transkey, const char* str); /*push back the 4 texts of 1 chunk at once*/ -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS -/* -Unknown chunks read from the PNG, or extra chunks the user wants to have added -in the encoded PNG. -*/ -typedef struct LodePNG_UnknownChunks -{ - /*There are 3 buffers, one for each position in the PNG where unknown chunks can appear - each buffer contains all unknown chunks for that position consecutively - The 3 buffers are the unknown chunks between certain critical chunks: - 0: IHDR-PLTE, 1: PLTE-IDAT, 2: IDAT-IEND - - Do not allocate or traverse this data yourself. Use the chunk traversing functions declared - later, such as LodePNG_chunk_next and LodePNG_append_chunk, to read/write this struct. - */ - unsigned char* data[3]; - size_t datasize[3]; /*size in bytes of the unknown chunks, given for protection*/ - -} LodePNG_UnknownChunks; - -/*init, cleanup and copy functions to use with this struct*/ -void LodePNG_UnknownChunks_init(LodePNG_UnknownChunks* chunks); -void LodePNG_UnknownChunks_cleanup(LodePNG_UnknownChunks* chunks); -/*return value is error code (0 means no error)*/ -unsigned LodePNG_UnknownChunks_copy(LodePNG_UnknownChunks* dest, const LodePNG_UnknownChunks* src); -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ - -/* -Information about the PNG image, except pixels and sometimes except width and height. -*/ -typedef struct LodePNG_InfoPng -{ - /*header (IHDR), palette (PLTE) and transparency (tRNS)*/ - - /* - Note: width and height are only used as information of a decoded PNG image. When encoding one, you don't have - to specify width and height in an LodePNG_Info struct, but you give them as parameters of the encode function. - The rest of the LodePNG_Info struct IS used by the encoder though! - */ - unsigned width; /*width of the image in pixels (ignored by encoder, but filled in by decoder)*/ - unsigned height; /*height of the image in pixels (ignored by encoder, but filled in by decoder)*/ - unsigned compressionMethod; /*compression method of the original file. Always 0.*/ - unsigned filterMethod; /*filter method of the original file*/ - unsigned interlaceMethod; /*interlace method of the original file*/ - LodePNG_InfoColor color; /*color type and bits, palette and transparency of the PNG file*/ - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /* - suggested background color (bKGD) - This color uses the same bit depth as the bitDepth value in this struct, which can be 1-bit to 16-bit. - - For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding - the encoder writes the red one. For palette PNGs: When decoding, the RGB value - will be stored, not a palette index. But when encoding, specify the index of - the palette in background_r, the other two are then ignored. - - The decoder does not use this background color to edit the color of pixels. - */ - unsigned background_defined; /*is a suggested background color given?*/ - unsigned background_r; /*red component of suggested background color*/ - unsigned background_g; /*green component of suggested background color*/ - unsigned background_b; /*blue component of suggested background color*/ - - /*non-international text chunks (tEXt and zTXt)*/ - LodePNG_Text text; - - /*international text chunks (iTXt)*/ - LodePNG_IText itext; - - /*time chunk (tIME)*/ - unsigned char time_defined; /*if 0, no tIME chunk was or will be generated in the PNG image*/ - LodePNG_Time time; - - /*phys chunk (pHYs)*/ - unsigned phys_defined; /*if 0, there is no pHYs chunk and the values below are undefined, if 1 else there is one*/ - unsigned phys_x; /*pixels per unit in x direction*/ - unsigned phys_y; /*pixels per unit in y direction*/ - unsigned char phys_unit; /*may be 0 (unknown unit) or 1 (metre)*/ -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - /*unknown chunks*/ - LodePNG_UnknownChunks unknown_chunks; -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ -} LodePNG_InfoPng; - -/*init, cleanup and copy functions to use with this struct*/ -void LodePNG_InfoPng_init(LodePNG_InfoPng* info); -void LodePNG_InfoPng_cleanup(LodePNG_InfoPng* info); -/*return value is error code (0 means no error)*/ -unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source); - -/* -Contains user-chosen information about the raw image data, which is independent of the PNG image -With raw images, I mean the image data in the form of the simple raw buffer to which the -compressed PNG data is decoded, or from which a PNG image can be encoded. -*/ -typedef struct LodePNG_InfoRaw -{ - LodePNG_InfoColor color; /*color info of the raw image, note that the same struct as for PNG data is used.*/ -} LodePNG_InfoRaw; - -/*init, cleanup and copy functions to use with this struct*/ -void LodePNG_InfoRaw_init(LodePNG_InfoRaw* info); -void LodePNG_InfoRaw_cleanup(LodePNG_InfoRaw* info); -/*return value is error code (0 means no error)*/ -unsigned LodePNG_InfoRaw_copy(LodePNG_InfoRaw* dest, const LodePNG_InfoRaw* source); - -/* -Converts raw buffer from one color type to another color type, based on -LodePNG_InfoColor structs to describe the input and output color type. -See the reference manual at the end of this header file to see which color conversions are supported. -return value = LodePNG error code (0 if all went ok, an error if the conversion isn't supported) -The out buffer must have size (w * h * bpp + 7) / 8, where bpp is the bits per pixel -of the output color type (LodePNG_InfoColor_getBpp) -*/ -unsigned LodePNG_convert(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoOut, - LodePNG_InfoColor* infoIn, unsigned w, unsigned h); - -#ifdef LODEPNG_COMPILE_DECODER - -/* ////////////////////////////////////////////////////////////////////////// */ -/* LodePNG Decoder */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/* -Settings for the decoder. This contains settings for the PNG and the Zlib -decoder, but not the Info settings from the Info structs. -*/ -typedef struct LodePNG_DecodeSettings -{ - LodePNG_DecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/ - - unsigned ignoreCrc; /*ignore CRC checksums*/ - unsigned color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/ - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - unsigned readTextChunks; /*if false but rememberUnknownChunks is true, they're stored in the unknown chunks*/ -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - /*store all bytes from unknown chunks in the InfoPng (off by default, useful for a png editor)*/ - unsigned rememberUnknownChunks; -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ -} LodePNG_DecodeSettings; - -void LodePNG_DecodeSettings_init(LodePNG_DecodeSettings* settings); - -/* -The LodePNG_Decoder struct has most input and output parameters the decoder uses, -such as the settings, the info of the PNG and the raw data, and the error. Only -the pixel buffer is not contained in this struct. -*/ -typedef struct LodePNG_Decoder -{ - LodePNG_DecodeSettings settings; /*the decoding settings*/ - LodePNG_InfoRaw infoRaw; /*specifies the format in which you would like to get the raw pixel buffer*/ - LodePNG_InfoPng infoPng; /*info of the PNG image obtained after decoding*/ - unsigned error; -} LodePNG_Decoder; - -/*init, cleanup and copy functions to use with this struct*/ -void LodePNG_Decoder_init(LodePNG_Decoder* decoder); -void LodePNG_Decoder_cleanup(LodePNG_Decoder* decoder); -void LodePNG_Decoder_copy(LodePNG_Decoder* dest, const LodePNG_Decoder* source); - -/* -Decode based on a LodePNG_Decoder. -This function allocates the out buffer and stores the size in *outsize. This buffer -needs to be freed after usage. -Other information about the PNG file, such as the size, colorType and extra chunks -are stored in the infoPng field of the LodePNG_Decoder. -*/ -void LodePNG_Decoder_decode(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize, - const unsigned char* in, size_t insize); - -/* -Read the PNG header, but not the actual data. This returns only the information -that is in the header chunk of the PNG, such as width, height and color type. The -information is placed in the infoPng field of the LodePNG_Decoder. -*/ -void LodePNG_Decoder_inspect(LodePNG_Decoder* decoder, const unsigned char* in, size_t insize); -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER -/* ////////////////////////////////////////////////////////////////////////// */ -/* LodePNG Encoder */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/*Settings for the encoder.*/ -typedef struct LodePNG_EncodeSettings -{ - LodePNG_CompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/ - - /*Brute-force-search PNG filters by compressing each filter for each scanline. - This gives better compression, at the cost of being super slow. - Don't enable this for normal image saving, compression can take minutes - instead of seconds. This is experimental. If enabled, compression still isn't - as good as some other PNG encoders and optimizers, except for some images. - If you enable this, also consider setting zlibsettings.windowSize to 32768, and consider - using a less than 24-bit per pixel colorType if the image has <= 256 colors, for optimal compression. - Default: 0 (false)*/ - unsigned bruteForceFilters; - - /*automatically use color type without alpha instead of given one, if given image is opaque*/ - unsigned autoLeaveOutAlphaChannel; - /*force creating a PLTE chunk if colortype is 2 or 6 (= a suggested palette). - If colortype is 3, PLTE is _always_ created.*/ - unsigned force_palette; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /*add LodePNG version as text chunk*/ - unsigned add_id; - /*encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks*/ - unsigned text_compression; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ -} LodePNG_EncodeSettings; - -void LodePNG_EncodeSettings_init(LodePNG_EncodeSettings* settings); - -/* -This struct has most input and output parameters the encoder uses, -such as the settings, the info of the PNG and the raw data, and the error. Only -the pixel buffer is not contained in this struct. -*/ -typedef struct LodePNG_Encoder -{ - /*compression settings of the encoder*/ - LodePNG_EncodeSettings settings; - /*the info specified by the user is not changed by the encoder. The encoder - will try to generate a PNG close to the given info.*/ - LodePNG_InfoPng infoPng; - /*put the properties of the input raw image in here*/ - LodePNG_InfoRaw infoRaw; - /*error value filled in if error happened, or 0 if all went ok*/ - unsigned error; -} LodePNG_Encoder; - -/*init, cleanup and copy functions to use with this struct*/ -void LodePNG_Encoder_init(LodePNG_Encoder* encoder); -void LodePNG_Encoder_cleanup(LodePNG_Encoder* encoder); -void LodePNG_Encoder_copy(LodePNG_Encoder* dest, const LodePNG_Encoder* source); - -/*This function allocates the out buffer with standard malloc and stores the size in *outsize.*/ -void LodePNG_Encoder_encode(LodePNG_Encoder* encoder, unsigned char** out, size_t* outsize, - const unsigned char* image, unsigned w, unsigned h); -#endif /*LODEPNG_COMPILE_ENCODER*/ - -/* ////////////////////////////////////////////////////////////////////////// */ -/* Chunk Traversing Utilities */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/* -LodePNG_chunk functions: -These functions need as input a large enough amount of allocated memory. -These functions can be used on raw PNG data, but they are exposed in the API -because they are needed if you want to traverse the unknown chunks stored -in the LodePNG_UnknownChunks struct, or add new ones to it. -*/ - -/*get the length of the data of the chunk. Total chunk length has 12 bytes more.*/ -unsigned LodePNG_chunk_length(const unsigned char* chunk); - -/*puts the 4-byte type in null terminated string*/ -void LodePNG_chunk_type(char type[5], const unsigned char* chunk); - -/*check if the type is the given type*/ -unsigned char LodePNG_chunk_type_equals(const unsigned char* chunk, const char* type); - -/* -These functions get properties of PNG chunks gotten from capitalization of chunk -type name, as defined by the PNG standard. -*/ - -/* -properties of PNG chunks gotten from capitalization of chunk type name, as defined by the standard -0: ancillary chunk, 1: it's one of the critical chunk types -*/ -unsigned char LodePNG_chunk_critical(const unsigned char* chunk); - -/*0: public, 1: private*/ -unsigned char LodePNG_chunk_private(const unsigned char* chunk); - -/*0: the chunk is unsafe to copy, 1: the chunk is safe to copy*/ -unsigned char LodePNG_chunk_safetocopy(const unsigned char* chunk); - -/*get pointer to the data of the chunk*/ -unsigned char* LodePNG_chunk_data(unsigned char* chunk); - -/*get pointer to the data of the chunk*/ -const unsigned char* LodePNG_chunk_data_const(const unsigned char* chunk); - -/*returns 0 if the crc is correct, 1 if it's incorrect*/ -unsigned LodePNG_chunk_check_crc(const unsigned char* chunk); - -/*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/ -void LodePNG_chunk_generate_crc(unsigned char* chunk); - -/*iterate to next chunks. don't use on IEND chunk, as there is no next chunk then*/ -unsigned char* LodePNG_chunk_next(unsigned char* chunk); -const unsigned char* LodePNG_chunk_next_const(const unsigned char* chunk); - -/* -Appends chunk to the data in out. The given chunk should already have its chunk header. -The out variable and outlength are updated to reflect the new reallocated buffer. -Returns error code (0 if it went ok) -*/ -unsigned LodePNG_append_chunk(unsigned char** out, size_t* outlength, const unsigned char* chunk); - -/* -Appends new chunk to out. The chunk to append is given by giving its length, type -and data separately. The type is a 4-letter string. -The out variable and outlength are updated to reflect the new reallocated buffer. -Returne error code (0 if it went ok) -*/ -unsigned LodePNG_create_chunk(unsigned char** out, size_t* outlength, unsigned length, - const char* type, const unsigned char* data); -#endif /*LODEPNG_COMPILE_PNG*/ - -#ifdef LODEPNG_COMPILE_ZLIB -/* ////////////////////////////////////////////////////////////////////////// */ -/* Zlib encoder and decoder */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/* -This zlib part can be used independently to zlib compress and decompress a -buffer. It cannot be used to create gzip files however, and it only supports the -part of zlib that is required for PNG, it does not support dictionaries. -*/ - -#ifdef LODEPNG_COMPILE_DECODER -/*Decompresses Zlib data. Reallocates the out buffer and appends the data. The -data must be according to the zlib specification. -Either, *out must be NULL and *outsize must be 0, or, *out must be a valid -buffer and *outsize its size in bytes. out must be freed by user after usage.*/ -unsigned LodePNG_zlib_decompress(unsigned char** out, size_t* outsize, - const unsigned char* in, size_t insize, const LodePNG_DecompressSettings* settings); -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER -/*Compresses data with Zlib. Reallocates the out buffer and appends the data. -The data is output in the format of the zlib specification. -Either, *out must be NULL and *outsize must be 0, or, *out must be a valid -buffer and *outsize its size in bytes. out must be freed by user after usage.*/ -unsigned LodePNG_zlib_compress(unsigned char** out, size_t* outsize, - const unsigned char* in, size_t insize, const LodePNG_CompressSettings* settings); -#endif /*LODEPNG_COMPILE_ENCODER*/ -#endif /*LODEPNG_COMPILE_ZLIB*/ - -#ifdef LODEPNG_COMPILE_DISK -/* -Load a file from disk into buffer. The function allocates the out buffer, and -after usage you are responsible for freeing it. -out: output parameter, contains pointer to loaded buffer. -outsize: output parameter, size of the allocated out buffer -filename: the path to the file to load -return value: error code (0 means ok) -*/ -unsigned LodePNG_loadFile(unsigned char** out, size_t* outsize, const char* filename); - -/* -Save a file from buffer to disk. Warning, if it exists, this function overwrites -the file without warning! -buffer: the buffer to write -buffersize: size of the buffer to write -filename: the path to the file to save to -return value: error code (0 means ok) -*/ -unsigned LodePNG_saveFile(const unsigned char* buffer, size_t buffersize, const char* filename); -#endif /*LODEPNG_COMPILE_DISK*/ - -#ifdef __cplusplus -/* ////////////////////////////////////////////////////////////////////////// */ -/* LodePNG C++ wrapper */ -/* ////////////////////////////////////////////////////////////////////////// */ - -//The LodePNG C++ wrapper uses classes with handy constructors and destructors -//instead of manual init and cleanup functions, and uses std::vectors instead of -//manually allocated memory buffers. - -namespace LodePNG -{ -#ifdef LODEPNG_COMPILE_ZLIB -//The C++ wrapper for the zlib part -#ifdef LODEPNG_COMPILE_DECODER - //Zlib-decompress an unsigned char buffer - unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize, - const LodePNG_DecompressSettings& settings = LodePNG_defaultDecompressSettings); - - //Zlib-decompress an std::vector - unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, - const LodePNG_DecompressSettings& settings = LodePNG_defaultDecompressSettings); -#endif //LODEPNG_COMPILE_DECODER - -#ifdef LODEPNG_COMPILE_ENCODER - //Zlib-compress an unsigned char buffer - unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize, - const LodePNG_CompressSettings& settings = LodePNG_defaultCompressSettings); - - //Zlib-compress an std::vector - unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, - const LodePNG_CompressSettings& settings = LodePNG_defaultCompressSettings); -#endif //LODEPNG_COMPILE_ENCODER -#endif //LODEPNG_COMPILE_ZLIB - -#ifdef LODEPNG_COMPILE_PNG -#ifdef LODEPNG_COMPILE_DECODER - /* - Class to decode a PNG image. Before decoding, settings can be set and - after decoding, extra information about the PNG can be retrieved. - Extends from the C-struct LodePNG_Decoder to add constructors and destructors - to initialize/cleanup it automatically. Beware, no virtual destructor is used. - */ - class Decoder : public LodePNG_Decoder - { - public: - - Decoder(); - ~Decoder(); - void operator=(const LodePNG_Decoder& other); - - //decode PNG buffer to raw out buffer. Width and height can be retrieved with getWidth() and - //getHeight() and error should be checked with hasError() and getError() - void decode(std::vector<unsigned char>& out, const unsigned char* in, size_t insize); - - //decode PNG buffer to raw out buffer. Width and height can be retrieved with getWidth() and - //getHeight() and error should be checked with hasError() and getError() - void decode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in); - - //inspect functions: get only the info from the PNG header. The info can then be retrieved with - //the functions of this class. - void inspect(const unsigned char* in, size_t insize); - - //inspect functions: get only the info from the PNG header. The info can then be retrieved with - //the functions of this class. - void inspect(const std::vector<unsigned char>& in); - - //error checking after decoding - bool hasError() const; - unsigned getError() const; - - //convenient access to some InfoPng parameters after decoding - unsigned getWidth() const; //width of image in pixels - unsigned getHeight() const; //height of image in pixels - unsigned getBpp(); //bits per pixel - unsigned getChannels(); //amount of channels - unsigned isGreyscaleType(); //is it a greyscale type? (colorType 0 or 4) - unsigned isAlphaType(); //has it an alpha channel? (colorType 2 or 6) - - //getters and setters for the decoding settings - const LodePNG_DecodeSettings& getSettings() const; - LodePNG_DecodeSettings& getSettings(); - void setSettings(const LodePNG_DecodeSettings& info); - - //getters and setters for the PNG image info, after decoding this describes information of the PNG image - const LodePNG_InfoPng& getInfoPng() const; - LodePNG_InfoPng& getInfoPng(); - void setInfoPng(const LodePNG_InfoPng& info); - void swapInfoPng(LodePNG_InfoPng& info); //faster than copying with setInfoPng - - //getters and setters for the raw image info, this determines in what format - //you get the pixel buffer from the decoder - const LodePNG_InfoRaw& getInfoRaw() const; - LodePNG_InfoRaw& getInfoRaw(); - void setInfoRaw(const LodePNG_InfoRaw& info); - }; -#endif //LODEPNG_COMPILE_DECODER - -#ifdef LODEPNG_COMPILE_ENCODER - /* - Class to encode a PNG image. Before encoding, settings can be set. - Extends from the C-struct LodePNG_Enoder to add constructors and destructors - to initialize/cleanup it automatically. Beware, no virtual destructor is used. - */ - class Encoder : public LodePNG_Encoder - { - public: - - Encoder(); - ~Encoder(); - void operator=(const LodePNG_Encoder& other); - - //encoding image to PNG buffer - void encode(std::vector<unsigned char>& out, const unsigned char* image, unsigned w, unsigned h); - - //encoding image to PNG buffer - void encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& image, unsigned w, unsigned h); - - //error checking after decoding - bool hasError() const; - unsigned getError() const; - - //convenient direct access to some parameters of the InfoPng - void clearPalette(); - void addPalette(unsigned char r, unsigned char g, unsigned char b, unsigned char a); //add 1 color to the palette -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - void clearText(); - void addText(const std::string& key, const std::string& str); //push back both texts at once - void clearIText(); - void addIText(const std::string& key, const std::string& langtag, - const std::string& transkey, const std::string& str); -#endif //LODEPNG_COMPILE_ANCILLARY_CHUNKS - - //getters and setters for the encoding settings - const LodePNG_EncodeSettings& getSettings() const; - LodePNG_EncodeSettings& getSettings(); - void setSettings(const LodePNG_EncodeSettings& info); - - //getters and setters for the PNG image info, this describes what color type - //and other settings the resulting PNG should have - const LodePNG_InfoPng& getInfoPng() const; - LodePNG_InfoPng& getInfoPng(); - void setInfoPng(const LodePNG_InfoPng& info); - void swapInfoPng(LodePNG_InfoPng& info); //faster than copying with setInfoPng - - //getters and setters for the raw image info, this describes how the encoder - //should interpret the input pixel buffer - const LodePNG_InfoRaw& getInfoRaw() const; - LodePNG_InfoRaw& getInfoRaw(); - void setInfoRaw(const LodePNG_InfoRaw& info); - }; -#endif //LODEPNG_COMPILE_ENCODER - -#ifdef LODEPNG_COMPILE_DISK - /* - Load a file from disk into an std::vector. If the vector is empty, then either - the file doesn't exist or is an empty file. - */ - void loadFile(std::vector<unsigned char>& buffer, const std::string& filename); - - /* - Save the binary data in an std::vector to a file on disk. The file is overwritten - without warning. - */ - void saveFile(const std::vector<unsigned char>& buffer, const std::string& filename); -#endif //LODEPNG_COMPILE_DISK -#endif //LODEPNG_COMPILE_PNG -} //namespace LodePNG -#endif /*end of __cplusplus wrapper*/ - -/* -TODO: -[.] test if there are no memory leaks or security exploits - done a lot but needs to be checked often -[.] check compatibility with vareous compilers - done but needs to be redone for every newer version -[ ] LZ77 encoder more like the one described in zlib - to make sure it's patentfree -[X] converting color to 16-bit per channel types -[ ] read all public PNG chunk types (but never let the color profile and gamma ones touch RGB values) -[ ] make sure encoder generates no chunks with size > (2^31)-1 -[ ] partial decoding (stream processing) -[ ] let the "isFullyOpaque" function check color keys and transparent palettes too -[X] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl" -[ ] don't stop decoding on errors like 69, 57, 58 (make warnings) -[ ] make option to choose if the raw image with non multiple of 8 bits per scanline should have padding bits or not -[ ] let the C++ wrapper catch exceptions coming from the standard library and return LodePNG error codes -*/ - -#endif /*LODEPNG_H inclusion guard*/ - -/* -LodePNG Documentation ---------------------- - -This documentations contains background information and examples. For the function -and class documentation, see the comments in the declarations above. - -0. table of contents --------------------- - - 1. about - 1.1. supported features - 1.2. features not supported - 2. C and C++ version - 3. security - 4. decoding - 5. encoding - 6. color conversions - 6.1. PNG color types - 6.2. Default Behaviour of LodePNG - 6.3. Color Conversions - 6.4. More Notes - 7. error values - 8. chunks and PNG editing - 9. compiler support - 10. examples - 10.1. decoder C++ example - 10.2. encoder C++ example - 10.3. decoder C example - 11. changes - 12. contact information - - -1. about --------- - -PNG is a file format to store raster images losslessly with good compression, -supporting different color types. It can be implemented in a patent-free way. - -LodePNG is a PNG codec according to the Portable Network Graphics (PNG) -Specification (Second Edition) - W3C Recommendation 10 November 2003. - -The specifications used are: - -*) Portable Network Graphics (PNG) Specification (Second Edition): - http://www.w3.org/TR/2003/REC-PNG-20031110 -*) RFC 1950 ZLIB Compressed Data Format version 3.3: - http://www.gzip.org/zlib/rfc-zlib.html -*) RFC 1951 DEFLATE Compressed Data Format Specification ver 1.3: - http://www.gzip.org/zlib/rfc-deflate.html - -The most recent version of LodePNG can currently be found at -http://members.gamedev.net/lode/projects/LodePNG/ - -LodePNG works both in C (ISO C90) and C++, with a C++ wrapper that adds -extra functionality. - -LodePNG exists out of two files: --lodepng.h: the header file for both C and C++ --lodepng.c(pp): give it the name lodepng.c or lodepng.cpp (or .cc) depending on your usage - -If you want to start using LodePNG right away without reading this doc, get the -files lodepng_examples.c or lodepng_examples.cpp to see how to use it in code, -or check the (smaller) examples in chapter 13 here. - -LodePNG is simple but only supports the basic requirements. To achieve -simplicity, the following design choices were made: There are no dependencies -on any external library. To decode PNGs, there's a Decoder struct or class that -can convert any PNG file data into an RGBA image buffer with a single function -call. To encode PNGs, there's an Encoder struct or class that can convert image -data into PNG file data with a single function call. To read and write files, -there are simple functions to convert the files to/from buffers in memory. - -This all makes LodePNG suitable for loading textures in games, demoscene -productions, saving a screenshot, images in programs that require them for simple -usage, ... It's less suitable for full fledged image editors, loading PNGs -over network (it requires all the image data to be available before decoding can -begin), life-critical systems, ... -LodePNG has a standards conformant decoder and encoder, and supports the ability -to make a somewhat conformant editor. - -1.1. supported features ------------------------ - -The following features are supported by the decoder: - -*) decoding of PNGs with any color type, bit depth and interlace mode, to a 24- or 32-bit color raw image, - or the same color type as the PNG -*) encoding of PNGs, from any raw image to 24- or 32-bit color, or the same color type as the raw image -*) Adam7 interlace and deinterlace for any color type -*) loading the image from harddisk or decoding it from a buffer from other sources than harddisk -*) support for alpha channels, including RGBA color model, translucent palettes and color keying -*) zlib decompression (inflate) -*) zlib compression (deflate) -*) CRC32 and ADLER32 checksums -*) handling of unknown chunks, allowing making a PNG editor that stores custom and unknown chunks. -*) the following chunks are supported (generated/interpreted) by both encoder and decoder: - IHDR: header information - PLTE: color palette - IDAT: pixel data - IEND: the final chunk - tRNS: transparency for palettized images - tEXt: textual information - zTXt: compressed textual information - iTXt: international textual information - bKGD: suggested background color - pHYs: physical dimensions - tIME: modification time - -1.2. features not supported ---------------------------- - -The following features are _not_ supported: - -*) some features needed to make a conformant PNG-Editor might be still missing. -*) partial loading/stream processing. All data must be available and is processed in one call. -*) The following public chunks are not supported but treated as unknown chunks by LodePNG - cHRM, gAMA, iCCP, sRGB, sBIT, hIST, sPLT - - -2. C and C++ version --------------------- - -The C version uses buffers allocated with alloc that you need to free() -yourself. On top of that, you need to use init and cleanup functions for each -struct whenever using a struct from the C version to avoid exploits and memory leaks. - -The C++ version has constructors and destructors that take care of these things, -and uses std::vectors in the interface for storing data. - -Both the C and the C++ version are contained in this file! The C++ code depends on -the C code, the C code works on its own. - -These files work without modification for both C and C++ compilers because all the -additional C++ code is in "#ifdef __cplusplus" blocks that make C-compilers ignore -it, and the C code is made to compile both with strict ISO C90 and C++. - -To use the C++ version, you need to rename the source file to lodepng.cpp (instead -of lodepng.c), and compile it with a C++ compiler. - -To use the C version, you need to rename the source file to lodepng.c (instead -of lodepng.cpp), and compile it with a C compiler. - - -3. Security ------------ - -As with most software, even if carefully designed, it's always possible that -LodePNG may contain possible exploits. - -If you discover a possible exploit, please let me know, and it will be fixed. - -When using LodePNG, care has to be taken with the C version of LodePNG, as well as the C-style -structs when working with C++. The following conventions are used for all C-style structs: - --if a struct has a corresponding init function, always call the init function when making a new one, to avoid exploits --if a struct has a corresponding cleanup function, call it before the struct disappears to avoid memory leaks --if a struct has a corresponding copy function, use the copy function instead of "=". - The destination must also be inited already! - -4. Decoding ------------ - -Decoding converts a PNG compressed image to a raw pixel buffer. - -Most documentation on using the decoder is at its declarations in the header -above. For C, simple decoding can be done with functions such as LodePNG_decode32, -and more advanced decoding can be done with the struct LodePNG_Decoder and its -functions. For C++, simple decoding can be done with the LodePNG::decode functions -and advanced decoding with the LodePNG::Decoder class. - -The Decoder contains 3 components: -*) LodePNG_InfoPng: it stores information about the PNG (the input) in an LodePNG_InfoPng struct, - don't modify this one yourself -*) Settings: you can specify a few other settings for the decoder to use -*) LodePNG_InfoRaw: here you can say what type of raw image (the output) you want to get - -Some of the parameters described below may be inside the sub-struct "LodePNG_InfoColor color". -In the C and C++ version, when using Info structs outside of the decoder or encoder, you need to use their -init and cleanup functions, but normally you use the ones in the decoder that are already handled -in the init and cleanup functions of the decoder itself. - -=LodePNG_InfoPng= - -This contains information such as the original color type of the PNG image, text -comments, suggested background color, etc... More details about the LodePNG_InfoPng struct -are at its declaration documentation. - -Because the dimensions of the image are important, there are shortcuts to get them in the -C++ version: use decoder.getWidth() and decoder.getHeight(). -In the C version, use decoder.infoPng.width and decoder.infoPng.height. - -=LodePNG_InfoRaw= - -In the LodePNG_InfoRaw struct of the Decoder, you can specify which color type you want -the resulting raw image to be. If this is different from the colorType of the -PNG, then the decoder will automatically convert the result to your LodePNG_InfoRaw -settings. Not all combinations of color conversions are supported though, see -a different section for information about the color modes and supported conversions. - -Palette of LodePNG_InfoRaw isn't used by the Decoder, when converting from palette color -to palette color, the values of the pixels are left untouched so that the colors -will change if the palette is different. Color key of LodePNG_InfoRaw is not used by the -Decoder. If setting color_convert is false then LodePNG_InfoRaw is completely ignored, -but it will be modified to match the color type of the PNG so will be overwritten. - -By default, 32-bit color is used for the result. - -=Settings= - -The Settings can be used to ignore the errors created by invalid CRC and Adler32 -chunks, and to disable the decoding of tEXt chunks. - -There's also a setting color_convert, true by default. If false, no conversion -is done, the resulting data will be as it was in the PNG (after decompression) -and you'll have to puzzle the colors of the pixels together yourself using the -color type information in the LodePNG_InfoPng. - - -5. Encoding ------------ - -Encoding converts a raw pixel buffer to a PNG compressed image. - -Most documentation on using the encoder is at its declarations in the header -above. For C, simple encoding can be done with functions such as LodePNG_encode32, -and more advanced decoding can be done with the struct LodePNG_Encoder and its -functions. For C++, simple encoding can be done with the LodePNG::encode functions -and advanced decoding with the LodePNG::Encoder class. - -Like the decoder, the encoder can also give errors. However it gives less errors -since the encoder input is trusted, the decoder input (a PNG image that could -be forged by anyone) is not trusted. - -Like the Decoder, the Encoder has 3 components: -*) LodePNG_InfoRaw: here you say what color type of the raw image (the input) has -*) Settings: you can specify a few settings for the encoder to use -*) LodePNG_InfoPng: the same LodePNG_InfoPng struct as created by the Decoder. For the encoder, -with this you specify how you want the PNG (the output) to be. - -Some of the parameters described below may be inside the sub-struct "LodePNG_InfoColor color". -In the C and C++ version, when using Info structs outside of the decoder or encoder, you need to use their -init and cleanup functions, but normally you use the ones in the encoder that are already handled -in the init and cleanup functions of the decoder itself. - -=LodePNG_InfoPng= - -The Decoder class stores information about the PNG image in an LodePNG_InfoPng object. With -the Encoder you can do the opposite: you give it an LodePNG_InfoPng object, and it'll try -to match the LodePNG_InfoPng you give as close as possible in the PNG it encodes. For -example in the LodePNG_InfoPng you can specify the color type you want to use, possible -tEXt chunks you want the PNG to contain, etc... For an explanation of all the -values in LodePNG_InfoPng see a further section. Not all PNG color types are supported -by the Encoder. - -The encoder will not always exactly match the LodePNG_InfoPng struct you give, -it tries as close as possible. Some things are ignored by the encoder. The width -and height of LodePNG_InfoPng are ignored as well, because instead the width and -height of the raw image you give in the input are used. In fact the encoder -currently uses only the following settings from it: --colorType and bitDepth: the ones it supports --text chunks, that you can add to the LodePNG_InfoPng with "addText" --the color key, if applicable for the given color type --the palette, if you encode to a PNG with colorType 3 --the background color: it'll add a bKGD chunk to the PNG if one is given --the interlaceMethod: None (0) or Adam7 (1) - -When encoding to a PNG with colorType 3, the encoder will generate a PLTE chunk. -If the palette contains any colors for which the alpha channel is not 255 (so -there are translucent colors in the palette), it'll add a tRNS chunk. - -=LodePNG_InfoRaw= - -You specify the color type of the raw image that you give to the input here, -including a possible transparent color key and palette you happen to be using in -your raw image data. - -By default, 32-bit color is assumed, meaning your input has to be in RGBA -format with 4 bytes (unsigned chars) per pixel. - -=Settings= - -The following settings are supported (some are in sub-structs): -*) autoLeaveOutAlphaChannel: when this option is enabled, when you specify a PNG -color type with alpha channel (not to be confused with the color type of the raw -image you specify!!), but the encoder detects that all pixels of the given image -are opaque, then it'll automatically use the corresponding type without alpha -channel, resulting in a smaller PNG image. -*) btype: the block type for LZ77. - 0 = uncompressed, 1 = fixed huffman tree, 2 = dynamic huffman tree (best compression) -*) useLZ77: whether or not to use LZ77 for compressed block types -*) windowSize: the window size used by the LZ77 encoder (1 - 32768) -*) force_palette: if colorType is 2 or 6, you can make the encoder write a PLTE - chunk if force_palette is true. This can used as suggested palette to convert - to by viewers that don't support more than 256 colors (if those still exist) -*) add_id: add text chunk "Encoder: LodePNG <version>" to the image. -*) text_compression: default 0. If 1, it'll store texts as zTXt instead of tEXt chunks. - zTXt chunks use zlib compression on the text. This gives a smaller result on - large texts but a larger result on small texts (such as a single program name). - It's all tEXt or all zTXt though, there's no separate setting per text yet. - - -6. color conversions --------------------- - -In LodePNG, the color mode (bits, channels and palette) used in the PNG image, -and the color mode used in the raw data, are separate and independently -configurable. Therefore, LodePNG needs to do conversions from one color mode to -another. Not all possible conversions are supported (e.g. converting to a palette -or a lower bit depth isn't supported). This section will explain which conversions -are supported and how to configure this. This explains for example when LodePNG -uses the settings in LodePNG_InfoPng, LodePNG_InfoRaw and Settings. - -6.1. PNG color types --------------------- - -A PNG image can have many color types, ranging from 1-bit color to 64-bit color, -as well as palettized color modes. After the zlib decompression and unfiltering -in the PNG image is done, the raw pixel data will have that color type and thus -a certain amount of bits per pixel. If you want the output raw image after -decoding to have another color type, a conversion is done by LodePNG. - -The PNG specification mentions the following color types: - -0: greyscale, bit depths 1, 2, 4, 8, 16 -2: RGB, bit depths 8 and 16 -3: palette, bit depths 1, 2, 4 and 8 -4: greyscale with alpha, bit depths 8 and 16 -6: RGBA, bit depths 8 and 16 - -Bit depth is the amount of bits per pixel per color channel. So the total amount -of bits per pixel = amount of channels * bitDepth. - -6.2. Default Behaviour of LodePNG ---------------------------------- - -By default, the Decoder will convert the data from the PNG to 32-bit RGBA color, -no matter what color type the PNG has, so that the result can be used directly -as a texture in OpenGL etc... without worries about what color type the original -image has. - -The Encoder assumes by default that the raw input you give it is a 32-bit RGBA -buffer and will store the PNG as either 32 bit or 24 bit depending on whether -or not any translucent pixels were detected in it. - -To get the default behaviour, don't change the values of LodePNG_InfoRaw and -LodePNG_InfoPng of the encoder, and don't change the values of LodePNG_InfoRaw -of the decoder. - -6.3. Color Conversions ----------------------- - -As explained in the sections about the Encoder and Decoder, you can specify -color types and bit depths in LodePNG_InfoPng and LodePNG_InfoRaw, to change the default behaviour -explained above. (for the Decoder you can only specify the LodePNG_InfoRaw, because the -LodePNG_InfoPng contains what the PNG file has). - -To avoid some confusion: --the Decoder converts from PNG to raw image --the Encoder converts from raw image to PNG --the color type and bit depth in LodePNG_InfoRaw, are those of the raw image --the color type and bit depth in LodePNG_InfoPng, are those of the PNG --if the color type of the LodePNG_InfoRaw and PNG image aren't the same, a conversion -between the color types is done if the color types are supported. If it is not -supported, an error is returned. If the types are the same, no conversion is done -and this is supported for any color type. - -Supported color conversions: --It's possible to load PNGs from any colortype and to save PNGs of any colorType. --Both encoder and decoder use the same converter. So both encoder and decoder -suport the same color types at the input and the output. So the decoder supports -any type of PNG image and can convert it to certain types of raw image, while the -encoder supports any type of raw data but only certain color types for the output PNG. --The converter can convert from _any_ input color type, to 24-bit RGB or 32-bit RGBA (8 bits per channel) --The converter can convert from _any_ input color type, to 48-bit RGB or 64-bit RGBA (16 bits per channel) --The converter can convert from greyscale input color type, to 8-bit greyscale or greyscale with alpha --The converter can convert from greyscale input color type, to 16-bit greyscale or greyscale with alpha --If both color types are the same, conversion from anything to anything is possible --Color types that are invalid according to the PNG specification are not allowed --When converting from a type with alpha channel to one without, the alpha channel information is discarded --When converting from a type without alpha channel to one with, the result will be opaque except - pixels that have the same color as the color key of the input if one was given --When converting from 16-bit bitDepth to 8-bit bitDepth, the 16-bit precision information is lost, - only the most significant byte is kept --When converting from 8-bit bitDepth to 16-bit bitDepth, the 8-bit byte is duplicated, so that 0 stays 0, and - the 8-bit maximum 255 is converted to the 16-bit maximum 65535. Something similar happens at bit level for - converting very low bit depths to 8 or 16 bit. --Converting from color to greyscale or to palette is not supported on purpose: there are multiple possible - algorithms to do this color reduction, LodePNG does not want to pick one and leaves this choice to the - user instead, because it's beyond the scope of PNG encoding. --Converting from a palette to a palette, only keeps the indices, it ignores the colors defined in the - palette without giving an error - -No conversion needed...: --If the color type of the PNG image and raw image are the same, then no -conversion is done, and all color types are supported. --In the encoder, you can make it save a PNG with any color by giving the -LodePNG_InfoRaw and LodePNG_InfoPng the same color type. --In the decoder, you can make it store the pixel data in the same color type -as the PNG has, by setting the color_convert setting to false. Settings in -infoRaw are then ignored. - -The function LodePNG_convert does this, which is available in the interface but -normally isn't needed since the encoder and decoder already call it. - -6.4. More Notes ---------------- - -In the PNG file format, if a less than 8-bit per pixel color type is used and the scanlines -have a bit amount that isn't a multiple of 8, then padding bits are used so that each -scanline starts at a fresh byte. But that is NOT true for the LodePNG input and output! -The raw input image you give to the encoder, and the raw output image you get from the decoder -will NOT have these padding bits, e.g. in the case of a 1-bit image with a width -of 7 pixels, the first pixel of the second scanline will the the 8th bit of the first byte, -not the first bit of a new byte. - -7. error values ---------------- - -All functions in LodePNG that return an error code, return 0 if everything went -OK, or one of the code defined by LodePNG if there was an error. - -The meaning of the LodePNG error values can be retrieved with the function -LodePNG_error_text: given the numerical error code, it returns a description -of the error in English as a string. - -Check the implementation of LodePNG_error_text to see the meaning of each error code. - - -8. chunks and PNG editing -------------------------- - -If you want to add extra chunks to a PNG you encode, or use LodePNG for a PNG -editor that should follow the rules about handling of unknown chunks, or if you -program is able to read other types of chunks than the ones handled by LodePNG, -then that's possible with the chunk functions of LodePNG. - -A PNG chunk has the following layout: - -4 bytes length -4 bytes type name -length bytes data -4 bytes CRC - - -8.1. iterating through chunks ------------------------------ - -If you have a buffer containing the PNG image data, then the first chunk (the -IHDR chunk) starts at byte number 8 of that buffer. The first 8 bytes are the -signature of the PNG and are not part of a chunk. But if you start at byte 8 -then you have a chunk, and can check the following things of it. - -NOTE: none of these functions check for memory buffer boundaries. To avoid -exploits, always make sure the buffer contains all the data of the chunks. -When using LodePNG_chunk_next, make sure the returned value is within the -allocated memory. - -unsigned LodePNG_chunk_length(const unsigned char* chunk): - -Get the length of the chunk's data. The total chunk length is this length + 12. - -void LodePNG_chunk_type(char type[5], const unsigned char* chunk): -unsigned char LodePNG_chunk_type_equals(const unsigned char* chunk, const char* type): - -Get the type of the chunk or compare if it's a certain type - -unsigned char LodePNG_chunk_critical(const unsigned char* chunk): -unsigned char LodePNG_chunk_private(const unsigned char* chunk): -unsigned char LodePNG_chunk_safetocopy(const unsigned char* chunk): - -Check if the chunk is critical in the PNG standard (only IHDR, PLTE, IDAT and IEND are). -Check if the chunk is private (public chunks are part of the standard, private ones not). -Check if the chunk is safe to copy. If it's not, then, when modifying data in a critical -chunk, unsafe to copy chunks of the old image may NOT be saved in the new one if your -program doesn't handle that type of unknown chunk. - -unsigned char* LodePNG_chunk_data(unsigned char* chunk): -const unsigned char* LodePNG_chunk_data_const(const unsigned char* chunk): - -Get a pointer to the start of the data of the chunk. - -unsigned LodePNG_chunk_check_crc(const unsigned char* chunk): -void LodePNG_chunk_generate_crc(unsigned char* chunk): - -Check if the crc is correct or generate a correct one. - -unsigned char* LodePNG_chunk_next(unsigned char* chunk): -const unsigned char* LodePNG_chunk_next_const(const unsigned char* chunk): - -Iterate to the next chunk. This works if you have a buffer with consecutive chunks. Note that these -functions do no boundary checking of the allocated data whatsoever, so make sure there is enough -data available in the buffer to be able to go to the next chunk. - -unsigned LodePNG_append_chunk(unsigned char** out, size_t* outlength, const unsigned char* chunk): -unsigned LodePNG_create_chunk(unsigned char** out, size_t* outlength, unsigned length, - const char* type, const unsigned char* data): - -These functions are used to create new chunks that are appended to the data in *out that has -length *outlength. The append function appends an existing chunk to the new data. The create -function creates a new chunk with the given parameters and appends it. Type is the 4-letter -name of the chunk. - - -8.2. chunks in infoPng ----------------------- - -The LodePNG_InfoPng struct contains a struct LodePNG_UnknownChunks in it. This -struct has 3 buffers (each with size) to contain 3 types of unknown chunks: -the ones that come before the PLTE chunk, the ones that come between the PLTE -and the IDAT chunks, and the ones that come after the IDAT chunks. -It's necessary to make the distionction between these 3 cases because the PNG -standard forces to keep the ordering of unknown chunks compared to the critical -chunks, but does not force any other ordering rules. - -infoPng.unknown_chunks.data[0] is the chunks before PLTE -infoPng.unknown_chunks.data[1] is the chunks after PLTE, before IDAT -infoPng.unknown_chunks.data[2] is the chunks after IDAT - -The chunks in these 3 buffers can be iterated through and read by using the same -way described in the previous subchapter. - -When using the decoder to decode a PNG, you can make it store all unknown chunks -if you set the option settings.rememberUnknownChunks to 1. By default, this option -is off and is 0. - -The encoder will always encode unknown chunks that are stored in the infoPng. If -you need it to add a particular chunk that isn't known by LodePNG, you can use -LodePNG_append_chunk or LodePNG_create_chunk to the chunk data in -infoPng.unknown_chunks.data[x]. - -Chunks that are known by LodePNG should not be added in that way. E.g. to make -LodePNG add a bKGD chunk, set background_defined to true and add the correct -parameters there and LodePNG will generate the chunk. - - -9. compiler support -------------------- - -No libraries other than the current standard C library are needed to compile -LodePNG. For the C++ version, only the standard C++ library is needed on top. -Add the files lodepng.c(pp) and lodepng.h to your project, include -lodepng.h where needed, and your program can read/write PNG files. - -Use optimization! For both the encoder and decoder, compiling with the best -optimizations makes a large difference. - -Make sure that LodePNG is compiled with the same compiler of the same version -and with the same settings as the rest of the program, or the interfaces with -std::vectors and std::strings in C++ can be incompatible resulting in bad things. - -CHAR_BITS must be 8 or higher, because LodePNG uses unsigned chars for octets. - -*) gcc and g++ - -LodePNG is developed in gcc so this compiler is natively supported. It gives no -warnings with compiler options "-Wall -Wextra -pedantic -ansi", with gcc and g++ -version 4.5.1 on Linux. - -*) Mingw and Bloodshed DevC++ - -The Mingw compiler (a port of gcc) used by Bloodshed DevC++ for Windows is fully -supported by LodePNG. - -*) Visual Studio 2005 and Visual C++ 2005 Express Edition - -Versions 20070604 up to 20080107 have been tested on VS2005 and work. Visual -studio may give warnings about 'fopen' being deprecated. A multiplatform library -can't support the proposed Visual Studio alternative however. - -If you're using LodePNG in VS2005 and don't want to see the deprecated warnings, -put this on top of lodepng.h before the inclusions: #define _CRT_SECURE_NO_DEPRECATE - -*) Visual Studio 6.0 - -The C++ version of LodePNG was not supported by Visual Studio 6.0 because Visual -Studio 6.0 doesn't follow the C++ standard and implements it incorrectly. -The current C version of LodePNG has not been tested in VS6 but may work now. - -*) Comeau C/C++ - -Vesion 20070107 compiles without problems on the Comeau C/C++ Online Test Drive -at http://www.comeaucomputing.com/tryitout in both C90 and C++ mode. - -*) Compilers on Macintosh - -LodePNG has been reported to work both with the gcc and LLVM for Macintosh, both -for C and C++. - -*) Other Compilers - -If you encounter problems on other compilers, I'm happy to help out make LodePNG -support the compiler if it supports the ISO C90 and C++ standard well enough and -the required modification doesn't require using non standard or less good C/C++ -code or headers. - - -10. examples ------------- - -This decoder and encoder example show the most basic usage of LodePNG (using the -classes, not the simple functions, which would be trivial) - -More complex examples can be found in: --lodepng_examples.c: 9 different examples in C, such as showing the image with SDL, ... --lodepng_examples.cpp: the same examples in C++ using the C++ wrapper of LodePNG - -These files can be found on the LodePNG website or searched for on the internet. - -10.1. decoder C++ example -------------------------- - -//////////////////////////////////////////////////////////////////////////////// -#include "lodepng.h" -#include <iostream> - -int main(int argc, char *argv[]) -{ - const char* filename = argc > 1 ? argv[1] : "test.png"; - - //load and decode - std::vector<unsigned char> buffer, image; //buffer will contain the PNG file, image will contain the raw pixels - LodePNG::loadFile(buffer, filename); //load the image file with given filename - LodePNG::Decoder decoder; - decoder.decode(image, buffer.size() ? &buffer[0] : 0, (unsigned)buffer.size()); //decode the png - - //if there's an error, display it - if(decoder.hasError()) - std::cout << "error " << decoder.getError() << ": "<< LodePNG_error_text(decoder.getError()) << std::endl; - - int width = decoder.getWidth(); //get the width in pixels - int height = decoder.getHeight(); //get the height in pixels - //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ... -} - -//alternative version using the "simple" function -int main(int argc, char *argv[]) -{ - const char* filename = argc > 1 ? argv[1] : "test.png"; - - //load and decode - std::vector<unsigned char> image; - unsigned width, height; - unsigned error = LodePNG::decode(image, width, height, filename); - - //if there's an error, display it - if(error != 0) std::cout << "error " << error << ": " << LodePNG_error_text(error) << std::endl; - - //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ... -} -//////////////////////////////////////////////////////////////////////////////// - - -10.2. encoder C++ example -------------------------- - -//////////////////////////////////////////////////////////////////////////////// -#include "lodepng.h" -#include <iostream> - -//saves image to filename given as argument. Warning, this overwrites the file without warning! -int main(int argc, char *argv[]) -{ - //check if user gave a filename - if(argc <= 1) - { - std::cout << "please provide a filename to save to\n"; - return 0; - } - - //generate some image - std::vector<unsigned char> image; - image.resize(512 * 512 * 4); - for(unsigned y = 0; y < 512; y++) - for(unsigned x = 0; x < 512; x++) - { - image[4 * 512 * y + 4 * x + 0] = 255 * !(x & y); - image[4 * 512 * y + 4 * x + 1] = x ^ y; - image[4 * 512 * y + 4 * x + 2] = x | y; - image[4 * 512 * y + 4 * x + 3] = 255; - } - - //encode and save, using the Encoder class - std::vector<unsigned char> buffer; - LodePNG::Encoder encoder; - encoder.encode(buffer, image, 512, 512); - LodePNG::saveFile(buffer, argv[1]); - - //the same as the 4 lines of code above, but in 1 call without the class: - //LodePNG::encode(argv[1], image, 512, 512); -} -//////////////////////////////////////////////////////////////////////////////// - - -10.3. Decoder C example ------------------------ - -This example loads the PNG from a file into a pixel buffer in 1 function call - -#include "lodepng.h" - -int main(int argc, char *argv[]) -{ - unsigned error; - unsigned char* image; - size_t width, height; - - if(argc <= 1) return 0; - - error = LodePNG_decode32_file(&image, &width, &height, filename); - - if(error != 0) printf("error %u: %s\n", error, LodePNG_error_text(error)); - - //use image here - - free(image); -} - - -11. changes ------------ - -The version number of LodePNG is the date of the change given in the format -yyyymmdd. - -Some changes aren't backwards compatible. Those are indicated with a (!) -symbol. - -*) 8 sep 2011: lz77 encoder lazy matching instead of greedy matching. -*) 23 aug 2011: tweaked the zlib compression parameters after benchmarking. - A bug with the PNG filtertype heuristic was fixed, so that it chooses much - better ones (it's quite significant). A setting to do an experimental, slow, - brute force search for PNG filter types is added. -*) 17 aug 2011 (!): changed some C zlib related function names. -*) 16 aug 2011: made the code less wide (max 120 characters per line). -*) 17 apr 2011: code cleanup. Bugfixes. Convert low to 16-bit per sample colors. -*) 21 feb 2011: fixed compiling for C90. Fixed compiling with sections disabled. -*) 11 dec 2010: encoding is made faster, based on suggestion by Peter Eastman - to optimize long sequences of zeros. -*) 13 nov 2010: added LodePNG_InfoColor_hasPaletteAlpha and - LodePNG_InfoColor_canHaveAlpha functions for convenience. -*) 7 nov 2010: added LodePNG_error_text function to get error code description. -*) 30 okt 2010: made decoding slightly faster -*) 26 okt 2010: (!) changed some C function and struct names (more consistent). - Reorganized the documentation and the declaration order in the header. -*) 08 aug 2010: only changed some comments and external samples. -*) 05 jul 2010: fixed bug thanks to warnings in the new gcc version. -*) 14 mar 2010: fixed bug where too much memory was allocated for char buffers. -*) 02 sep 2008: fixed bug where it could create empty tree that linux apps could - read by ignoring the problem but windows apps couldn't. -*) 06 jun 2008: added more error checks for out of memory cases. -*) 26 apr 2008: added a few more checks here and there to ensure more safety. -*) 06 mar 2008: crash with encoding of strings fixed -*) 02 feb 2008: support for international text chunks added (iTXt) -*) 23 jan 2008: small cleanups, and #defines to divide code in sections -*) 20 jan 2008: support for unknown chunks allowing using LodePNG for an editor. -*) 18 jan 2008: support for tIME and pHYs chunks added to encoder and decoder. -*) 17 jan 2008: ability to encode and decode compressed zTXt chunks added - Also vareous fixes, such as in the deflate and the padding bits code. -*) 13 jan 2008: Added ability to encode Adam7-interlaced images. Improved - filtering code of encoder. -*) 07 jan 2008: (!) changed LodePNG to use ISO C90 instead of C++. A - C++ wrapper around this provides an interface almost identical to before. - Having LodePNG be pure ISO C90 makes it more portable. The C and C++ code - are together in these files but it works both for C and C++ compilers. -*) 29 dec 2007: (!) changed most integer types to unsigned int + other tweaks -*) 30 aug 2007: bug fixed which makes this Borland C++ compatible -*) 09 aug 2007: some VS2005 warnings removed again -*) 21 jul 2007: deflate code placed in new namespace separate from zlib code -*) 08 jun 2007: fixed bug with 2- and 4-bit color, and small interlaced images -*) 04 jun 2007: improved support for Visual Studio 2005: crash with accessing - invalid std::vector element [0] fixed, and level 3 and 4 warnings removed -*) 02 jun 2007: made the encoder add a tag with version by default -*) 27 may 2007: zlib and png code separated (but still in the same file), - simple encoder/decoder functions added for more simple usage cases -*) 19 may 2007: minor fixes, some code cleaning, new error added (error 69), - moved some examples from here to lodepng_examples.cpp -*) 12 may 2007: palette decoding bug fixed -*) 24 apr 2007: changed the license from BSD to the zlib license -*) 11 mar 2007: very simple addition: ability to encode bKGD chunks. -*) 04 mar 2007: (!) tEXt chunk related fixes, and support for encoding - palettized PNG images. Plus little interface change with palette and texts. -*) 03 mar 2007: Made it encode dynamic Huffman shorter with repeat codes. - Fixed a bug where the end code of a block had length 0 in the Huffman tree. -*) 26 feb 2007: Huffman compression with dynamic trees (BTYPE 2) now implemented - and supported by the encoder, resulting in smaller PNGs at the output. -*) 27 jan 2007: Made the Adler-32 test faster so that a timewaste is gone. -*) 24 jan 2007: gave encoder an error interface. Added color conversion from any - greyscale type to 8-bit greyscale with or without alpha. -*) 21 jan 2007: (!) Totally changed the interface. It allows more color types - to convert to and is more uniform. See the manual for how it works now. -*) 07 jan 2007: Some cleanup & fixes, and a few changes over the last days: - encode/decode custom tEXt chunks, separate classes for zlib & deflate, and - at last made the decoder give errors for incorrect Adler32 or Crc. -*) 01 jan 2007: Fixed bug with encoding PNGs with less than 8 bits per channel. -*) 29 dec 2006: Added support for encoding images without alpha channel, and - cleaned out code as well as making certain parts faster. -*) 28 dec 2006: Added "Settings" to the encoder. -*) 26 dec 2006: The encoder now does LZ77 encoding and produces much smaller files now. - Removed some code duplication in the decoder. Fixed little bug in an example. -*) 09 dec 2006: (!) Placed output parameters of public functions as first parameter. - Fixed a bug of the decoder with 16-bit per color. -*) 15 okt 2006: Changed documentation structure -*) 09 okt 2006: Encoder class added. It encodes a valid PNG image from the - given image buffer, however for now it's not compressed. -*) 08 sep 2006: (!) Changed to interface with a Decoder class -*) 30 jul 2006: (!) LodePNG_InfoPng , width and height are now retrieved in different - way. Renamed decodePNG to decodePNGGeneric. -*) 29 jul 2006: (!) Changed the interface: image info is now returned as a - struct of type LodePNG::LodePNG_Info, instead of a vector, which was a bit clumsy. -*) 28 jul 2006: Cleaned the code and added new error checks. - Corrected terminology "deflate" into "inflate". -*) 23 jun 2006: Added SDL example in the documentation in the header, this - example allows easy debugging by displaying the PNG and its transparency. -*) 22 jun 2006: (!) Changed way to obtain error value. Added - loadFile function for convenience. Made decodePNG32 faster. -*) 21 jun 2006: (!) Changed type of info vector to unsigned. - Changed position of palette in info vector. Fixed an important bug that - happened on PNGs with an uncompressed block. -*) 16 jun 2006: Internally changed unsigned into unsigned where - needed, and performed some optimizations. -*) 07 jun 2006: (!) Renamed functions to decodePNG and placed them - in LodePNG namespace. Changed the order of the parameters. Rewrote the - documentation in the header. Renamed files to lodepng.cpp and lodepng.h -*) 22 apr 2006: Optimized and improved some code -*) 07 sep 2005: (!) Changed to std::vector interface -*) 12 aug 2005: Initial release (C++, decoder only) - - -12. contact information ------------------------ - -Feel free to contact me with suggestions, problems, comments, ... concerning -LodePNG. If you encounter a PNG image that doesn't work properly with this -decoder, feel free to send it and I'll use it to find and fix the problem. - -My email address is (puzzle the account and domain together with an @ symbol): -Domain: gmail dot com. -Account: lode dot vandevenne. - - -Copyright (c) 2005-2011 Lode Vandevenne -*/ - -#endif - |