First LD
All right, I’m in, this’ll be my first LD.
Below are personal code libraries/other code libraries that I will be using
Lodepng.h
/*
LodePNG version 20110417
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.
*/
#define LODEPNG_COMPILE_ZLIB /*deflate&zlib encoder and deflate&zlib decoder*/
#define LODEPNG_COMPILE_PNG /*png encoder and png decoder*/
#define LODEPNG_COMPILE_DECODER /*deflate&zlib decoder and png decoder*/
#define LODEPNG_COMPILE_ENCODER /*deflate&zlib encoder and png encoder*/
#define LODEPNG_COMPILE_DISK /*the optional built in harddisk file loading and saving functions*/
#define LODEPNG_COMPILE_ANCILLARY_CHUNKS /*any code or struct datamember related to chunks other than IHDR, IDAT, PLTE, tRNS, IEND*/
#define LODEPNG_COMPILE_UNKNOWN_CHUNKS /*handling of unknown chunks*/
#define LODEPNG_COMPILE_ERROR_TEXT /*ability to convert error numerical codes to English text string*/
/* ////////////////////////////////////////////////////////////////////////// */
/* 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
#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); /*return value is error*/
/*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); /*return value is error*/
/*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); /*return value is error*/
#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); /*return value is error*/
/*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 = 6, 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 = 6, 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 = 6, 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 = 6, 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 = 6, 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 = 6, 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 = 6, 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 LodeZlib_DecompressSettings
{
unsigned ignoreAdler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/
} LodeZlib_DecompressSettings;
extern const LodeZlib_DecompressSettings LodeZlib_defaultDecompressSettings;
void LodeZlib_DecompressSettings_init(LodeZlib_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 LodeZlib_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.*/
} LodeZlib_CompressSettings;
extern const LodeZlib_CompressSettings LodeZlib_defaultCompressSettings;
void LodeZlib_CompressSettings_init(LodeZlib_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);
unsigned LodePNG_InfoColor_copy(LodePNG_InfoColor* dest, const LodePNG_InfoColor* source); /*return value is error code (0 means no error)*/
/*Use these functions instead of allocating palette manually*/
void LodePNG_InfoColor_clearPalette(LodePNG_InfoColor* info);
unsigned LodePNG_InfoColor_addPalette(LodePNG_InfoColor* info, unsigned char r, unsigned char g, unsigned char b, unsigned char a); /*add 1 color to the palette*/
/*additional color info*/
unsigned LodePNG_InfoColor_getBpp(const LodePNG_InfoColor* info); /*get the total amount of bits per pixel, based on colorType and bitDepth in the struct*/
unsigned LodePNG_InfoColor_getChannels(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_isGreyscaleType(const LodePNG_InfoColor* info); /*is it a greyscale type? (only colorType 0 or 4)*/
unsigned LodePNG_InfoColor_isAlphaType(const LodePNG_InfoColor* info); /*has it got an alpha channel? (only colorType 2 or 6)*/
unsigned LodePNG_InfoColor_isPaletteType(const LodePNG_InfoColor* info); /*has it got a palette? (only colorType 3)*/
unsigned LodePNG_InfoColor_hasPaletteAlpha(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.*/
/*
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);
unsigned LodePNG_Text_copy(LodePNG_Text* dest, const LodePNG_Text* source); /*return value is error code (0 means no error)*/
/*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.*/
size_t num; /*the amount of international texts in this PNG*/
char** keys; /*the English keyword of the text chunk (e.g. "Comment")*/
char** langtags; /*the language tag for this text's international language, ISO/IEC 646 string, e.g. ISO 639 language tag*/
char** transkeys; /*keyword translated to the international language - UTF-8 string*/
char** strings; /*the actual international text - UTF-8 string*/
} 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);
unsigned LodePNG_IText_copy(LodePNG_IText* dest, const LodePNG_IText* source); /*return value is error code (0 means no error)*/
/*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);
unsigned LodePNG_UnknownChunks_copy(LodePNG_UnknownChunks* dest, const LodePNG_UnknownChunks* src); /*return value is error code (0 means no error)*/
#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);
unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source); /*return value is error code (0 means no error)*/
/*
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);
unsigned LodePNG_InfoRaw_copy(LodePNG_InfoRaw* dest, const LodePNG_InfoRaw* source); /*return value is error code (0 means no error)*/
/*
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
{
LodeZlib_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
unsigned rememberUnknownChunks; /*store all bytes from unknown chunks in the InfoPng (off by default, useful for a png editor)*/
#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); /*read the png header*/
#endif /*LODEPNG_COMPILE_DECODER*/
#ifdef LODEPNG_COMPILE_ENCODER
/* ////////////////////////////////////////////////////////////////////////// */
/* LodePNG Encoder */
/* ////////////////////////////////////////////////////////////////////////// */
/*Settings for the encoder.*/
typedef struct LodePNG_EncodeSettings
{
LodeZlib_CompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/
unsigned autoLeaveOutAlphaChannel; /*automatically use color type without alpha instead of given one, if given image is opaque*/
unsigned force_palette; /*force creating a PLTE chunk if colortype is 2 or 6 (= a suggested palette). If colortype is 3, PLTE is _always_ created.*/
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
unsigned add_id; /*add LodePNG version as text chunk*/
unsigned text_compression; /*encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks*/
#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
{
LodePNG_EncodeSettings settings; /*compression settings of the encoder*/
LodePNG_InfoPng infoPng; /*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_InfoRaw infoRaw; /*put the properties of the input raw image in here*/
unsigned error; /*error value filled in if error happened, or 0 if all went ok*/
} 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.
*/
/*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.*/
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 is "LodeZlib". A C++ wrapper is available further on.
LodeZlib can be used 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.
Either, *out must be NULL and *outsize must be 0, or, *out must be a valid buffer and *outsize its size in bytes.*/
unsigned LodeZlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DecompressSettings* settings);
#endif /*LODEPNG_COMPILE_DECODER*/
#ifdef LODEPNG_COMPILE_ENCODER
/*Compresses data with Zlib. Reallocates the out buffer and appends the data.
Either, *out must be NULL and *outsize must be 0, or, *out must be a valid buffer and *outsize its size in bytes.*/
unsigned LodeZlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_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, 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.
#ifdef LODEPNG_COMPILE_ZLIB
//The C++ wrapper for LodeZlib
namespace LodeZlib
{
#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 LodeZlib_DecompressSettings& settings = LodeZlib_defaultDecompressSettings);
//Zlib-decompress an std::vector
unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, const LodeZlib_DecompressSettings& settings = LodeZlib_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 LodeZlib_CompressSettings& settings = LodeZlib_defaultCompressSettings);
//Zlib-compress an std::vector
unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, const LodeZlib_CompressSettings& settings = LodeZlib_defaultCompressSettings);
#endif //LODEPNG_COMPILE_ENCODER
} //namespace LodeZlib
#endif //LODEPNG_COMPILE_ZLIB
#ifdef LODEPNG_COMPILE_PNG
namespace LodePNG
{
#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
} //namespace LodePNG
#endif //LODEPNG_COMPILE_PNG
#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 ever touch RGB values, that is very annoying for textures as well as images in a browser)
[ ] 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 that the decoder stores in the error at the very end? and make some errors just let it stop with this one chunk but still do the next ones)
[ ] make option to choose if the raw image with non multiple of 8 bits per scanline should have padding bits or not, if people like storing raw images that way
[ ] let the C++ wrapper catch exceptions coming from the standard library and return LodePNG error codes instead, like the C version does. This is about std::vector allocations and about the saveFile and loadFile functions.
*/
#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.
*) 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
*/
lodepng.cpp
#include "stdafx.h"
/*
LodePNG version 20110417
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.
*/
/*
The manual and changelog can be found in the header file "lodepng.h"
Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for C.
*/
#include "lodepng.h"
#include
#include
#ifdef __cplusplus
#include
#endif /*__cplusplus*/
#define VERSION_STRING "20110417"
/* ////////////////////////////////////////////////////////////////////////// */
/* / Tools For C / */
/* ////////////////////////////////////////////////////////////////////////// */
/*
Often in case of an error a value is assigned to a variable and then it breaks
out of a loop (to go to the cleanup phase of a function). This macro does that.
This is done for having shorter and more readable code. I find it more readable
especially for memory allocations, because you have to read less error handling
code in between the algorithms. To me, a memory vector resize on one line is
easier to read than one on 5 lines.
Example: if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(9924);
*/
#define CERROR_BREAK(errorvar, code)\
{\
errorvar = code;\
break;\
}
/*version of CERROR_BREAK that assumes the common case where the error variable is named "error"*/
#define ERROR_BREAK(code) CERROR_BREAK(error, code)
/*
About these tools (vector, uivector, ucvector and string):
-LodePNG was originally written in C++. The vectors replace the std::vectors that were used in the C++ version.
-The string tools are made to avoid problems with compilers that declare things like strncat as deprecated.
-They're not used in the interface, only internally in this file, so all their functions are made static.
*/
#ifdef LODEPNG_COMPILE_ZLIB
#ifdef LODEPNG_COMPILE_ENCODER
typedef struct vector /*dynamic vector of void* pointers. This one is used only by the deflate compressor*/
{
void* data;
size_t size; /*in groups of bytes depending on type*/
size_t allocsize; /*in bytes*/
unsigned typesize; /*sizeof the type you store in data*/
} vector;
static unsigned vector_resize(vector* p, size_t size) /*returns 1 if success, 0 if failure ==> nothing done*/
{
if(size * p->typesize > p->allocsize)
{
size_t newsize = size * p->typesize * 2;
void* data = realloc(p->data, newsize);
if(data)
{
p->allocsize = newsize;
p->data = data;
p->size = size;
}
else return 0;
}
else p->size = size;
return 1;
}
static unsigned vector_resized(vector* p, size_t size, void dtor(void*)) /*resize and use destructor on elements if it gets smaller*/
{
size_t i;
if(size
size)
{
for(i = size; i
size; i++)
{
dtor(&((char*)(p->data))[i * p->typesize]);
}
}
return vector_resize(p, size);
}
static void vector_cleanup(void* p)
{
((vector*)p)->size = ((vector*)p)->allocsize = 0;
free(((vector*)p)->data);
((vector*)p)->data = NULL;
}
static void vector_cleanupd(vector* p, void dtor(void*)) /*clear and use destructor on elements*/
{
vector_resized(p, 0, dtor);
vector_cleanup(p);
}
static void vector_init(vector* p, unsigned typesize)
{
p->data = NULL;
p->size = p->allocsize = 0;
p->typesize = typesize;
}
static void vector_swap(vector* p, vector* q) /*they're supposed to have the same typesize*/
{
size_t tmp;
void* tmpp;
tmp = p->size; p->size = q->size; q->size = tmp;
tmp = p->allocsize; p->allocsize = q->allocsize; q->allocsize = tmp;
tmpp = p->data; p->data = q->data; q->data = tmpp;
}
static void* vector_get(vector* p, size_t index)
{
return &((char*)p->data)[index * p->typesize];
}
#endif /*LODEPNG_COMPILE_ENCODER*/
#endif /*LODEPNG_COMPILE_ZLIB*/
/* /////////////////////////////////////////////////////////////////////////// */
#ifdef LODEPNG_COMPILE_ZLIB
/*dynamic vector of unsigned ints*/
typedef struct uivector
{
unsigned* data;
size_t size; /*size in number of unsigned longs*/
size_t allocsize; /*allocated size in bytes*/
} uivector;
static void uivector_cleanup(void* p)
{
((uivector*)p)->size = ((uivector*)p)->allocsize = 0;
free(((uivector*)p)->data);
((uivector*)p)->data = NULL;
}
/*returns 1 if success, 0 if failure ==> nothing done*/
static unsigned uivector_resize(uivector* p, size_t size)
{
if(size * sizeof(unsigned) > p->allocsize)
{
size_t newsize = size * sizeof(unsigned) * 2;
void* data = realloc(p->data, newsize);
if(data)
{
p->allocsize = newsize;
p->data = (unsigned*)data;
p->size = size;
}
else return 0;
}
else p->size = size;
return 1;
}
/*resize and give all new elements the value*/
static unsigned uivector_resizev(uivector* p, size_t size, unsigned value)
{
size_t oldsize = p->size, i;
if(!uivector_resize(p, size)) return 0;
for(i = oldsize; i data[i] = value;
return 1;
}
static void uivector_init(uivector* p)
{
p->data = NULL;
p->size = p->allocsize = 0;
}
#ifdef LODEPNG_COMPILE_ENCODER
/*returns 1 if success, 0 if failure ==> nothing done*/
static unsigned uivector_push_back(uivector* p, unsigned c)
{
if(!uivector_resize(p, p->size + 1)) return 0;
p->data[p->size - 1] = c;
return 1;
}
/*copy q to p, returns 1 if success, 0 if failure ==> nothing done*/
static unsigned uivector_copy(uivector* p, const uivector* q)
{
size_t i;
if(!uivector_resize(p, q->size)) return 0;
for(i = 0; i size; i++) p->data[i] = q->data[i];
return 1;
}
static void uivector_swap(uivector* p, uivector* q)
{
size_t tmp;
unsigned* tmpp;
tmp = p->size; p->size = q->size; q->size = tmp;
tmp = p->allocsize; p->allocsize = q->allocsize; q->allocsize = tmp;
tmpp = p->data; p->data = q->data; q->data = tmpp;
}
#endif /*LODEPNG_COMPILE_ENCODER*/
#endif /*LODEPNG_COMPILE_ZLIB*/
/* /////////////////////////////////////////////////////////////////////////// */
/*dynamic vector of unsigned chars*/
typedef struct ucvector
{
unsigned char* data;
size_t size; /*used size*/
size_t allocsize; /*allocated size*/
} ucvector;
static void ucvector_cleanup(void* p)
{
((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0;
free(((ucvector*)p)->data);
((ucvector*)p)->data = NULL;
}
/*returns 1 if success, 0 if failure ==> nothing done*/
static unsigned ucvector_resize(ucvector* p, size_t size)
{
if(size * sizeof(unsigned char) > p->allocsize)
{
size_t newsize = size * sizeof(unsigned char) * 2;
void* data = realloc(p->data, newsize);
if(data)
{
p->allocsize = newsize;
p->data = (unsigned char*)data;
p->size = size;
}
else return 0; /*error: not enough memory*/
}
else p->size = size;
return 1;
}
#ifdef LODEPNG_COMPILE_DECODER
#ifdef LODEPNG_COMPILE_PNG
/*resize and give all new elements the value*/
static unsigned ucvector_resizev(ucvector* p, size_t size, unsigned char value)
{
size_t oldsize = p->size, i;
if(!ucvector_resize(p, size)) return 0;
for(i = oldsize; i data[i] = value;
return 1;
}
#endif /*LODEPNG_COMPILE_PNG*/
#endif /*LODEPNG_COMPILE_DECODER*/
static void ucvector_init(ucvector* p)
{
p->data = NULL;
p->size = p->allocsize = 0;
}
#ifdef LODEPNG_COMPILE_ZLIB
/*you can both convert from vector to buffer&size and vica versa*/
static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size)
{
p->data = buffer;
p->allocsize = p->size = size;
}
#endif /*LODEPNG_COMPILE_ZLIB*/
/*returns 1 if success, 0 if failure ==> nothing done*/
static unsigned ucvector_push_back(ucvector* p, unsigned char c)
{
if(!ucvector_resize(p, p->size + 1)) return 0;
p->data[p->size - 1] = c;
return 1;
}
/* /////////////////////////////////////////////////////////////////////////// */
#ifdef LODEPNG_COMPILE_PNG
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
/*returns 1 if success, 0 if failure ==> nothing done*/
static unsigned string_resize(char** out, size_t size)
{
char* data = (char*)realloc(*out, size + 1);
if(data)
{
data[size] = 0; /*null termination char*/
*out = data;
}
return data != 0;
}
/*init a {char*, size_t} pair for use as string*/
static void string_init(char** out)
{
*out = NULL;
string_resize(out, 0);
}
/*free the above pair again*/
static void string_cleanup(char** out)
{
free(*out);
*out = NULL;
}
static void string_set(char** out, const char* in)
{
size_t insize = strlen(in), i = 0;
if(string_resize(out, insize))
{
for(i = 0; i data[bitstream->size - 1]) |= (bit << ((*bitpointer) & 0x7)); /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/
(*bitpointer)++;
}
static void addBitsToStream(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
{
size_t i;
for(i = 0; i > i) & 1));
}
static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
{
size_t i;
for(i = 0; i > (nbits - 1 - i)) & 1));
}
#endif /*LODEPNG_COMPILE_ENCODER*/
#ifdef LODEPNG_COMPILE_DECODER
#define READBIT(bitpointer, bitstream) ((bitstream[bitpointer >> 3] >> (bitpointer & 0x7)) & (unsigned char)1)
static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream)
{
unsigned char result = (unsigned char)(READBIT(*bitpointer, bitstream));
(*bitpointer)++;
return result;
}
static unsigned readBitsFromStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
{
unsigned result = 0, i;
for(i = 0; i < nbits; i++)
{
result += ((unsigned)READBIT(*bitpointer, bitstream)) <symbols);
}
/*argument c is void* so that this dtor can be given as function pointer to the vector resize function*/
static void Coin_cleanup(void* c)
{
uivector_cleanup(&((Coin*)c)->symbols);
}
static void Coin_copy(Coin* c1, const Coin* c2)
{
c1->weight = c2->weight;
uivector_copy(&c1->symbols, &c2->symbols);
}
static void addCoins(Coin* c1, const Coin* c2)
{
size_t i;
for(i = 0; i symbols.size; i++) uivector_push_back(&c1->symbols, c2->symbols.data[i]);
c1->weight += c2->weight;
}
/*
Coin_sort: This uses a simple combsort to sort the data. This function is not critical for
overall encoding speed and the data amount isn't that large.
*/
static void Coin_sort(Coin* data, size_t amount)
{
size_t gap = amount;
unsigned char swapped = 0;
while((gap > 1) || swapped)
{
size_t i;
gap = (gap * 10) / 13; /*shrink factor 1.3*/
if(gap == 9 || gap == 10) gap = 11; /*combsort11*/
if(gap < 1) gap = 1;
swapped = 0;
for(i = 0; i < amount - gap; i++)
{
size_t j = i + gap;
if(data[j].weight < data[i].weight)
{
float temp = data[j].weight; data[j].weight = data[i].weight; data[i].weight = temp;
uivector_swap(&data[i].symbols, &data[j].symbols);
swapped = 1;
}
}
}
}
#endif /*LODEPNG_COMPILE_ENCODER*/
/*
Huffman tree struct, containing multiple representations of the tree
*/
typedef struct HuffmanTree
{
uivector tree2d;
uivector tree1d;
uivector lengths; /*the lengths of the codes of the 1d-tree*/
unsigned maxbitlen; /*maximum number of bits a single code can get*/
unsigned numcodes; /*number of symbols in the alphabet = number of codes*/
} HuffmanTree;
/*function used for debug purposes to draw the tree in ascii art*/
/*#include
static void HuffmanTree_draw(HuffmanTree* tree)
{
std::cout << "tree. length: " <numcodes << " maxbitlen: " <maxbitlen << std::endl;
for(size_t i = 0; i tree1d.size; i++)
{
if(tree->lengths.data[i])
std::cout << i << " " <tree1d.data[i] << " " <lengths.data[i] << std::endl;
}
std::cout <tree2d);
uivector_init(&tree->tree1d);
uivector_init(&tree->lengths);
}
static void HuffmanTree_cleanup(HuffmanTree* tree)
{
uivector_cleanup(&tree->tree2d);
uivector_cleanup(&tree->tree1d);
uivector_cleanup(&tree->lengths);
}
/*the tree representation used by the decoder. return value is error*/
static unsigned HuffmanTree_make2DTree(HuffmanTree* tree)
{
unsigned nodefilled = 0; /*up to which node it is filled*/
unsigned treepos = 0; /*position in the tree (1 of the numcodes columns)*/
unsigned n, i;
if(!uivector_resize(&tree->tree2d, tree->numcodes * 2)) return 9901;
/*
convert tree1d[] to tree2d[][]. In the 2D array, a value of 32767 means
uninited, a value >= numcodes is an address to another bit, a value < numcodes
is a code. The 2 rows are the 2 possible bit values (0 or 1), there are as
many columns as codes - 1.
A good huffmann tree has N * 2 - 1 nodes, of which N - 1 are internal nodes.
Here, the internal nodes are stored (what their 0 and 1 option point to).
There is only memory for such good tree currently, if there are more nodes
(due to too long length codes), error 55 will happen
*/
for(n = 0; n numcodes * 2; n++)
{
tree->tree2d.data[n] = 32767; /*32767 here means the tree2d isn't filled there yet*/
}
for(n = 0; n numcodes; n++) /*the codes*/
{
for(i = 0; i lengths.data[n]; i++) /*the bits for this code*/
{
unsigned char bit = (unsigned char)((tree->tree1d.data[n] >> (tree->lengths.data[n] - i - 1)) & 1);
if(treepos > tree->numcodes - 2) return 55; /*error 55: oversubscribed; see description in header*/
if(tree->tree2d.data[2 * treepos + bit] == 32767) /*not yet filled in*/
{
if(i + 1 == tree->lengths.data[n]) /*last bit*/
{
tree->tree2d.data[2 * treepos + bit] = n; /*put the current code in it*/
treepos = 0;
}
else /*put address of the next step in here, first that address has to be found of course (it's just nodefilled + 1)...*/
{
nodefilled++;
tree->tree2d.data[2 * treepos + bit] = nodefilled + tree->numcodes; /*addresses encoded with numcodes added to it*/
treepos = nodefilled;
}
}
else treepos = tree->tree2d.data[2 * treepos + bit] - tree->numcodes;
}
}
for(n = 0; n numcodes * 2; n++)
{
if(tree->tree2d.data[n] == 32767) tree->tree2d.data[n] = 0; /*remove possible remaining 32767's*/
}
return 0;
}
/*
HuffmanTree_makeFromLengths2
numcodes, lengths and maxbitlen must already be filled in correctly.
return value is error.
*/
static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree)
{
uivector blcount;
uivector nextcode;
unsigned bits, n, error = 0;
uivector_init(&blcount);
uivector_init(&nextcode);
if(!uivector_resize(&tree->tree1d, tree->numcodes)
|| !uivector_resizev(&blcount, tree->maxbitlen + 1, 0)
|| !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0))
error = 9902; /*alloc fail*/
if(!error)
{
/*step 1: count number of instances of each code length*/
for(bits = 0; bits numcodes; bits++) blcount.data[tree->lengths.data[bits]]++;
/*step 2: generate the nextcode values*/
for(bits = 1; bits maxbitlen; bits++) nextcode.data[bits] = (nextcode.data[bits - 1] + blcount.data[bits - 1]) << 1;
/*step 3: generate all the codes*/
for(n = 0; n numcodes; n++) if(tree->lengths.data[n] != 0) tree->tree1d.data[n] = nextcode.data[tree->lengths.data[n]]++;
}
uivector_cleanup(&blcount);
uivector_cleanup(&nextcode);
if(!error) return HuffmanTree_make2DTree(tree);
else return error;
}
/*
HuffmanTree_makeFromLengths
given the code lengths (as stored in the PNG file), generate the tree as defined
by Deflate. maxbitlen is the maximum bits that a code in the tree can have.
return value is error.
*/
static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen, size_t numcodes, unsigned maxbitlen)
{
unsigned i;
if(!uivector_resize(&tree->lengths, numcodes)) return 9903;
for(i = 0; i lengths.data[i] = bitlen[i];
tree->numcodes = (unsigned)numcodes; /*number of symbols*/
tree->maxbitlen = maxbitlen;
return HuffmanTree_makeFromLengths2(tree);
}
#ifdef LODEPNG_COMPILE_ENCODER
static unsigned HuffmanTree_fillInCoins(vector* coins, const unsigned* frequencies, unsigned numcodes, size_t sum)
{
unsigned i;
for(i = 0; i size + 1))
{
vector_cleanup(coins);
return 9904; /*alloc fail*/
}
coin = (Coin*)(vector_get(coins, coins->size - 1));
Coin_init(coin);
coin->weight = frequencies[i] / (float)sum;
uivector_push_back(&coin->symbols, i);
}
if(coins->size) Coin_sort((Coin*)coins->data, coins->size);
return 0;
}
/*
HuffmanTree_makeFromFrequencies
Create the Huffman tree given the symbol frequencies
*/
static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies, size_t numcodes, unsigned maxbitlen)
{
unsigned i, j;
size_t sum = 0, numpresent = 0;
unsigned error = 0;
vector prev_row; /*type Coin, the previous row of coins*/
vector coins; /*type Coin, the coins of the currently calculated row*/
tree->maxbitlen = maxbitlen;
for(i = 0; i 0)
{
numpresent++;
sum += frequencies[i];
}
}
if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/
tree->numcodes = (unsigned)numcodes; /*number of symbols*/
uivector_resize(&tree->lengths, 0);
if(!uivector_resizev(&tree->lengths, tree->numcodes, 0)) return 9905;
if(numpresent == 0) /*there are no symbols at all, in that case add one symbol of value 0 to the tree (see RFC 1951 section 3.2.7) */
{
tree->lengths.data[0] = 1;
return HuffmanTree_makeFromLengths2(tree);
}
else if(numpresent == 1) /*the package merge algorithm gives wrong results if there's only one symbol (theoretically 0 bits would then suffice, but we need a proper symbol for zlib)*/
{
for(i = 0; i lengths.data[i] = 1;
return HuffmanTree_makeFromLengths2(tree);
}
vector_init(&coins, sizeof(Coin));
vector_init(&prev_row, sizeof(Coin));
/*Package-Merge algorithm represented by coin collector's problem
For every symbol, maxbitlen coins will be created*/
/*first row, lowest denominator*/
error = HuffmanTree_fillInCoins(&coins, frequencies, tree->numcodes, sum);
if(!error)
{
for(j = 1; j <= maxbitlen && !error; j++) /*each of the remaining rows*/
{
vector_swap(&coins, &prev_row); /*swap instead of copying*/
if(!vector_resized(&coins, 0, Coin_cleanup)) ERROR_BREAK(9906 /*alloc fail*/);
for(i = 0; i + 1 < prev_row.size; i += 2)
{
if(!vector_resize(&coins, coins.size + 1)) ERROR_BREAK(9907 /*alloc fail*/);
Coin_init((Coin*)vector_get(&coins, coins.size - 1));
Coin_copy((Coin*)vector_get(&coins, coins.size - 1), (Coin*)vector_get(&prev_row, i));
addCoins((Coin*)vector_get(&coins, coins.size - 1), (Coin*)vector_get(&prev_row, i + 1)); /*merge the coins into packages*/
}
if(j numcodes, sum);
}
}
}
if(!error)
{
/*keep the coins with lowest weight, so that they add up to the amount of symbols - 1*/
vector_resized(&coins, numpresent - 1, Coin_cleanup);
/*calculate the lenghts of each symbol, as the amount of times a coin of each symbol is used*/
for(i = 0; i < coins.size; i++)
{
Coin* coin = (Coin*)vector_get(&coins, i);
for(j = 0; j symbols.size; j++) tree->lengths.data[coin->symbols.data[j]]++;
}
error = HuffmanTree_makeFromLengths2(tree);
}
vector_cleanupd(&coins, Coin_cleanup);
vector_cleanupd(&prev_row, Coin_cleanup);
return error;
}
static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index)
{
return tree->tree1d.data[index];
}
static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index)
{
return tree->lengths.data[index];
}
#endif /*LODEPNG_COMPILE_ENCODER*/
/*get the literal and length code tree of a deflated block with fixed tree, as specified in the deflate specification*/
static unsigned generateFixedLitLenTree(HuffmanTree* tree)
{
unsigned i, error = 0;
uivector bitlen;
uivector_init(&bitlen);
if(!uivector_resize(&bitlen, NUM_DEFLATE_CODE_SYMBOLS)) error = 9909;
if(!error)
{
/*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/
for(i = 0; i <= 143; i++) bitlen.data[i] = 8;
for(i = 144; i <= 255; i++) bitlen.data[i] = 9;
for(i = 256; i <= 279; i++) bitlen.data[i] = 7;
for(i = 280; i <= 287; i++) bitlen.data[i] = 8;
error = HuffmanTree_makeFromLengths(tree, bitlen.data, NUM_DEFLATE_CODE_SYMBOLS, 15);
}
uivector_cleanup(&bitlen);
return error;
}
/*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/
static unsigned generateFixedDistanceTree(HuffmanTree* tree)
{
unsigned i, error = 0;
uivector bitlen;
uivector_init(&bitlen);
if(!uivector_resize(&bitlen, NUM_DISTANCE_SYMBOLS)) error = 9910;
/*there are 32 distance codes, but 30-31 are unused*/
if(!error)
{
for(i = 0; i inbitlength) return (unsigned)(-1); /*error: end of input memory reached without endcode*/
/*
decode the symbol from the tree
the "readBitFromStream" code is inlined in the expression below because this is the biggest bottleneck while decoding
*/
ct = codetree->tree2d.data[(treepos << 1) + READBIT(*bp, in)];
(*bp)++;
if(ct numcodes) return ct; /*the symbol is decoded, return it*/
else treepos = ct - codetree->numcodes; /*symbol not yet decoded, instead move tree position*/
if(treepos >= codetree->numcodes) return (unsigned)(-1); /*error: it appeared outside the codetree*/
}
}
#endif /*LODEPNG_COMPILE_DECODER*/
#ifdef LODEPNG_COMPILE_DECODER
/* ////////////////////////////////////////////////////////////////////////// */
/* / Inflator / */
/* ////////////////////////////////////////////////////////////////////////// */
/*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/
static void getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d)
{
/*error checking not done, this is fixed stuff, it works, it doesn't depend on the image*/
/*TODO: out of memory errors could still happen...*/
generateFixedLitLenTree(tree_ll);
generateFixedDistanceTree(tree_d);
}
/*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/
static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d,
const unsigned char* in, size_t* bp, size_t inlength)
{
/*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/
unsigned error = 0;
unsigned n, HLIT, HDIST, HCLEN, i;
size_t inbitlength = inlength * 8;
/*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/
uivector bitlen_ll; /*lit,len code lengths*/
uivector bitlen_d; /*dist code lengths*/
uivector bitlen_cl; /*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/
HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/
if((*bp) >> 3 >= inlength - 2) return 49; /*the bit pointer is or will go past the memory*/
HLIT = readBitsFromStream(bp, in, 5) + 257; /*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/
HDIST = readBitsFromStream(bp, in, 5) + 1; /*number of distance codes. Unlike the spec, the value 1 is added to it here already*/
HCLEN = readBitsFromStream(bp, in, 4) + 4; /*number of code length codes. Unlike the spec, the value 4 is added to it here already*/
HuffmanTree_init(&tree_cl);
uivector_init(&bitlen_ll);
uivector_init(&bitlen_d);
uivector_init(&bitlen_cl);
while(!error)
{
/*read the code length codes out of 3 * (amount of code length codes) bits*/
if(!uivector_resize(&bitlen_cl, NUM_CODE_LENGTH_CODES)) ERROR_BREAK(9911);
for(i = 0; i < NUM_CODE_LENGTH_CODES; i++)
{
if(i < HCLEN) bitlen_cl.data[CLCL_ORDER[i]] = readBitsFromStream(bp, in, 3);
else bitlen_cl.data[CLCL_ORDER[i]] = 0; /*if not, it must stay 0*/
}
error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl.data, bitlen_cl.size, 7);
if(error) break;
/*now we can use this tree to read the lengths for the tree that this function will return*/
uivector_resizev(&bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS, 0);
uivector_resizev(&bitlen_d, NUM_DISTANCE_SYMBOLS, 0);
i = 0;
if(!bitlen_ll.data || !bitlen_d.data) ERROR_BREAK(9912); /*alloc fail*/
/*i is the current symbol we're reading in the part that contains the code lengths of lit/len codes and dist codes*/
while(i < HLIT + HDIST)
{
unsigned code = huffmanDecodeSymbol(in, bp, &tree_cl, inbitlength);
if(code <= 15) /*a length code*/
{
if(i > 3 >= inlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
replength += readBitsFromStream(bp, in, 2);
if((i - 1) < HLIT) value = bitlen_ll.data[i - 1];
else value = bitlen_d.data[i - HLIT - 1];
/*repeat this value in the next lengths*/
for(n = 0; n = HLIT + HDIST) ERROR_BREAK(13); /*error: i is larger than the amount of codes*/
if(i > 3 >= inlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
replength += readBitsFromStream(bp, in, 3);
/*repeat this value in the next lengths*/
for(n = 0; n = HLIT + HDIST) ERROR_BREAK(14); /*error: i is larger than the amount of codes*/
if(i > 3 >= inlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
replength += readBitsFromStream(bp, in, 7);
/*repeat this value in the next lengths*/
for(n = 0; n = HLIT + HDIST) ERROR_BREAK(15); /*error: i is larger than the amount of codes*/
if(i inlength * 8 ? 10 : 11; /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol (10=no endcode, 11=wrong jump outside of tree)*/
}
else error = 16; /*unexisting code, this can never happen*/
break;
}
}
if(error) break;
if(bitlen_ll.data[256] == 0) ERROR_BREAK(64); /*the length of the end code 256 must be larger than 0*/
/*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/
error = HuffmanTree_makeFromLengths(tree_ll, &bitlen_ll.data[0], bitlen_ll.size, 15);
if(error) break;
error = HuffmanTree_makeFromLengths(tree_d, &bitlen_d.data[0], bitlen_d.size, 15);
break; /*end of error-while*/
}
uivector_cleanup(&bitlen_cl);
uivector_cleanup(&bitlen_ll);
uivector_cleanup(&bitlen_d);
HuffmanTree_cleanup(&tree_cl);
return error;
}
/*inflate a block with dynamic of fixed Huffman tree*/
static unsigned inflateHuffmanBlock(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength, unsigned btype)
{
unsigned error = 0;
HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/
HuffmanTree tree_d; /*the huffman tree for distance codes*/
size_t inbitlength = inlength * 8;
HuffmanTree_init(&tree_ll);
HuffmanTree_init(&tree_d);
if(btype == 1) getTreeInflateFixed(&tree_ll, &tree_d);
else if(btype == 2)
{
error = getTreeInflateDynamic(&tree_ll, &tree_d, in, bp, inlength);
}
for(;;) /*decode all symbols until end reached*/
{
/*code_ll is literal, length or end code*/
unsigned code_ll = huffmanDecodeSymbol(in, bp, &tree_ll, inbitlength);
if(code_ll = out->size)
{
/*reserve more room at once*/
if(!ucvector_resize(out, ((*pos) + 1) * 2)) ERROR_BREAK(9913 /*alloc fail*/);
}
out->data[(*pos)] = (unsigned char)(code_ll);
(*pos)++;
}
else if(code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll > 3) >= inlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
length += readBitsFromStream(bp, in, numextrabits_l);
/*part 3: get distance code*/
code_d = huffmanDecodeSymbol(in, bp, &tree_d, inbitlength);
if(code_d > 29)
{
if(code_ll == (unsigned)(-1)) /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
{
error = (*bp) > inlength * 8 ? 10 : 11; /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol (10=no endcode, 11=wrong jump outside of tree)*/
}
else error = 18; /*error: invalid distance code (30-31 are never used)*/
break;
}
distance = DISTANCEBASE[code_d];
/*part 4: get extra bits from distance*/
numextrabits_d = DISTANCEEXTRA[code_d];
if(((*bp) >> 3) >= inlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
distance += readBitsFromStream(bp, in, numextrabits_d);
/*part 5: fill in all the out[n] values based on the length and dist*/
start = (*pos);
backward = start - distance;
if((*pos) + length >= out->size)
{
/*reserve more room at once*/
if(!ucvector_resize(out, ((*pos) + length) * 2)) ERROR_BREAK(9914 /*alloc fail*/);
}
for(forward = 0; forward data[(*pos)] = out->data[backward];
(*pos)++;
backward++;
if(backward >= start) backward = start - distance;
}
}
else if(code_ll == 256)
{
break; /*end code, break the loop*/
}
else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
{
error = (*bp) > inlength * 8 ? 10 : 11; /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol (10=no endcode, 11=wrong jump outside of tree)*/
break;
}
}
HuffmanTree_cleanup(&tree_ll);
HuffmanTree_cleanup(&tree_d);
return error;
}
static unsigned inflateNoCompression(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength)
{
/*go to first boundary of byte*/
size_t p;
unsigned LEN, NLEN, n, error = 0;
while(((*bp) & 0x7) != 0) (*bp)++;
p = (*bp) / 8; /*byte position*/
/*read LEN (2 bytes) and NLEN (2 bytes)*/
if(p >= inlength - 4) return 52; /*error, bit pointer will jump past memory*/
LEN = in[p] + 256 * in[p + 1]; p += 2;
NLEN = in[p] + 256 * in[p + 1]; p += 2;
/*check if 16-bit NLEN is really the one's complement of LEN*/
if(LEN + NLEN != 65535) return 21; /*error: NLEN is not one's complement of LEN*/
if((*pos) + LEN >= out->size)
{
if(!ucvector_resize(out, (*pos) + LEN)) return 9915;
}
/*read the literal data: LEN bytes are now stored in the out buffer*/
if(p + LEN > inlength) return 23; /*error: reading outside of in buffer*/
for(n = 0; n data[(*pos)++] = in[p++];
(*bp) = p * 8;
return error;
}
/*inflate the deflated data (cfr. deflate spec); return value is the error*/
unsigned LodeFlate_inflate(ucvector* out, const unsigned char* in, size_t insize, size_t inpos)
{
size_t bp = 0; /*bit pointer in the "in" data, current byte is bp >> 3, current bit is bp & 0x7 (from lsb to msb of the byte)*/
unsigned BFINAL = 0;
size_t pos = 0; /*byte position in the out buffer*/
unsigned error = 0;
while(!BFINAL)
{
unsigned BTYPE;
if(bp + 2 >= insize * 8) return 52; /*error, bit pointer will jump past memory*/
BFINAL = readBitFromStream(&bp, &in[inpos]);
BTYPE = 1 * readBitFromStream(&bp, &in[inpos]);
BTYPE += 2 * readBitFromStream(&bp, &in[inpos]);
if(BTYPE == 3) return 20; /*error: invalid BTYPE*/
else if(BTYPE == 0) error = inflateNoCompression(out, &in[inpos], &bp, &pos, insize); /*no compression*/
else error = inflateHuffmanBlock(out, &in[inpos], &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/
if(error) return error;
}
/*Only now we know the true size of out, resize it to that*/
if(!ucvector_resize(out, pos)) error = 9916;
return error;
}
#endif /*LODEPNG_COMPILE_DECODER*/
#ifdef LODEPNG_COMPILE_ENCODER
/* ////////////////////////////////////////////////////////////////////////// */
/* / Deflator / */
/* ////////////////////////////////////////////////////////////////////////// */
static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258;
/*bitlen is the size in bits of the code*/
static void addHuffmanSymbol(size_t* bp, ucvector* compressed, unsigned code, unsigned bitlen)
{
addBitsToStreamReversed(bp, compressed, code, bitlen);
}
/*search the index in the array, that has the largest value smaller than or equal to the given value, given array must be sorted (if no value is smaller, it returns the size of the given array)*/
static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value)
{
/*linear search implementation*/
/*for(size_t i = 1; i value) return i - 1;
return array_size - 1;*/
/*binary search implementation (not that much faster) (precondition: array_size > 0)*/
size_t left = 1;
size_t right = array_size - 1;
while(left <= right)
{
size_t mid = (left + right) / 2;
if(array[mid] value) right = mid - 1; /*the value to find is more to the left*/
else return mid - 1;
}
return array_size - 1;
}
static void addLengthDistance(uivector* values, size_t length, size_t distance)
{
/*values in encoded vector are those used by deflate:
0-255: literal bytes
256: end
257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits)
286-287: invalid*/
unsigned length_code = (unsigned)searchCodeIndex(LENGTHBASE, 29, length);
unsigned extra_length = (unsigned)(length - LENGTHBASE[length_code]);
unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance);
unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]);
uivector_push_back(values, length_code + FIRST_LENGTH_CODE_INDEX);
uivector_push_back(values, extra_length);
uivector_push_back(values, dist_code);
uivector_push_back(values, extra_distance);
}
#if 0
/*the "brute force" version of the encodeLZ7 algorithm, not used anymore, kept here for reference*/
static void encodeLZ77_brute(uivector* out, const unsigned char* in, size_t insize, unsigned windowSize)
{
size_t pos;
/*using pointer instead of vector for input makes it faster when NOT using optimization when compiling; no influence if optimization is used*/
for(pos = 0; pos < insize; pos++)
{
size_t length = 0, offset = 0; /*the length and offset found for the current position*/
size_t max_offset = pos < windowSize ? pos : windowSize; /*how far back to test*/
size_t current_offset;
/**search for the longest string**/
for(current_offset = 1; current_offset < max_offset; current_offset++) /*search backwards through all possible distances (=offsets)*/
{
size_t backpos = pos - current_offset;
if(in[backpos] == in[pos])
{
/*test the next characters*/
size_t current_length = 1;
size_t backtest = backpos + 1;
size_t foretest = pos + 1;
while(foretest < insize && in[backtest] == in[foretest] && current_length = pos) backpos -= current_offset; /*continue as if we work on the decoded bytes after pos by jumping back before pos*/
current_length++;
backtest++;
foretest++;
}
if(current_length > length)
{
length = current_length; /*the longest length*/
offset = current_offset; /*the offset that is related to this longest length*/
if(current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break; /*you can jump out of this for loop once a length of max length is found (gives significant speed gain)*/
}
}
}
/**encode it as length/distance pair or literal value**/
if(length = size) return 0;
amount = HASH_NUM_CHARACTERS;
if(pos + amount >= size) amount = size - pos;
for(i = 0; i < amount; i++) result ^= (data[pos + i] < size - pos) max_count = size - pos;
for(i = 0; i < max_count; i++)
{
if(data[pos + i] != 0)
return (unsigned int)i;
}
return (unsigned int)max_count;
}
/*LZ77-encode the data using a hash table technique to let it encode faster. Return value is error code*/
static unsigned encodeLZ77(uivector* out, const unsigned char* in, size_t insize, unsigned windowSize)
{
/**generate hash table**/
vector table; /*HASH_NUM_VALUES uivectors; this represents what would be an std::vector<std::vector > in C++*/
uivector tablepos1, tablepos2;
uivector initialZerosTable; /*hash == 0 indicates a possible common case of a long sequence of zeros, store and use the amount here for a speedup*/
unsigned pos, i, error = 0;
vector_init(&table, sizeof(uivector));
if(!vector_resize(&table, HASH_NUM_VALUES)) return 9917;
for(i = 0; i < HASH_NUM_VALUES; i++)
{
uivector* v = (uivector*)vector_get(&table, i);
uivector_init(v);
}
/*remember start and end positions in the tables to search in*/
uivector_init(&tablepos1);
uivector_init(&tablepos2);
uivector_init(&initialZerosTable);
if(!uivector_resizev(&tablepos1, HASH_NUM_VALUES, 0)) error = 9918;
if(!uivector_resizev(&tablepos2, HASH_NUM_VALUES, 0)) error = 9919;
if(!error)
{
unsigned length, offset, tablepos, max_offset;
unsigned hash, initialZeros;
unsigned backpos, current_offset, t1, t2, skip, current_length;
const unsigned char *lastptr, *foreptr, *backptr;
for(pos = 0; pos < insize; pos++)
{
length = 0, offset = 0; /*the length and offset found for the current position*/
max_offset = pos data[tablepos1.data[hash]] data[tablepos2.data[hash]] < pos)
{
tablepos2.data[hash]++; /*it now points to the first value in the table for which the index is larger than or equal to pos*/
}
t1 = tablepos1.data[hash];
t2 = tablepos2.data[hash];
lastptr = &in[insize = t1 && tablepos data[tablepos];
current_offset = pos - backpos;
/*test the next characters*/
foreptr = &in[pos];
backptr = &in[backpos];
if(hash == 0)
{
skip = initialZerosTable.data[tablepos];
if(skip > initialZeros) skip = initialZeros;
if(skip > insize - pos) skip = (unsigned int)(insize - pos);
backptr += skip;
foreptr += skip;
}
while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/
{
++backptr;
++foreptr;
}
current_length = (unsigned)(foreptr - &in[pos]);
if(current_length > length)
{
length = current_length; /*the longest length*/
offset = current_offset; /*the offset that is related to this longest length*/
if(current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break; /*you can jump out of this for loop once a length of max length is found (gives significant speed gain)*/
}
}
/**encode it as length/distance pair or literal value**/
if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/
{
if(!uivector_push_back(out, in[pos])) ERROR_BREAK(9921 /*alloc fail*/);
}
else
{
unsigned j, local_hash;
addLengthDistance(out, length, offset);
for(j = 0; j < length - 1; j++)
{
pos++;
local_hash = getHash(in, insize, pos);
if(!uivector_push_back((uivector*)vector_get(&table, local_hash), pos)) ERROR_BREAK(9922 /*alloc fail*/);
if(local_hash == 0)
{
if(!uivector_push_back(&initialZerosTable, countInitialZeros(in, insize, pos))) ERROR_BREAK(9922 /*alloc fail*/);
}
}
}
} /*end of the loop through each character of input*/
} /*end of "if(!error)"*/
/*cleanup*/
for(i = 0; i < table.size; i++)
{
uivector* v = (uivector*)vector_get(&table, i);
uivector_cleanup(v);
}
vector_cleanup(&table);
uivector_cleanup(&tablepos1);
uivector_cleanup(&tablepos2);
uivector_cleanup(&initialZerosTable);
return error;
}
/* /////////////////////////////////////////////////////////////////////////// */
static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize)
{
/*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte, 2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/
size_t i, j, numdeflateblocks = datasize / 65536 + 1;
unsigned datapos = 0;
for(i = 0; i < numdeflateblocks; i++)
{
unsigned BFINAL, BTYPE, LEN, NLEN;
unsigned char firstbyte;
BFINAL = (i == numdeflateblocks - 1);
BTYPE = 0;
firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1));
ucvector_push_back(out, firstbyte);
LEN = 65535;
if(datasize - datapos < 65535) LEN = (unsigned)datasize - datapos;
NLEN = 65535 - LEN;
ucvector_push_back(out, (unsigned char)(LEN % 256));
ucvector_push_back(out, (unsigned char)(LEN / 256));
ucvector_push_back(out, (unsigned char)(NLEN % 256));
ucvector_push_back(out, (unsigned char)(NLEN / 256));
/*Decompressed data*/
for(j = 0; j < 65535 && datapos < datasize; j++)
{
ucvector_push_back(out, data[datapos++]);
}
}
return 0;
}
/*
write the lz77-encoded data, which has lit, len and dist codes, to compressed stream using huffman trees.
tree_ll: the tree for lit and len codes.
tree_d: the tree for distance codes.
*/
static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encoded, const HuffmanTree* tree_ll, const HuffmanTree* tree_d)
{
size_t i = 0;
for(i = 0; i size; i++)
{
unsigned val = lz77_encoded->data[i];
addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_ll, val), HuffmanTree_getLength(tree_ll, val));
if(val > 256) /*for a length code, 3 more things have to be added*/
{
unsigned length_index = val - FIRST_LENGTH_CODE_INDEX;
unsigned n_length_extra_bits = LENGTHEXTRA[length_index];
unsigned length_extra_bits = lz77_encoded->data[++i];
unsigned distance_code = lz77_encoded->data[++i];
unsigned distance_index = distance_code;
unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index];
unsigned distance_extra_bits = lz77_encoded->data[++i];
addBitsToStream(bp, out, length_extra_bits, n_length_extra_bits);
addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_d, distance_code), HuffmanTree_getLength(tree_d, distance_code));
addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits);
}
}
}
/*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/
static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t datasize, const LodeZlib_CompressSettings* settings)
{
unsigned error = 0;
/*
A block is compressed as follows: The PNG data is lz77 encoded, resulting in
literal bytes and length/distance pairs. This is then huffman compressed with
two huffman trees. One huffman tree is used for the lit and len values ("ll"),
another huffman tree is used for the dist values ("d"). These two trees are
stored using their code lengths, and to compress even more these code lengths
are also run-length encoded and huffman compressed. This gives a huffman tree
of code lengths "cl". The code lenghts used to describe this third tree are
the code length code lengths ("clcl").
*/
uivector lz77_encoded; /*The lz77 encoded data, represented with integers since there will also be length and distance codes in it*/
HuffmanTree tree_ll; /*tree for lit,len values*/
HuffmanTree tree_d; /*tree for distance codes*/
HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/
uivector frequencies_ll; /*frequency of lit,len codes*/
uivector frequencies_d; /*frequency of dist codes*/
uivector frequencies_cl; /*frequency of code length codes*/
uivector bitlen_lld; /*lit,len,dist code lenghts (int bits), literally (without repeat codes).*/
uivector bitlen_lld_e; /*bitlen_lld encoded with repeat codes (shorter: this is a rudemtary run length compression)*/
uivector bitlen_cl; /*code length code lengths ("clcl"). The bit lengths of codes to represent tree_cl (these are written as is in the file, it would be crazy to compress these using yet another huffman tree that needs to be represented by yet another set of code lengths)*/
/*
Due to the huffman compression of huffman tree representations ("two levels"), there are some anologies:
bitlen_lld is to tree_cl what data is to tree_ll and tree_d.
bitlen_lld_e is to bitlen_lld what lz77_encoded is to data.
bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded.
*/
unsigned BFINAL = 1; /*make only one block... the first and final one*/
size_t numcodes_ll, numcodes_d, i;
size_t bp = 0; /*the bit pointer*/
unsigned HLIT, HDIST, HCLEN;
uivector_init(&lz77_encoded);
HuffmanTree_init(&tree_ll);
HuffmanTree_init(&tree_d);
HuffmanTree_init(&tree_cl);
uivector_init(&frequencies_ll);
uivector_init(&frequencies_d);
uivector_init(&frequencies_cl);
uivector_init(&bitlen_lld);
uivector_init(&bitlen_lld_e);
uivector_init(&bitlen_cl);
/*This while loop is never loops due to a break at the end, it is here to allow breaking out of it to the cleanup phase on error conditions.*/
while(!error)
{
if(settings->useLZ77)
{
error = encodeLZ77(&lz77_encoded, data, datasize, settings->windowSize); /*LZ77 encoded*/
if(error) break;
}
else
{
if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(9923 /*alloc fail*/);
for(i = 0; i < datasize; i++) lz77_encoded.data[i] = data[i]; /*no LZ77, but still will be Huffman compressed*/
}
if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(9924 /*alloc fail*/);
if(!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(9925 /*alloc fail*/);
/*Count the frequencies of lit, len and dist codes*/
for(i = 0; i 256)
{
unsigned dist = lz77_encoded.data[i + 2];
frequencies_d.data[dist]++;
i += 3;
}
}
frequencies_ll.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/
/*Make both huffman trees, one for the lit and len codes, one for the dist codes*/
error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll.data, frequencies_ll.size, 15);
if(error) break;
error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, frequencies_d.size, 15);
if(error) break;
numcodes_ll = tree_ll.numcodes; if(numcodes_ll > 286) numcodes_ll = 286;
numcodes_d = tree_d.numcodes; if(numcodes_d > 30) numcodes_d = 30;
/*store the code lengths of both generated trees in bitlen_lld*/
for(i = 0; i < numcodes_ll; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_ll, (unsigned)i));
for(i = 0; i < numcodes_d; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_d, (unsigned)i));
/*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times), 17 (3-10 zeroes), 18 (11-138 zeroes)*/
for(i = 0; i < (unsigned)bitlen_lld.size; i++)
{
unsigned j = 0; /*amount of repititions*/
while(i + j + 1 = 2) /*repeat code for zeroes*/
{
j++; /*include the first zero*/
if(j 138) j = 138;
uivector_push_back(&bitlen_lld_e, 18);
uivector_push_back(&bitlen_lld_e, j - 11);
}
i += (j - 1);
}
else if(j >= 3) /*repeat code for value other than zero*/
{
size_t k;
unsigned num = j / 6, rest = j % 6;
uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
for(k = 0; k = 3)
{
uivector_push_back(&bitlen_lld_e, 16);
uivector_push_back(&bitlen_lld_e, rest - 3);
}
else j -= rest;
i += j;
}
else /*too short to benefit from repeat code*/
{
uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
}
}
/*generate tree_cl, the huffmantree of huffmantrees*/
if(!uivector_resizev(&frequencies_cl, NUM_CODE_LENGTH_CODES, 0)) ERROR_BREAK(9926 /*alloc fail*/);
for(i = 0; i = 16) i++;
}
error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl.data, frequencies_cl.size, 7);
if(error) break;
if(!uivector_resize(&bitlen_cl, NUM_CODE_LENGTH_CODES)) ERROR_BREAK(9927 /*alloc fail*/);
for(i = 0; i 4)
{
/*remove zeros at the end, but minimum size must be 4*/
if(!uivector_resize(&bitlen_cl, bitlen_cl.size - 1)) ERROR_BREAK(9928 /*alloc fail*/);
}
if(error) break;
/*
Write everything into the output
After the BFINAL and BTYPE, the dynamic block consists out of the following:
- 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN
- (HCLEN+4)*3 bits code lengths of code length alphabet
- HLIT + 257 code lenghts of lit/length alphabet (encoded using the code length alphabet, + possible repetition codes 16, 17, 18)
- HDIST + 1 code lengths of distance alphabet (encoded using the code length alphabet, + possible repetition codes 16, 17, 18)
- compressed data
- 256 (end code)
*/
/*Write block type*/
addBitToStream(&bp, out, BFINAL);
addBitToStream(&bp, out, 0); /*first bit of BTYPE "dynamic"*/
addBitToStream(&bp, out, 1); /*second bit of BTYPE "dynamic"*/
/*write the HLIT, HDIST and HCLEN values*/
HLIT = (unsigned)(numcodes_ll - 257);
HDIST = (unsigned)(numcodes_d - 1);
HCLEN = (unsigned)bitlen_cl.size - 4;
addBitsToStream(&bp, out, HLIT, 5);
addBitsToStream(&bp, out, HDIST, 5);
addBitsToStream(&bp, out, HCLEN, 4);
/*write the code lenghts of the code length alphabet*/
for(i = 0; i < HCLEN + 4; i++) addBitsToStream(&bp, out, bitlen_cl.data[i], 3);
/*write the lenghts of the lit/len AND the dist alphabet*/
for(i = 0; i useLZ77) /*LZ77 encoded*/
{
uivector lz77_encoded;
uivector_init(&lz77_encoded);
error = encodeLZ77(&lz77_encoded, data, datasize, settings->windowSize);
if(!error) writeLZ77data(&bp, out, &lz77_encoded, &tree_ll, &tree_d);
uivector_cleanup(&lz77_encoded);
}
else /*no LZ77, but still will be Huffman compressed*/
{
for(i = 0; i btype == 0) error = deflateNoCompression(out, data, datasize);
else if(settings->btype == 1) error = deflateFixed(out, data, datasize, settings);
else if(settings->btype == 2) error = deflateDynamic(out, data, datasize, settings);
else error = 61;
return error;
}
#endif /*LODEPNG_COMPILE_DECODER*/
/* ////////////////////////////////////////////////////////////////////////// */
/* / Adler32 */
/* ////////////////////////////////////////////////////////////////////////// */
static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len)
{
unsigned s1 = adler & 0xffff;
unsigned s2 = (adler >> 16) & 0xffff;
while(len > 0)
{
/*at least 5550 sums can be done before the sums overflow, saving us from a lot of module divisions*/
unsigned amount = len > 5550 ? 5550 : len;
len -= amount;
while(amount > 0)
{
s1 = (s1 + *data++);
s2 = (s2 + s1);
amount--;
}
s1 %= 65521;
s2 %= 65521;
}
return (s2 <> 24) & 0xff));
ucvector_push_back(buffer, (unsigned char)((value >> 16) & 0xff));
ucvector_push_back(buffer, (unsigned char)((value >> 8) & 0xff));
ucvector_push_back(buffer, (unsigned char)((value ) & 0xff));
}
#endif /*LODEPNG_COMPILE_ENCODER*/
unsigned LodeZlib_read32bitInt(const unsigned char* buffer)
{
return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];
}
/* ////////////////////////////////////////////////////////////////////////// */
/* / Zlib / */
/* ////////////////////////////////////////////////////////////////////////// */
#ifdef LODEPNG_COMPILE_DECODER
unsigned LodeZlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DecompressSettings* settings)
{
unsigned error = 0;
unsigned CM, CINFO, FDICT;
ucvector outv;
if(insize > 4) & 15;
/*FCHECK = in[1] & 31; //FCHECK is already tested above*/
FDICT = (in[1] >> 5) & 1;
/*FLEVEL = (in[1] >> 6) & 3; //not really important, all it does it to give a compiler warning about unused variable, we don't care what encoding setting the encoder used*/
if(CM != 8 || CINFO > 7) return 25; /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/
if(FDICT != 0) return 26; /*error: the specification of PNG says about the zlib stream: "The additional flags shall not specify a preset dictionary."*/
ucvector_init_buffer(&outv, *out, *outsize); /*ucvector-controlled version of the output buffer, for dynamic array*/
error = LodeFlate_inflate(&outv, in, insize, 2);
*out = outv.data;
*outsize = outv.size;
if(error) return error;
if(!settings->ignoreAdler32)
{
unsigned ADLER32 = LodeZlib_read32bitInt(&in[insize - 4]);
unsigned checksum = adler32(outv.data, (unsigned)outv.size);
if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/
}
return 0; /*no error*/
}
#endif /*LODEPNG_COMPILE_DECODER*/
#ifdef LODEPNG_COMPILE_ENCODER
unsigned LodeZlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_CompressSettings* settings)
{
/*initially, *out must be NULL and outsize 0, if you just give some random *out that's pointing to a non allocated buffer, this'll crash*/
ucvector deflatedata, outv;
size_t i;
unsigned error;
unsigned ADLER32;
/*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/
unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/
unsigned FLEVEL = 0;
unsigned FDICT = 0;
unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64;
unsigned FCHECK = 31 - CMFFLG % 31;
CMFFLG += FCHECK;
ucvector_init_buffer(&outv, *out, *outsize); /*ucvector-controlled version of the output buffer, for dynamic array*/
ucvector_push_back(&outv, (unsigned char)(CMFFLG / 256));
ucvector_push_back(&outv, (unsigned char)(CMFFLG % 256));
ucvector_init(&deflatedata);
error = LodeFlate_deflate(&deflatedata, in, insize, settings);
if(!error)
{
ADLER32 = adler32(in, (unsigned)insize);
for(i = 0; i btype = 2; /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/
settings->useLZ77 = 1;
settings->windowSize = 2048; /*this is a good tradeoff between speed and compression ratio*/
}
const LodeZlib_CompressSettings LodeZlib_defaultCompressSettings = {2, 1, 2048};
#endif /*LODEPNG_COMPILE_ENCODER*/
#ifdef LODEPNG_COMPILE_DECODER
void LodeZlib_DecompressSettings_init(LodeZlib_DecompressSettings* settings)
{
settings->ignoreAdler32 = 0;
}
const LodeZlib_DecompressSettings LodeZlib_defaultDecompressSettings = {0};
#endif /*LODEPNG_COMPILE_DECODER*/
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* // End of Zlib related code, now comes the PNG related code that uses it// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
/* ////////////////////////////////////////////////////////////////////////// */
#ifdef LODEPNG_COMPILE_PNG
/*
The two functions below (LodePNG_decompress and LodePNG_compress) directly call the
LodeZlib_decompress and LodeZlib_compress functions. The only purpose of the functions
below, is to provide the ability to let LodePNG use a different Zlib encoder by only
changing the two functions below, instead of changing it inside the vareous places
in the other LodePNG functions.
*out must be NULL and *outsize must be 0 initially, and after the function is done,
*out must point to the decompressed data, *outsize must be the size of it, and must
be the size of the useful data in bytes, not the alloc size.
*/
#ifdef LODEPNG_COMPILE_DECODER
static unsigned LodePNG_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DecompressSettings* settings)
{
/*replace this by custom function call to use an alterntive zlib codec*/
return LodeZlib_decompress(out, outsize, in, insize, settings);
}
#endif /*LODEPNG_COMPILE_DECODER*/
#ifdef LODEPNG_COMPILE_ENCODER
static unsigned LodePNG_compress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_CompressSettings* settings)
{
/*replace this by custom function call to use an alterntive zlib codec*/
return LodeZlib_compress(out, outsize, in, insize, settings);
}
#endif /*LODEPNG_COMPILE_ENCODER*/
/* ////////////////////////////////////////////////////////////////////////// */
/* / CRC32 / */
/* ////////////////////////////////////////////////////////////////////////// */
static unsigned Crc32_crc_table_computed = 0;
static unsigned Crc32_crc_table[256];
/*Make the table for a fast CRC.*/
static void Crc32_make_crc_table(void)
{
unsigned c, k, n;
for(n = 0; n < 256; n++)
{
c = n;
for(k = 0; k > 1);
else c = c >> 1;
}
Crc32_crc_table[n] = c;
}
Crc32_crc_table_computed = 1;
}
/*Update a running CRC with the bytes buf[0..len-1]--the CRC should be
initialized to all 1's, and the transmitted value is the 1's complement of the
final running CRC (see the crc() routine below).*/
static unsigned Crc32_update_crc(const unsigned char* buf, unsigned crc, size_t len)
{
unsigned c = crc;
size_t n;
if(!Crc32_crc_table_computed) Crc32_make_crc_table();
for(n = 0; n > 8);
}
return c;
}
/*Return the CRC of the bytes buf[0..len-1].*/
static unsigned Crc32_crc(const unsigned char* buf, size_t len)
{
return Crc32_update_crc(buf, 0xffffffffL, len) ^ 0xffffffffL;
}
/* ////////////////////////////////////////////////////////////////////////// */
/* / Reading and writing single bits and bytes from/to stream for LodePNG / */
/* ////////////////////////////////////////////////////////////////////////// */
static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream)
{
unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1);
(*bitpointer)++;
return result;
}
static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
{
unsigned result = 0;
size_t i;
for(i = nbits - 1; i < nbits; i--)
{
result += (unsigned)readBitFromReversedStream(bitpointer, bitstream) <> 3] |= (bit <> 3] &= (unsigned char)(~(1 <> 3] |= (1 << (7 - ((*bitpointer) & 0x7)));
(*bitpointer)++;
}
static unsigned LodePNG_read32bitInt(const unsigned char* buffer)
{
return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] <> 24) & 0xff);
buffer[1] = (unsigned char)((value >> 16) & 0xff);
buffer[2] = (unsigned char)((value >> 8) & 0xff);
buffer[3] = (unsigned char)((value ) & 0xff);
}
#ifdef LODEPNG_COMPILE_ENCODER
static void LodePNG_add32bitInt(ucvector* buffer, unsigned value)
{
ucvector_resize(buffer, buffer->size + 4); /*todo: give error if resize failed*/
LodePNG_set32bitInt(&buffer->data[buffer->size - 4], value);
}
#endif /*LODEPNG_COMPILE_ENCODER*/
/* ////////////////////////////////////////////////////////////////////////// */
/* / PNG chunks / */
/* ////////////////////////////////////////////////////////////////////////// */
unsigned LodePNG_chunk_length(const unsigned char* chunk) /*get the length of the data of the chunk. Total chunk length has 12 bytes more.*/
{
return LodePNG_read32bitInt(&chunk[0]);
}
void LodePNG_chunk_type(char type[5], const unsigned char* chunk) /*puts the 4-byte type in null terminated string*/
{
unsigned i;
for(i = 0; i < 4; i++) type[i] = chunk[4 + i];
type[4] = 0; /*null termination char*/
}
unsigned char LodePNG_chunk_type_equals(const unsigned char* chunk, const char* type) /*check if the type is the given type*/
{
if(strlen(type) != 4) return 0;
return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]);
}
/*properties of PNG chunks gotten from capitalization of chunk type name, as defined by the standard*/
unsigned char LodePNG_chunk_critical(const unsigned char* chunk) /*0: ancillary chunk, 1: it's one of the critical chunk types*/
{
return((chunk[4] & 32) == 0);
}
unsigned char LodePNG_chunk_private(const unsigned char* chunk) /*0: public, 1: private*/
{
return((chunk[6] & 32) != 0);
}
unsigned char LodePNG_chunk_safetocopy(const unsigned char* chunk) /*0: the chunk is unsafe to copy, 1: the chunk is safe to copy*/
{
return((chunk[7] & 32) != 0);
}
unsigned char* LodePNG_chunk_data(unsigned char* chunk) /*get pointer to the data of the chunk*/
{
return &chunk[8];
}
const unsigned char* LodePNG_chunk_data_const(const unsigned char* chunk) /*get pointer to the data of the chunk*/
{
return &chunk[8];
}
unsigned LodePNG_chunk_check_crc(const unsigned char* chunk) /*returns 0 if the crc is correct, error code if it's incorrect*/
{
unsigned length = LodePNG_chunk_length(chunk);
unsigned CRC = LodePNG_read32bitInt(&chunk[length + 8]);
unsigned checksum = Crc32_crc(&chunk[4], length + 4); /*the CRC is taken of the data and the 4 chunk type letters, not the length*/
if(CRC != checksum) return 1;
else return 0;
}
void LodePNG_chunk_generate_crc(unsigned char* chunk) /*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/
{
unsigned length = LodePNG_chunk_length(chunk);
unsigned CRC = Crc32_crc(&chunk[4], length + 4);
LodePNG_set32bitInt(chunk + 8 + length, CRC);
}
unsigned char* LodePNG_chunk_next(unsigned char* chunk) /*don't use on IEND chunk, as there is no next chunk then*/
{
unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
return &chunk[total_chunk_length];
}
const unsigned char* LodePNG_chunk_next_const(const unsigned char* chunk) /*don't use on IEND chunk, as there is no next chunk then*/
{
unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
return &chunk[total_chunk_length];
}
unsigned LodePNG_append_chunk(unsigned char** out, size_t* outlength, const unsigned char* chunk) /*appends chunk that was already created, to the data. Returns error code.*/
{
unsigned i;
unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
unsigned char *chunk_start, *new_buffer;
size_t new_length = (*outlength) + total_chunk_length;
if(new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/
new_buffer = (unsigned char*)realloc(*out, new_length);
if(!new_buffer) return 9929; /*alloc fail*/
(*out) = new_buffer;
(*outlength) = new_length;
chunk_start = &(*out)[new_length - total_chunk_length];
for(i = 0; i < total_chunk_length; i++) chunk_start[i] = chunk[i];
return 0;
}
unsigned LodePNG_create_chunk(unsigned char** out, size_t* outlength, unsigned length, const char* type, const unsigned char* data) /*appends new chunk to out. Returns error code; may change memory address of out buffer*/
{
unsigned i;
unsigned char *chunk, *new_buffer;
size_t new_length = (*outlength) + length + 12;
if(new_length < length + 12 || new_length < (*outlength)) return 77; /*integer overflow happened*/
new_buffer = (unsigned char*)realloc(*out, new_length);
if(!new_buffer) return 9930; /*alloc fail*/
(*out) = new_buffer;
(*outlength) = new_length;
chunk = &(*out)[(*outlength) - length - 12];
/*1: length*/
LodePNG_set32bitInt(chunk, (unsigned)length);
/*2: chunk name (4 letters)*/
chunk[4] = type[0];
chunk[5] = type[1];
chunk[6] = type[2];
chunk[7] = type[3];
/*3: the data*/
for(i = 0; i key_defined = 0;
info->key_r = info->key_g = info->key_b = 0;
info->colorType = 6;
info->bitDepth = 8;
info->palette = 0;
info->palettesize = 0;
}
void LodePNG_InfoColor_cleanup(LodePNG_InfoColor* info)
{
LodePNG_InfoColor_clearPalette(info);
}
void LodePNG_InfoColor_clearPalette(LodePNG_InfoColor* info)
{
if(info->palette) free(info->palette);
info->palettesize = 0;
}
unsigned LodePNG_InfoColor_addPalette(LodePNG_InfoColor* info, unsigned char r, unsigned char g, unsigned char b, unsigned char a)
{
unsigned char* data;
/*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with the max of 256 colors, it'll have the exact alloc size*/
if(!(info->palettesize & (info->palettesize - 1))) /*if palettesize is 0 or a power of two*/
{
/*allocated data must be at least 4* palettesize (for 4 color bytes)*/
size_t alloc_size = info->palettesize == 0 ? 4 : info->palettesize * 4 * 2;
data = (unsigned char*)realloc(info->palette, alloc_size);
if(!data) return 9931; /*alloc fail*/
else info->palette = data;
}
info->palette[4 * info->palettesize + 0] = r;
info->palette[4 * info->palettesize + 1] = g;
info->palette[4 * info->palettesize + 2] = b;
info->palette[4 * info->palettesize + 3] = a;
info->palettesize++;
return 0;
}
unsigned LodePNG_InfoColor_getBpp(const LodePNG_InfoColor* info)
{
return getBpp(info->colorType, info->bitDepth); /*calculate bits per pixel out of colorType and bitDepth*/
}
unsigned LodePNG_InfoColor_getChannels(const LodePNG_InfoColor* info)
{
return getNumColorChannels(info->colorType);
}
unsigned LodePNG_InfoColor_isGreyscaleType(const LodePNG_InfoColor* info)
{
return info->colorType == 0 || info->colorType == 4;
}
unsigned LodePNG_InfoColor_isAlphaType(const LodePNG_InfoColor* info)
{
return (info->colorType & 4) != 0;
}
unsigned LodePNG_InfoColor_isPaletteType(const LodePNG_InfoColor* info)
{
return info->colorType == 3;
}
unsigned LodePNG_InfoColor_hasPaletteAlpha(const LodePNG_InfoColor* info)
{
size_t i;
for(i = 0; i palettesize; i++)
{
if(info->palette[i * 4 + 3] key_defined
|| LodePNG_InfoColor_isAlphaType(info)
|| LodePNG_InfoColor_hasPaletteAlpha(info);
}
unsigned LodePNG_InfoColor_equal(const LodePNG_InfoColor* info1, const LodePNG_InfoColor* info2)
{
return info1->colorType == info2->colorType
&& info1->bitDepth == info2->bitDepth; /*palette and color key not compared*/
}
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
void LodePNG_UnknownChunks_init(LodePNG_UnknownChunks* chunks)
{
unsigned i;
for(i = 0; i data[i] = 0;
for(i = 0; i datasize[i] = 0;
}
void LodePNG_UnknownChunks_cleanup(LodePNG_UnknownChunks* chunks)
{
unsigned i;
for(i = 0; i data[i]);
}
unsigned LodePNG_UnknownChunks_copy(LodePNG_UnknownChunks* dest, const LodePNG_UnknownChunks* src)
{
unsigned i;
LodePNG_UnknownChunks_cleanup(dest);
for(i = 0; i datasize[i] = src->datasize[i];
dest->data[i] = (unsigned char*)malloc(src->datasize[i]);
if(!dest->data[i] && dest->datasize[i]) return 9932; /*alloc fail*/
for(j = 0; j datasize[i]; j++) dest->data[i][j] = src->data[i][j];
}
return 0;
}
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
void LodePNG_Text_init(LodePNG_Text* text)
{
text->num = 0;
text->keys = NULL;
text->strings = NULL;
}
void LodePNG_Text_cleanup(LodePNG_Text* text)
{
LodePNG_Text_clear(text);
}
unsigned LodePNG_Text_copy(LodePNG_Text* dest, const LodePNG_Text* source)
{
size_t i = 0;
dest->keys = 0;
dest->strings = 0;
dest->num = 0;
for(i = 0; i num; i++)
{
unsigned error = LodePNG_Text_add(dest, source->keys[i], source->strings[i]);
if(error) return error;
}
return 0;
}
void LodePNG_Text_clear(LodePNG_Text* text)
{
size_t i;
for(i = 0; i num; i++)
{
string_cleanup(&text->keys[i]);
string_cleanup(&text->strings[i]);
}
free(text->keys);
free(text->strings);
}
unsigned LodePNG_Text_add(LodePNG_Text* text, const char* key, const char* str)
{
char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1)));
char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1)));
if(!new_keys || !new_strings)
{
free(new_keys);
free(new_strings);
return 9933; /*alloc fail*/
}
text->num++;
text->keys = new_keys;
text->strings = new_strings;
string_init(&text->keys[text->num - 1]);
string_set(&text->keys[text->num - 1], key);
string_init(&text->strings[text->num - 1]);
string_set(&text->strings[text->num - 1], str);
return 0;
}
/******************************************************************************/
void LodePNG_IText_init(LodePNG_IText* text)
{
text->num = 0;
text->keys = NULL;
text->langtags = NULL;
text->transkeys = NULL;
text->strings = NULL;
}
void LodePNG_IText_cleanup(LodePNG_IText* text)
{
LodePNG_IText_clear(text);
}
unsigned LodePNG_IText_copy(LodePNG_IText* dest, const LodePNG_IText* source)
{
size_t i = 0;
dest->keys = 0;
dest->langtags = 0;
dest->transkeys = 0;
dest->strings = 0;
dest->num = 0;
for(i = 0; i num; i++)
{
unsigned error = LodePNG_IText_add(dest, source->keys[i], source->langtags[i], source->transkeys[i], source->strings[i]);
if(error) return error;
}
return 0;
}
void LodePNG_IText_clear(LodePNG_IText* text)
{
size_t i;
for(i = 0; i num; i++)
{
string_cleanup(&text->keys[i]);
string_cleanup(&text->langtags[i]);
string_cleanup(&text->transkeys[i]);
string_cleanup(&text->strings[i]);
}
free(text->keys);
free(text->langtags);
free(text->transkeys);
free(text->strings);
}
unsigned LodePNG_IText_add(LodePNG_IText* text, const char* key, const char* langtag, const char* transkey, const char* str)
{
char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1)));
char** new_langtags = (char**)(realloc(text->langtags, sizeof(char*) * (text->num + 1)));
char** new_transkeys = (char**)(realloc(text->transkeys, sizeof(char*) * (text->num + 1)));
char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1)));
if(!new_keys || !new_langtags || !new_transkeys || !new_strings)
{
free(new_keys);
free(new_langtags);
free(new_transkeys);
free(new_strings);
return 9934; /*alloc fail*/
}
text->num++;
text->keys = new_keys;
text->langtags = new_langtags;
text->transkeys = new_transkeys;
text->strings = new_strings;
string_init(&text->keys[text->num - 1]);
string_set(&text->keys[text->num - 1], key);
string_init(&text->langtags[text->num - 1]);
string_set(&text->langtags[text->num - 1], langtag);
string_init(&text->transkeys[text->num - 1]);
string_set(&text->transkeys[text->num - 1], transkey);
string_init(&text->strings[text->num - 1]);
string_set(&text->strings[text->num - 1], str);
return 0;
}
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
void LodePNG_InfoPng_init(LodePNG_InfoPng* info)
{
info->width = info->height = 0;
LodePNG_InfoColor_init(&info->color);
info->interlaceMethod = 0;
info->compressionMethod = 0;
info->filterMethod = 0;
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
info->background_defined = 0;
info->background_r = info->background_g = info->background_b = 0;
LodePNG_Text_init(&info->text);
LodePNG_IText_init(&info->itext);
info->time_defined = 0;
info->phys_defined = 0;
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
LodePNG_UnknownChunks_init(&info->unknown_chunks);
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
}
void LodePNG_InfoPng_cleanup(LodePNG_InfoPng* info)
{
LodePNG_InfoColor_cleanup(&info->color);
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
LodePNG_Text_cleanup(&info->text);
LodePNG_IText_cleanup(&info->itext);
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
LodePNG_UnknownChunks_cleanup(&info->unknown_chunks);
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
}
unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source)
{
unsigned error = 0;
LodePNG_InfoPng_cleanup(dest);
*dest = *source;
LodePNG_InfoColor_init(&dest->color);
error = LodePNG_InfoColor_copy(&dest->color, &source->color); if(error) return error;
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
error = LodePNG_Text_copy(&dest->text, &source->text); if(error) return error;
error = LodePNG_IText_copy(&dest->itext, &source->itext); if(error) return error;
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
LodePNG_UnknownChunks_init(&dest->unknown_chunks);
error = LodePNG_UnknownChunks_copy(&dest->unknown_chunks, &source->unknown_chunks); if(error) return error;
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
return error;
}
void LodePNG_InfoPng_swap(LodePNG_InfoPng* a, LodePNG_InfoPng* b)
{
LodePNG_InfoPng temp = *a;
*a = *b;
*b = temp;
}
unsigned LodePNG_InfoColor_copy(LodePNG_InfoColor* dest, const LodePNG_InfoColor* source)
{
size_t i;
LodePNG_InfoColor_cleanup(dest);
*dest = *source;
dest->palette = (unsigned char*)malloc(source->palettesize * 4);
if(!dest->palette && source->palettesize) return 9935; /*alloc fail*/
for(i = 0; i palettesize * 4; i++) dest->palette[i] = source->palette[i];
return 0;
}
void LodePNG_InfoRaw_init(LodePNG_InfoRaw* info)
{
LodePNG_InfoColor_init(&info->color);
}
void LodePNG_InfoRaw_cleanup(LodePNG_InfoRaw* info)
{
LodePNG_InfoColor_cleanup(&info->color);
}
unsigned LodePNG_InfoRaw_copy(LodePNG_InfoRaw* dest, const LodePNG_InfoRaw* source)
{
unsigned error = 0;
LodePNG_InfoRaw_cleanup(dest);
*dest = *source;
LodePNG_InfoColor_init(&dest->color);
error = LodePNG_InfoColor_copy(&dest->color, &source->color);
return error; /*this variable could be removed, but it's more clear what is returned this way*/
}
/* ////////////////////////////////////////////////////////////////////////// */
/*convert from any color type to RGB or RGBA with 8 bits per sample*/
static unsigned LodePNG_convert_rgb_a_8(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
{
size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
if(infoIn->bitDepth == 8)
{
switch(infoIn->colorType)
{
case 0: /*greyscale color*/
for(i = 0; i key_defined && in[i] == infoIn->key_r ? 0 : 255;
}
break;
case 2: /*RGB color*/
for(i = 0; i < numpixels; i++)
{
for(c = 0; c key_defined == 1 && in[3 * i + 0] == infoIn->key_r && in[3 * i + 1] == infoIn->key_g && in[3 * i + 2] == infoIn->key_b)
out[bytes * i + 3] = 0;
else out[bytes * i + 3] = 255;
}
}
break;
case 3: /*indexed color (palette)*/
for(i = 0; i = infoIn->palettesize) return 46; /*invalid palette index*/
for(c = 0; c palette[4 * in[i] + c];
}
break;
case 4: /*greyscale with alpha*/
for(i = 0; i < numpixels; i++)
{
out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[2 * i + 0];
if(alpha) out[bytes * i + 3] = in[2 * i + 1];
}
break;
case 6: /*RGB with alpha*/
for(i = 0; i < numpixels; i++)
{
for(c = 0; c bitDepth == 16)
{
switch(infoIn->colorType)
{
case 0: /*greyscale color*/
for(i = 0; i key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r ? 0 : 255;
}
break;
case 2: /*RGB color*/
for(i = 0; i < numpixels; i++)
{
if(alpha) out[bytes * i + 3] = 255;
for(c = 0; c key_defined && 256U * in[6 * i + 0] + in[6 * i + 1] == infoIn->key_r
&& 256U * in[6 * i + 2] + in[6 * i + 3] == infoIn->key_g && 256U * in[6 * i + 4] + in[6 * i + 5] == infoIn->key_b)
out[bytes * i + 3] = 0;
else out[bytes * i + 3] = 255;
}
}
break;
case 4: /*greyscale with alpha*/
for(i = 0; i < numpixels; i++)
{
out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[4 * i];
if(alpha) out[bytes * i + 3] = in[4 * i + 2];
}
break;
case 6: /*RGB with alpha*/
for(i = 0; i < numpixels; i++)
{
for(c = 0; c bitDepth is less than 8 bit per channel*/
{
switch(infoIn->colorType)
{
case 0: /*greyscale color*/
for(i = 0; i bitDepth);
unsigned highest = ((1U <bitDepth) - 1U); /*highest possible value for this bit depth*/
out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = (unsigned char)((value * 255) / highest); /*scale value from 0 to 255*/
if(alpha) out[bytes * i + 3] = infoIn->key_defined && value == infoIn->key_r ? 0 : 255;
}
break;
case 3: /*indexed color (palette)*/
for(i = 0; i bitDepth);
if(value >= infoIn->palettesize) return 47;
for(c = 0; c palette[4 * value + c];
}
break;
default: break;
}
}
return 0;
}
/*convert from any greyscale color type to 8-bit greyscale with or without alpha channel*/
static unsigned LodePNG_convert_grey_8(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
{
size_t i, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
if(infoIn->bitDepth == 8)
{
switch(infoIn->colorType)
{
case 0: /*greyscale color*/
for(i = 0; i key_defined && in[i] == infoIn->key_r ? 0 : 255;
}
break;
case 4: /*greyscale with alpha*/
for(i = 0; i bitDepth == 16)
{
switch(infoIn->colorType)
{
case 0: /*greyscale color*/
for(i = 0; i key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r)
{
out[bytes * i + 1] = 0;
}
}
break;
case 4: /*greyscale with alpha*/
for(i = 0; i bitDepth is less than 8 bit per channel*/
{
if(infoIn->colorType != 0) return 31; /*colorType 0 is the only greyscale type with < 8 bits per channel*/
for(i = 0; i bitDepth);
unsigned highest = ((1U <bitDepth) - 1U); /*highest possible value for this bit depth*/
out[bytes * i] = (unsigned char)((value * 255) / highest); /*scale value from 0 to 255*/
if(alpha)
{
if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 1] = 0;
else out[bytes * i + 1] = 255;
}
}
}
return 0;
}
/*convert from any color type to RGB or RGBA with 8 bits per sample*/
static unsigned LodePNG_convert_rgb_a_16(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
{
size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
if(infoIn->bitDepth == 8)
{
switch(infoIn->colorType)
{
case 0: /*greyscale color*/
for(i = 0; i key_defined && in[i] == infoIn->key_r) out[bytes * i + 6] = out[bytes * i + 7] = 0;
else out[bytes * i + 6] = out[bytes * i + 7] = 255;
}
}
break;
case 2: /*RGB color*/
for(i = 0; i key_defined == 1 && in[3 * i + 0] == infoIn->key_r
&& in[3 * i + 1] == infoIn->key_g && in[3 * i + 2] == infoIn->key_b)
out[bytes * i + 6] = out[bytes * i + 7] = 0;
else out[bytes * i + 6] = out[bytes * i + 7] = 255;
}
}
break;
case 3: /*indexed color (palette)*/
for(i = 0; i = infoIn->palettesize) return 46; /*invalid palette index*/
for(c = 0; c palette[4 * in[i] + c];
}
}
break;
case 4: /*greyscale with alpha*/
for(i = 0; i < numpixels; i++)
{
out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[i];
out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[i];
if(alpha)
{
out[bytes * i + 6] = out[bytes * i + 7] = in[2 * i + 1];
}
}
break;
case 6: /*RGB with alpha*/
for(i = 0; i < numpixels; i++)
{
for(c = 0; c bitDepth == 16)
{
switch(infoIn->colorType)
{
case 0: /*greyscale color*/
for(i = 0; i key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r)
out[bytes * i + 6] = out[bytes * i + 7] = 0;
else out[bytes * i + 6] = out[bytes * i + 7] = 255;
}
}
break;
case 2: /*RGB color*/
for(i = 0; i < numpixels; i++)
{
for(c = 0; c key_defined && 256U * in[6 * i + 0] + in[6 * i + 1] == infoIn->key_r
&& 256U * in[6 * i + 2] + in[6 * i + 3] == infoIn->key_g && 256U * in[6 * i + 4] + in[6 * i + 5] == infoIn->key_b)
out[bytes * i + 6] = out[bytes * i + 7] = 0;
else out[bytes * i + 6] = out[bytes * i + 7] = 255;
}
}
break;
case 4: /*greyscale with alpha*/
for(i = 0; i < numpixels; i++)
{
out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[4 * i + 0];
out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[4 * i + 1];
if(alpha)
{
out[bytes * i + 6] = in[4 * i + 2];
out[bytes * i + 7] = in[4 * i + 3];
}
}
break;
case 6: /*RGB with alpha*/
for(i = 0; i < numpixels; i++)
{
for(c = 0; c bitDepth is less than 8 bit per channel*/
{
switch(infoIn->colorType)
{
case 0: /*greyscale color*/
for(i = 0; i bitDepth);
unsigned highest = ((1U <bitDepth) - 1U); /*highest possible value for this bit depth*/
out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] =
out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = (unsigned char)((value * 255) / highest); /*scale value from 0 to 255*/
if(alpha)
{
if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 6] = out[bytes * i + 7] = 0;
else out[bytes * i + 6] = out[bytes * i + 7] = 255;
}
}
break;
case 3: /*indexed color (palette)*/
for(i = 0; i bitDepth);
if(value >= infoIn->palettesize) return 47;
for(c = 0; c palette[4 * value + c];
}
}
break;
default: break;
}
}
return 0;
}
/*convert from any greyscale color type to 16-bit greyscale with or without alpha channel*/
static unsigned LodePNG_convert_grey_16(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
{
size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
if(infoIn->bitDepth == 8)
{
switch(infoIn->colorType)
{
case 0: /*greyscale color*/
for(i = 0; i key_defined && in[i] == infoIn->key_r) out[bytes * i + 2] = out[bytes * i + 3] = 0;
else out[bytes * i + 2] = out[bytes * i + 3] = 255;
}
}
break;
case 4: /*greyscale with alpha*/
for(i = 0; i bitDepth == 16)
{
switch(infoIn->colorType)
{
case 0: /*greyscale color*/
for(i = 0; i key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r)
out[bytes * i + 2] = out[bytes * i + 3] = 0;
else out[bytes * i + 2] = out[bytes * i + 3] = 255;
}
}
break;
case 4: /*greyscale with alpha*/
for(i = 0; i < numpixels; i++)
{
for(c = 0; c bitDepth is less than 8 bit per channel*/
{
if(infoIn->colorType != 0) return 31; /*colorType 0 is the only greyscale type with < 8 bits per channel*/
for(i = 0; i bitDepth);
unsigned highest = ((1U <bitDepth) - 1U); /*highest possible value for this bit depth*/
out[bytes * i] = out[bytes * i + 1] = (unsigned char)((value * 255) / highest); /*scale value from 0 to 255*/
if(alpha)
{
if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 2] = out[bytes * i + 3] = 0;
else out[bytes * i + 2] = out[bytes * i + 3] = 255;
}
}
}
return 0;
}
/*
converts from any color type to 24-bit or 32-bit (later maybe more supported). return value = LodePNG error code
the out buffer must have (w * h * bpp + 7) / 8 bytes, where bpp is the bits per pixel of the output color type (LodePNG_InfoColor_getBpp)
for < 8 bpp images, there may _not_ be padding bits at the end of scanlines.
*/
unsigned LodePNG_convert(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoOut, LodePNG_InfoColor* infoIn, unsigned w, unsigned h)
{
size_t numpixels = w * h; /*amount of pixels*/
unsigned bytes = LodePNG_InfoColor_getBpp(infoOut) / 8; /*bytes per pixel in the output image*/
unsigned alpha = LodePNG_InfoColor_isAlphaType(infoOut); /*use 8-bit alpha channel*/
/*cases where in and out already have the same format*/
if(LodePNG_InfoColor_equal(infoIn, infoOut))
{
size_t i;
size_t size = (numpixels * LodePNG_InfoColor_getBpp(infoIn) + 7) / 8;
for(i = 0; i colorType == 2 || infoOut->colorType == 6) && infoOut->bitDepth == 8)
{
LodePNG_convert_rgb_a_8(out, in, infoIn, numpixels, bytes, alpha);
}
else if(LodePNG_InfoColor_isGreyscaleType(infoOut) && infoOut->bitDepth == 8) /*conversion from greyscale to greyscale*/
{
if(!LodePNG_InfoColor_isGreyscaleType(infoIn)) return 62; /*converting from non greyscale to grey is not supported*/
LodePNG_convert_grey_8(out, in, infoIn, numpixels, bytes, alpha);
}
else if((infoOut->colorType == 2 || infoOut->colorType == 6) && infoOut->bitDepth == 16)
{
LodePNG_convert_rgb_a_16(out, in, infoIn, numpixels, bytes, alpha);
}
else if(LodePNG_InfoColor_isGreyscaleType(infoOut) && infoOut->bitDepth == 16) /*conversion from greyscale to greyscale*/
{
if(!LodePNG_InfoColor_isGreyscaleType(infoIn)) return 62; /*converting from non greyscale to grey is not supported*/
LodePNG_convert_grey_16(out, in, infoIn, numpixels, bytes, alpha);
}
else return 59; /*invalid color mode*/
return 0;
}
/*
Paeth predicter, used by PNG filter type 4
The parameters are of type short, but should come from unsigned chars, the shorts
are only needed to make the paeth calculation correct.
*/
static unsigned char paethPredictor(short a, short b, short c)
{
short pa = abs(b - c);
short pb = abs(a - c);
short pc = abs(a + b - c - c);
/*short pc = a + b - c;
short pa = abs(pc - a);
short pb = abs(pc - b);
pc = abs(pc - c);*/
if(pa <= pb && pa <= pc) return (unsigned char)a;
else if(pb <= pc) return (unsigned char)b;
else return (unsigned char)c;
}
/*shared values used by multiple Adam7 related functions*/
static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/
static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/
static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/
static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/
static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8], size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp)
{
/*the passstart values have 8 values: the 8th one actually indicates the byte after the end of the 7th (= last) pass*/
unsigned i;
/*calculate width and height in pixels of each pass*/
for(i = 0; i < 7; i++)
{
passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i];
passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i];
if(passw[i] == 0) passh[i] = 0;
if(passh[i] == 0) passw[i] = 0;
}
filter_passstart[0] = padded_passstart[0] = passstart[0] = 0;
for(i = 0; i error = 48; /*the given data is empty*/
return;
}
if(inlength error = 27; /*error: the data length is smaller than the length of a PNG header*/
return;
}
/*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/
LodePNG_InfoPng_cleanup(&decoder->infoPng);
LodePNG_InfoPng_init(&decoder->infoPng);
decoder->error = 0;
if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71 || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10)
{
decoder->error = 28; /*error: the first 8 bytes are not the correct PNG signature*/
return;
}
if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R')
{
decoder->error = 29; /*error: it doesn't start with a IHDR chunk!*/
return;
}
/*read the values given in the header*/
decoder->infoPng.width = LodePNG_read32bitInt(&in[16]);
decoder->infoPng.height = LodePNG_read32bitInt(&in[20]);
decoder->infoPng.color.bitDepth = in[24];
decoder->infoPng.color.colorType = in[25];
decoder->infoPng.compressionMethod = in[26];
decoder->infoPng.filterMethod = in[27];
decoder->infoPng.interlaceMethod = in[28];
if(!decoder->settings.ignoreCrc)
{
unsigned CRC = LodePNG_read32bitInt(&in[29]);
unsigned checksum = Crc32_crc(&in[12], 17);
if(CRC != checksum)
{
decoder->error = 57; /*invalid CRC*/
return;
}
}
if(decoder->infoPng.compressionMethod != 0) { decoder->error = 32; return; } /*error: only compression method 0 is allowed in the specification*/
if(decoder->infoPng.filterMethod != 0) { decoder->error = 33; return; } /*error: only filter method 0 is allowed in the specification*/
if(decoder->infoPng.interlaceMethod > 1) { decoder->error = 34; return; } /*error: only interlace methods 0 and 1 exist in the specification*/
decoder->error = checkColorValidity(decoder->infoPng.color.colorType, decoder->infoPng.color.bitDepth);
}
static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon, size_t bytewidth, unsigned char filterType, size_t length)
{
/*
For PNG filter method 0
unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte, the filter works byte per byte (bytewidth = 1)
precon is the previous unfiltered scanline, recon the result, scanline the current one
the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead
recon and scanline MAY be the same memory address! precon must be disjoint.
*/
size_t i;
switch(filterType)
{
case 0:
for(i = 0; i < length; i++) recon[i] = scanline[i];
break;
case 1:
for(i = 0; i < bytewidth; i++) recon[i] = scanline[i];
for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth];
break;
case 2:
if(precon)
{
for(i = 0; i < length; i++) recon[i] = scanline[i] + precon[i];
}
else
{
for(i = 0; i < length; i++) recon[i] = scanline[i];
}
break;
case 3:
if(precon)
{
for(i = 0; i < bytewidth; i++) recon[i] = scanline[i] + precon[i] / 2;
for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2);
}
else
{
for(i = 0; i < bytewidth; i++) recon[i] = scanline[i];
for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth] / 2;
}
break;
case 4:
if(precon)
{
for(i = 0; i < bytewidth; i++)
{
recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/
}
for(i = bytewidth; i < length; i++)
{
recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth]));
}
}
else
{
for(i = 0; i < bytewidth; i++)
{
recon[i] = scanline[i];
}
for(i = bytewidth; i < length; i++)
{
recon[i] = (scanline[i] + recon[i - bytewidth]); /*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/
}
}
break;
default: return 36; /*error: unexisting filter type given*/
}
return 0;
}
static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
{
/*
For PNG filter method 0
this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 it's called 7 times)
out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline
w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel
in and out are allowed to be the same memory address (but are not the same size because in has the extra filter bytes)
*/
unsigned y;
unsigned char* prevline = 0;
size_t bytewidth = (bpp + 7) / 8; /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
size_t linebytes = (w * bpp + 7) / 8;
for(y = 0; y < h; y++)
{
size_t outindex = linebytes * y;
size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
unsigned char filterType = in[inindex];
unsigned error = unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes);
if(error) return error;
prevline = &out[outindex];
}
return 0;
}
static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
{
/*Note: this function works on image buffers WITHOUT padding bits at end of scanlines with non-multiple-of-8 bit amounts, only between reduced images is padding
out must be big enough AND must be 0 everywhere if bpp = 8)
{
for(i = 0; i < 7; i++)
{
unsigned x, y, b;
size_t bytewidth = bpp / 8;
for(y = 0; y < passh[i]; y++)
for(x = 0; x < passw[i]; x++)
{
size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth;
size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
for(b = 0; b < bytewidth; b++)
{
out[pixeloutstart + b] = in[pixelinstart + b];
}
}
}
}
else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
{
for(i = 0; i < 7; i++)
{
unsigned x, y, b;
unsigned ilinebits = bpp * passw[i];
unsigned olinebits = bpp * w;
size_t obp, ibp; /*bit pointers (for out and in buffer)*/
for(y = 0; y < passh[i]; y++)
for(x = 0; x < passw[i]; x++)
{
ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
for(b = 0; b = ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits
also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7
only useful if (ilinebits - olinebits) is a value in the range 1..7
*/
unsigned y;
size_t diff = ilinebits - olinebits;
size_t ibp = 0, obp = 0; /*input and output bit pointers*/
for(y = 0; y < h; y++)
{
size_t x;
for(x = 0; x < olinebits; x++)
{
unsigned char bit = readBitFromReversedStream(&ibp, in);
setBitOfReversedStream(&obp, out, bit);
}
ibp += diff;
}
}
/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from the IDAT chunks (with filter index bytes and possible padding bits)*/
static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, const LodePNG_InfoPng* infoPng) /*return value is error*/
{
/*
This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype. Steps:
*) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp color);
unsigned w = infoPng->width;
unsigned h = infoPng->height;
unsigned error = 0;
if(bpp == 0) return 31; /*error: invalid colortype*/
if(infoPng->interlaceMethod == 0)
{
if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
{
error = unfilter(in, in, w, h, bpp);
if(error) return error;
removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h);
}
else error = unfilter(out, in, w, h, bpp); /*we can immediatly filter into the out buffer, no other steps needed*/
}
else /*interlaceMethod is 1 (Adam7)*/
{
unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8];
unsigned i;
Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
for(i = 0; i < 7; i++)
{
error = unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp);
if(error) return error;
if(bpp infoPng*/
if(decoder->error) return;
ucvector_init(&idat);
chunk = &in[33]; /*first byte of the first chunk after the header*/
while(!IEND) /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk. IDAT data is put at the start of the in buffer*/
{
unsigned chunkLength;
const unsigned char* data; /*the data in the chunk*/
if((size_t)((chunk - in) + 12) > insize || chunk error, 30); /*error: size of the in buffer too small to contain next chunk*/
chunkLength = LodePNG_chunk_length(chunk); /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/
if(chunkLength > 2147483647) CERROR_BREAK(decoder->error, 63); /*chunk length larger than the max PNG chunk size*/
if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) error, 64); /*error: size of the in buffer too small to contain next chunk*/
data = LodePNG_chunk_data_const(chunk);
/*IDAT chunk, containing compressed image data*/
if(LodePNG_chunk_type_equals(chunk, "IDAT"))
{
size_t oldsize = idat.size;
if(!ucvector_resize(&idat, oldsize + chunkLength)) CERROR_BREAK(decoder->error, 9936 /*alloc fail*/);
for(i = 0; i infoPng.color.palette) free(decoder->infoPng.color.palette);
decoder->infoPng.color.palettesize = chunkLength / 3;
decoder->infoPng.color.palette = (unsigned char*)malloc(4 * decoder->infoPng.color.palettesize);
if(!decoder->infoPng.color.palette && decoder->infoPng.color.palettesize)
{
decoder->infoPng.color.palettesize = 0;
CERROR_BREAK(decoder->error, 9937); /*alloc fail*/
}
if(decoder->infoPng.color.palettesize > 256) CERROR_BREAK(decoder->error, 38); /*error: palette too big*/
for(i = 0; i infoPng.color.palettesize; i++)
{
decoder->infoPng.color.palette[4 * i + 0] = data[pos++]; /*R*/
decoder->infoPng.color.palette[4 * i + 1] = data[pos++]; /*G*/
decoder->infoPng.color.palette[4 * i + 2] = data[pos++]; /*B*/
decoder->infoPng.color.palette[4 * i + 3] = 255; /*alpha*/
}
critical_pos = 2;
}
/*palette transparency chunk (tRNS)*/
else if(LodePNG_chunk_type_equals(chunk, "tRNS"))
{
if(decoder->infoPng.color.colorType == 3)
{
if(chunkLength > decoder->infoPng.color.palettesize) CERROR_BREAK(decoder->error, 38); /*error: more alpha values given than there are palette entries*/
for(i = 0; i infoPng.color.palette[4 * i + 3] = data[i];
}
else if(decoder->infoPng.color.colorType == 0)
{
if(chunkLength != 2) CERROR_BREAK(decoder->error, 30); /*error: this chunk must be 2 bytes for greyscale image*/
decoder->infoPng.color.key_defined = 1;
decoder->infoPng.color.key_r = decoder->infoPng.color.key_g = decoder->infoPng.color.key_b = 256 * data[0] + data[1];
}
else if(decoder->infoPng.color.colorType == 2)
{
if(chunkLength != 6) CERROR_BREAK(decoder->error, 41); /*error: this chunk must be 6 bytes for RGB image*/
decoder->infoPng.color.key_defined = 1;
decoder->infoPng.color.key_r = 256 * data[0] + data[1];
decoder->infoPng.color.key_g = 256 * data[2] + data[3];
decoder->infoPng.color.key_b = 256 * data[4] + data[5];
}
else CERROR_BREAK(decoder->error, 42); /*error: tRNS chunk not allowed for other color models*/
}
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
/*background color chunk (bKGD)*/
else if(LodePNG_chunk_type_equals(chunk, "bKGD"))
{
if(decoder->infoPng.color.colorType == 3)
{
if(chunkLength != 1) CERROR_BREAK(decoder->error, 43); /*error: this chunk must be 1 byte for indexed color image*/
decoder->infoPng.background_defined = 1;
decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_b = data[0];
}
else if(decoder->infoPng.color.colorType == 0 || decoder->infoPng.color.colorType == 4)
{
if(chunkLength != 2) CERROR_BREAK(decoder->error, 44); /*error: this chunk must be 2 bytes for greyscale image*/
decoder->infoPng.background_defined = 1;
decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_b = 256 * data[0] + data[1];
}
else if(decoder->infoPng.color.colorType == 2 || decoder->infoPng.color.colorType == 6)
{
if(chunkLength != 6) CERROR_BREAK(decoder->error, 45); /*error: this chunk must be 6 bytes for greyscale image*/
decoder->infoPng.background_defined = 1;
decoder->infoPng.background_r = 256 * data[0] + data[1];
decoder->infoPng.background_g = 256 * data[2] + data[3];
decoder->infoPng.background_b = 256 * data[4] + data[5];
}
}
/*text chunk (tEXt)*/
else if(LodePNG_chunk_type_equals(chunk, "tEXt"))
{
if(decoder->settings.readTextChunks)
{
char *key = 0, *str = 0;
while(!decoder->error) /*not really a while loop, only used to break on error*/
{
unsigned length, string2_begin;
length = 0;
while(length = chunkLength) CERROR_BREAK(decoder->error, 75); /*error, end reached, no null terminator?*/
key = (char*)malloc(length + 1);
if(!key) CERROR_BREAK(decoder->error, 9938); /*alloc fail*/
key[length] = 0;
for(i = 0; i chunkLength) CERROR_BREAK(decoder->error, 75); /*error, end reached, no null terminator?*/
length = chunkLength - string2_begin;
str = (char*)malloc(length + 1);
if(!str) CERROR_BREAK(decoder->error, 9939); /*alloc fail*/
str[length] = 0;
for(i = 0; i error = LodePNG_Text_add(&decoder->infoPng.text, key, str);
break;
}
free(key);
free(str);
}
}
/*compressed text chunk (zTXt)*/
else if(LodePNG_chunk_type_equals(chunk, "zTXt"))
{
if(decoder->settings.readTextChunks)
{
unsigned length, string2_begin;
char *key = 0;
ucvector decoded;
ucvector_init(&decoded);
while(!decoder->error) /*not really a while loop, only used to break on error*/
{
for(length = 0; length = chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
key = (char*)malloc(length + 1);
if(!key) CERROR_BREAK(decoder->error, 9940); /*alloc fail*/
key[length] = 0;
for(i = 0; i error, 72); /*the 0 byte indicating compression must be 0*/
string2_begin = length + 2;
if(string2_begin > chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
length = chunkLength - string2_begin;
decoder->error = LodePNG_decompress(&decoded.data, &decoded.size, (unsigned char*)(&data[string2_begin]), length, &decoder->settings.zlibsettings);
if(decoder->error) break;
ucvector_push_back(&decoded, 0);
decoder->error = LodePNG_Text_add(&decoder->infoPng.text, key, (char*)decoded.data);
break;
}
free(key);
ucvector_cleanup(&decoded);
if(decoder->error) break;
}
}
/*international text chunk (iTXt)*/
else if(LodePNG_chunk_type_equals(chunk, "iTXt"))
{
if(decoder->settings.readTextChunks)
{
unsigned length, begin, compressed;
char *key = 0, *langtag = 0, *transkey = 0;
ucvector decoded;
ucvector_init(&decoded);
while(!decoder->error) /*not really a while loop, only used to break on error*/
{
/*Quick check if the chunk length isn't too small. Even without check it'd still fail with other error checks below if it's too short. This just gives a different error code.*/
if(chunkLength error, 30); /*iTXt chunk too short*/
/*read the key*/
for(length = 0; length = chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination char found*/
key = (char*)malloc(length + 1);
if(!key) CERROR_BREAK(decoder->error, 9941); /*alloc fail*/
key[length] = 0;
for(i = 0; i error, 72); /*the 0 byte indicating compression must be 0*/
/*read the langtag*/
begin = length + 3;
length = 0;
for(i = begin; i = chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination char found*/
langtag = (char*)malloc(length + 1);
if(!langtag) CERROR_BREAK(decoder->error, 9942); /*alloc fail*/
langtag[length] = 0;
for(i = 0; i < length; i++) langtag[i] = data[begin + i];
/*read the transkey*/
begin += length + 1;
length = 0;
for(i = begin; i = chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
transkey = (char*)malloc(length + 1);
if(!transkey) CERROR_BREAK(decoder->error, 9943); /*alloc fail*/
transkey[length] = 0;
for(i = 0; i chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
length = chunkLength - begin;
if(compressed)
{
decoder->error = LodePNG_decompress(&decoded.data, &decoded.size, (unsigned char*)(&data[begin]), length, &decoder->settings.zlibsettings);
if(decoder->error) break;
ucvector_push_back(&decoded, 0);
}
else
{
if(!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(decoder->error, 9944 /*alloc fail*/);
decoded.data[length] = 0;
for(i = 0; i error = LodePNG_IText_add(&decoder->infoPng.itext, key, langtag, transkey, (char*)decoded.data);
break;
}
free(key);
free(langtag);
free(transkey);
ucvector_cleanup(&decoded);
if(decoder->error) break;
}
}
else if(LodePNG_chunk_type_equals(chunk, "tIME"))
{
if(chunkLength != 7) CERROR_BREAK(decoder->error, 73); /*invalid tIME chunk size*/
decoder->infoPng.time_defined = 1;
decoder->infoPng.time.year = 256 * data[0] + data[+ 1];
decoder->infoPng.time.month = data[2];
decoder->infoPng.time.day = data[3];
decoder->infoPng.time.hour = data[4];
decoder->infoPng.time.minute = data[5];
decoder->infoPng.time.second = data[6];
}
else if(LodePNG_chunk_type_equals(chunk, "pHYs"))
{
if(chunkLength != 9) CERROR_BREAK(decoder->error, 74); /*invalid pHYs chunk size*/
decoder->infoPng.phys_defined = 1;
decoder->infoPng.phys_x = 16777216 * data[0] + 65536 * data[1] + 256 * data[2] + data[3];
decoder->infoPng.phys_y = 16777216 * data[4] + 65536 * data[5] + 256 * data[6] + data[7];
decoder->infoPng.phys_unit = data[8];
}
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
else /*it's not an implemented chunk type, so ignore it: skip over the data*/
{
if(LodePNG_chunk_critical(chunk)) CERROR_BREAK(decoder->error, 69); /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/
unknown = 1;
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
if(decoder->settings.rememberUnknownChunks)
{
LodePNG_UnknownChunks* unknown = &decoder->infoPng.unknown_chunks;
decoder->error = LodePNG_append_chunk(&unknown->data[critical_pos - 1], &unknown->datasize[critical_pos - 1], chunk);
if(decoder->error) break;
}
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
}
if(!decoder->settings.ignoreCrc && !unknown) /*check CRC if wanted, only on known chunk types*/
{
if(LodePNG_chunk_check_crc(chunk)) CERROR_BREAK(decoder->error, 57); /*invalid CRC*/
}
if(!IEND) chunk = LodePNG_chunk_next_const(chunk);
}
if(!decoder->error)
{
ucvector scanlines;
ucvector_init(&scanlines);
/*maximum final image length is already reserved in the vector's length - this is not really necessary*/
if(!ucvector_resize(&scanlines, ((decoder->infoPng.width * (decoder->infoPng.height * LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7)) / 8) + decoder->infoPng.height))
{
decoder->error = 9945;
}
if(!decoder->error)
{
decoder->error = LodePNG_decompress(&scanlines.data, &scanlines.size, idat.data, idat.size, &decoder->settings.zlibsettings); /*decompress with the Zlib decompressor*/
}
if(!decoder->error)
{
ucvector outv;
ucvector_init(&outv);
if(!ucvector_resizev(&outv, (decoder->infoPng.height * decoder->infoPng.width * LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7) / 8, 0)) decoder->error = 9946;
if(!decoder->error) decoder->error = postProcessScanlines(outv.data, scanlines.data, &decoder->infoPng);
*out = outv.data;
*outsize = outv.size;
}
ucvector_cleanup(&scanlines);
}
ucvector_cleanup(&idat);
}
void LodePNG_Decoder_decode(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize)
{
*out = 0;
*outsize = 0;
decodeGeneric(decoder, out, outsize, in, insize);
if(decoder->error) return;
if(!decoder->settings.color_convert || LodePNG_InfoColor_equal(&decoder->infoRaw.color, &decoder->infoPng.color))
{
/*same color type, no copying or converting of data needed*/
/*store the infoPng color settings on the infoRaw so that the infoRaw still reflects what colorType
the raw image has to the end user*/
if(!decoder->settings.color_convert)
{
decoder->error = LodePNG_InfoColor_copy(&decoder->infoRaw.color, &decoder->infoPng.color);
if(decoder->error) return;
}
}
else
{
/*color conversion needed; sort of copy of the data*/
unsigned char* data = *out;
/*TODO: check if this works according to the statement in the documentation: "The converter can convert from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/
if(!(decoder->infoRaw.color.colorType == 2 || decoder->infoRaw.color.colorType == 6) && !(decoder->infoRaw.color.bitDepth == 8))
{
decoder->error = 56; /*unsupported color mode conversion*/
return;
}
*outsize = (decoder->infoPng.width * decoder->infoPng.height * LodePNG_InfoColor_getBpp(&decoder->infoRaw.color) + 7) / 8;
*out = (unsigned char*)malloc(*outsize);
if(!(*out))
{
decoder->error = 9947; /*alloc fail*/
*outsize = 0;
}
else decoder->error = LodePNG_convert(*out, data, &decoder->infoRaw.color, &decoder->infoPng.color, decoder->infoPng.width, decoder->infoPng.height);
free(data);
}
}
unsigned LodePNG_decode(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize, unsigned colorType, unsigned bitDepth)
{
unsigned error;
size_t dummy_size;
LodePNG_Decoder decoder;
LodePNG_Decoder_init(&decoder);
decoder.infoRaw.color.colorType = colorType;
decoder.infoRaw.color.bitDepth = bitDepth;
LodePNG_Decoder_decode(&decoder, out, &dummy_size, in, insize);
error = decoder.error;
*w = decoder.infoPng.width;
*h = decoder.infoPng.height;
LodePNG_Decoder_cleanup(&decoder);
return error;
}
unsigned LodePNG_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
{
return LodePNG_decode(out, w, h, in, insize, 6, 8);
}
unsigned LodePNG_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
{
return LodePNG_decode(out, w, h, in, insize, 2, 8);
}
#ifdef LODEPNG_COMPILE_DISK
unsigned LodePNG_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename, unsigned colorType, unsigned bitDepth)
{
unsigned char* buffer;
size_t buffersize;
unsigned error;
error = LodePNG_loadFile(&buffer, &buffersize, filename);
if(!error) error = LodePNG_decode(out, w, h, buffer, buffersize, colorType, bitDepth);
free(buffer);
return error;
}
unsigned LodePNG_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
{
return LodePNG_decode_file(out, w, h, filename, 6, 8);
}
unsigned LodePNG_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
{
return LodePNG_decode_file(out, w, h, filename, 2, 8);
}
#endif /*LODEPNG_COMPILE_DISK*/
void LodePNG_DecodeSettings_init(LodePNG_DecodeSettings* settings)
{
settings->color_convert = 1;
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
settings->readTextChunks = 1;
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
settings->ignoreCrc = 0;
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
settings->rememberUnknownChunks = 0;
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
LodeZlib_DecompressSettings_init(&settings->zlibsettings);
}
void LodePNG_Decoder_init(LodePNG_Decoder* decoder)
{
LodePNG_DecodeSettings_init(&decoder->settings);
LodePNG_InfoRaw_init(&decoder->infoRaw);
LodePNG_InfoPng_init(&decoder->infoPng);
decoder->error = 1;
}
void LodePNG_Decoder_cleanup(LodePNG_Decoder* decoder)
{
LodePNG_InfoRaw_cleanup(&decoder->infoRaw);
LodePNG_InfoPng_cleanup(&decoder->infoPng);
}
void LodePNG_Decoder_copy(LodePNG_Decoder* dest, const LodePNG_Decoder* source)
{
LodePNG_Decoder_cleanup(dest);
*dest = *source;
LodePNG_InfoRaw_init(&dest->infoRaw);
LodePNG_InfoPng_init(&dest->infoPng);
dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw); if(dest->error) return;
dest->error = LodePNG_InfoPng_copy(&dest->infoPng, &source->infoPng); if(dest->error) return;
}
#endif /*LODEPNG_COMPILE_DECODER*/
#ifdef LODEPNG_COMPILE_ENCODER
/* ////////////////////////////////////////////////////////////////////////// */
/* / PNG Encoder / */
/* ////////////////////////////////////////////////////////////////////////// */
/*chunkName must be string of 4 characters*/
static unsigned addChunk(ucvector* out, const char* chunkName, const unsigned char* data, size_t length)
{
unsigned error = LodePNG_create_chunk(&out->data, &out->size, (unsigned)length, chunkName, data);
if(error) return error;
out->allocsize = out->size; /*fix the allocsize again*/
return 0;
}
static void writeSignature(ucvector* out)
{
/*8 bytes PNG signature, aka the magic bytes*/
ucvector_push_back(out, 137);
ucvector_push_back(out, 80);
ucvector_push_back(out, 78);
ucvector_push_back(out, 71);
ucvector_push_back(out, 13);
ucvector_push_back(out, 10);
ucvector_push_back(out, 26);
ucvector_push_back(out, 10);
}
static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h, unsigned bitDepth, unsigned colorType, unsigned interlaceMethod)
{
unsigned error = 0;
ucvector header;
ucvector_init(&header);
LodePNG_add32bitInt(&header, w); /*width*/
LodePNG_add32bitInt(&header, h); /*height*/
ucvector_push_back(&header, (unsigned char)bitDepth); /*bit depth*/
ucvector_push_back(&header, (unsigned char)colorType); /*color type*/
ucvector_push_back(&header, 0); /*compression method*/
ucvector_push_back(&header, 0); /*filter method*/
ucvector_push_back(&header, interlaceMethod); /*interlace method*/
error = addChunk(out, "IHDR", header.data, header.size);
ucvector_cleanup(&header);
return error;
}
static unsigned addChunk_PLTE(ucvector* out, const LodePNG_InfoColor* info)
{
unsigned error = 0;
size_t i;
ucvector PLTE;
ucvector_init(&PLTE);
for(i = 0; i palettesize * 4; i++)
{
if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]); /*add all channels except alpha channel*/
}
error = addChunk(out, "PLTE", PLTE.data, PLTE.size);
ucvector_cleanup(&PLTE);
return error;
}
static unsigned addChunk_tRNS(ucvector* out, const LodePNG_InfoColor* info)
{
unsigned error = 0;
size_t i;
ucvector tRNS;
ucvector_init(&tRNS);
if(info->colorType == 3)
{
for(i = 0; i palettesize; i++) ucvector_push_back(&tRNS, info->palette[4 * i + 3]); /*add only alpha channel*/
}
else if(info->colorType == 0)
{
if(info->key_defined)
{
ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
}
}
else if(info->colorType == 2)
{
if(info->key_defined)
{
ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
ucvector_push_back(&tRNS, (unsigned char)(info->key_g / 256));
ucvector_push_back(&tRNS, (unsigned char)(info->key_g % 256));
ucvector_push_back(&tRNS, (unsigned char)(info->key_b / 256));
ucvector_push_back(&tRNS, (unsigned char)(info->key_b % 256));
}
}
error = addChunk(out, "tRNS", tRNS.data, tRNS.size);
ucvector_cleanup(&tRNS);
return error;
}
static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize, LodeZlib_CompressSettings* zlibsettings)
{
ucvector zlibdata;
unsigned error = 0;
/*compress with the Zlib compressor*/
ucvector_init(&zlibdata);
error = LodePNG_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings);
if(!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size);
ucvector_cleanup(&zlibdata);
return error;
}
static unsigned addChunk_IEND(ucvector* out)
{
unsigned error = 0;
error = addChunk(out, "IEND", 0, 0);
return error;
}
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring) /*add text chunk*/
{
unsigned error = 0;
size_t i;
ucvector text;
ucvector_init(&text);
for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&text, (unsigned char)keyword[i]);
ucvector_push_back(&text, 0);
for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&text, (unsigned char)textstring[i]);
error = addChunk(out, "tEXt", text.data, text.size);
ucvector_cleanup(&text);
return error;
}
static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring, LodeZlib_CompressSettings* zlibsettings)
{
unsigned error = 0;
ucvector data, compressed;
size_t i, textsize = strlen(textstring);
ucvector_init(&data);
ucvector_init(&compressed);
for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
ucvector_push_back(&data, 0); /* 0 termination char*/
ucvector_push_back(&data, 0); /*compression method: 0*/
error = LodePNG_compress(&compressed.data, &compressed.size, (unsigned char*)textstring, textsize, zlibsettings);
if(!error)
{
for(i = 0; i < compressed.size; i++) ucvector_push_back(&data, compressed.data[i]);
error = addChunk(out, "zTXt", data.data, data.size);
}
ucvector_cleanup(&compressed);
ucvector_cleanup(&data);
return error;
}
static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, const char* keyword, const char* langtag, const char* transkey, const char* textstring, LodeZlib_CompressSettings* zlibsettings)
{
unsigned error = 0;
ucvector data, compressed_data;
size_t i, textsize = strlen(textstring);
ucvector_init(&data);
for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
ucvector_push_back(&data, 0); /*null termination char*/
ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/
ucvector_push_back(&data, 0); /*compression method*/
for(i = 0; langtag[i] != 0; i++) ucvector_push_back(&data, (unsigned char)langtag[i]);
ucvector_push_back(&data, 0); /*null termination char*/
for(i = 0; transkey[i] != 0; i++) ucvector_push_back(&data, (unsigned char)transkey[i]);
ucvector_push_back(&data, 0); /*null termination char*/
if(compressed)
{
ucvector_init(&compressed_data);
error = LodePNG_compress(&compressed_data.data, &compressed_data.size, (unsigned char*)textstring, textsize, zlibsettings);
if(!error)
{
for(i = 0; i color.colorType == 0 || info->color.colorType == 4)
{
ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
}
else if(info->color.colorType == 2 || info->color.colorType == 6)
{
ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
ucvector_push_back(&bKGD, (unsigned char)(info->background_g / 256));
ucvector_push_back(&bKGD, (unsigned char)(info->background_g % 256));
ucvector_push_back(&bKGD, (unsigned char)(info->background_b / 256));
ucvector_push_back(&bKGD, (unsigned char)(info->background_b % 256));
}
else if(info->color.colorType == 3)
{
ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); /*palette index*/
}
error = addChunk(out, "bKGD", bKGD.data, bKGD.size);
ucvector_cleanup(&bKGD);
return error;
}
static unsigned addChunk_tIME(ucvector* out, const LodePNG_Time* time)
{
unsigned error = 0;
unsigned char* data = (unsigned char*)malloc(7);
if(!data) return 9948; /*alloc fail*/
data[0] = (unsigned char)(time->year / 256);
data[1] = (unsigned char)(time->year % 256);
data[2] = time->month;
data[3] = time->day;
data[4] = time->hour;
data[5] = time->minute;
data[6] = time->second;
error = addChunk(out, "tIME", data, 7);
free(data);
return error;
}
static unsigned addChunk_pHYs(ucvector* out, const LodePNG_InfoPng* info)
{
unsigned error = 0;
ucvector data;
ucvector_init(&data);
LodePNG_add32bitInt(&data, info->phys_x);
LodePNG_add32bitInt(&data, info->phys_y);
ucvector_push_back(&data, info->phys_unit);
error = addChunk(out, "pHYs", data.data, data.size);
ucvector_cleanup(&data);
return error;
}
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline, size_t length, size_t bytewidth, unsigned char filterType)
{
size_t i;
switch(filterType)
{
case 0:
for(i = 0; i < length; i++) out[i] = scanline[i];
break;
case 1:
if(prevline)
{
for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
for(i = bytewidth; i < length ; i++) out[i] = scanline[i] - scanline[i - bytewidth];
}
else
{
for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth];
}
break;
case 2:
if(prevline)
{
for(i = 0; i < length; i++) out[i] = scanline[i] - prevline[i];
}
else
{
for(i = 0; i < length; i++) out[i] = scanline[i];
}
break;
case 3:
if(prevline)
{
for(i = 0; i < bytewidth; i++) out[i] = scanline[i] - prevline[i] / 2;
for(i = bytewidth; i < length; i++) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) / 2);
}
else
{
for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth] / 2;
}
break;
case 4:
if(prevline)
{
for(i = 0; i < bytewidth; i++) out[i] = (scanline[i] - prevline[i]); /*paethPredictor(0, prevline[i], 0) is always prevline[i]*/
for(i = bytewidth; i < length; i++) out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth]));
}
else
{
for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
for(i = bytewidth; i < length; i++) out[i] = (scanline[i] - scanline[i - bytewidth]); /*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/
}
break;
default: return; /*unexisting filter type given*/
}
}
static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, const LodePNG_InfoColor* info)
{
/*
For PNG filter method 0
out must be a buffer with as size: h + (w * h * bpp + 7) / 8, because there are the scanlines with 1 extra byte per scanline
There is a nice heuristic described here: http://www.cs.toronto.edu/~cosmin/pngtech/optipng.html. It says:
* If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e. use fixed filtering, with the filter None).
* (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply all five filters and select the filter that produces the smallest sum of absolute values per row.
Here the above method is used mostly. Note though that it appears to be better to use the adaptive filtering on the plasma 8-bit palette example, but that image isn't the best reference for palette images in general.
*/
unsigned bpp = LodePNG_InfoColor_getBpp(info);
size_t linebytes = (w * bpp + 7) / 8; /*the width of a scanline in bytes, not including the filter type*/
size_t bytewidth = (bpp + 7) / 8; /*bytewidth is used for filtering, is 1 when bpp colorType == 3 || info->bitDepth < 8) heuristic = 0;
else heuristic = 1;
if(heuristic == 0) /*None filtertype for everything*/
{
for(y = 0; y < h; y++)
{
size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
size_t inindex = linebytes * y;
const unsigned TYPE = 0;
out[outindex] = TYPE; /*filter type byte*/
filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, TYPE);
prevline = &in[inindex];
}
}
else if(heuristic == 1) /*adaptive filtering*/
{
size_t sum[5];
ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
size_t smallest = 0;
unsigned type, bestType = 0;
for(type = 0; type < 5; type++) ucvector_init(&attempt[type]);
for(type = 0; type < 5; type++)
{
if(!ucvector_resize(&attempt[type], linebytes)) ERROR_BREAK(9949 /*alloc fail*/);
}
if(!error)
{
for(y = 0; y < h; y++)
{
/*try the 5 filter types*/
for(type = 0; type < 5; type++)
{
filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
/*calculate the sum of the result*/
sum[type] = 0;
for(x = 0; x < attempt[type].size; x+=3) sum[type] += attempt[type].data[x]; /*note that not all pixels are checked to speed this up while still having probably the best choice*/
/*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
if(type == 0 || sum[type] < smallest)
{
bestType = type;
smallest = sum[type];
}
}
prevline = &in[y * linebytes];
/*now fill the out values*/
out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
}
}
for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
}
#if 0 /*deflate the scanline with a fixed tree after every filter attempt to see which one deflates best. This is slow, and _does not work as expected_: the heuristic gives smaller result!*/
else if(heuristic == 2) /*adaptive filtering by using deflate*/
{
size_t size[5];
ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
size_t smallest;
unsigned type = 0, bestType = 0;
unsigned char* dummy;
LodeZlib_CompressSettings deflatesettings = LodeZlib_defaultCompressSettings;
deflatesettings.btype = 1; /*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose, to simulate the true case where the tree is the same for the whole image*/
for(type = 0; type < 5; type++)
{
ucvector_init(&attempt[type]);
ucvector_resize(&attempt[type], linebytes); /*todo: give error if resize failed*/
}
for(y = 0; y < h; y++) /*try the 5 filter types*/
{
for(type = 0; type < 5; type++)
{
filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
size[type] = 0;
dummy = 0;
LodePNG_compress(&dummy, &size[type], attempt[type].data, attempt[type].size, &deflatesettings);
free(dummy);
/*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/
if(type == 0 || size[type] < smallest)
{
bestType = type;
smallest = size[type];
}
}
prevline = &in[y * linebytes];
out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
}
for(type = 0; type = ilinebits*/
unsigned y;
size_t diff = olinebits - ilinebits;
size_t obp = 0, ibp = 0; /*bit pointers*/
for(y = 0; y < h; y++)
{
size_t x;
for(x = 0; x no, fill in some value in the padding bits too, to avoid "Use of uninitialised value of size ###" warning from valgrind*/
for(x = 0; x = 8)
{
for(i = 0; i < 7; i++)
{
unsigned x, y, b;
size_t bytewidth = bpp / 8;
for(y = 0; y < passh[i]; y++)
for(x = 0; x < passw[i]; x++)
{
size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth;
for(b = 0; b < bytewidth; b++)
{
out[pixeloutstart + b] = in[pixelinstart + b];
}
}
}
}
else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
{
for(i = 0; i < 7; i++)
{
unsigned x, y, b;
unsigned ilinebits = bpp * passw[i];
unsigned olinebits = bpp * w;
size_t obp, ibp; /*bit pointers (for out and in buffer)*/
for(y = 0; y < passh[i]; y++)
for(x = 0; x < passw[i]; x++)
{
ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
obp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
for(b = 0; b < bpp; b++)
{
unsigned char bit = readBitFromReversedStream(&ibp, in);
setBitOfReversedStream(&obp, out, bit);
}
}
}
}
}
/*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image*/
static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in, const LodePNG_InfoPng* infoPng) /*return value is error*/
{
/*
This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps:
*) if no Adam7: 1) add padding bits (= posible extra bits per scanline if bpp color);
unsigned w = infoPng->width;
unsigned h = infoPng->height;
unsigned error = 0;
if(infoPng->interlaceMethod == 0)
{
*outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/
*out = (unsigned char*)malloc(*outsize);
if(!(*out) && (*outsize)) error = 9950; /*alloc fail*/
if(!error)
{
if(bpp color);
}
ucvector_cleanup(&padded);
}
else error = filter(*out, in, w, h, &infoPng->color); /*we can immediatly filter into the out buffer, no other steps needed*/
}
}
else /*interlaceMethod is 1 (Adam7)*/
{
unsigned char* adam7 = (unsigned char*)malloc((h * w * bpp + 7) / 8);
if(!adam7 && ((h * w * bpp + 7) / 8)) error = 9952; /*alloc fail*/
while(!error) /*not a real while loop, used to break out to cleanup to avoid a goto*/
{
unsigned passw[7], passh[7];
size_t filter_passstart[8], padded_passstart[8], passstart[8];
unsigned i;
Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
*outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/
*out = (unsigned char*)malloc(*outsize);
if(!(*out) && (*outsize)) ERROR_BREAK(9953 /*alloc fail*/);
Adam7_interlace(adam7, in, w, h, bpp);
for(i = 0; i < 7; i++)
{
if(bpp color);
}
ucvector_cleanup(&padded);
}
else
{
error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]], passw[i], passh[i], &infoPng->color);
}
}
break;
}
free(adam7);
}
return error;
}
/*palette must have 4 * palettesize bytes allocated*/
static unsigned isPaletteFullyOpaque(const unsigned char* palette, size_t palettesize) /*palette given in format RGBARGBARGBARGBA...*/
{
size_t i;
for(i = 0; i colorType == 6)
{
if(info->bitDepth == 8)
{
for(i = 0; i < numpixels; i++)
{
if(image[i * 4 + 3] != 255) return 0;
}
}
else
{
for(i = 0; i colorType == 4)
{
if(info->bitDepth == 8)
{
for(i = 0; i < numpixels; i++)
{
if(image[i * 2 + 1] != 255) return 0;
}
}
else
{
for(i = 0; i colorType == 3)
{
/*when there's a palette, we could check every pixel for translucency, but much quicker is to just check the palette*/
return(isPaletteFullyOpaque(info->palette, info->palettesize));
}
return 0; /*color type that isn't supported by this function yet, so assume there is transparency to be safe*/
}
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize)
{
unsigned char* inchunk = data;
while((size_t)(inchunk - data) data, &out->size, inchunk);
if(error) return error; /*error: not enough memory*/
out->allocsize = out->size; /*fix the allocsize again*/
inchunk = LodePNG_chunk_next(inchunk);
}
return 0;
}
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
void LodePNG_Encoder_encode(LodePNG_Encoder* encoder, unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
{
LodePNG_InfoPng info;
ucvector outv;
unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/
size_t datasize = 0;
/*provide some proper output values if error will happen*/
*out = 0;
*outsize = 0;
encoder->error = 0;
info = encoder->infoPng; /*UNSAFE copy to avoid having to cleanup! but we will only change primitive parameters, and not invoke the cleanup function nor touch the palette's buffer so we use it safely*/
info.width = w;
info.height = h;
if(encoder->settings.autoLeaveOutAlphaChannel && isFullyOpaque(image, w, h, &encoder->infoRaw.color))
{
/*go to a color type without alpha channel*/
if(info.color.colorType == 6) info.color.colorType = 2;
else if(info.color.colorType == 4) info.color.colorType = 0;
}
if(encoder->settings.zlibsettings.windowSize > 32768)
{
encoder->error = 60; /*error: windowsize larger than allowed*/
return;
}
if(encoder->settings.zlibsettings.btype > 2)
{
encoder->error = 61; /*error: unexisting btype*/
return;
}
if(encoder->infoPng.interlaceMethod > 1)
{
encoder->error = 71; /*error: unexisting interlace mode*/
return;
}
if((encoder->error = checkColorValidity(info.color.colorType, info.color.bitDepth))) return; /*error: unexisting color type given*/
if((encoder->error = checkColorValidity(encoder->infoRaw.color.colorType, encoder->infoRaw.color.bitDepth))) return; /*error: unexisting color type given*/
if(!LodePNG_InfoColor_equal(&encoder->infoRaw.color, &info.color))
{
unsigned char* converted;
size_t size = (w * h * LodePNG_InfoColor_getBpp(&info.color) + 7) / 8;
if((info.color.colorType != 6 && info.color.colorType != 2) || (info.color.bitDepth != 8))
{
encoder->error = 59; /*for the output image, only these types are supported*/
return;
}
converted = (unsigned char*)malloc(size);
if(!converted && size) encoder->error = 9955; /*alloc fail*/
if(!encoder->error) encoder->error = LodePNG_convert(converted, image, &info.color, &encoder->infoRaw.color, w, h);
if(!encoder->error) preProcessScanlines(&data, &datasize, converted, &info);/*filter(data.data, converted.data, w, h, LodePNG_InfoColor_getBpp(&info.color));*/
free(converted);
}
else preProcessScanlines(&data, &datasize, image, &info);/*filter(data.data, image, w, h, LodePNG_InfoColor_getBpp(&info.color));*/
ucvector_init(&outv);
while(!encoder->error) /*not really a while loop, this is only used to break out if an error happens to avoid goto's to do the ucvector cleanup*/
{
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
size_t i;
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
/*write signature and chunks*/
writeSignature(&outv);
/*IHDR*/
addChunk_IHDR(&outv, w, h, info.color.bitDepth, info.color.colorType, info.interlaceMethod);
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
/*unknown chunks between IHDR and PLTE*/
if(info.unknown_chunks.data[0])
{
encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[0], info.unknown_chunks.datasize[0]);
if(encoder->error) break;
}
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
/*PLTE*/
if(info.color.colorType == 3)
{
if(info.color.palettesize == 0 || info.color.palettesize > 256)
{
encoder->error = 68; /*invalid palette size*/
break;
}
addChunk_PLTE(&outv, &info.color);
}
if(encoder->settings.force_palette && (info.color.colorType == 2 || info.color.colorType == 6))
{
if(info.color.palettesize == 0 || info.color.palettesize > 256)
{
encoder->error = 68; /*invalid palette size*/
break;
}
addChunk_PLTE(&outv, &info.color);
}
/*tRNS*/
if(info.color.colorType == 3 && !isPaletteFullyOpaque(info.color.palette, info.color.palettesize))
{
addChunk_tRNS(&outv, &info.color);
}
if((info.color.colorType == 0 || info.color.colorType == 2) && info.color.key_defined)
{
addChunk_tRNS(&outv, &info.color);
}
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
/*bKGD (must come between PLTE and the IDAt chunks*/
if(info.background_defined) addChunk_bKGD(&outv, &info);
/*pHYs (must come before the IDAT chunks)*/
if(info.phys_defined) addChunk_pHYs(&outv, &info);
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
/*unknown chunks between PLTE and IDAT*/
if(info.unknown_chunks.data[1])
{
encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[1], info.unknown_chunks.datasize[1]);
if(encoder->error) break;
}
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
/*IDAT (multiple IDAT chunks must be consecutive)*/
encoder->error = addChunk_IDAT(&outv, data, datasize, &encoder->settings.zlibsettings);
if(encoder->error) break;
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
/*tIME*/
if(info.time_defined) addChunk_tIME(&outv, &info.time);
/*tEXt and/or zTXt*/
for(i = 0; i 79)
{
encoder->error = 66; /*text chunk too large*/
break;
}
if(strlen(info.text.keys[i]) error = 67; /*text chunk too small*/
break;
}
if(encoder->settings.text_compression)
addChunk_zTXt(&outv, info.text.keys[i], info.text.strings[i], &encoder->settings.zlibsettings);
else
addChunk_tEXt(&outv, info.text.keys[i], info.text.strings[i]);
}
/*LodePNG version id in text chunk*/
if(encoder->settings.add_id)
{
unsigned alread_added_id_text = 0;
for(i = 0; i < info.text.num; i++)
{
if(!strcmp(info.text.keys[i], "LodePNG"))
{
alread_added_id_text = 1;
break;
}
}
if(alread_added_id_text == 0)
addChunk_tEXt(&outv, "LodePNG", VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/
}
/*iTXt*/
for(i = 0; i 79)
{
encoder->error = 66; /*text chunk too large*/
break;
}
if(strlen(info.itext.keys[i]) error = 67; /*text chunk too small*/
break;
}
addChunk_iTXt(&outv, encoder->settings.text_compression,
info.itext.keys[i], info.itext.langtags[i], info.itext.transkeys[i], info.itext.strings[i],
&encoder->settings.zlibsettings);
}
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
/*unknown chunks between IDAT and IEND*/
if(info.unknown_chunks.data[2])
{
encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[2], info.unknown_chunks.datasize[2]);
if(encoder->error) break;
}
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
/*IEND*/
addChunk_IEND(&outv);
break; /*this isn't really a while loop; no error happened so break out now!*/
}
free(data);
/*instead of cleaning the vector up, give it to the output*/
*out = outv.data;
*outsize = outv.size;
}
unsigned LodePNG_encode(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h, unsigned colorType, unsigned bitDepth)
{
unsigned error;
LodePNG_Encoder encoder;
LodePNG_Encoder_init(&encoder);
encoder.infoRaw.color.colorType = colorType;
encoder.infoRaw.color.bitDepth = bitDepth;
encoder.infoPng.color.colorType = colorType;
encoder.infoPng.color.bitDepth = bitDepth;
LodePNG_Encoder_encode(&encoder, out, outsize, image, w, h);
error = encoder.error;
LodePNG_Encoder_cleanup(&encoder);
return error;
}
unsigned LodePNG_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
{
return LodePNG_encode(out, outsize, image, w, h, 6, 8);
}
unsigned LodePNG_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
{
return LodePNG_encode(out, outsize, image, w, h, 2, 8);
}
#ifdef LODEPNG_COMPILE_DISK
unsigned LodePNG_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h, unsigned colorType, unsigned bitDepth)
{
unsigned char* buffer;
size_t buffersize;
unsigned error = LodePNG_encode(&buffer, &buffersize, image, w, h, colorType, bitDepth);
if(!error) error = LodePNG_saveFile(buffer, buffersize, filename);
free(buffer);
return error;
}
unsigned LodePNG_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
{
return LodePNG_encode_file(filename, image, w, h, 6, 8);
}
unsigned LodePNG_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
{
return LodePNG_encode_file(filename, image, w, h, 2, 8);
}
#endif /*LODEPNG_COMPILE_DISK*/
void LodePNG_EncodeSettings_init(LodePNG_EncodeSettings* settings)
{
LodeZlib_CompressSettings_init(&settings->zlibsettings);
settings->autoLeaveOutAlphaChannel = 1;
settings->force_palette = 0;
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
settings->add_id = 1;
settings->text_compression = 0;
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
}
void LodePNG_Encoder_init(LodePNG_Encoder* encoder)
{
LodePNG_EncodeSettings_init(&encoder->settings);
LodePNG_InfoPng_init(&encoder->infoPng);
LodePNG_InfoRaw_init(&encoder->infoRaw);
encoder->error = 1;
}
void LodePNG_Encoder_cleanup(LodePNG_Encoder* encoder)
{
LodePNG_InfoPng_cleanup(&encoder->infoPng);
LodePNG_InfoRaw_cleanup(&encoder->infoRaw);
}
void LodePNG_Encoder_copy(LodePNG_Encoder* dest, const LodePNG_Encoder* source)
{
LodePNG_Encoder_cleanup(dest);
*dest = *source;
LodePNG_InfoPng_init(&dest->infoPng);
LodePNG_InfoRaw_init(&dest->infoRaw);
dest->error = LodePNG_InfoPng_copy(&dest->infoPng, &source->infoPng);
if(dest->error) return;
dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw);
if(dest->error) return;
}
#endif /*LODEPNG_COMPILE_ENCODER*/
#endif /*LODEPNG_COMPILE_PNG*/
/* ////////////////////////////////////////////////////////////////////////// */
/* / File IO / */
/* ////////////////////////////////////////////////////////////////////////// */
#ifdef LODEPNG_COMPILE_DISK
unsigned LodePNG_loadFile(unsigned char** out, size_t* outsize, const char* filename) /*designed for loading files from hard disk in a dynamically allocated buffer*/
{
FILE* file;
long size;
/*provide some proper output values if error will happen*/
*out = 0;
*outsize = 0;
fopen_s(&file,filename, "rb");
if(!file) return 78;
/*get filesize:*/
fseek(file , 0 , SEEK_END);
size = ftell(file);
rewind(file);
/*read contents of the file into the vector*/
*outsize = 0;
*out = (unsigned char*)malloc((size_t)size);
if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file);
fclose(file);
if(!(*out) && size) return 9900; /*the above malloc failed*/
return 0;
}
/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
unsigned LodePNG_saveFile(const unsigned char* buffer, size_t buffersize, const char* filename)
{
FILE* file;
fopen_s(&file, filename, "wb" );
if(!file) return 79;
fwrite((char*)buffer , 1 , buffersize, file);
fclose(file);
return 0;
}
#endif /*LODEPNG_COMPILE_DISK*/
#ifdef LODEPNG_COMPILE_ERROR_TEXT
/*
This returns the description of a numerical error code in English. This is also
the documentation of all the error codes.
*/
const char* LodePNG_error_text(unsigned code)
{
switch(code)
{
case 0: return "no error, everything went ok";
case 1: return "nothing done yet"; /*the Encoder/Decoder has done nothing yet, so error checking makes no sense yet*/
case 10: return "end of input memory reached without huffman end code"; /*while huffman decoding*/
case 11: return "error in code tree made it jump outside of huffman tree"; /*while huffman decoding*/
case 13: return "problem while processing dynamic deflate block";
case 14: return "problem while processing dynamic deflate block";
case 15: return "problem while processing dynamic deflate block";
case 16: return "unexisting code while processing dynamic deflate block";
case 17: return "end of out buffer memory reached while inflating";
case 18: return "invalid distance code while inflating";
case 19: return "end of out buffer memory reached while inflating";
case 20: return "invalid deflate block BTYPE encountered while decoding";
case 21: return "NLEN is not ones complement of LEN in a deflate block";
/*end of out buffer memory reached while inflating:
This can happen if the inflated deflate data is longer than the amount of bytes required to fill up
all the pixels of the image, given the color depth and image dimensions. Something that doesn't
happen in a normal, well encoded, PNG image.*/
case 22: return "end of out buffer memory reached while inflating";
case 23: return "end of in buffer memory reached while inflating";
case 24: return "invalid FCHECK in zlib header";
case 25: return "invalid compression method in zlib header";
case 26: return "FDICT encountered in zlib header while it's not used for PNG";
case 27: return "PNG file is smaller than a PNG header";
case 28: return "incorrect PNG signature, it's no PNG or corrupted"; /*Checks the magic file header, the first 8 bytes of the PNG file*/
case 29: return "first chunk is not the header chunk";
case 30: return "chunk length too large, chunk broken off at end of file";
case 31: return "illegal PNG color type or bpp";
case 32: return "illegal PNG compression method";
case 33: return "illegal PNG filter method";
case 34: return "illegal PNG interlace method";
case 35: return "chunk length of a chunk is too large or the chunk too small";
case 36: return "illegal PNG filter type encountered";
case 37: return "illegal bit depth for this color type given";
case 38: return "the palette is too big"; /*more than 256 colors*/
case 39: return "more palette alpha values given in tRNS chunk than there are colors in the palette";
case 40: return "tRNS chunk has wrong size for greyscale image";
case 41: return "tRNS chunk has wrong size for RGB image";
case 42: return "tRNS chunk appeared while it was not allowed for this color type";
case 43: return "bKGD chunk has wrong size for palette image";
case 44: return "bKGD chunk has wrong size for greyscale image";
case 45: return "bKGD chunk has wrong size for RGB image";
case 46: return "a value in indexed image is larger than the palette size (bitdepth = 8)"; /*Is the palette too small?*/
case 47: return "a value in indexed image is larger than the palette size (bitdepth = 9900 && code <= 9999) return "memory allocation failed";
return "unknown error code";
}
#endif /*LODEPNG_COMPILE_ERROR_TEXT*/
#ifdef __cplusplus
/* ////////////////////////////////////////////////////////////////////////// */
/* / C++ RAII wrapper / */
/* ////////////////////////////////////////////////////////////////////////// */
#ifdef LODEPNG_COMPILE_ZLIB
namespace LodeZlib
{
#ifdef LODEPNG_COMPILE_DECODER
unsigned decompress(std::vector& out, const unsigned char* in, size_t insize, const LodeZlib_DecompressSettings& settings)
{
unsigned char* buffer = 0;
size_t buffersize = 0;
unsigned error = LodeZlib_decompress(&buffer, &buffersize, in, insize, &settings);
if(buffer)
{
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
free(buffer);
}
return error;
}
unsigned decompress(std::vector& out, const std::vector& in, const LodeZlib_DecompressSettings& settings)
{
return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings);
}
#endif //LODEPNG_COMPILE_DECODER
#ifdef LODEPNG_COMPILE_ENCODER
unsigned compress(std::vector& out, const unsigned char* in, size_t insize, const LodeZlib_CompressSettings& settings)
{
unsigned char* buffer = 0;
size_t buffersize = 0;
unsigned error = LodeZlib_compress(&buffer, &buffersize, in, insize, &settings);
if(buffer)
{
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
free(buffer);
}
return error;
}
unsigned compress(std::vector& out, const std::vector& in, const LodeZlib_CompressSettings& settings)
{
return compress(out, in.empty() ? 0 : &in[0], in.size(), settings);
}
#endif //LODEPNG_COMPILE_ENCODER
} //namespace LodeZlib
#endif //LODEPNG_COMPILE_ZLIB
#ifdef LODEPNG_COMPILE_PNG
namespace LodePNG
{
#ifdef LODEPNG_COMPILE_DECODER
Decoder::Decoder()
{
LodePNG_Decoder_init(this);
}
Decoder::~Decoder()
{
LodePNG_Decoder_cleanup(this);
}
void Decoder::operator=(const LodePNG_Decoder& other)
{
LodePNG_Decoder_copy(this, &other);
}
bool Decoder::hasError() const
{
return error != 0;
}
unsigned Decoder::getError() const
{
return error;
}
unsigned Decoder::getWidth() const
{
return infoPng.width;
}
unsigned Decoder::getHeight() const
{
return infoPng.height;
}
unsigned Decoder::getBpp()
{
return LodePNG_InfoColor_getBpp(&infoPng.color);
}
unsigned Decoder::getChannels()
{
return LodePNG_InfoColor_getChannels(&infoPng.color);
}
unsigned Decoder::isGreyscaleType()
{
return LodePNG_InfoColor_isGreyscaleType(&infoPng.color);
}
unsigned Decoder::isAlphaType()
{
return LodePNG_InfoColor_isAlphaType(&infoPng.color);
}
void Decoder::decode(std::vector& out, const unsigned char* in, size_t insize)
{
unsigned char* buffer;
size_t buffersize;
LodePNG_Decoder_decode(this, &buffer, &buffersize, in, insize);
if(buffer)
{
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
free(buffer);
}
}
void Decoder::decode(std::vector& out, const std::vector& in)
{
decode(out, in.empty() ? 0 : &in[0], in.size());
}
void Decoder::inspect(const unsigned char* in, size_t insize)
{
LodePNG_Decoder_inspect(this, in, insize);
}
void Decoder::inspect(const std::vector& in)
{
inspect(in.empty() ? 0 : &in[0], in.size());
}
const LodePNG_DecodeSettings& Decoder::getSettings() const
{
return settings;
}
LodePNG_DecodeSettings& Decoder::getSettings()
{
return settings;
}
void Decoder::setSettings(const LodePNG_DecodeSettings& settings)
{
this->settings = settings;
}
const LodePNG_InfoPng& Decoder::getInfoPng() const
{
return infoPng;
}
LodePNG_InfoPng& Decoder::getInfoPng()
{
return infoPng;
}
void Decoder::setInfoPng(const LodePNG_InfoPng& info)
{
error = LodePNG_InfoPng_copy(&this->infoPng, &info);
}
void Decoder::swapInfoPng(LodePNG_InfoPng& info)
{
LodePNG_InfoPng_swap(&this->infoPng, &info);
}
const LodePNG_InfoRaw& Decoder::getInfoRaw() const
{
return infoRaw;
}
LodePNG_InfoRaw& Decoder::getInfoRaw()
{
return infoRaw;
}
void Decoder::setInfoRaw(const LodePNG_InfoRaw& info)
{
error = LodePNG_InfoRaw_copy(&this->infoRaw, &info);
}
#endif //LODEPNG_COMPILE_DECODER
/* ////////////////////////////////////////////////////////////////////////// */
#ifdef LODEPNG_COMPILE_ENCODER
Encoder::Encoder()
{
LodePNG_Encoder_init(this);
}
Encoder::~Encoder()
{
LodePNG_Encoder_cleanup(this);
}
void Encoder::operator=(const LodePNG_Encoder& other)
{
LodePNG_Encoder_copy(this, &other);
}
bool Encoder::hasError() const
{
return error != 0;
}
unsigned Encoder::getError() const
{
return error;
}
void Encoder::encode(std::vector& out, const unsigned char* image, unsigned w, unsigned h)
{
unsigned char* buffer;
size_t buffersize;
LodePNG_Encoder_encode(this, &buffer, &buffersize, image, w, h);
if(buffer)
{
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
free(buffer);
}
}
void Encoder::encode(std::vector& out, const std::vector& image, unsigned w, unsigned h)
{
encode(out, image.empty() ? 0 : &image[0], w, h);
}
void Encoder::clearPalette()
{
LodePNG_InfoColor_clearPalette(&infoPng.color);
}
void Encoder::addPalette(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
{
error = LodePNG_InfoColor_addPalette(&infoPng.color, r, g, b, a);
}
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
void Encoder::clearText()
{
LodePNG_Text_clear(&infoPng.text);
}
void Encoder::addText(const std::string& key, const std::string& str)
{
error = LodePNG_Text_add(&infoPng.text, key.c_str(), str.c_str());
}
void Encoder::clearIText()
{
LodePNG_IText_clear(&infoPng.itext);
}
void Encoder::addIText(const std::string& key, const std::string& langtag, const std::string& transkey, const std::string& str)
{
error = LodePNG_IText_add(&infoPng.itext, key.c_str(), langtag.c_str(), transkey.c_str(), str.c_str());
}
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
const LodePNG_EncodeSettings& Encoder::getSettings() const
{
return settings;
}
LodePNG_EncodeSettings& Encoder::getSettings()
{
return settings;
}
void Encoder::setSettings(const LodePNG_EncodeSettings& settings)
{
this->settings = settings;
}
const LodePNG_InfoPng& Encoder::getInfoPng() const
{
return infoPng;
}
LodePNG_InfoPng& Encoder::getInfoPng()
{
return infoPng;
}
void Encoder::setInfoPng(const LodePNG_InfoPng& info)
{
error = LodePNG_InfoPng_copy(&this->infoPng, &info);
}
void Encoder::swapInfoPng(LodePNG_InfoPng& info)
{
LodePNG_InfoPng_swap(&this->infoPng, &info);
}
const LodePNG_InfoRaw& Encoder::getInfoRaw() const
{
return infoRaw;
}
LodePNG_InfoRaw& Encoder::getInfoRaw()
{
return infoRaw;
}
void Encoder::setInfoRaw(const LodePNG_InfoRaw& info)
{
error = LodePNG_InfoRaw_copy(&this->infoRaw, &info);
}
#endif //LODEPNG_COMPILE_ENCODER
/* ////////////////////////////////////////////////////////////////////////// */
#ifdef LODEPNG_COMPILE_DISK
void loadFile(std::vector& buffer, const std::string& filename) //designed for loading files from hard disk in an std::vector
{
std::ifstream file(filename.c_str(), std::ios::in|std::ios::binary|std::ios::ate);
/*get filesize*/
std::streamsize size = 0;
if(file.seekg(0, std::ios::end).good()) size = file.tellg();
if(file.seekg(0, std::ios::beg).good()) size -= file.tellg();
/*read contents of the file into the vector*/
buffer.resize(size_t(size));
if(size > 0) file.read((char*)(&buffer[0]), size);
}
/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
void saveFile(const std::vector& buffer, const std::string& filename)
{
std::ofstream file(filename.c_str(), std::ios::out|std::ios::binary);
file.write(buffer.empty() ? 0 : (char*)&buffer[0], std::streamsize(buffer.size()));
}
#endif /*LODEPNG_COMPILE_DISK*/
/* ////////////////////////////////////////////////////////////////////////// */
#ifdef LODEPNG_COMPILE_DECODER
unsigned decode(std::vector& out, unsigned& w, unsigned& h, const unsigned char* in, size_t insize, unsigned colorType, unsigned bitDepth)
{
Decoder decoder;
decoder.getInfoRaw().color.colorType = colorType;
decoder.getInfoRaw().color.bitDepth = bitDepth;
decoder.decode(out, in, insize);
w = decoder.getWidth();
h = decoder.getHeight();
return decoder.getError();
}
unsigned decode(std::vector& out, unsigned& w, unsigned& h, const std::vector& in, unsigned colorType, unsigned bitDepth)
{
return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colorType, bitDepth);
}
#ifdef LODEPNG_COMPILE_DISK
unsigned decode(std::vector& out, unsigned& w, unsigned& h, const std::string& filename, unsigned colorType, unsigned bitDepth)
{
std::vector buffer;
loadFile(buffer, filename);
return decode(out, w, h, buffer, colorType, bitDepth);
}
#endif //LODEPNG_COMPILE_DECODER
#endif /*LODEPNG_COMPILE_DISK*/
#ifdef LODEPNG_COMPILE_ENCODER
unsigned encode(std::vector& out, const unsigned char* in, unsigned w, unsigned h, unsigned colorType, unsigned bitDepth)
{
Encoder encoder;
encoder.getInfoRaw().color.colorType = colorType;
encoder.getInfoRaw().color.bitDepth = bitDepth;
encoder.getInfoPng().color.colorType = colorType;
encoder.getInfoPng().color.bitDepth = bitDepth;
encoder.encode(out, in, w, h);
return encoder.getError();
}
unsigned encode(std::vector& out, const std::vector& in, unsigned w, unsigned h, unsigned colorType, unsigned bitDepth)
{
return encode(out, in.empty() ? 0 : &in[0], w, h, colorType, bitDepth);
}
#ifdef LODEPNG_COMPILE_DISK
unsigned encode(const std::string& filename, const unsigned char* in, unsigned w, unsigned h, unsigned colorType, unsigned bitDepth)
{
std::vector buffer;
Encoder encoder;
encoder.getInfoRaw().color.colorType = colorType;
encoder.getInfoRaw().color.bitDepth = bitDepth;
encoder.encode(buffer, in, w, h);
if(!encoder.hasError()) saveFile(buffer, filename);
return encoder.getError();
}
unsigned encode(const std::string& filename, const std::vector& in, unsigned w, unsigned h, unsigned colorType, unsigned bitDepth)
{
return encode(filename, in.empty() ? 0 : &in[0], w, h, colorType, bitDepth);
}
#endif /*LODEPNG_COMPILE_DISK*/
#endif //LODEPNG_COMPILE_ENCODER
} //namespace LodePNG
#endif //LODEPNG_COMPILE_PNG
#endif /*__cplusplus C++ RAII wrapper*/
and cwindow.h
#ifndef CWINDOW_H
#define CWINDOW_H
// Inclusions
#include "windows.h" // Window Tools
#include "GL/gl.h" // Open GL Library
#include "GL/glu.h"
#include "iostream" // Console I/O
// Namespaces
using namespace std;
// Window Reference
HWND hwnd;
// OpenGL References
HDC hdevc;
HGLRC hgevc;
// Function Pointers
void (*c_destruct)(void);
void (*c_mouseAction)(WPARAM,bool);
void (*c_mouseMove)(int,int);
void (*c_keyAction)(WPARAM,bool);
// Variables
int c_awid, c_ahei;
// Close Window
void closeWindow()
{
// Call Destructors
c_destruct();
// Destroy OpenGL Context
wglMakeCurrent( NULL, NULL );
wglDeleteContext(hgevc);
ReleaseDC(hwnd,hdevc);
// Destroy the Window
DestroyWindow(hwnd);
UnregisterClass(_T("Test"), GetModuleHandle(NULL));
}
// Window Processes
LRESULT CALLBACK WndProc(HWND thwnd, UINT msg, WPARAM wpar, LPARAM lpar)
{
switch(msg)
{
// When Resizing Screen
case WM_SIZE:
// Resize back to original size
RECT t;
GetWindowRect(hwnd,&t);
MoveWindow(hwnd,t.left,t.top,c_awid,c_ahei,true);
break;
// Keyboard Presses Detected
case WM_KEYDOWN:
c_keyAction(wpar,true);
break;
case WM_KEYUP:
c_keyAction(wpar,false);
break;
// Mouse Action
case WM_LBUTTONDOWN: case WM_RBUTTONDOWN:
c_mouseAction(wpar,true);
break;
case WM_LBUTTONUP:
c_mouseAction(MK_LBUTTON,false);
case WM_RBUTTONUP:
c_mouseAction(MK_RBUTTON,false);
break;
// Mouse Movement Detected
case WM_MOUSEMOVE:
c_mouseMove(LOWORD(lpar),HIWORD(lpar));
break;
// Window Closed
case WM_DESTROY:
PostQuitMessage(0);
break;
}
return DefWindowProc(thwnd, msg, wpar, lpar);
}
// Create the new Window
void newWindow(LPCWSTR tname, int tawid, int tahei)
{
cout << "Declare Styles" << endl;
// Declare Window Styles
DWORD dwExWindowStyle;
DWORD dwWindowStyle;
cout << "Setting Window Properties" << endl;
// Define Window Properties
WNDCLASS wcWindowClass;
wcWindowClass.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
wcWindowClass.lpfnWndProc = WndProc;
wcWindowClass.cbClsExtra = 0;
wcWindowClass.cbWndExtra = 0;
wcWindowClass.hInstance = GetModuleHandle(NULL);
wcWindowClass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wcWindowClass.hCursor = LoadCursor(NULL, IDC_ARROW);
wcWindowClass.hbrBackground = NULL;
wcWindowClass.lpszMenuName = NULL;
wcWindowClass.lpszClassName = _T("Test");
RegisterClass(&wcWindowClass);
cout << "Window Styling" << endl;
// Define Window Styles
dwExWindowStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;
dwWindowStyle = WS_OVERLAPPEDWINDOW| WS_CLIPSIBLINGS | WS_CLIPCHILDREN;
cout << "Creating Window" << endl;
// Build Window
hwnd = CreateWindowEx(dwExWindowStyle,_T("Test"), tname, dwWindowStyle, 0, 0, tawid, tahei, NULL, NULL, GetModuleHandle(NULL), NULL);
cout << "Defining Pixel Format" << endl;
// Define Pixel Format
PIXELFORMATDESCRIPTOR pfd;
memset(&pfd, 0, sizeof(PIXELFORMATDESCRIPTOR));
pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 32;
cout << "New OpenGL Context" << endl;
// Create New OpenGL Context
cout << "Getting Draw Context" << endl;
hdevc = GetDC(hwnd);
cout << "Picking Pixel Format" << endl;
int htpf = ChoosePixelFormat(hdevc,&pfd);
cout << "Set Pixel Format" << endl;
SetPixelFormat(hdevc,htpf,&pfd);
cout << "Making OpenGL Context" << endl;
hgevc = wglCreateContext(hdevc);
cout << "Picking OpenGL Context" << endl;
wglMakeCurrent(hdevc,hgevc);
cout << "Preparing OpenGL Context" << endl;
// Prepare OpenGL Context
glViewport(0,0,tawid,tahei);
glClearColor(0.875,0.875,0.875,0);
// Enable Transparent Textures
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_BLEND);
glDisable(GL_DEPTH_TEST); // Disable Depth Tests
cout << "Setting up Projections" << endl;
// Setup Projections
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(1,tawid+1,tahei-37,-37,0,1);
glMatrixMode(GL_MODELVIEW); // Prepare to Draw
cout << "Seeding Game" << endl;
srand((unsigned int)time(NULL));
cout << "Showing Window" << endl;
// Save Window Size
c_awid = tawid; c_ahei = tahei;
// Show the Window
ShowWindow(hwnd,SW_SHOW);
SetForegroundWindow(hwnd);
SetFocus(hwnd);
}
// Define Functions to Use
void defDestruct(void (*t)(void)) {c_destruct = t;}
void defMouseAction(void (*t)(WPARAM,bool)) {c_mouseAction = t;}
void defMouseMove(void (*t)(int,int)) {c_mouseMove = t;}
void defKeyAction(void (*t)(WPARAM,bool)) {c_keyAction = t;}
void c_swapBuffer() {SwapBuffers(hdevc);}
#endif
<