diff options
Diffstat (limited to 'graphics/decoders/png.h')
-rw-r--r-- | graphics/decoders/png.h | 78 |
1 files changed, 4 insertions, 74 deletions
diff --git a/graphics/decoders/png.h b/graphics/decoders/png.h index ca204f6dd3..e52ddabd7d 100644 --- a/graphics/decoders/png.h +++ b/graphics/decoders/png.h @@ -24,33 +24,12 @@ * PNG decoder used in engines: * - sword25 * Dependencies: - * - zlib + * - libpng */ #ifndef GRAPHICS_PNG_H #define GRAPHICS_PNG_H -// PNG decoder, based on the W3C specs: -// http://www.w3.org/TR/PNG/ -// Parts of the code have been adapted from LodePNG, by Lode Vandevenne: -// http://members.gamedev.net/lode/projects/LodePNG/ - -// All the numbers are BE: http://www.w3.org/TR/PNG/#7Integers-and-byte-order - -// Note: At the moment, this decoder only supports non-interlaced images, and -// does not support truecolor/grayscale images with 16bit depth. -// -// Theoretically, interlaced images shouldn't be needed for games, as -// interlacing is only useful for images in websites. -// -// PNG images with 16bit depth (i.e. 48bit images) are quite rare, and can -// theoretically contain more than 16.7 millions of colors (the so-called "deep -// color" representation). In essence, each of the R, G, B and A components in -// them is specified with 2 bytes, instead of 1. However, the PNG specification -// always refers to color components with 1 byte each, so this part of the spec -// is a bit unclear. For now, these won't be supported, until a suitable sample -// is found. - #include "common/scummsys.h" #include "common/textconsole.h" #include "graphics/decoders/image_decoder.h" @@ -73,62 +52,13 @@ public: void destroy(); const Graphics::Surface *getSurface() const { return _outputSurface; } const byte *getPalette() const { return _palette; } - uint16 getPaletteColorCount() const { return _paletteEntries; } - + uint16 getPaletteColorCount() const { return _paletteColorCount; } private: - enum PNGColorType { - kGrayScale = 0, // bit depths: 1, 2, 4, 8, 16 - kTrueColor = 2, // bit depths: 8, 16 - kIndexed = 3, // bit depths: 1, 2, 4, 8 - kGrayScaleWithAlpha = 4, // bit depths: 8, 16 - kTrueColorWithAlpha = 6 // bit depths: 8, 16 - }; - - enum PNGInterlaceType { - kNonInterlaced = 0, - kInterlaced = 1 - }; - - struct PNGHeader { - uint32 width; - uint32 height; - byte bitDepth; - PNGColorType colorType; - byte compressionMethod; - byte filterMethod; - PNGInterlaceType interlaceType; - }; - - void readHeaderChunk(); - byte getNumColorChannels() const; - - void readPaletteChunk(); - void readTransparencyChunk(uint32 chunkLength); - - void constructImage(); - void unfilterScanLine(byte *dest, const byte *scanLine, const byte *prevLine, uint16 byteWidth, byte filterType, uint16 length); - byte paethPredictor(int16 a, int16 b, int16 c); - - // The original file stream Common::SeekableReadStream *_stream; - // The unzipped image data stream - Common::SeekableReadStream *_imageData; - - PNGHeader _header; - - byte _palette[256 * 3]; // RGB - byte _paletteTransparency[256]; - uint16 _paletteEntries; - uint16 _transparentColor[3]; - bool _transparentColorSpecified; - - byte *_compressedBuffer; - uint32 _compressedBufferSize; + byte *_palette; + uint16 _paletteColorCount; Graphics::Surface *_outputSurface; - Graphics::PixelFormat findPixelFormat() const; - int getBytesPerPixel() const; - void constructOutput(const byte *surface); }; } // End of namespace Graphics |