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Diffstat (limited to 'graphics/decoders/png.cpp')
-rw-r--r-- | graphics/decoders/png.cpp | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/graphics/decoders/png.cpp b/graphics/decoders/png.cpp new file mode 100644 index 0000000000..4f917b44b1 --- /dev/null +++ b/graphics/decoders/png.cpp @@ -0,0 +1,241 @@ +/* ScummVM - Graphic Adventure Engine + * + * ScummVM is the legal property of its developers, whose names + * are too numerous to list here. Please refer to the COPYRIGHT + * file distributed with this source distribution. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + */ + +// Since we need to work with libpng here, we need to allow all symbols +// to avoid compilation issues. +#define FORBIDDEN_SYMBOL_ALLOW_ALL +#include "common/scummsys.h" + +#ifdef USE_PNG +#include <png.h> +#endif + +#include "graphics/decoders/png.h" + +#include "graphics/pixelformat.h" +#include "graphics/surface.h" + +#include "common/stream.h" + +namespace Graphics { + +PNGDecoder::PNGDecoder() : _outputSurface(0), _palette(0), _paletteColorCount(0) { +} + +PNGDecoder::~PNGDecoder() { + destroy(); +} + +void PNGDecoder::destroy() { + if (_outputSurface) { + _outputSurface->free(); + delete _outputSurface; + _outputSurface = 0; + } + delete[] _palette; + _palette = NULL; +} + +#ifdef USE_PNG +// libpng-error-handling: +void pngError(png_structp pngptr, png_const_charp errorMsg) { + error("%s", errorMsg); +} + +void pngWarning(png_structp pngptr, png_const_charp warningMsg) { + warning("%s", warningMsg); +} + +// libpng-I/O-helper: +void pngReadFromStream(png_structp pngPtr, png_bytep data, png_size_t length) { + void *readIOptr = png_get_io_ptr(pngPtr); + Common::SeekableReadStream *stream = (Common::SeekableReadStream *)readIOptr; + stream->read(data, length); +} +#endif + +/* + * This code is based on Broken Sword 2.5 engine + * + * Copyright (c) Malte Thiesen, Daniel Queteschiner and Michael Elsdoerfer + * + * Licensed under GNU GPL v2 + * + */ + +bool PNGDecoder::loadStream(Common::SeekableReadStream &stream) { +#ifdef USE_PNG + destroy(); + + _stream = &stream; + + // First, check the PNG signature + if (_stream->readUint32BE() != MKTAG(0x89, 'P', 'N', 'G')) { + delete _stream; + return false; + } + if (_stream->readUint32BE() != MKTAG(0x0d, 0x0a, 0x1a, 0x0a)) { + delete _stream; + return false; + } + + // The following is based on the guide provided in: + //http://www.libpng.org/pub/png/libpng-1.2.5-manual.html#section-3 + //http://www.libpng.org/pub/png/libpng-1.4.0-manual.pdf + // along with the png-loading code used in the sword25-engine. + png_structp pngPtr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); + if (!pngPtr) { + delete _stream; + return false; + } + png_infop infoPtr = png_create_info_struct(pngPtr); + if (!infoPtr) { + png_destroy_read_struct(&pngPtr, NULL, NULL); + delete _stream; + return false; + } + png_infop endInfo = png_create_info_struct(pngPtr); + if (!endInfo) { + png_destroy_read_struct(&pngPtr, &infoPtr, NULL); + delete _stream; + return false; + } + + png_set_error_fn(pngPtr, NULL, pngError, pngWarning); + // TODO: The manual says errors should be handled via setjmp + + png_set_read_fn(pngPtr, _stream, pngReadFromStream); + png_set_crc_action(pngPtr, PNG_CRC_DEFAULT, PNG_CRC_WARN_USE); + // We already verified the PNG-header + png_set_sig_bytes(pngPtr, 8); + + // Read PNG header + png_read_info(pngPtr, infoPtr); + + // No handling for unknown chunks yet. + int bitDepth, colorType, width, height, interlaceType; + png_uint_32 w, h; + png_get_IHDR(pngPtr, infoPtr, &w, &h, &bitDepth, &colorType, &interlaceType, NULL, NULL); + width = w; + height = h; + + // Allocate memory for the final image data. + // To keep memory framentation low this happens before allocating memory for temporary image data. + _outputSurface = new Graphics::Surface(); + + // Images of all color formats except PNG_COLOR_TYPE_PALETTE + // will be transformed into ARGB images + if (colorType == PNG_COLOR_TYPE_PALETTE && !png_get_valid(pngPtr, infoPtr, PNG_INFO_tRNS)) { + int numPalette = 0; + png_colorp palette = NULL; + uint32 success = png_get_PLTE(pngPtr, infoPtr, &palette, &numPalette); + if (success != PNG_INFO_PLTE) { + png_destroy_read_struct(&pngPtr, &infoPtr, NULL); + return false; + } + _paletteColorCount = numPalette; + _palette = new byte[_paletteColorCount * 3]; + for (int i = 0; i < _paletteColorCount; i++) { + _palette[(i * 3)] = palette[i].red; + _palette[(i * 3) + 1] = palette[i].green; + _palette[(i * 3) + 2] = palette[i].blue; + + } + _outputSurface->create(width, height, Graphics::PixelFormat::createFormatCLUT8()); + png_set_packing(pngPtr); + } else { + _outputSurface->create(width, height, Graphics::PixelFormat(4, 8, 8, 8, 8, 24, 16, 8, 0)); + if (!_outputSurface->pixels) { + error("Could not allocate memory for output image."); + } + if (bitDepth == 16) + png_set_strip_16(pngPtr); + if (bitDepth < 8) + png_set_expand(pngPtr); + if (png_get_valid(pngPtr, infoPtr, PNG_INFO_tRNS)) + png_set_expand(pngPtr); + if (colorType == PNG_COLOR_TYPE_GRAY || + colorType == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_gray_to_rgb(pngPtr); + + // PNGs are Big-Endian: +#ifdef SCUMM_LITTLE_ENDIAN + png_set_bgr(pngPtr); + png_set_swap_alpha(pngPtr); + if (colorType != PNG_COLOR_TYPE_RGB_ALPHA) + png_set_filler(pngPtr, 0xff, PNG_FILLER_BEFORE); +#else + if (colorType != PNG_COLOR_TYPE_RGB_ALPHA) + png_set_filler(pngPtr, 0xff, PNG_FILLER_AFTER); +#endif + + } + + // After the transformations have been registered, the image data is read again. + png_set_interlace_handling(pngPtr); + png_read_update_info(pngPtr, infoPtr); + png_get_IHDR(pngPtr, infoPtr, &w, &h, &bitDepth, &colorType, NULL, NULL, NULL); + width = w; + height = h; + + if (interlaceType == PNG_INTERLACE_NONE) { + // PNGs without interlacing can simply be read row by row. + for (int i = 0; i < height; i++) { + png_read_row(pngPtr, (png_bytep)_outputSurface->getBasePtr(0, i), NULL); + } + } else { + // PNGs with interlacing require us to allocate an auxillary + // buffer with pointers to all row starts. + + // Allocate row pointer buffer + png_bytep *rowPtr = new png_bytep[height]; + if (!rowPtr) { + error("Could not allocate memory for row pointers."); + } + + // Initialize row pointers + for (int i = 0; i < height; i++) + rowPtr[i] = (png_bytep)_outputSurface->getBasePtr(0, i); + + // Read image data + png_read_image(pngPtr, rowPtr); + + // Free row pointer buffer + delete[] rowPtr; + } + + // Read additional data at the end. + png_read_end(pngPtr, NULL); + + // Destroy libpng structures + png_destroy_read_struct(&pngPtr, &infoPtr, NULL); + + // We no longer need the file stream, thus close it here + _stream = 0; + + return true; +#else + return false; +#endif +} + +} // End of Graphics namespace |