png_loader.h

/* 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef PSP_PNG_IMAGE_H
#define PSP_PNG_IMAGE_H

#include <png.h>

class PngLoader {
private:
    bool basicImageLoad();      // common operation
    bool findImageDimensions(); // find dimensions of a given PNG file
    bool loadImageIntoBuffer();

    static void warningFn(png_structp png_ptr, png_const_charp warning_msg);
    static void errorFn(png_structp png_ptr, png_const_charp warning_msg);
    static void libReadFunc(png_structp pngPtr, png_bytep data, png_size_t length);

    Common::SeekableReadStream &_file;
    Buffer *_buffer;
    Palette *_palette;

    uint32 _width;
    uint32 _height;
    uint32 _paletteSize;
    Buffer::HowToSize _sizeBy;

    // PNG lib values
    int _bitDepth;
    png_structp _pngPtr;
    png_infop _infoPtr;
    int _colorType;
    uint32 _channels;

public:
    enum Status {
        OK,
        OUT_OF_MEMORY,
        BAD_FILE
    };

    PngLoader(Common::SeekableReadStream &file, Buffer &buffer, Palette &palette,
        Buffer::HowToSize sizeBy = Buffer::kSizeByTextureSize) :
            _file(file), _buffer(&buffer), _palette(&palette),
            _width(0), _height(0), _paletteSize(0),
            _bitDepth(0), _sizeBy(sizeBy), _pngPtr(0),
            _infoPtr(0), _colorType(0), _channels(0) {}
    ~PngLoader();

    PngLoader::Status allocate();
    bool load();
};

#endif /* PSP_PNG_IMAGE_H */