GnashImagePng.h

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// GnashImagePng.h: libpng wrapper for Gnash.
// 
//   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Free Software
//   Foundation, Inc
// 
// 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, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
//

#ifndef GNASH_IMAGE_PNG_H
#define GNASH_IMAGE_PNG_H

#include <memory>

#include "dsodefs.h"
#include "GnashImage.h"
#include <boost/scoped_array.hpp>


extern "C" {
#ifdef HAVE_PNG_H
#include <png.h>
#else
#warning "This system doesn't have png.h installed!"
#endif
}

// Forward declarations
namespace gnash {
    class IOChannel;
}

namespace gnash {
namespace image {

class PngInput : public Input
{

public:

    //
    PngInput(boost::shared_ptr<IOChannel> in);
    
    ~PngInput();
    
    void read();

    //
    size_t getHeight() const;

    //
    size_t getWidth() const;

    //
    void readScanline(unsigned char* imageData);

    //
    DSOEXPORT static std::auto_ptr<Input> create(
            boost::shared_ptr<IOChannel> in)
    {
        std::auto_ptr<Input> ret ( new PngInput(in) );
        if (ret.get()) ret->read();
        return ret;
    }

private:

    // State needed for input.
    png_structp _pngPtr;
    png_infop _infoPtr;
    boost::scoped_array<png_bytep> _rowPtrs;
    boost::scoped_array<png_byte> _pixelData;
   
    // A counter for keeping track of the last row copied.
    size_t _currentRow;

    void init();

    // Return number of components (i.e. == 3 for RGB
    // data).
    size_t getComponents() const;

};

// Class object for writing PNG image data.
class PngOutput : public Output
{

public:

    //
    PngOutput(boost::shared_ptr<IOChannel> out, size_t width,
            size_t height, int quality);
    
    ~PngOutput();

    void writeImageRGB(const unsigned char* rgbData);
    
    void writeImageRGBA(const unsigned char* rgbaData);

    static std::auto_ptr<Output> create(boost::shared_ptr<IOChannel> out,
            size_t width, size_t height, int quality);
    
private:

    void init();

    png_structp _pngPtr;
    png_infop _infoPtr;
    
};

} // namespace image
} // namespace gnash



#endif