libbase/GnashImageGif.h

   1 // GnashImageGif.h: gif_lib wrapper for Gnash.
   2 //
   3 //   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Free Software
   4 //   Foundation, Inc
   5 //
   6 // This program is free software; you can redistribute it and/or modify
   7 // it under the terms of the GNU General Public License as published by
   8 // the Free Software Foundation; either version 3 of the License, or
   9 // (at your option) any later version.
  10 //
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software
  18 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19 //
  20
  21 #ifndef GNASH_IMAGE_GIF_H
  22 #define GNASH_IMAGE_GIF_H
  23
  24 #include <memory>
  25
  26 #include "dsodefs.h"
  27 #include "GnashImage.h"
  28 #include <boost/scoped_array.hpp>
  29 #include <boost/shared_ptr.hpp>
  30
  31 extern "C" {
  32 #include <gif_lib.h>
  33 }
  34
  35 // Forward declarations
  36 namespace gnash { class IOChannel; }
  37
  38 namespace gnash {
  39 namespace image {
  40
  41 class GifInput : public Input
  42 {
  43
  44 public:
  45
  46     /// Construct a GifInput object to read from an IOChannel.
  47     //
  48     /// @param in   The stream to read GIF data from. Ownership is shared
  49     ///             between caller and GifInput, so it is freed
  50     ///             automatically when the last owner is destroyed.
  51     GifInput(boost::shared_ptr<IOChannel> in);
  52
  53     ~GifInput();
  54
  55     /// Begin processing the image data.
  56     void read();
  57
  58     /// Get the image's height in pixels.
  59     //
  60     /// @return     The height of the image in pixels.
  61     size_t getHeight() const;
  62
  63     /// Get the image's width in pixels.
  64     //
  65     /// @return     The width of the image in pixels.
  66     size_t getWidth() const;
  67
  68     /// Get number of components (channels)
  69     //
  70     /// @return     The number of components, e.g. 3 for RGB
  71     size_t getComponents() const { return 3; }
  72
  73     /// Read a scanline's worth of image data into the given buffer.
  74     //
  75     /// The amount of data read is getWidth() * getComponents().
  76     ///
  77     /// @param rgbData  The buffer for writing raw RGB data to.
  78     void readScanline(unsigned char* rgb_data);
  79
  80     /// Create a GifInput and transfer ownership to the caller.
  81     //
  82     /// @param in   The IOChannel to read GIF data from.
  83     DSOEXPORT static std::auto_ptr<Input> create(
  84             boost::shared_ptr<IOChannel> in)
  85     {
  86         std::auto_ptr<Input> ret(new GifInput(in));
  87         if (ret.get()) ret->read();
  88         return ret;
  89     }
  90
  91 private:
  92
  93     /// Initialize gif_lib
  94     void init();
  95
  96     /// Process a single image record
  97     //
  98     /// @return     false if no image was parsed, true if we have an image.
  99     bool processRecord(GifRecordType record);
 100
 101     // State needed for input.
 102     GifFileType* _gif;
 103
 104     // A counter for keeping track of the last row copied.
 105     size_t _currentRow;
 106
 107     typedef boost::scoped_array<GifPixelType> PixelRow;
 108
 109     // A 2-dimensional scoped array holding the unpacked pixel data.
 110     boost::scoped_array<PixelRow> _gifData;
 111
 112
 113
 114 };
 115
 116 } // namespace image
 117 } // namespace gnash
 118
 119
 120 #endif