/******************************************************************************

 *

 * $Id$

 *

 *

 * Copyright (C) 1997-2009 by Dimitri van Heesch.

 *

 * Permission to use, copy, modify, and distribute this software and its

 * documentation under the terms of the GNU General Public License is hereby 

 * granted. No representations are made about the suitability of this software 

 * for any purpose. It is provided "as is" without express or implied warranty.

 * See the GNU General Public License for more details.

 *

 * All output generated with Doxygen is not covered by this license.

 *

 */

#ifndef _GIFENC_H

#define _GIFENC_H

#include <qfile.h>

typedef unsigned char  Byte;

typedef unsigned short Word;

struct Color

{

  Byte red;

  Byte green;

  Byte blue;

};

const int hashTableSize=5003;     // size of the hash table 

class GifEncoder

{

  public:

    GifEncoder(Byte *rawBytes,Color *p,int w,int h,Byte d,int t);

   ~GifEncoder();

    void writeGIF(QFile &fp);

  protected:

    void putWord( Word w, QFile &fp );

    void putByte( Byte b, QFile &fp );

    void compress(int csize, QFile &fp);

    void writeCode(int code, QFile &fp);

    void writeChar( Byte c, QFile &fp );

    void writePacket(QFile &fp);

    void clearHashTable();

    int nextPixel()

    {

      if ( --numPixels < 0) return EOF;

      return *dataPtr++;

    }

  private:

    const int colorResolution;      // 8 bit for Red, Green and Blue;

    const int globalPaletteFlag;

    const int bits;

    const int maxMaxCode; 

    // image variables

    int width;             // image width 

    int height;            // image height 

    Byte depth;            // bits per CLUT entry 

    int transIndex;        // index of the transparant color; -1 = none 

    Color *palette;        // pointer to the color palette 

    int numPixels;         // total number of pixel (i.e. width * height)

    Byte *data;            // pointer to the image data (one byte per pixel) 

    Byte *dataPtr;         // pointer located at the current pixel.

    // compression variables

    bool clearFlag;        // clear hash table flag

    int  freeEntry;        // first free entry in the hash table

    unsigned int curAccum; // encoded bit accumulator

    int curBits;           // number of bits in curAccum

    Byte accum[256];       // Buffer for a packet

    int aCount;            // Number of characters so far in this 'packet'

    int nBits;             // number of bits/code

    int maxCode;           // maximum code, given n_bits

    int initBits;          // initial number of bits

    int EOFCode;           // code for signaling the end of the file

    int ClearCode;         // the clear code for the decompressor

    // tables

    int htab[hashTableSize];       // the hash table

    Word codetab[hashTableSize];   // the code table

};

#endif