1 /******************************************************************************

     2  *

     3  * $Id$

     4  *

     5  *

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

     7  *

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

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

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

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

    12  * See the GNU General Public License for more details.

    13  *

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

    15  *

    16  */

    17 

    18 #ifndef _GIFENC_H

    19 #define _GIFENC_H

    20 #include <qfile.h>

    21 

    22 typedef unsigned char  Byte;

    23 typedef unsigned short Word;

    24 

    25 struct Color

    26 {

    27   Byte red;

    28   Byte green;

    29   Byte blue;

    30 };

    31 

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

    33 

    34 class GifEncoder

    35 {

    36   public:

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

    38    ~GifEncoder();

    39     void writeGIF(QFile &fp);

    40    

    41   protected:

    42     void putWord( Word w, QFile &fp );

    43     void putByte( Byte b, QFile &fp );

    44     void compress(int csize, QFile &fp);

    45     void writeCode(int code, QFile &fp);

    46     void writeChar( Byte c, QFile &fp );

    47     void writePacket(QFile &fp);

    48     void clearHashTable();

    49     int nextPixel()

    50     {

    51       if ( --numPixels < 0) return EOF;

    52       return *dataPtr++;

    53     }

    54 

    55     

    56   private:

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

    58     const int globalPaletteFlag;

    59     const int bits;

    60     const int maxMaxCode; 

    61 

    62     // image variables

    63     int width;             // image width 

    64     int height;            // image height 

    65     Byte depth;            // bits per CLUT entry 

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

    67     Color *palette;        // pointer to the color palette 

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

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

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

    71     

    72     // compression variables

    73     bool clearFlag;        // clear hash table flag

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

    75     unsigned int curAccum; // encoded bit accumulator

    76     int curBits;           // number of bits in curAccum

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

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

    79     int nBits;             // number of bits/code

    80     int maxCode;           // maximum code, given n_bits

    81     int initBits;          // initial number of bits

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

    83     int ClearCode;         // the clear code for the decompressor

    84     

    85     // tables

    86     int htab[hashTableSize];       // the hash table

    87     Word codetab[hashTableSize];   // the code table

    88 };

    89 

    90 #endif