src/add-ons/translators/gif/GIFLoad.h

   1 ////////////////////////////////////////////////////////////////////////////////
   2 //
   3 //      File: GIFLoad.h
   4 //
   5 //      Date: December 1999
   6 //
   7 //      Author: Daniel Switkin
   8 //
   9 //      Copyright 2003 (c) by Daniel Switkin. This file is made publically available
  10 //      under the BSD license, with the stipulations that this complete header must
  11 //      remain at the top of the file indefinitely, and credit must be given to the
  12 //      original author in any about box using this software.
  13 //
  14 ////////////////////////////////////////////////////////////////////////////////
  15
  16 // Additional authors:  John Scipione, <jscipione@gmail.com>
  17
  18 #ifndef GIF_LOAD_H
  19 #define GIF_LOAD_H
  20
  21
  22 #include <DataIO.h>
  23 #include "LoadPalette.h"
  24
  25
  26 #define GIF_INTERLACED          0x40
  27 #define GIF_LOCALCOLORMAP       0x80
  28
  29 #define ENTRY_COUNT                     4354
  30         // 4354 = 4096 + 256 + 1 + 1
  31         // 4096 for the image data, 256 for the color codes,
  32         // 1 for the clear code, 1 for the end code
  33
  34
  35 typedef struct Memblock {
  36         unsigned char   data[ENTRY_COUNT];
  37         int                             offset;
  38         Memblock*               next;
  39 } Memblock;
  40
  41
  42 const int gl_pass_starts_at[]           = { 0, 4, 2, 1, 0 };
  43 const int gl_increment_pass_by[]        = { 8, 8, 4, 2, 0 };
  44
  45
  46 class GIFLoad {
  47 public:
  48                                                                 GIFLoad(BPositionIO* input,
  49                                                                         BPositionIO* output);
  50         virtual                                         ~GIFLoad();
  51
  52                         bool                            fatalerror;
  53
  54 private:
  55                         bool                            ReadGIFHeader();
  56                         bool                            ReadGIFLoopBlock();
  57                         bool                            ReadGIFControlBlock();
  58                         bool                            ReadGIFImageHeader();
  59                         bool                            ReadGIFImageData();
  60                         bool                            ReadGIFCommentBlock();
  61                         bool                            ReadGIFUnknownBlock(unsigned char c);
  62
  63                         bool                            InitFrame(int codeSize);
  64                         short                           NextCode();
  65                         void                            ResetTable();
  66
  67                         unsigned char*          MemblockAllocate(int size);
  68                         void                            MemblockDeleteAll();
  69
  70                         inline  bool            OutputColor(unsigned char* string, int size);
  71
  72                         BPositionIO*            fInput;
  73                         BPositionIO*            fOutput;
  74                         LoadPalette*            fPalette;
  75
  76                         bool                            fInterlaced;
  77
  78                         int                                     fPass;
  79                         int                                     fRow;
  80
  81                         int                                     fWidth;
  82                         int                                     fHeight;
  83
  84                         unsigned char           fOldCode[ENTRY_COUNT];
  85                         unsigned int            fOldCodeLength;
  86
  87                         short                           fNewCode;
  88                         int                                     fBits;
  89                         int                                     fMaxCode;
  90                         int                                     fCodeSize;
  91
  92                         short                           fClearCode;
  93                         short                           fEndCode;
  94                         short                           fNextCode;
  95
  96                         unsigned char*          fTable[ENTRY_COUNT];
  97                         short                           fEntrySize[ENTRY_COUNT];
  98                         Memblock*                       fHeadMemblock;
  99
 100                         int                                     fBitCount;
 101                         unsigned int            fBitBuffer;
 102                         unsigned char           fByteCount;
 103                         unsigned char           fByteBuffer[255];
 104
 105                         uint32*                         fScanLine;
 106                         int                                     fScanlinePosition;
 107 };
 108
 109
 110 #endif  // GIF_LOAD_H