The Ecere SDK - sdk/blob - ecere/src/gfx/bitmaps/GIFFormat.ec

   1 namespace gfx::bitmaps;
   2
   3 #include "gif_lib.h"
   4
   5 import "Display"
   6
   7 static int ReadData(GifFileType * gifFile, GifByteType * bytes, int size)
   8 {
   9    File f = gifFile->UserData;
  10    return f.Read(bytes, 1, size);
  11 }
  12
  13 /*static int WriteData(GifFileType * gifFile, GifByteType * bytes, int size)
  14 {
  15    File f = gifFile->UserData;
  16    return f.Write(bytes, 1, size);
  17 }
  18 */
  19 static const char * extensions[] = { "gif", null };
  20
  21 class GIFFormat : BitmapFormat
  22 {
  23    class_property(extensions) = extensions;
  24
  25    bool Load(Bitmap bitmap, File f)
  26    {
  27       bool result = false;
  28
  29 #if GIFLIB_MAJOR > 5
  30       GifFileType * gifFile = DGifOpen(f, ReadData, null);
  31 #else
  32       GifFileType * gifFile = DGifOpen(f, ReadData);
  33 #endif
  34       if(gifFile)
  35       {
  36          DGifSlurp(gifFile);
  37          if(bitmap.Allocate(null, gifFile->SWidth, gifFile->SHeight, 0, pixelFormat888, false))
  38          {
  39             uint y;
  40             ColorAlpha * picture = (ColorAlpha *)bitmap.picture;
  41             int transparent = -1;
  42             struct SavedImage * image = &gifFile->SavedImages[0];
  43             int c;
  44             ColorMapObject * colorMap = gifFile->SColorMap;
  45
  46             if(!colorMap) colorMap = gifFile->Image.ColorMap;
  47
  48             for(c = 0; c<image->ExtensionBlockCount; c++)
  49             {
  50                ExtensionBlock * block = &image->ExtensionBlocks[c];
  51                if(block->Function == 249)
  52                {
  53                   if(block->Bytes[0])
  54                      transparent = (byte)block->Bytes[3];
  55                }
  56             }
  57             if(colorMap)
  58             {
  59                int colorCount = colorMap->ColorCount;
  60                if(!gifFile->Image.Interlace)
  61                {
  62                   for(y = 0; y < gifFile->SHeight; y++)
  63                   {
  64                      uint x;
  65                      for(x = 0; x < gifFile->SWidth; x++)
  66                      {
  67                         byte index = image->RasterBits[y*gifFile->SWidth+x];
  68                         if(index == transparent || index >= colorCount)
  69                            picture[y * bitmap.stride + x] = 0; //&= 0xFFFFFF;
  70                         else
  71                            picture[y * bitmap.stride + x] = ColorAlpha { 255, {
  72                               colorMap->Colors[index].Red,
  73                               colorMap->Colors[index].Green,
  74                               colorMap->Colors[index].Blue } };
  75                      }
  76                   }
  77                }
  78                else
  79                {
  80                   int startline[4] = {0, 4, 2, 1};
  81                   int offset[4] = {8, 8, 4, 2};
  82                   int group;
  83                   uint i;
  84                   for(group=0,i=0;group<4;group++)
  85                   {
  86                      uint y;
  87                      for(y = startline[group]; y < gifFile->SHeight; y += offset[group], i++)
  88                      {
  89                         uint x;
  90                         for(x = 0; x < gifFile->SWidth; x++)
  91                         {
  92                            byte index = image->RasterBits[i*gifFile->SWidth+x];
  93                            if(index == transparent)
  94                               picture[y * bitmap.stride + x] = 0;// &= 0xFFFFFF;
  95                            else
  96                               picture[y * bitmap.stride + x] = ColorAlpha { 255, {
  97                                  colorMap->Colors[index].Red,
  98                                  colorMap->Colors[index].Green,
  99                                  colorMap->Colors[index].Blue } };
 100                         }
 101                      }
 102                   }
 103                }
 104                bitmap.transparent = (transparent != -1) ? true : false;
 105                result = true;
 106             }
 107          }
 108          DGifCloseFile(gifFile);
 109       }
 110
 111       if(!result)
 112          bitmap.Free();
 113       return result;
 114    }
 115
 116    bool Save(Bitmap bitmap, const char * filename, void * options)
 117    {
 118       bool result = false;
 119       return result;
 120    }
 121
 122    ColorAlpha * LoadPalette(const char * fileName, const char * type)
 123    {
 124       ColorAlpha * result = null;
 125       return result;
 126    }
 127 }