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

   1 namespace gfx::bitmaps;
   2
   3 import "Display"
   4
   5 #if !defined(__EMSCRIPTEN__) && !defined(__pnacl__)
   6
   7 #include "gif_lib.h"
   8
   9 static int ReadData(GifFileType * gifFile, GifByteType * bytes, int size)
  10 {
  11    File f = gifFile->UserData;
  12    return f.Read(bytes, 1, size);
  13 }
  14
  15 /*static int WriteData(GifFileType * gifFile, GifByteType * bytes, int size)
  16 {
  17    File f = gifFile->UserData;
  18    return f.Write(bytes, 1, size);
  19 }
  20 */
  21 static const char * extensions[] = { "gif", null };
  22
  23 class GIFFormat : BitmapFormat
  24 {
  25    class_property(extensions) = extensions;
  26
  27    bool Load(Bitmap bitmap, File f)
  28    {
  29       bool result = false;
  30
  31 #if GIFLIB_MAJOR >= 5
  32       GifFileType * gifFile = DGifOpen(f, ReadData, null);
  33 #else
  34       GifFileType * gifFile = DGifOpen(f, ReadData);
  35 #endif
  36       if(gifFile)
  37       {
  38          DGifSlurp(gifFile);
  39          if(bitmap.Allocate(null, gifFile->SWidth, gifFile->SHeight, 0, pixelFormat888, false))
  40          {
  41             uint y;
  42             ColorAlpha * picture = (ColorAlpha *)bitmap.picture;
  43             int transparent = -1;
  44             struct SavedImage * image = &gifFile->SavedImages[0];
  45             int c;
  46             ColorMapObject * colorMap = gifFile->SColorMap;
  47
  48             if(!colorMap) colorMap = gifFile->Image.ColorMap;
  49
  50             for(c = 0; c<image->ExtensionBlockCount; c++)
  51             {
  52                ExtensionBlock * block = &image->ExtensionBlocks[c];
  53                if(block->Function == 249)
  54                {
  55                   if(block->Bytes[0])
  56                      transparent = (byte)block->Bytes[3];
  57                }
  58             }
  59             if(colorMap)
  60             {
  61                int colorCount = colorMap->ColorCount;
  62                if(!gifFile->Image.Interlace)
  63                {
  64                   for(y = 0; y < gifFile->SHeight; y++)
  65                   {
  66                      uint x;
  67                      for(x = 0; x < gifFile->SWidth; x++)
  68                      {
  69                         byte index = image->RasterBits[y*gifFile->SWidth+x];
  70                         if(index == transparent || index >= colorCount)
  71                            picture[y * bitmap.stride + x] = 0; //&= 0xFFFFFF;
  72                         else
  73                            picture[y * bitmap.stride + x] = ColorAlpha { 255, {
  74                               colorMap->Colors[index].Red,
  75                               colorMap->Colors[index].Green,
  76                               colorMap->Colors[index].Blue } };
  77                      }
  78                   }
  79                }
  80                else
  81                {
  82                   int startline[4] = {0, 4, 2, 1};
  83                   int offset[4] = {8, 8, 4, 2};
  84                   int group;
  85                   uint i;
  86                   for(group=0,i=0;group<4;group++)
  87                   {
  88                      uint y;
  89                      for(y = startline[group]; y < gifFile->SHeight; y += offset[group], i++)
  90                      {
  91                         uint x;
  92                         for(x = 0; x < gifFile->SWidth; x++)
  93                         {
  94                            byte index = image->RasterBits[i*gifFile->SWidth+x];
  95                            if(index == transparent)
  96                               picture[y * bitmap.stride + x] = 0;// &= 0xFFFFFF;
  97                            else
  98                               picture[y * bitmap.stride + x] = ColorAlpha { 255, {
  99                                  colorMap->Colors[index].Red,
 100                                  colorMap->Colors[index].Green,
 101                                  colorMap->Colors[index].Blue } };
 102                         }
 103                      }
 104                   }
 105                }
 106                bitmap.transparent = (transparent != -1) ? true : false;
 107                result = true;
 108             }
 109          }
 110 #if GIFLIB_MAJOR >= 5
 111          DGifCloseFile(gifFile, null);
 112 #else
 113          DGifCloseFile(gifFile);
 114 #endif
 115       }
 116
 117       if(!result)
 118          bitmap.Free();
 119       return result;
 120    }
 121
 122    bool Save(Bitmap bitmap, const char * filename, void * options)
 123    {
 124       bool result = false;
 125       return result;
 126    }
 127
 128    ColorAlpha * LoadPalette(const char * fileName, const char * type)
 129    {
 130       ColorAlpha * result = null;
 131       return result;
 132    }
 133 }
 134
 135 #endif // !defined(__EMSCRIPTEN__)