public RawImage DecodeImage( Rectangle rect )
{
// Calculate the integral rectangle, i.e. on block boundaries
Rectangle integralrect = CoordMap.FitToGrid( rect );
// Get the size of the rectangle in blocks
Size size = CoordMap.ActualToBlocks( integralrect.Size );
// Create the image
RawImage image = new RawImage( zoom, integralrect );
ImageDecoder decoder = new ImageDecoder( image );
#if false
// Create a grid of decompressed blocks first
Point gridloc = integralrect.Location;
for ( int y=0; y<size.Height; ++y ) {
for ( int x=0; x<size.Width; ++x ) {
MapBlock self = (MapBlock)this[GetBlockIndex( gridloc )];
MapBlock right = (MapBlock)this[GetBlockIndex( gridloc.X + BlockSize, gridloc.Y )];
MapBlock bottom = (MapBlock)this[GetBlockIndex( gridloc.X, gridloc.Y + BlockSize )];
MapBlock bottomright = (MapBlock)this[GetBlockIndex( gridloc.X + BlockSize, gridloc.Y + BlockSize )];
decoder.Decode4( x << BlockFactor, y << BlockFactor, self, right, bottom, bottomright );
gridloc.X = NormalizeX( gridloc.X + (BlockSize << zoom) );
}
gridloc.Y += BlockSize << zoom;
gridloc.X = integralrect.Location.X;
}
#else
// Create a grid of decompressed blocks first
Point gridloc = new Point( NormalizeX( integralrect.Right - BlockSize ), integralrect.Bottom - BlockSize);
for ( int x=size.Width-1; x>=0; --x ) {
MapBlock self = (MapBlock)this[GetBlockIndex( gridloc )];
MapBlock right = (MapBlock)this[GetBlockIndex( gridloc.X + BlockSize, gridloc.Y )];
MapBlock bottom = (MapBlock)this[GetBlockIndex( gridloc.X, gridloc.Y + BlockSize )];
MapBlock bottomright = (MapBlock)this[GetBlockIndex( gridloc.X + BlockSize, gridloc.Y + BlockSize )];
gridloc.Y -= BlockSize;
decoder.Decode4( x << BlockFactor, (size.Height-1) << BlockFactor, self, right, bottom, bottomright );
for ( int y=size.Height-2; y>=0; --y ) {
self = (MapBlock)this[GetBlockIndex( gridloc )];
right = (MapBlock)this[GetBlockIndex( gridloc.X + BlockSize, gridloc.Y )];
decoder.Decode2( x << BlockFactor, y << BlockFactor, self, right );
gridloc.Y -= BlockSize;
}
gridloc.X = NormalizeX( gridloc.X - BlockSize );
gridloc.Y = integralrect.Bottom - BlockSize;
}
#endif
return image;
}
public RawImage DecodeBlockImage( MapBlock block, Point location )
{
location = CoordMap.FitToGrid( location );
RawImage image = new RawImage( zoom, new Rectangle( location, new Size( BlockSize, BlockSize ) ) );
ImageDecoder decoder = new ImageDecoder( image );
decoder.Decode1( 0, 0, block );
return image;
}
