OpenLayer Offline Manual

OpenLayer | RenderMode | AlphaFrom AlphaFrom
AlphaFrom( | const Bitmap &alphaFrom, float anchorX = 0.0, float anchorY = 0.0 );
The Bitmap will be rendered with an additional alpha channel from an another Bitmap. The values of the alpha channels are multiplied together to get the final value. The results are clipped to the areas of both of the Bitmaps. This effectively means that the parts outside the alphaFrom Bitmap are considered to be transparent. Note that only one GainAlphaMode can take effect at a time! Examples Bitmap myBmp( ... ), alphaBmp( ... ); // Render myBmp with an extra alpha channel from alphaBmp // // The alpha channel is positioned inside myBmp at x = 20.0, y = 10.0 // myBmp.Blit( 200.0, 100.0, AlphaFrom( alphaBmp, 20.0, 10.0 )); Parent Class RenderMode Back to the main page of the manual Questions about AlphaFrom? Click here.