# File lib/rubygame/surface.rb, line 581 def to_display_alpha newsurf = if( Rubygame.init_video_system() == 0 ) SDL.DisplayFormatAlpha( @struct ) else nil end if( newsurf.nil? or newsurf.pointer.null?) raise( Rubygame::SDLError, "Could not convert the Surface to display format "+ "with alpha channel: #{SDL.GetError()}" ) end # Wrap it return self.class.new( newsurf ) end