nl_tokens: Execute a function on each point in an image
pl_tokens: function ( fn ) { for ( var y = 0 ; y < this . getHeight ( ) ; y ++ ) { for ( var x = 0 ; x < this . getWidth ( ) ; x ++ ) { var rgba = this . getColor ( x , y ) ; var out = fn . <mask> ( this , x , y , rgba ) ; this . setColor ( x , y , ( out || rgba ) ) ; } } return this ; }