Copy pixels from source, completely replacing the pixels at destPoint.
copyPixels erases the target location specified by destPoint and sourceRect,
then draws over it.
NOTE: drawPixels is more performant.
Source
void copyPixels(BitmapData source, Rectangle<num> sourceRect, Point<num> destPoint) {
var updateBatch = new BitmapDataUpdateBatch(this);
updateBatch.copyPixels(source, sourceRect, destPoint);
updateBatch.update();
}