Sets the sprite scale as an absolute multiple of its original size. For example a scale value of 2 would double the sprite's size whilst a value of 1 will return it to its original size. This function scales from the sprite's center of rotation (its current offset point) so any increase in size will keep the offset point stationary whilst all four sides expand away from it. To scale from the top left corner use SetSpriteScale.
SetSpriteScaleByOffset( iSpriteIndex, x, y )