It's too bad,why you always want to modify the 'BoundsRect' ?
You don't consider test tile,dummy tile...etc.

But here a sample perfect to solve the problem.
This way is also easy,simple than modify BoundsRect.
http://www.afterwarp.net/forum/attac...4&d=1145473991

It use Asphyre but the sprite engine is the same as DelphiX.