daft 2d graphics question

BlitzMax Forums/BlitzMax Beginners Area/daft 2d graphics question

The forum is locked. These are the original blitzbasic.com forums, kept so they can still be read. No new topics, replies or edits can be made here. To join in, head over to the Blitz3D+ forums.

I needed something to do to get into coding in BlitzMax so I figured I would write yet another space invaders clone. It was all going well till I get to the bit where I have to apply damage to the shields when a bullet or bomb hits them.
Each shield is a TImage. Im probably being a div but I cant see how I can delete a group of pixels from the shield image. Initially I just thought I would have a small explosion bitmap and I could just remove my explosion image from my shield image. But looking through the help I cant see how I can do it.
So.. please.. can someone explain to me how I am supposed to achieve what Im after ?

Thanx