Hi All Jumpman is comming on extreamly well.. the windows stuff seems to be working and I;m getting good results with the GL stuff.. I have stumbled onto something I;m not to sure on how to do.. my engine first draws the background (or black if it dosn''t have one) and then the level objects over that.. now what I want to do is erase bits of the forground (be replaced with the background) by using a image mask.. in my old amiga days you could have 3 sources for the blitter which would do the job but gl texturing is a one way process.. Is there anyway I can copy from one texture (the background) based on bits set in another (the mask).. I will need to do this quiet a few times per frame. for those who are interested its for the HotFoot effect. many thanks for those who can help.. Chris Jumpman - Under Construction

I found an answer.. Stencil Buffers..

after a bit of experimenting, it will do what I need to do.. costs me about 50fps but I''m still getting 200+ and its only for a few levels or levels with that requirement..

can anybody tell me if stencil buffers can be used to blend in a graphic.. ie .. bit like an alpha channel when the destination pixel is effected by the value of the stencil buffer (assuming the buffer is 8 bit) ??

Jumpman - Under Construction