I am trying to draw a terrain scene overlayed with a circular mask.
I can do this fine with an overlay plane using colour index mode by drawing a black rectangle over the entire screen and then drawing a transparent circle (using glut) to ‘cut-out’ my circular mask.
However, how can I do this without an overlay or stencil plane? I am thinking of a GeForce4 type PC where they might not be available. I have heard about ‘pbuffers’ but can’t find any examples on using them.
Thanks in advance.