Re: gl overlay on performer image
Rob Mace (mace++at++lum.esd.sgi.com)
Sat, 5 Nov 1994 00:22:24 GMT
> I have been trying to draw a simple bitmap using gl calls
> from a pfChanDrawFunc callback... Everything works ok
> except that the image I draw is always "on top" of the
> performer image. I have called lsetdepth, ortho, and zbuffer
> but to no avail. When I move the far plane in my bitmap image
> does disappear at the correct value. When I look at an object
> in front of my bitmap it ALWAYS appears to be behind it even
> though it disappears when I move my near plane out and my
> bitmap remains...
If you are writing your bitmap using gl pixel drawing commands
then the reason it shows up on top is that pixel drawing is
not zbuffered.
If you wish it to be zbuffered store it as a texture and draw a
polgon with it on it. The only other way would be to use point
commands to draw each pixel.
Am I understanding what you are trying to do?
Rob Mace
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