alpha blended textures ???

OpenGL OpenGL: Advanced Coding
1

ftp://ftp.scene.org/incoming/BUENZLI00/demo/vantage-a_simple_way.zip

above is a link to a demo we released last weekend. however, there’s an ugly bug in it : on most cards (non-matrox cards probably) the alpha blended textures look ugly. for example you can see the background of the font, which should be totally transparent.

does anybody know what i’m doing wrong ?

(if you need to see the code, say which part and i’ll post it)

tom

2

Tom,

Looked at your demo. I can’t tell from just looking at it, except that you’re obviously not culling texels that are not in the glyph. I would suggest making sure the
alpha for the texels outside the glyph are zero, then use the alpha test to remove all fragments (before blending) that have alpha==0.

If you have trouble with this, send me an email at cass@nvidia.com.

Thanks -
Cass