From: Loren P. <pe...@pa...> - 2004-03-18 03:13:49
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On Mar 17, 2004, at 4:38 PM, Dietrich Epp wrote: > It is possible to do this without the stencil buffer, and to make it > work on sprites with alpha blending. Draw the sprite with no blending > and glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_TRUE). Then draw the > sprite (same polygons) with the static texture in screen coordinates, > using glBlendFunc(GL_DEST_ALPHA, GL_ONE_MINUS_DEST_ALPHA). I think that this trick works by storing the sprite's alpha in the video buffer. > Are there any sprites with alpha blending though? I thought they all > used alpha tests instead. Many of the sprites use alpha blending -- that's what's used to make semitransparent flames and bolts. |