Looks like this effect has a lot of weird names; 'glow', 'bloom', 'High dynamic range', 'seperable gaussian blur' - but no matter what you call it, it involves rendering to a texture and a full-screen blended sprite, so a real no-no for low end cards.
jfk - I did try using a 64x64 texture for this, but the filtering on the full-screen overlay sprite just wasn't enough to smooth out the pixels on a texture and having a contrast filter just makes the edges more noticable. Maybe adding a blur filter might do it, damn costly tho! The blur filter would have to read texels, so the texture would have to be copied back the AGP bus the slow direction - then edited in system memory - then copied back up to the card :(
Hmmm, using flag 256 on the texture - would that be faster or slower if you edit the pixels every frame in system memory? I guess when you lock it, it would get copied from vram anyway, so it might not make much difference - just wondering... ;)
jfk - I did try using a 64x64 texture for this, but the filtering on the full-screen overlay sprite just wasn't enough to smooth out the pixels on a texture and having a contrast filter just makes the edges more noticable. Maybe adding a blur filter might do it, damn costly tho! The blur filter would have to read texels, so the texture would have to be copied back the AGP bus the slow direction - then edited in system memory - then copied back up to the card :(
Hmmm, using flag 256 on the texture - would that be faster or slower if you edit the pixels every frame in system memory? I guess when you lock it, it would get copied from vram anyway, so it might not make much difference - just wondering... ;)