Re: driver level sub-pixel rendering?

[Nicolai H. <pre...@gm...>]

On Friday 31 March 2006 19:49, Keith Packard wrote:
> On Fri, 2006-03-31 at 09:33 -0700, Brian Paul wrote:
>=20
> > AFAIK, nobody's hardware does that.
> >=20
> > When that kind of antialiasing is done for text, I think it's the job=20
> > of the font rendering code to do so.
>=20
> It's not the construction of the glyphs that's at issue here, I don't
> think. The glyphs are drawn to the screen using a separate alpha channel
> for each component in the pixel, an operation which isn't directly
> supported by the GL API at present. I don't know what we'd need in the
> hardware for this to be efficient though; I believe it is possible to do
> it today using three passes for each string, which seems horrendous
> until you realize how slow it will be to do the same thing with the CPU.

Surely you could just use an RGB texture instead of an ALPHA texture? Then=
=20
it's just a matter of setting the appropriate texture environments and=20
blending modes.

cu,
Nicolai