Le Tue, 02 Jun 2009 15:32:07 +0200 Roland Scheidegger <[email protected]> a écrit:
> >> If there are other chipsets that cannot do true separate alpha blend, we > >> can always use PIPE_CAP to let Mesa know, and Mesa can do the fragment > >> program alteration itself. (r3xx and r4xx also have this, so it might be > >> useful later on.) > > > > I did more tests. I think I was wrong, in fact, when using > > BlendEquationSeparate functions, no triangle rendering command is sent > > to the gpu, so I suppose it's all software rendering. The shader > > program is a single instruction to set current color, plus it resend > > all tcl engine state. > > > > But it's good news if a fragment program can do this instead, so adding > > the PIPE_CAP should be useful, if other cards need it also. > > How do you do this with a fragment shader? > I think if you wanted to do this, you'd need to redirect all normal > rendering as opaque to a temporary surface. Then, you could use a > fragment shader for doing the blend (using the temporary surface and the > destination surface as textures), outputting to another temporary > surface. Then copy back the 2nd temporary to the original destination. > Maybe... Well, my last question is still valid though. If no fragment program work can do it easily, is it a good idea to have a PIPE_CAP for it? so Mesa knows how to deal with it, even falling back to software rendering? > Not sure though why r3xx gets mentioned here, should easily handle this > (even r200 can do it...) -- Patrice Mandin WWW: http://pmandin.atari.org/ Programmeur Linux, Atari Spécialité: Développement, jeux ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Mesa3d-dev mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
