On Wed, Oct 06, 2004 at 10:32:57AM -0700, Ian Romanick wrote: > Ville Syrjälä wrote: > >On Mon, Oct 04, 2004 at 04:24:19PM -0700, Ian Romanick wrote: > > > >>I think the right answer is to apply the fix for reading alpha from the > >>framebuffer and ignore the 888 modes. Since the hardware is operating > >>in 8888 mode, pretending to be 888 is just wrong. We'd have to go > >>through and make sure that 0xff is *always* written as the output from > >>the alpha blend stage in 888 mode. Yuck. > > > >The 888 mode would be useful for the 24+8 overlay case if we change it to > >not touch the alpha bits. But the drm would require a small change since > >the swap ioctl always sets PLNWT to 0xffffffff. > > Ah. Okay. Other than the changes to the swap routine, how much effort > is it to make the hardware not draw to the alpha bits?
Apart from the swap case I think it should as simple as making sure mgaDDColorMask() sets the mask properly. That should take care of drawing and clearing I think. I have that in code but never actually tested it since DirectFB doesn't support overlay modes. > >I actually have (in my Mesa 5 for DirectFBGL tree) span functions for > >(a)rgb 332, 555, 1555, 565, 888, 8888, and depth/stencil 16/0, 32/0, 15/1, > >24/8. The 555 and 888 functions don't touch the alpha bit(s). > > Some of those modes will be useful when pbuffers are supported. Does > the MGA actually support a 15/1 depth/stencil mode? It does. Well G400/G450/G550 do. G200 doesn't support stencil at all. -- Ville Syrjälä [EMAIL PROTECTED] http://www.sci.fi/~syrjala/ ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl -- _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
