On Mon, Apr 25, 2011 at 7:22 PM, Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> wrote: > On Mon, 25 Apr 2011 16:16:18 -0700 > Keith Packard <keithp@xxxxxxxxxx> wrote: > >> On Mon, 25 Apr 2011 15:12:20 -0700, Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> wrote: >> >> > Overlays are a bit like half-CRTCs. They have a location and fb, but >> > don't drive outputs directly. Add support for handling them to the core >> > KMS code. >> >> Are overlays/underlays not associated with a specific CRTC? To my mind, >> overlays are another scanout buffer associated with a specific CRTC, so >> you'd create a scanout buffer and attach that to a specific scanout slot >> in a crtc, with the 'default' slot being the usual graphics plane. > > Yes, that matches my understanding as well. I've deliberately made the > implementation flexible there though, under the assumption that some > hardware allows a plane to be directed at more than one CRTC (though > probably not simultaneously). A lot of older hardware had one overlay that could be sourced to any crtc, just not simultaneously. The tricky part is the formats and capabilities: alpha blending, color/chromakey, gamma correction, etc. Even the current crtc gamma stuff is somewhat lacking in in terms of what hardware is capable of (PWL vs. LUT, user defined conversion matrices, gamut remapping, etc.). Alex _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
