On Tue, Nov 13, 2018 at 11:43:12PM +0000, Lionel Landwerlin wrote: > On 13/11/2018 23:22, Matt Roper wrote: > > It's worth noting that we don't seem to be able to test this feature > > with CRC's. Originally we wanted to draw a color into a plane's FB > > (with Cairo) and then compare the CRC to turning off all planes and just > > setting the CRTC background to the same color. However the precision > > and rounding of the color components causes the CRC's to come out > > differently, even though the end result is visually identical. So at > > the moment this test is mainly useful for visual inspection in > > interactive mode. > Hey Matt, > Out of curiosity, are the CRCs different only when with 16bpc? Or with 8bpc > too? Both 8 and 16 give different CRC's. I suspect it's because cairo handles the color values (which get passed as double) slightly differently internally, although I haven't ruled out a slight inaccuracy on the hardware side. Given the alpha problems on gen9/gen10, it wouldn't surprise me if it turns out that our hardware is also treating a 10bpc component of 0x3ff as 0.999 rather than 1.0. Matt > > Thanks, > > - > Lionel > > > -- Matt Roper Graphics Software Engineer IoTG Platform Enabling & Development Intel Corporation (916) 356-2795 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
