From: Matt Roper <matthew.d.roper@intel.com>
To: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: igt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org
Subject: Re: [igt-dev] [Intel-gfx] [PATCH i-g-t v2] tests/kms_crtc_background_color: overhaul for latest ABI proposal (v2)
Date: Tue, 13 Nov 2018 15:53:53 -0800 [thread overview]
Message-ID: <20181113235353.GA25613@mdroper-desk.amr.corp.intel.com> (raw)
In-Reply-To: <8275fd1b-5a61-7f48-6817-e0fdad42d0dc@intel.com>
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
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next prev parent reply other threads:[~2018-11-13 23:53 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20181113232149.22753-1-matthew.d.roper@intel.com>
2018-11-13 23:22 ` [igt-dev] [PATCH i-g-t v2] tests/kms_crtc_background_color: overhaul for latest ABI proposal (v2) Matt Roper
2018-11-13 23:43 ` [igt-dev] [Intel-gfx] " Lionel Landwerlin
2018-11-13 23:53 ` Matt Roper [this message]
2018-11-14 1:34 ` [igt-dev] ✓ Fi.CI.BAT: success for " Patchwork
2018-11-14 4:48 ` [igt-dev] ✗ Fi.CI.IGT: failure " Patchwork
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