Hello Ville, > -----Original Message----- > From: dri-devel <dri-devel-boun...@lists.freedesktop.org> On Behalf Of Ville > Syrjälä > Sent: Tuesday, October 31, 2023 9:37 PM > To: Jani Nikula <jani.nik...@linux.intel.com> > Cc: intel-...@lists.freedesktop.org; dri-devel@lists.freedesktop.org > Subject: Re: [Intel-gfx] [PATCH 1/4] drm: Fix color LUT rounding > > On Tue, Oct 31, 2023 at 11:15:35AM +0200, Jani Nikula wrote: > > On Fri, 13 Oct 2023, Ville Syrjala <ville.syrj...@linux.intel.com> wrote: > > > entrirely. But perhaps a better idea would be to follow the OpenGL > > > int<->float conversion rules, in which case we get the following > > > results: > > > > Do you have a pointer to the rules handy, I couldn't find it. :( > > Eg. '2.3.5 Fixed-Point Data Conversions' in GL 4.6 spec. The section number > probably changes depending on which version of the spec you look at. >
This section particularly talks about conversion of normalized fixed point to floating point numbers and vice versa. Pardon my limited knowledge on the topic but aren't we just doing a scaling factor conversion(Q0.16 -> Q0.8) in these patches? I could not draw a direct relation between the formulas in the section[1] and what we are doing here.(but it could be just me!) Regards Chaitanya [1] https://registry.khronos.org/OpenGL/specs/gl/glspec46.core.pdf '2.3.5 Fixed-Point Data Conversions' > > > > Might also add the reference to the commit message and/or comment. > > > > BR, > > Jani. > > > > -- > > Jani Nikula, Intel > > -- > Ville Syrjälä > Intel