[Mesa-dev] [Bug 49788] New: vega statetracker unpack methof for RGB 565 is wrong

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=49788

             Bug #: 49788
           Summary: vega statetracker unpack methof for RGB 565 is wrong
    Classification: Unclassified
           Product: Mesa
           Version: git
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: major
          Priority: medium
         Component: Mesa core
        AssignedTo: mesa-dev at lists.freedesktop.org
        ReportedBy: andreas.betz at elektrobit.com


Hi,

i just wanted to show an RGB 565 image using the OpenVG emulation of mesa and
i've found that MESA calculates the RGB 565 wrong.

in src/galium/state_trackers/vega/cg_translate.c
function _vega_unpack_float_span_rgba
the case for VG_sRGB_565 is calculated the following way:

clr[0] = ((*src >> 10) & 31)/31.;
clr[1] = ((*src >>  5) & 95)/95.;
clr[2] = ((*src >>  0) & 31)/31.;

That is wrong.

The correct code is:
clr[0] = ((*src >> 11) & 31)/31.;
clr[1] = ((*src >>  5) & 63)/63.;
clr[2] = ((*src >>  0) & 31)/31.;

Greetings
Andy

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