[Mesa-dev] [Bug 99849] Dashed lines (drawn via GLAMOR) are not rendered correctly

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=99849

--- Comment #6 from Roland Scheidegger <sroland at vmware.com> ---
FWIW I've actually captured a replay and when playing back on a nvidia blob, it
doesn't show a dashed line neither (just solid).

I'm inclined to believe this is a glamor bug. The shader does
       float pattern = texture2D(dash, vec2(dash_offset, 0.5)).w;
       if (pattern == 0.0)
               discard;

But the texture bound at that time is indeed GL_RED, so of course the result of
the texture lookup is always 1.0 no matter what.
Fixing the shader (use .r instead) gets a dashed line.
I have no idea how that can work anywhere (and even less of an idea why it
would be different on intel hw), or maybe glamor uses alpha textures sometimes
instead, I couldn't quite figure out how the 8 bit format gets mapped to a gl
format in the end...

No idea what's the right component for glamor bugs, though...

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20170228/79e252e5/attachment.html>