[Mesa-dev] [Bug 77161] [softpipe] piglit fbo-generatemipmap-cubemap S3TC_DXT1 regression

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=77161

--- Comment #2 from Roland Scheidegger <sroland at vmware.com> ---
I don't think this qualifies as a blocker. Cubemaps aren't quite right on
softpipe anyway due to doing face selection per quad (which I suspect is also
what's causing this bug, probably pick the wrong face, since it considers the
average of all 2x2 pixels to chose the face, no matter if those pixels are
actually inside the primitive or not). The driver can do seamless filtering
(probably useless here I guess) but the initial face selection is always per
quad. If this is what's happening here, this is not easily fixable (don't even
have the information which pixels are lit in the sampling code and doing per
pixel face selection is anything but trivial though obviously can be done. Or
could try to be clever and use per-pixel faces when the derivatives aren't
needed).
Some cpu based blitter instead of relying on u_blitter for softpipe would also
be possible (and be at least an order of magnitude faster).
As a side note, I suspect we need to allow some form of casting cube to 2d
(array) resources at some point and vice versa, though possibly some drivers
can't do it. (d3d10.1 no longer has cube map resources, it's all just 2d
(arrays).) This would be less work for everyone (who can do it) and eliminate
such issues for free.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/mesa-dev/attachments/20140521/ea0b16da/attachment.html>