[Mesa-dev] [Mesa-stable] [PATCH v2 2/5] meta: fix meta clear of layered framebuffers

Ian Romanick idr at freedesktop.org
Sat Nov 23 16:12:11 PST 2013

On 11/23/2013 03:21 PM, Paul Berry wrote:
> On 23 November 2013 12:58, Ian Romanick <idr at freedesktop.org
> <mailto:idr at freedesktop.org>> wrote:
>     On 11/20/2013 02:29 PM, Paul Berry wrote:
>     >>From section 4.4.7 (Layered Framebuffers) of the GLSL 3.2 spec:
>     >
>     >     When the Clear or ClearBuffer* commands are used to clear a
>     >     layered framebuffer attachment, all layers of the attachment are
>     >     cleared.
>     >
>     > This patch fixes meta clears to properly clear all layers of a layered
>     > framebuffer attachment.  We accomplish this by adding a geometry
>     > shader to the meta clear program which sets gl_Layer to a uniform
>     > value.  When clearing a layered framebuffer, we execute in a loop,
>     > setting the uniform to point to each layer in turn.
>     >
>     > Cc: "10.0" <mesa-stable at lists.freedesktop.org
>     <mailto:mesa-stable at lists.freedesktop.org>>
>     The previous version of this patch was NAKed by you because it made
>     https://bugs.freedesktop.org/show_bug.cgi?id=71870 worse.  Is that now
>     fixed by this version?  I didn't notice any mention of the issue...
> No, no version of this patch was ever NAKed.  The only difference
> between v1 and v2 of the patch was that I had to make some minor
> adjustments to reflect the changes I made in v2 of patch 1/5 ("mesa:
> Track number of layers in layered framebuffers").  (That's why the patch
> doesn't have a "v2" annotation in the commit message--the adjustments
> were too minor to be worth mentioning).
> It was only after I committed this patch that Tapani discovered that it
> made bug 71870 worse.  I am still awaiting additional information from
> Tapani so that I can reproduce the bug and track it down.
> I tried to clarify the situation
> in http://lists.freedesktop.org/archives/mesa-dev/2013-November/048899.html.
>  What I said there still stands: I believe patches 1, 3, 4, and 5 are
> safe to cherry pick to 10.0*.  Patch 2 definitely should be not be
> cherry-picked to 10.0 until we figure out what's going on with bug 71870.

That's what I meant by NAKed. :)

> *However, if you wanted to err on the safe side and keep the entire
> patch series out of 10.0 until we have more information, that would be
> understandable too.

The rest of the series has some unknowns, but we also know that it makes
some things better (demonstrated by passing piglit tests).  It seems
safe enough to pick over.  If this were an X.Y.1 release, I might hold
off.  I think it's okay for 10.0 because it's all new functionality for
this release.

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