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<th>Priority</th>
<td>medium
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<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Varying passed from gs->fs corrupted if not first similar draw."
href="https://bugs.freedesktop.org/show_bug.cgi?id=79685">79685</a>
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<th>Assignee</th>
<td>idr@freedesktop.org
</td>
</tr>
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<th>Summary</th>
<td>Varying passed from gs->fs corrupted if not first similar draw.
</td>
</tr>
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<th>QA Contact</th>
<td>intel-3d-bugs@lists.freedesktop.org
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux (All)
</td>
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<th>Reporter</th>
<td>david@ingeniumdigital.com
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<th>Hardware</th>
<td>x86-64 (AMD64)
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Version</th>
<td>10.1
</td>
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<th>Component</th>
<td>Drivers/DRI/i965
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<th>Product</th>
<td>Mesa
</td>
</tr></table>
<p>
<div>
<pre>This is a strange one.
I've got a bunch of simple objects being rendered (rectangles and ellipses),
using different gs+fs, but the same vs. One of the gs+fs pairs passes a vec2
varying from the gs->fs. If this object is the first (nonempty) drawcall in the
frame, it renders correctly as a circle (the varying being "texture
coordinates" as it were). If another gs+fs combination runs first, the varying
is not passed through correctly.
Example apitrace: <a href="http://davidgow.net/stuff/gs-fs-var.trace.bz2">http://davidgow.net/stuff/gs-fs-var.trace.bz2</a>
- At call #180, we should see an ellipse, but see a rectangle.
<a href="http://davidgow.net/stuff/gs-fs-var-bad.png">http://davidgow.net/stuff/gs-fs-var-bad.png</a>
- If we change the glUseProgram in call #175 to use program 13, we see the
ellipse at call #180.
<a href="http://davidgow.net/stuff/gs-fs-var-good.png">http://davidgow.net/stuff/gs-fs-var-good.png</a>
The source for program 13 is located here:
<a href="http://davidgow.net/stuff/gs-fs-var.glsldump">http://davidgow.net/stuff/gs-fs-var.glsldump</a>
This code correctly displays the ellipse on both the nvidia and fglrx drivers,
but fails on both Mesa 10.1 (Ubuntu 14.04) and Mesa git (2211696-) IVB.
Am I doing anything obviously wrong?
Thanks,
— David</pre>
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