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<body><span class="vcard"><a class="email" href="mailto:danylo.piliaiev@gmail.com" title="Danylo <danylo.piliaiev@gmail.com>"> <span class="fn">Danylo</span></a>
</span> changed
<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED NOTOURBUG - [DXVK] The Witness - transparent objects are not drawn correctly"
href="https://bugs.freedesktop.org/show_bug.cgi?id=108726">bug 108726</a>
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<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
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<td style="text-align:right;">Resolution</td>
<td>---
</td>
<td>NOTOURBUG
</td>
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<td style="text-align:right;">CC</td>
<td>
</td>
<td>danylo.piliaiev@gmail.com
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</tr>
<tr>
<td style="text-align:right;">Status</td>
<td>NEEDINFO
</td>
<td>RESOLVED
</td>
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<b><a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED NOTOURBUG - [DXVK] The Witness - transparent objects are not drawn correctly"
href="https://bugs.freedesktop.org/show_bug.cgi?id=108726#c11">Comment # 11</a>
on <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED NOTOURBUG - [DXVK] The Witness - transparent objects are not drawn correctly"
href="https://bugs.freedesktop.org/show_bug.cgi?id=108726">bug 108726</a>
from <span class="vcard"><a class="email" href="mailto:danylo.piliaiev@gmail.com" title="Danylo <danylo.piliaiev@gmail.com>"> <span class="fn">Danylo</span></a>
</span></b>
<pre>The culprit is incorrect usage of dual source blending.
commit 00fc56a68d21d7aa91b95f0eaacba59a96c466f5 (HEAD -> master)
Author: Danylo Piliaiev <<a href="mailto:danylo.piliaiev@gmail.com">danylo.piliaiev@gmail.com</a>>
Date: Fri Jul 20 12:54:42 2018 +0300
anv: Disable dual source blending when shader doesn't support it on gen8+
Dual source blending behaviour is undefined when shader doesn't
have second color output.
"If SRC1 is included in a src/dst blend factor and
a DualSource RT Write message is not used, results
are UNDEFINED. (This reflects the same restriction in DX APIs,
where undefined results are produced if “o1” is not written
by a PS – there are no default values defined)."
Dismissing fragment in such situation leads to a hang on gen8+
if depth test in enabled.
Since blending cannot be gracefully fixed in such case and the result
is undefined - blending is simply disabled.
v2 (Jason Ekstrand):
- Apply the workaround to each individual entry
- Emit a warning through debug_report
Signed-off-by: Danylo Piliaiev <<a href="mailto:danylo.piliaiev@globallogic.com">danylo.piliaiev@globallogic.com</a>>
Reviewed-by: Jason Ekstrand <<a href="mailto:jason@jlekstrand.net">jason@jlekstrand.net</a>>
Reviewed-by: Kenneth Graunke <<a href="mailto:kenneth@whitecape.org">kenneth@whitecape.org</a>>
After this commit blending is disabled when rendering with incorrect dual
source blending setup. I can see the error in logs and relevant draw call in
RenderDoc. (Also the same commit exists for OpenGL)
The verdict - not a mesa's bug, most likely it's a game's bug.
When I made that commit I though I was fixing some esoteric issue and now it's
a second game in a month which exhibits it.</pre>
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