<html>
<head>
<base href="https://bugs.freedesktop.org/" />
</head>
<body><span class="vcard"><a class="email" href="mailto:zackr@vmware.com" title="Zack Rusin <zackr@vmware.com>"> <span class="fn">Zack Rusin</span></a>
</span> changed
<a class="bz_bug_link
bz_status_NEW "
title="NEW --- - piglit ext_transform_feedback-change-size offset-grow regression"
href="https://bugs.freedesktop.org/show_bug.cgi?id=64172">bug 64172</a>
<br>
<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
<tr>
<td style="text-align:right;">Keywords</td>
<td>regression
</td>
<td>
</td>
</tr></table>
<p>
<div>
<b><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - piglit ext_transform_feedback-change-size offset-grow regression"
href="https://bugs.freedesktop.org/show_bug.cgi?id=64172#c1">Comment # 1</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW --- - piglit ext_transform_feedback-change-size offset-grow regression"
href="https://bugs.freedesktop.org/show_bug.cgi?id=64172">bug 64172</a>
from <span class="vcard"><a class="email" href="mailto:zackr@vmware.com" title="Zack Rusin <zackr@vmware.com>"> <span class="fn">Zack Rusin</span></a>
</span></b>
<pre>Unfortunately, this is not a regression. We were over overflowing without the
patch, now we're simply correctly computing the overflow.
Mesa's transformfeedback.c:compute_transform_feedback_buffer_sizes
incorrectly computes size for gallium's so targets: in particular it does:
GLsizeiptr available_space
= buffer_size <= offset ? 0 : buffer_size - offset;
computed_size = available_space;
and returns that as the size of the buffer. Then when setting gallium stream
output targets it sets the computed_size as the new buffer size and
then it also sets the same offset it used when computing the computed_size. So
essentially for gallium:
buffer_size = buffer_size - offset
offset = offset
which means that gallium's stream output target's buffer size is always
'offset' less than it should be. I'm not going to have time to fix this right
now..</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the assignee for the bug.</li>
</ul>
</body>
</html>