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<base href="https://bugs.freedesktop.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Access violation on glDrawArrays with count >= 2048"
href="https://bugs.freedesktop.org/show_bug.cgi?id=107295">107295</a>
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<th>Summary</th>
<td>Access violation on glDrawArrays with count >= 2048
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<th>Product</th>
<td>Mesa
</td>
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<th>Version</th>
<td>18.0
</td>
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<th>Hardware</th>
<td>x86 (IA32)
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<th>OS</th>
<td>Windows (All)
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>major
</td>
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<th>Priority</th>
<td>medium
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<th>Component</th>
<td>Drivers/Gallium/llvmpipe
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<th>Assignee</th>
<td>mesa-dev@lists.freedesktop.org
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<th>Reporter</th>
<td>paul@binksoftware.nl
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<th>QA Contact</th>
<td>mesa-dev@lists.freedesktop.org
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<p>
<div>
<pre>I found this issue first on a 10.x version. The issue still remains in version
18.0.
I use an OpenGL 3.3 Core context and a set of shaders that converts points to
simple flat shaded cones using a geometry shader given the following:
* Position, normal and color as vertex attributes
* Base radius and length as uniforms
The cones are made out of 8 sides (16 triangles total including the base).
Calling glDrawArrays(GL_POINTS, 0, 3000) will cause an access violation in the
DLL (opengl32). All points are stored into a single buffer object described by
a VAO. Further testing shows that the maximum count that will not crash is
2047. Splitting the call works fine, i.e.:
glDrawArrays(GL_POINTS, 0, 1500)
glDrawArrays(GL_POINTS, 1500, 1500)
According to llvmpipe, the maximum recommended vertex count for draw range
elements is 3000 (there's no specific value for just glDrawArrays). This is
just a recommended value, where larger values may only decrease performance,
but it's already crashing way before 3000 is reached.</pre>
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