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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 - Wrong and unstable image rendering from GLSL fragment shaders"
href="https://bugs.freedesktop.org/show_bug.cgi?id=99919">99919</a>
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<th>Summary</th>
<td>Wrong and unstable image rendering from GLSL fragment shaders
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<th>Product</th>
<td>Mesa
</td>
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<th>Version</th>
<td>17.0
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<th>Hardware</th>
<td>x86-64 (AMD64)
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<th>OS</th>
<td>Linux (All)
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>medium
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<th>Component</th>
<td>Mesa core
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<th>Assignee</th>
<td>mesa-dev@lists.freedesktop.org
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<th>Reporter</th>
<td>h.evrard@imperial.ac.uk
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<th>QA Contact</th>
<td>mesa-dev@lists.freedesktop.org
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<pre>Created <span class=""><a href="attachment.cgi?id=129862" name="attach_129862" title="Archive with pair of shaders and their expected renderings">attachment 129862</a> <a href="attachment.cgi?id=129862&action=edit" title="Archive with pair of shaders and their expected renderings">[details]</a></span>
Archive with pair of shaders and their expected renderings
Steps to Reproduce:
-------------------------------
1. Obtain and build the latest release of get-image, a simple tool that
creates a .png image from a fragment shader
<a href="https://github.com/mc-imperial/get-image">https://github.com/mc-imperial/get-image</a>
2. From a terminal, execute:
/path/to/get_image/linux_out/install/bin/get_image original.frag
This will create output.png, which should look like original.png
3. From a terminal, execute:
/path/to/get_image/linux_out/install/bin/get_image variant.frag
This will create output.png, which should look like variant.png
Expected Results:
-------------------------------
Both shaders should render an image that looks like original.png. This
is because the only difference between the .frag files is:
- a for loop of 1 iteration
- inside this loop, a "if" which condition is sure to be false at
runtime (we control the value of injectionSwitch to ensure this)
Actual Results:
-------------------------------
The shaders render completely different images, which they should not.
Moreover, the variant.frag file rendering seems unstable, i.e. it does
not always render the same image, but it always renders an image
different from the expected one.</pre>
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