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      <base href="https://bugs.freedesktop.org/">
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Reading back an EGL Pbuffer using the OpenGL API returns garbled output"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=108977">108977</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Reading back an EGL Pbuffer using the OpenGL API returns garbled output
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>Mesa
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>18.2
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>Other
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>medium
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>EGL
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>mesa-dev@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>matthieu.bouron@gmail.com
          </td>
        </tr>

        <tr>
          <th>QA Contact</th>
          <td>mesa-dev@lists.freedesktop.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=142750" name="attach_142750" title="EGL pbuffer test">attachment 142750</a> <a href="attachment.cgi?id=142750&action=edit" title="EGL pbuffer test">[details]</a></span>
EGL pbuffer test

Hello,

I am currently facing an issue while reading back EGL Pbuffers using
glReadPixels() with the OpenGL API as the output is garbled. It properly works
with the OpenGL ES API though.

I can reproduce the issue on different machines running Arch Linux with mesa
18.2.5 on X using the following GPU: Intel HD 5500, Intel Iris 580 Pro, AMD RX
580.

I am not able to reproduce the issue on an NVDIA GTX 1070 running the
proprietary driver.

I have attached a sample code that reproduces the issue:

On OpenGL:
gcc `pkg-config --libs egl gl` -Wall egl-pbuffer.c -o egl-pbuffer
&&./egl-pbuffer
0xff69fc07 0xff69fc07 0xff69fc07 0xff69fc07 
0xff69fc07 0xff11a1e4 0xff000000 0xff000000 
0xff69fc07 0xff000000 0xff7fc700 0xff000000 
0xff69fc07 0xff000000 0xff000000 0xff3a4e3b 

On OpenGLES (adding the -es parameter to ./egl-pbuffer):
gcc `pkg-config --libs egl gl` -Wall egl-pbuffer.c -o egl-pbuffer
&&./egl-pbuffer -es
0xff0000ff 0xff0000ff 0xff0000ff 0xff0000ff 
0xff0000ff 0xff0000ff 0xff0000ff 0xff0000ff 
0xff0000ff 0xff0000ff 0xff0000ff 0xff0000ff 
0xff0000ff 0xff0000ff 0xff0000ff 0xff0000ff</pre>
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