<html>
    <head>
      <base href="https://bugs.freedesktop.org/">
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - [gallium] glCopyPixels is affected by enabled texture state"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=96943">96943</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[gallium] glCopyPixels is affected by enabled texture state
          </td>
        </tr>

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

        <tr>
          <th>Version</th>
          <td>git
          </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>Mesa core
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>imirkin@alum.mit.edu
          </td>
        </tr>

        <tr>
          <th>QA Contact</th>
          <td>mesa-dev@lists.freedesktop.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>The recently rewritten copy-pixels test has exposed some failures in st/mesa.
When there's an overlapping copy (among other conditions), the operation
becomes a fb read + draw of that texture with the current fragment shader
modified in the same way as glDrawPixels does it. (So this problem might extend
itself to glDrawPixels as well).

Doing a glDisable(GL_TEXTURE_2D) before the glCopyPixels() call in the piglit
fixes the issue. Effectively that texture is being multiplied with the copied
data, whereas from what I can tell, it shouldn't be. I think the multiplication
comes from the ff-generated shader.

[An alternative is that the piglit test and i965 are wrong and what gallium is
doing is correct. I don't think that's the case, since the only disagreement is
on the overlapped copy.]</pre>
        </div>
      </p>


      <hr>
      <span>You are receiving this mail because:</span>

      <ul>
          <li>You are the assignee for the bug.</li>
          <li>You are the QA Contact for the bug.</li>
      </ul>
    </body>
</html>