<div class="refentry" id="gl_FragDepth">

<div class="titlepage"></div>

<div class="refnamediv">

<h2>Name</h2>

<p>gl_FragDepth — establishes a depth value for the current fragment</p>

</div>

<div class="refsynopsisdiv">

<h2>Declaration</h2>

<code class="fieldsynopsis"><span class="modifier">out </span><span class="type">float </span><span class="varname">gl_FragDepth </span>;</code>

</div>

<div class="refsect1" id="description">

<h2>Description</h2>

<p>

Available only in the fragment language, <code class="varname">gl_FragDepth</code> is an output variable

that is used to establish the depth value for the current fragment. If depth buffering is enabled

and no shader writes to <code class="varname">gl_FragDepth</code>, then the fixed function value for

depth will be used (this value is contained in the z component of <a class="citerefentry" href="gl_FragCoord"><span class="citerefentry"><span class="refentrytitle">gl_FragCoord</span></span></a>)

otherwise, the value written to <code class="varname">gl_FragDepth</code> is used.

If a shader statically assigns to <code class="varname">gl_FragDepth</code>, then the value of the fragment's depth

may be undefined for executions of the shader that don't take that path. That is, if the set of linked fragment

shaders statically contain a write to <code class="varname">gl_FragDepth</code>, then it is responsible for always

writing it.

</p>

</div>

{$pipelinestall}{$examples}

<div class="refsect1" id="versions">

<h2>Version Support</h2>

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<span class="bold"><strong>OpenGL Shading Language Version</strong></span>

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<span class="bold"><strong>Variable Name</strong></span>

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<span class="bold"><strong>1.10</strong></span>

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<span class="bold"><strong>1.20</strong></span>

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<span class="bold"><strong>1.30</strong></span>

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<span class="bold"><strong>1.40</strong></span>

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<span class="bold"><strong>1.50</strong></span>

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<span class="bold"><strong>3.30</strong></span>

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<span class="bold"><strong>4.00</strong></span>

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<span class="bold"><strong>4.10</strong></span>

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<span class="bold"><strong>4.20</strong></span>

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<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">

<span class="bold"><strong>4.30</strong></span>

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<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">

<span class="bold"><strong>4.40</strong></span>

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<th style="text-align: center; border-bottom: 2px solid ; ">

<span class="bold"><strong>4.50</strong></span>

</th>

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</thead>

<tbody>

<tr>

<td style="text-align: left; border-right: 2px solid ; ">gl_FragDepth</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; border-right: 2px solid ; ">✔</td>

<td style="text-align: center; ">✔</td>

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</tbody>

</table>

</div>

</div>

<div class="refsect1" id="seealso">

<h2>See Also</h2>

<p>

<a class="citerefentry" href="gl_FragCoord"><span class="citerefentry"><span class="refentrytitle">gl_FragCoord</span></span></a>

</p>

</div>

<div class="refsect1" id="Copyright">

<h2>Copyright</h2>

<p>

Copyright © 2011-2014 Khronos Group.

This material may be distributed subject to the terms and conditions set forth in

the Open Publication License, v 1.0, 8 June 1999.

<a class="link" href="https://opencontent.org/openpub/" target="_top">https://opencontent.org/openpub/</a>.

</p>

</div>

</div>