<div class="refentry" lang="en" xml:lang="en"><a id="glDepthRange"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glDepthRange — specify mapping of depth values from normalized device coordinates to window coordinates</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table><tr><td><code class="funcdef">void <b class="fsfunc">glDepthRange</b>(</code></td><td>GLclampd  </td><td><var class="pdparam">nearVal</var>, </td></tr><tr><td> </td><td>GLclampd  </td><td><var class="pdparam">farVal</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>nearVal</code></em></span></dt><dd><p>

Specifies the mapping of the near clipping plane to window coordinates.

The initial value is 0.

</p></dd><dt><span class="term"><em class="parameter"><code>farVal</code></em></span></dt><dd><p>

Specifies the mapping of the far clipping plane to window coordinates.

The initial value is 1.

</p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>

After clipping and division by <span class="emphasis"><em>w</em></span>,

depth coordinates range from

<math overflow="scroll">

<mn>-1</mn>

</math>

to 1,

corresponding to the near and far clipping planes.

<code class="function">glDepthRange</code> specifies a linear mapping of the normalized depth coordinates

in this range to window depth coordinates.

Regardless of the actual depth buffer implementation,

window coordinate depth values are treated as though they range

from 0 through 1 (like color components).

Thus,

the values accepted by <code class="function">glDepthRange</code> are both clamped to this range

before they are accepted.

</p><p>

The setting of (0,1) maps the near plane to 0 and

the far plane to 1.

With this mapping,

the depth buffer range is fully utilized.

</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>

It is not necessary that <em class="parameter"><code>nearVal</code></em> be less than <em class="parameter"><code>farVal</code></em>.

Reverse mappings such as

<math overflow="scroll">

<mrow>

<mi mathvariant="italic">nearVal</mi>

<mo>=</mo>

<mn>1</mn>

</mrow>

</math>,

and

<math overflow="scroll">

<mrow>

<mi mathvariant="italic">farVal</mi>

<mo>=</mo>

<mn>0</mn>

</mrow>

</math>

are acceptable.

</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>

<code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glDepthRange</code>

is executed between the execution of <a class="citerefentry" href="glBegin"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>

and the corresponding execution of <a class="citerefentry" href="glEnd"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.

</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>

<a class="citerefentry" href="glGet"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_DEPTH_RANGE</code>

</p></div>

{$pipelinestall}{$examples}

<div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>

<a class="citerefentry" href="glDepthFunc"><span class="citerefentry"><span class="refentrytitle">glDepthFunc</span></span></a>,

<a class="citerefentry" href="glPolygonOffset"><span class="citerefentry"><span class="refentrytitle">glPolygonOffset</span></span></a>,

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

</p></div><div class="refsect1" lang="en" xml:lang="en"><div id="Copyright"><h2>Copyright</h2><p>

Copyright © 1991-2006

Silicon Graphics, Inc. This document is licensed under the SGI

Free Software B License. For details, see

<a class="ulink" href="https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/" target="_top">https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/</a>.

</p></div></div></div>