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

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

<div class="refnamediv">

<h2>Name</h2>

<p>glEnable — enable or disable server-side GL capabilities</p>

</div>

<div class="refsynopsisdiv">

<h2>C Specification</h2>

<div class="funcsynopsis">

<table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table">

<tr>

<td>

<code class="funcdef">void <strong class="fsfunc">glEnable</strong>(</code>

</td>

<td>GLenum <var class="pdparam">cap</var><code>)</code>;</td>

</tr>

</table>

<div class="funcprototype-spacer"> </div>

</div>

<div class="funcsynopsis">

<table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table">

<tr>

<td>

<code class="funcdef">void <strong class="fsfunc">glDisable</strong>(</code>

</td>

<td>GLenum <var class="pdparam">cap</var><code>)</code>;</td>

</tr>

</table>

<div class="funcprototype-spacer"> </div>

</div>

</div>

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

<h2>Parameters</h2>

<div class="variablelist">

<dl class="variablelist">

<dt>

<span class="term">

<em class="parameter">

<code>cap</code>

</em>

</span>

</dt>

<dd>

<p>

Specifies a symbolic constant indicating a GL capability.

</p>

</dd>

</dl>

</div>

</div>

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

<h2>Description</h2>

<p>

<code class="function">glEnable</code> and

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

enable and disable various capabilities. Use

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

or

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

to determine the current setting of any capability. The initial

value for each capability with the exception of

<code class="constant">GL_DITHER</code> is <code class="constant">GL_FALSE</code>.

The initial value for <code class="constant">GL_DITHER</code> is

<code class="constant">GL_TRUE</code>.

</p>

<p>

Both <code class="function">glEnable</code> and <a class="citerefentry" href="glDisable"><span class="citerefentry"><span class="refentrytitle">glDisable</span></span></a> take a single argument, <em class="parameter"><code>cap</code></em>,

which can assume one of the following values:

</p>

<div class="variablelist">

<dl class="variablelist">

<dt>

<span class="term">

<code class="constant">GL_BLEND</code>

</span>

</dt>

<dd>

<p>

If enabled,

blend the computed fragment color values with the values in the color

buffers. See <a class="citerefentry" href="glBlendFunc"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a>.

</p>

</dd>

<dt>

<span class="term">

<code class="constant">GL_CULL_FACE</code>

</span>

</dt>

<dd>

<p>

</p>

<p>

If enabled,

cull polygons based on their winding in window coordinates.

See <a class="citerefentry" href="glCullFace"><span class="citerefentry"><span class="refentrytitle">glCullFace</span></span></a>.

</p>

</dd>

<dt>

<span class="term">

<code class="constant">GL_DEPTH_TEST</code>

</span>

</dt>

<dd>

<p>

If enabled,

do depth comparisons and update the depth buffer. Note that even if

the depth buffer exists and the depth mask is non-zero, the

depth buffer is not updated if the depth test is disabled. See

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

<a class="citerefentry" href="glDepthRangef"><span class="citerefentry"><span class="refentrytitle">glDepthRangef</span></span></a>.

</p>

</dd>

<dt>

<span class="term"><code class="constant">GL_DITHER</code> </span>

</dt>

<dd>

<p>

If enabled,

dither color components or indices before they are written to the

color buffer.

</p>

</dd>

<dt>

<span class="term">

<code class="constant">GL_POLYGON_OFFSET_FILL</code>

</span>

</dt>

<dd>

<p>

If enabled, an offset is added to depth values of a polygon's

fragments before the depth comparison is performed.

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

</p>

</dd>

<dt>

<span class="term">

<code class="constant">GL_PRIMITIVE_RESTART_FIXED_INDEX</code>

</span>

</dt>

<dd>

<p>

Enables primitive restarting. If enabled, any one of the draw commands

which transfers a set of generic attribute array elements to the GL will restart

the primitive when the index of the vertex is equal to

<math overflow="scroll">

<msup>

<mn>2</mn>

<mi>n</mi>

</msup>

<mo>−</mo>

<mn>1</mn>

</math>

where <span class="emphasis"><em>n</em></span> is 8, 16 or 32 if the type is

<code class="constant">GL_UNSIGNED_BYTE</code>,

<code class="constant">GL_UNSIGNED_SHORT</code>, or

<code class="constant">GL_UNSIGNED_INT</code>, respectively.

</p>

</dd>

<dt>

<span class="term">

<code class="constant">GL_RASTERIZER_DISCARD</code>

</span>

</dt>

<dd>

<p>

If enabled, primitives are discarded immediately before the rasterization stage,

but after the optional transform feedback stage.

<a class="citerefentry" href="glClear"><span class="citerefentry"><span class="refentrytitle">glClear</span></span></a> and

<a class="citerefentry" href="glClearBuffer"><span class="citerefentry"><span class="refentrytitle">glClearBuffer</span></span></a>* commands

are also ignored.

</p>

</dd>

<dt>

<span class="term">

<code class="constant">GL_SAMPLE_ALPHA_TO_COVERAGE</code>

</span>

</dt>

<dd>

<p>

If enabled,

compute a temporary coverage value where each bit is determined by the

alpha value at the corresponding sample location. The temporary coverage

value is then ANDed with the fragment coverage value.

</p>

</dd>

<dt>

<span class="term">

<code class="constant">GL_SAMPLE_COVERAGE</code>

</span>

</dt>

<dd>

<p>

If enabled,

the fragment's coverage is ANDed with the temporary coverage value. If

<code class="constant">GL_SAMPLE_COVERAGE_INVERT</code> is set to <code class="constant">GL_TRUE</code>, invert the coverage

value.

See <a class="citerefentry" href="glSampleCoverage"><span class="citerefentry"><span class="refentrytitle">glSampleCoverage</span></span></a>.

</p>

</dd>

<dt>

<span class="term">

<code class="constant">GL_SAMPLE_MASK</code>

</span>

</dt>

<dd>

<p>

If enabled, the fragment's coverage is ANDed with the coverage value <code class="constant">GL_SAMPLE_MASK_VALUE</code>.

See <a class="citerefentry" href="glSampleMaski"><span class="citerefentry"><span class="refentrytitle">glSampleMaski</span></span></a>.

</p>

</dd>

<dt>

<span class="term">

<code class="constant">GL_SCISSOR_TEST</code>

</span>

</dt>

<dd>

<p>

If enabled,

discard fragments that are outside the scissor rectangle.

See <a class="citerefentry" href="glScissor"><span class="citerefentry"><span class="refentrytitle">glScissor</span></span></a>.

</p>

</dd>

<dt>

<span class="term">

<code class="constant">GL_STENCIL_TEST</code>

</span>

</dt>

<dd>

<p>

If enabled,

do stencil testing and update the stencil buffer.

See <a class="citerefentry" href="glStencilFunc"><span class="citerefentry"><span class="refentrytitle">glStencilFunc</span></span></a> and <a class="citerefentry" href="glStencilOp"><span class="citerefentry"><span class="refentrytitle">glStencilOp</span></span></a>.

</p>

</dd>

</dl>

</div>

</div>

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

<h2>Errors</h2>

<p>

<code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>cap</code></em> is not one of the values

listed previously.

</p>

</div>

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

<h2>Associated Gets</h2>

<p>

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

</p>

<p>

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

</p>

</div>

{$pipelinestall}{$examples}

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

<h2>API Version Support</h2>

<div class="informaltable">

<table style="border-collapse: collapse; border-top: 2px solid ; border-bottom: 2px solid ; border-left: 2px solid ; border-right: 2px solid ; ">

<colgroup>

<col style="text-align: left; "/>

<col style="text-align: center; " class="firstvers"/>

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

<col style="text-align: center; " class="lastvers"/>

</colgroup>

<thead>

<tr>

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

</th>

<th style="text-align: center; border-bottom: 2px solid ; " colspan="3">

<span class="bold"><strong>OpenGL ES API Version</strong></span>

</th>

</tr>

<tr>

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

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

</th>

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

<span class="bold"><strong>2.0</strong></span>

</th>

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

<span class="bold"><strong>3.0</strong></span>

</th>

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

<span class="bold"><strong>3.1</strong></span>

</th>

</tr>

</thead>

<tbody>

<tr>

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

<code class="function">glEnable</code>

</td>

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

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

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

</tr>

<tr>

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

<code class="function">glDisable</code>

</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>

</tr>

</tbody>

</table>

</div>

</div>

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

<h2>See Also</h2>

<p>

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

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

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

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

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

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

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

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

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

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

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

</p>

</div>

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

<h2>Copyright</h2>

<p>

Copyright © 1991-2006 Silicon Graphics, Inc.

Copyright © 2010-2014 Khronos Group.

This document is licensed under the SGI Free Software B License.

For details, see

<a class="link" 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>