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OpenGL ES 1.0 and EGL 1.0 reference manual and man pages (written by
Claude Knaus, based on OpenGL SI man pages).

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.2//EN" "DTD/docbook/docbookx.dtd">

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<refentry id="glEnable">
  <refmeta>
    <refentrytitle>glEnable</refentrytitle>
    <manvolnum>3G</manvolnum>
  </refmeta>

  <refnamediv>
    <refdescriptor>glEnable</refdescriptor>
    <refname>glEnable</refname>
    <refname>glDisable</refname>
    <refpurpose>enable or disable server-side GL capabilities</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <title>C Specification</title>

    <funcsynopsis>
      <funcprototype>
        <funcdef>void <function>glEnable</function></funcdef>
        <paramdef>GLenum <parameter>cap</parameter></paramdef>
      </funcprototype>
      <funcprototype>
        <funcdef>void <function>glDisable</function></funcdef>
        <paramdef>GLenum <parameter>cap</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Parameters</title>

    <variablelist>
      <varlistentry>
        <term>
          <parameter>cap</parameter>
        </term>

        <listitem>
          <para>Specifies a symbolic constant indicating a GL capability.</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Description</title>

    <para><function>glEnable</function> and <function>glDisable</function>
    enable and disable various capabilities. The initial value for
    each capability with the exception of 
    <constant>GL_DITHER</constant> and 
    <constant>GL_MULTISAMPLE</constant> is 
    <constant>GL_FALSE</constant>. The initial value for 
    <constant>GL_DITHER</constant> and 
    <constant>GL_MULTISAMPLE</constant> is 
    <constant>GL_TRUE</constant>.</para>

    <para>Both <function>glEnable</function> and <function>glDisable</function>
    take a single argument, <parameter>cap</parameter>,
    which can assume one of the following values:</para>

    <variablelist>
      <varlistentry>
        <term>
          <constant>GL_ALPHA_TEST</constant>
        </term>

        <listitem>
          <para>If enabled, do alpha testing. See 
          <citerefentry><refentrytitle>glAlphaFunc</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_BLEND</constant>
        </term>

        <listitem>
          <para>If enabled, blend the incoming color values
          with the values in the color buffers. See 
          <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_COLOR_LOGIC_OP</constant>
        </term>

        <listitem>
          <para>If enabled, apply the currently selected logical
          operation to the incoming color and color buffer values. See 
          <citerefentry><refentrytitle>glLogicOp</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_COLOR_MATERIAL</constant>
        </term>

        <listitem>
          <para>If enabled, have ambient and diffuse material
          parameters track the current color.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_CULL_FACE</constant>
        </term>

        <listitem>
          <para>If enabled, cull polygons based on their winding in
          window coordinates. See 
          <citerefentry><refentrytitle>glCullFace</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_DEPTH_TEST</constant>
        </term>

        <listitem>
          <para>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 
          <citerefentry><refentrytitle>glDepthFunc</refentrytitle></citerefentry>,
          <citerefentry><refentrytitle>glDepthMask</refentrytitle></citerefentry>,
          and 
          <citerefentry><refentrytitle>glDepthRange</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_DITHER</constant>
        </term>

        <listitem>
          <para>If enabled, dither color components or indices
          before they are written to the color buffer.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_FOG</constant>
        </term>

        <listitem>
          <para>If enabled, blend a fog color into the
          posttexturing color. See 
          <citerefentry><refentrytitle>glFog</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_LIGHT</constant><replaceable>i</replaceable>
        </term>

        <listitem>
          <para>If enabled, include light <replaceable>i</replaceable>
          in the evaluation of the lighting equation. See 
          <citerefentry><refentrytitle>glLightModel</refentrytitle></citerefentry>
          and 
          <citerefentry><refentrytitle>glLight</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_LIGHTING</constant>
        </term>

        <listitem>
          <para>If enabled, use the current lighting parameters to
          compute the vertex color. Otherwise, simply
          associate the current color with each vertex. See 
          <citerefentry><refentrytitle>glMaterial</refentrytitle></citerefentry>, 
          <citerefentry><refentrytitle>glLightModel</refentrytitle></citerefentry>, and 
          <citerefentry><refentrytitle>glLight</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_LINE_SMOOTH</constant>
        </term>

        <listitem>
          <para>If enabled, draw lines with correct filtering.
          Otherwise, draw aliased lines. See 
          <citerefentry><refentrytitle>glLineWidth</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_MULTISAMPLE</constant>
        </term>

        <listitem>
          <para>If enabled, perform multisampling of fragments
          for single-pass antialiasing and other effects. See
          <citerefentry><refentrytitle>glSampleCoverage</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_NORMALIZE</constant>
        </term>

        <listitem>
          <para>If enabled, normal vectors 
          are scaled to unit length after transformation. See 
          <citerefentry><refentrytitle>glNormal</refentrytitle></citerefentry> and
          <citerefentry><refentrytitle>glNormalPointer</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_POINT_SMOOTH</constant>
        </term>

        <listitem>
          <para>If enabled, draw points with proper filtering.
          Otherwise, draw aliased points. See 
          <citerefentry><refentrytitle>glPointSize</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_POLYGON_OFFSET_FILL</constant>
        </term>

        <listitem>
          <para>If enabled,
          an offset is added to depth values of a polygon's
          fragments before the depth comparison is performed. See 
          <citerefentry><refentrytitle>glPolygonOffset</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_RESCALE_NORMAL</constant>
        </term>

        <listitem>
          <para>If enabled, normal vectors are scaled
          by a factor derived from the modelview matrix. See 
          <citerefentry><refentrytitle>glNormal</refentrytitle></citerefentry> and
          <citerefentry><refentrytitle>glNormalPointer</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_SAMPLE_ALPHA_TO_MASK</constant>
        </term>

        <listitem>
          <para>If enabled, convert fragment alpha values to
          multisample coverage modification masks.  See
          <citerefentry><refentrytitle>glSampleCoverage</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_SAMPLE_ALPHA_TO_ONE</constant>
        </term>

        <listitem>
          <para>If enabled, set fragment alpha to the maximum
          permissible value after computing multisample
          coverage modification masks.  See
          <citerefentry><refentrytitle>glSampleCoverage</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_SAMPLE_MASK</constant>
        </term>

        <listitem>
          <para>If enabled, apply a mask to modify fragment
          coverage during multisampling.  See
          <citerefentry><refentrytitle>glSampleCoverage</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_SCISSOR_TEST</constant>
        </term>

        <listitem>
          <para>If enabled, discard fragments that are outside the
          scissor rectangle. See 
          <citerefentry><refentrytitle>glScissor</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_STENCIL_TEST</constant>
        </term>

        <listitem>
          <para>If enabled, do stencil testing and update the
          stencil buffer. See 
          <citerefentry><refentrytitle>glStencilFunc</refentrytitle></citerefentry>,
          <citerefentry><refentrytitle>glStencilMask</refentrytitle></citerefentry>,
          and 
          <citerefentry><refentrytitle>glStencilOp</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term>
          <constant>GL_TEXTURE_2D</constant>
        </term>

        <listitem>
          <para>If enabled, two-dimensional texturing is performed
          for the active texture unit. See 
          <citerefentry><refentrytitle>glActiveTexture</refentrytitle></citerefentry>, 
          <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
          <citerefentry><refentrytitle>glCompressedTexImage2D</refentrytitle></citerefentry>,
          and
          <citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry>.</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Errors</title>

    <para><constant>GL_INVALID_ENUM</constant> is generated if 
    <parameter>cap</parameter> 
    is not one of the values listed previously.</para>
  </refsect1>

  <refsect1>
    <title>See Also</title>

    <para>
    <citerefentry><refentrytitle>glActiveTexture</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glAlphaFunc</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glCompressedTexImage2D</refentrytitle></citerefentry>,
    <citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry>,
    <citerefentry><refentrytitle>glCullFace</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glDepthFunc</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glDepthRange</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glEnableClientState</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glFog</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glLight</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glLightModel</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glLineWidth</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glLogicOp</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glMaterial</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glNormal</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glPointSize</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glPolygonOffset</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glSampleCoverage</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glScissor</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glStencilFunc</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glStencilOp</refentrytitle></citerefentry>, 
    <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>
    </para>
  </refsect1>
</refentry>