upstream-man-pages/man2/glBlendColor.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
   3               "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
   4 <refentry id="glBlendColor">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glBlendColor</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glBlendColor</refname>
  17         <refpurpose>set the blend color</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glBlendColor</function></funcdef>
  23                 <paramdef>GLclampf <parameter>red</parameter></paramdef>
  24                 <paramdef>GLclampf <parameter>green</parameter></paramdef>
  25                 <paramdef>GLclampf <parameter>blue</parameter></paramdef>
  26                 <paramdef>GLclampf <parameter>alpha</parameter></paramdef>
  27             </funcprototype>
  28         </funcsynopsis>
  29     </refsynopsisdiv>
  30     <!-- eqn: ignoring delim $$ -->
  31     <refsect1 id="parameters"><title>Parameters</title>
  32         <variablelist>
  33         <varlistentry>
  34             <term><parameter>red</parameter></term>
  35             <term><parameter>green</parameter></term>
  36             <term><parameter>blue</parameter></term>
  37             <term><parameter>alpha</parameter></term>
  38             <listitem>
  39                 <para>
  40                     specify the components of <constant>GL_BLEND_COLOR</constant>
  41                 </para>
  42             </listitem>
  43         </varlistentry>
  44         </variablelist>
  45     </refsect1>
  46     <refsect1 id="description"><title>Description</title>
  47         <para>
  48             The <constant>GL_BLEND_COLOR</constant> may be used to calculate the source and destination
  49             blending factors. The color components are clamped to the range
  50             <inlineequation><mml:math>
  51                 <!-- eqn: [0,1]:-->
  52                 <mml:mfenced open="[" close="]">
  53                     <mml:mn>0</mml:mn>
  54                     <mml:mn>1</mml:mn>
  55                 </mml:mfenced>
  56             </mml:math></inlineequation>
  57             before being stored. See <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry> for a complete description of the
  58             blending operations.
  59             Initially the <constant>GL_BLEND_COLOR</constant> is set to (0, 0, 0, 0).
  60         </para>
  61     </refsect1>
  62     <refsect1 id="notes"><title>Notes</title>
  63         <para>
  64             <function>glBlendColor</function> is part of the <code>ARB_imaging</code> subset. <function>glBlendColor</function> is present only
  65             if <code>ARB_imaging</code> is returned when <citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry> is called with
  66             <constant>GL_EXTENSIONS</constant> as its argument.
  67         </para>
  68     </refsect1>
  69     <refsect1 id="errors"><title>Errors</title>
  70         <para>
  71             <constant>GL_INVALID_OPERATION</constant> is generated if <function>glBlendColor</function> is executed
  72             between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding
  73             execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
  74         </para>
  75         <para>
  76         </para>
  77     </refsect1>
  78     <refsect1 id="associatedgets"><title>Associated Gets</title>
  79         <para>
  80             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with an argument of <constant>GL_BLEND_COLOR</constant>
  81         </para>
  82     </refsect1>
  83     <refsect1 id="seealso"><title>See Also</title>
  84         <para>
  85             <citerefentry><refentrytitle>glBlendEquation</refentrytitle></citerefentry>,
  86             <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry>,
  87             <citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry>
  88         </para>
  89     </refsect1>
  90     <refsect1 id="Copyright"><title>Copyright</title>
  91         <para>
  92             Copyright <trademark class="copyright"></trademark> 1991-2006
  93             Silicon Graphics, Inc. This document is licensed under the SGI
  94             Free Software B License. For details, see
  95             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
  96         </para>
  97     </refsect1>
  98 </refentry>