upstream-doc/man4/glPatchParameter.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="glPatchParameter">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2010</year>
   9                 <holder>Khronos Group.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glPatchParameter</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glPatchParameter</refname>
  17         <refpurpose>specifies the parameters for patch primitives</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glPatchParameteri</function></funcdef>
  23                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  24                 <paramdef>GLint <parameter>value</parameter></paramdef>
  25             </funcprototype>
  26         </funcsynopsis>
  27         <funcsynopsis>
  28             <funcprototype>
  29                 <funcdef>void <function>glPatchParameterfv</function></funcdef>
  30                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  31                 <paramdef>const GLfloat *<parameter>values</parameter></paramdef>
  32             </funcprototype>
  33         </funcsynopsis>
  34     </refsynopsisdiv>
  35     <!-- eqn: ignoring delim $$ -->
  36     <refsect1 id="parameters"><title>Parameters</title>
  37         <variablelist>
  38         <varlistentry>
  39             <term><parameter>pname</parameter></term>
  40             <listitem>
  41                 <para>
  42                     Specifies the name of the parameter to set. The symbolc constants <constant>GL_PATCH_VERTICES</constant>,
  43                     <constant>GL_PATCH_DEFAULT_OUTER_LEVEL</constant>, and <constant>GL_PATCH_DEFAULT_INNER_LEVEL</constant> are accepted.
  44                 </para>
  45             </listitem>
  46         </varlistentry>
  47         <varlistentry>
  48             <term><parameter>value</parameter></term>
  49             <listitem>
  50                 <para>
  51                     Specifies the new value for the parameter given by <parameter>pname</parameter>.
  52                 </para>
  53             </listitem>
  54         </varlistentry>
  55         <varlistentry>
  56             <term><parameter>values</parameter></term>
  57             <listitem>
  58                 <para>
  59                     Specifies the address of an array containing the new values for the parameter given by <parameter>pname</parameter>.
  60                 </para>
  61             </listitem>
  62         </varlistentry>
  63         </variablelist>
  64     </refsect1>
  65     <refsect1 id="description"><title>Description</title>
  66         <para>
  67             <function>glPatchParameter</function> specifies the parameters that will be used for patch primitives. <parameter>pname</parameter>
  68             specifies the parameter to modify and must be either <constant>GL_PATCH_VERTICES</constant>, <constant>GL_PATCH_DEFAULT_OUTER_LEVEL</constant>
  69             or <constant>GL_PATCH_DEFAULT_INNER_LEVEL</constant>. For <function>glPatchParameteri</function>, <parameter>value</parameter> specifies
  70             the new value for the parameter specified by <parameter>pname</parameter>. For <function>glPatchParameterfv</function>, <parameter>values</parameter>
  71             specifies the address of an array containing the new values for the parameter specified by <parameter>pname</parameter>.
  72         </para>
  73         <para>
  74             When <parameter>pname</parameter> is <constant>GL_PATCH_VERTICES</constant>, <parameter>value</parameter> specifies the number
  75             of vertices that will be used to make up a single patch primitive. Patch primitives are consumed by the tessellation control
  76             shader (if present) and subsequently used for tessellation. When primitives are specified using
  77             <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry> or a similar function, each patch will be made
  78             from <parameter>parameter</parameter> control points, each represented by a vertex taken from the enabeld vertex arrays.
  79             <parameter>parameter</parameter> must be greater than zero, and less than or equal to the value of <constant>GL_MAX_PATCH_VERTICES</constant>.
  80          </para>
  81          <para>
  82             When <parameter>pname</parameter> is <constant>GL_PATCH_DEFAULT_OUTER_LEVEL</constant> or <constant>GL_PATCH_DEFAULT_INNER_LEVEL</constant>,
  83             <parameter>values</parameter> contains the address of an array contiaining the default outer or inner tessellation levels, respectively,
  84             to be used when no tessellation control shader is present.
  85          </para>
  86     </refsect1>
  87     <refsect1 id="errors"><title>Errors</title>
  88         <para>
  89             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>pname</parameter> is not an accepted value.
  90         </para>
  91         <para>
  92             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>pname</parameter> is <constant>GL_PATCH_VERTICES</constant>
  93             and <parameter>value</parameter> is less than or equal to zero, or greater than the value of <constant>GL_MAX_PATCH_VERTICES</constant>.
  94         </para>
  95     </refsect1>
  96     <refsect1 id="seealso"><title>See Also</title>
  97         <para>
  98             <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>,
  99             <citerefentry><refentrytitle>glDrawArraysInstanced</refentrytitle></citerefentry>,
 100             <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,
 101             <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,
 102         </para>
 103     </refsect1>
 104     <refsect1 id="Copyright"><title>Copyright</title>
 105         <para>
 106             Copyright <trademark class="copyright"></trademark> 2010 Khronos Group.
 107             This material may be distributed subject to the terms and conditions set forth in
 108             the Open Publication License, v 1.0, 8 June 1999.
 109             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 110         </para>
 111     </refsect1>
 112 </refentry>