upstream-man-pages/man4/glGetActiveUniformName.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="glGetActiveUniformName">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2010</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glGetActiveUniformName</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glGetActiveUniformName</refname>
  17         <refpurpose>query the name of an active uniform</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glGetActiveUniformName</function></funcdef>
  23                 <paramdef>GLuint <parameter>program</parameter></paramdef>
  24                 <paramdef>GLuint <parameter>uniformIndex</parameter></paramdef>
  25                 <paramdef>GLsizei <parameter>bufSize</parameter></paramdef>
  26                 <paramdef>GLsizei *<parameter>length</parameter></paramdef>
  27                 <paramdef>GLchar *<parameter>uniformName</parameter></paramdef>
  28             </funcprototype>
  29         </funcsynopsis>
  30     </refsynopsisdiv>
  31     <!-- eqn: ignoring delim $$ -->
  32     <refsect1 id="parameters"><title>Parameters</title>
  33         <variablelist>
  34         <varlistentry>
  35             <term><parameter>program</parameter></term>
  36             <listitem>
  37                 <para>
  38                     Specifies the program containing the active uniform index <parameter>uniformIndex</parameter>.
  39                 </para>
  40             </listitem>
  41         </varlistentry>
  42         <varlistentry>
  43             <term><parameter>uniformIndex</parameter></term>
  44             <listitem>
  45                 <para>
  46                     Specifies the index of the active uniform whose name to query.
  47                 </para>
  48             </listitem>
  49         </varlistentry>
  50         <varlistentry>
  51             <term><parameter>bufSize</parameter></term>
  52             <listitem>
  53                 <para>
  54                     Specifies the size of the buffer, in units of <code>GLchar</code>, of the buffer whose address is specified in <parameter>uniformName</parameter>.
  55                 </para>
  56             </listitem>
  57         </varlistentry>
  58         <varlistentry>
  59             <term><parameter>length</parameter></term>
  60             <listitem>
  61                 <para>
  62                     Specifies the address of a variable that will receive the number of characters that were or would have been written to the buffer addressed by <parameter>uniformName</parameter>.
  63                 </para>
  64             </listitem>
  65         </varlistentry>
  66         <varlistentry>
  67             <term><parameter>uniformName</parameter></term>
  68             <listitem>
  69                 <para>
  70                     Specifies the address of a buffer into which the GL will place the name of the active uniform at <parameter>uniformIndex</parameter> within <parameter>program</parameter>.
  71                 </para>
  72             </listitem>
  73         </varlistentry>
  74         </variablelist>
  75     </refsect1>
  76     <refsect1 id="description"><title>Description</title>
  77         <para>
  78             <function>glGetActiveUniformName</function> returns the name of the active uniform at <parameter>uniformIndex</parameter> within <parameter>program</parameter>.
  79             If <parameter>uniformName</parameter> is not <code>NULL</code>, up to <parameter>bufSize</parameter> characters (including a nul-terminator) will be written into
  80             the array whose address is specified by <parameter>uniformName</parameter>. If <parameter>length</parameter> is not <code>NULL</code>, the number of characters
  81             that were (or would have been) written into <parameter>uniformName</parameter> (not including the nul-terminator) will be placed in the variable whose address
  82             is specified in <parameter>length</parameter>. If <parameter>length</parameter> is <code>NULL</code>, no length is returned. The length of the longest uniform
  83             name in <parameter>program</parameter> is given by the value of <constant>GL_ACTIVE_UNIFORM_MAX_LENGTH</constant>, which can be queried with
  84             <citerefentry><refentrytitle>glGetProgram</refentrytitle></citerefentry>.
  85         </para>
  86         <para>
  87             If <function>glGetActiveUniformName</function> is not successful, nothing is written to <parameter>length</parameter> or <parameter>uniformName</parameter>.
  88         </para>
  89         <para>
  90             <parameter>program</parameter> must be the name of a program for which the command <citerefentry><refentrytitle>glLinkProgram</refentrytitle></citerefentry>
  91             has been issued in the past. It is not necessary for <parameter>program</parameter> to have been linked successfully. The link could have failed because
  92             the number of active uniforms exceeded the limit.
  93         </para>
  94         <para>
  95             <parameter>uniformIndex</parameter> must be an active uniform index of the program <parameter>program</parameter>, in the range zero to
  96             <constant>GL_ACTIVE_UNIFORMS</constant> - 1. The value of <constant>GL_ACTIVE_UNIFORMS</constant> can be queried with
  97             <citerefentry><refentrytitle>glGetProgram</refentrytitle></citerefentry>.
  98         </para>
  99     </refsect1>
 100     <refsect1 id="errors"><title>Errors</title>
 101         <para>
 102             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>uniformIndex</parameter> is greater than or equal to the value
 103             of <constant>GL_ACTIVE_UNIFORMS</constant>.
 104         </para>
 105         <para>
 106             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>bufSize</parameter> is negative.
 107         </para>
 108         <para>
 109             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>program</parameter> is not the name of a program object for which
 110             <citerefentry><refentrytitle>glLinkProgram</refentrytitle></citerefentry> has been issued.
 111         </para>
 112     </refsect1>
 113     <refsect1 id="seealso"><title>See Also</title>
 114         <para>
 115             <citerefentry><refentrytitle>glGetActiveUniform</refentrytitle></citerefentry>,
 116             <citerefentry><refentrytitle>glGetUniformIndices</refentrytitle></citerefentry>,
 117             <citerefentry><refentrytitle>glGetProgram</refentrytitle></citerefentry>,
 118             <citerefentry><refentrytitle>glLinkProgram</refentrytitle></citerefentry>
 119         </para>
 120     </refsect1>
 121     <refsect1 id="Copyright"><title>Copyright</title>
 122         <para>
 123             Copyright <trademark class="copyright"></trademark> 2010 Khronos Group.
 124             This material may be distributed subject to the terms and conditions set forth in
 125             the Open Publication License, v 1.0, 8 June 1999.
 126             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 127         </para>
 128     </refsect1>
 129 </refentry>