upstream-doc/man3/glGetActiveUniformBlockName.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="glGetActiveUniformBlockName">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2010</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glGetActiveUniformBlockName</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glGetActiveUniformBlockName</refname>
  17         <refpurpose>retrieve the name of an active uniform block</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glGetActiveUniformBlockName</function></funcdef>
  23                 <paramdef>GLuint <parameter>program</parameter></paramdef>
  24                 <paramdef>GLuint <parameter>uniformBlockIndex</parameter></paramdef>
  25                 <paramdef>GLsizei <parameter>bufSize</parameter></paramdef>
  26                 <paramdef>GLsizei *<parameter>length</parameter></paramdef>
  27                 <paramdef>GLchar *<parameter>uniformBlockName</parameter></paramdef>
  28             </funcprototype>
  29         </funcsynopsis>
  30     </refsynopsisdiv>
  31     <refsect1 id="parameters"><title>Parameters</title>
  32         <variablelist>
  33         <varlistentry>
  34             <term><parameter>program</parameter></term>
  35             <listitem>
  36                 <para>
  37                     Specifies the name of a program containing the uniform block.
  38                 </para>
  39             </listitem>
  40         </varlistentry>
  41         <varlistentry>
  42             <term><parameter>uniformBlockIndex</parameter></term>
  43             <listitem>
  44                 <para>
  45                     Specifies the index of the uniform block within <parameter>program</parameter>.
  46                 </para>
  47             </listitem>
  48         </varlistentry>
  49         <varlistentry>
  50             <term><parameter>bufSize</parameter></term>
  51             <listitem>
  52                 <para>
  53                     Specifies the size of the buffer addressed by <parameter>uniformBlockName</parameter>.
  54                 </para>
  55             </listitem>
  56         </varlistentry>
  57                 <varlistentry>
  58             <term><parameter>length</parameter></term>
  59             <listitem>
  60                 <para>
  61                     Specifies the address of a variable to receive the number of characters that were written to <parameter>uniformBlockName</parameter>.
  62                 </para>
  63             </listitem>
  64         </varlistentry>
  65         <varlistentry>
  66             <term><parameter>uniformBlockName</parameter></term>
  67             <listitem>
  68                 <para>
  69                     Specifies the address an array of characters to receive the name of the uniform block at <parameter>uniformBlockIndex</parameter>.
  70                 </para>
  71             </listitem>
  72         </varlistentry>
  73         </variablelist>
  74     </refsect1>
  75     <refsect1 id="description"><title>Description</title>
  76         <para>
  77             <function>glGetActiveUniformBlockName</function> retrieves the name of the active uniform block at <parameter>uniformBlockIndex</parameter>
  78             within <parameter>program</parameter>.
  79         </para>
  80         <para>
  81             <parameter>program</parameter> must be the name of a program object for which the command
  82             <citerefentry><refentrytitle>glLinkProgram</refentrytitle></citerefentry> must have been called in the past, although it is not required that
  83             <citerefentry><refentrytitle>glLinkProgram</refentrytitle></citerefentry> must have succeeded. The link could have failed because the number
  84             of active uniforms exceeded the limit.
  85         </para>
  86         <para>
  87             <parameter>uniformBlockIndex</parameter> is an active uniform block index of <parameter>program</parameter>, and must be less than the value
  88             of <constant>GL_ACTIVE_UNIFORM_BLOCKS</constant>.
  89         </para>
  90         <para>
  91             Upon success, the name of the uniform block identified by <parameter>unifomBlockIndex</parameter> is returned into
  92             <parameter>uniformBlockName</parameter>. The name is nul-terminated. The actual number of characters written into <parameter>uniformBlockName</parameter>,
  93             excluding the nul terminator, is returned in <parameter>length</parameter>. If <parameter>length</parameter> is <code>NULL</code>, no length is returned.
  94         </para>
  95         <para>
  96             <parameter>bufSize</parameter> contains the maximum number of characters (including the nul terminator) that will be written into
  97             <parameter>uniformBlockName</parameter>.
  98         </para>
  99         <para>
 100             If an error occurs, nothing will be written to <parameter>uniformBlockName</parameter> or <parameter>length</parameter>.
 101         </para>
 102     </refsect1>
 103     <refsect1 id="errors"><title>Errors</title>
 104         <para>
 105             <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>program</parameter> is not the name of a program object for which
 106             <citerefentry><refentrytitle>glLinkProgram</refentrytitle></citerefentry> has been called in the past.
 107         </para>
 108         <para>
 109             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>uniformBlockIndex</parameter> is greater than or equal to the value
 110             of <constant>GL_ACTIVE_UNIFORM_BLOCKS</constant> or is not the index of an active uniform block in <parameter>program</parameter>.
 111         </para>
 112     </refsect1>
 113     <refsect1 id="notes"><title>Notes</title>
 114         <para>
 115             <function>glGetActiveUniformBlockName</function> is available only if the GL version is 3.1 or greater.
 116         </para>
 117     </refsect1>
 118     <refsect1 id="seealso"><title>See Also</title>
 119         <para>
 120             <citerefentry><refentrytitle>glGetActiveUniformBlock</refentrytitle></citerefentry>,
 121             <citerefentry><refentrytitle>glGetUniformBlockIndex</refentrytitle></citerefentry>
 122         </para>
 123     </refsect1>
 124     <refsect1 id="Copyright"><title>Copyright</title>
 125         <para>
 126             Copyright <trademark class="copyright"></trademark> 2010 Khronos Group.
 127             This material may be distributed subject to the terms and conditions set forth in
 128             the Open Publication License, v 1.0, 8 June 1999.
 129             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 130         </para>
 131     </refsect1>
 132 </refentry>