upstream-doc/man4/glGetProgramResourceLocationIndex.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="glGetProgramResourceLocationIndex">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2012</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glGetProgramResourceLocationIndex</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glGetProgramResourceLocationIndex</refname>
  17         <refpurpose>query the fragment color index of a named variable within a program</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>GLint <function>glGetProgramResourceLocationIndex</function></funcdef>
  23                 <paramdef>GLuint <parameter>program</parameter></paramdef>
  24                 <paramdef>GLenum <parameter>programInterface</parameter></paramdef>
  25                 <paramdef>const char * <parameter>name</parameter></paramdef>
  26             </funcprototype>
  27         </funcsynopsis>
  28     </refsynopsisdiv>
  29     <refsect1 id="parameters"><title>Parameters</title>
  30         <variablelist>
  31         <varlistentry>
  32             <term><parameter>program</parameter></term>
  33             <listitem>
  34                 <para>
  35                     The name of a program object whose resources to query.
  36                 </para>
  37             </listitem>
  38         </varlistentry>
  39         <varlistentry>
  40             <term><parameter>programInterface</parameter></term>
  41             <listitem>
  42                 <para>
  43                     A token identifying the interface within <parameter>program</parameter> containing the resource named <parameter>name</parameter>.
  44                 </para>
  45             </listitem>
  46         </varlistentry>
  47         <varlistentry>
  48             <term><parameter>name</parameter></term>
  49             <listitem>
  50                 <para>
  51                     The name of the resource to query the location of.
  52                 </para>
  53             </listitem>
  54         </varlistentry>
  55         </variablelist>
  56     </refsect1>
  57     <refsect1 id="description"><title>Description</title>
  58         <para>
  59             <function>glGetProgramResourceLocation</function> returns the fragment color index assigned
  60             to the variable named <parameter>name</parameter> in interface <parameter>programInterface</parameter> of program
  61             object <parameter>program</parameter>.  <parameter>program</parameter> must be the name of a program that has been
  62             linked successfully. <parameter>programInterface</parameter> must
  63             be one of <constant>PROGRAM_OUTPUT</constant>.
  64             The value -1 will be returned if an error occurs, if <parameter>name</parameter> does not identify an active variable on
  65             <parameter>programInterface</parameter>, or if <parameter>name</parameter> identifies an active variable that does
  66             not have a valid location assigned, as described above.  The locations
  67             returned by these commands are the same locations returned when querying
  68             the <constant>GL_LOCATION</constant> and <constant>GL_LOCATION_INDEX</constant> resource properties.
  69         </para>
  70         <para>
  71             A string provided to <function>glGetProgramResourceLocationIndex</function> is considered to match an active variable if:
  72         </para>
  73         <itemizedlist>
  74             <listitem>
  75                 <para>
  76                     the string exactly matches the name of the active variable
  77                 </para>
  78             </listitem>
  79             <listitem>
  80                 <para>
  81                     if the string identifies the base name of an active array, where the
  82                     string would exactly match the name of the variable if the suffix
  83                     "[0]" were appended to the string
  84                 </para>
  85             </listitem>
  86             <listitem>
  87                 <para>
  88                     if the string identifies an active element of the array, where the
  89                     string ends with the concatenation of the "[" character, an integer
  90                     <emphasis>with no "+" sign, extra leading zeroes, or whitespace</emphasis> identifying an
  91                     array element, and the "]" character, the integer is less than the
  92                     number of active elements of the array variable, and where the string
  93                     would exactly match the enumerated name of the array if the decimal
  94                     integer were replaced with zero.
  95                 </para>
  96             </listitem>
  97         </itemizedlist>
  98         <para>
  99             Any other string is considered not to identify an active variable.  If the
 100             string specifies an element of an array variable,
 101             <function>glGetProgramResourceLocation</function> returns the
 102             location assigned to that element.  If it
 103             specifies the base name of an array, it identifies the resources
 104             associated with the first element of the array.
 105         </para>
 106     </refsect1>
 107     <refsect1 id="errors"><title>Errors</title>
 108         <para>
 109             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>program</parameter>
 110             is not the name of an existing program object.
 111         </para>
 112         <para>
 113             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>programInterface</parameter>
 114             is not one of the accepted interface types.
 115         </para>
 116         <para>
 117             <constant>GL_INVALID_OPERATION</constant> is generated if <parameter>program</parameter>
 118             has not been linked successfully.
 119         </para>
 120     </refsect1>
 121     <refsect1 id="seealso"><title>See Also</title>
 122         <para>
 123             <citerefentry><refentrytitle>glGetProgramResourceName</refentrytitle></citerefentry>,
 124             <citerefentry><refentrytitle>glGetProgramResourceIndex</refentrytitle></citerefentry>,
 125             <citerefentry><refentrytitle>glGetGetProgramResource</refentrytitle></citerefentry>,
 126             <citerefentry><refentrytitle>glGetProgramResourceLocationIndex</refentrytitle></citerefentry>.
 127         </para>
 128     </refsect1>
 129     <refsect1 id="Copyright"><title>Copyright</title>
 130         <para>
 131             Copyright <trademark class="copyright"></trademark> 2012 Khronos Group.
 132             This material may be distributed subject to the terms and conditions set forth in
 133             the Open Publication License, v 1.0, 8 June 1999.
 134             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 135         </para>
 136     </refsect1>
 137 </refentry>