upstream-doc/manglsl/imageLoad.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="imageLoad">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2011</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>imageLoad</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>imageLoad</refname>
  17         <refpurpose>load a single texel from an image</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>Declaration</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>gvec4 <function>imageLoad</function></funcdef>
  23                 <paramdef>gimage1D <parameter>image</parameter></paramdef>
  24                 <paramdef>int <parameter>P</parameter></paramdef>
  25             </funcprototype>
  26             <funcprototype>
  27                 <funcdef>gvec4 <function>imageLoad</function></funcdef>
  28                 <paramdef>gimage2D <parameter>image</parameter></paramdef>
  29                 <paramdef>ivec2 <parameter>P</parameter></paramdef>
  30             </funcprototype>
  31             <funcprototype>
  32                 <funcdef>gvec4 <function>imageLoad</function></funcdef>
  33                 <paramdef>gimage3D <parameter>image</parameter></paramdef>
  34                 <paramdef>ivec3 <parameter>P</parameter></paramdef>
  35             </funcprototype>
  36             <funcprototype>
  37                 <funcdef>gvec4 <function>imageLoad</function></funcdef>
  38                 <paramdef>gimage2DRect <parameter>image</parameter></paramdef>
  39                 <paramdef>ivec2 <parameter>P</parameter></paramdef>
  40             </funcprototype>
  41             <funcprototype>
  42                 <funcdef>gvec4 <function>imageLoad</function></funcdef>
  43                 <paramdef>gimageCube <parameter>image</parameter></paramdef>
  44                 <paramdef>ivec3 <parameter>P</parameter></paramdef>
  45             </funcprototype>
  46             <funcprototype>
  47                 <funcdef>gvec4 <function>imageLoad</function></funcdef>
  48                 <paramdef>gbufferImage <parameter>image</parameter></paramdef>
  49                 <paramdef>int <parameter>P</parameter></paramdef>
  50             </funcprototype>
  51             <funcprototype>
  52                 <funcdef>gvec4 <function>imageLoad</function></funcdef>
  53                 <paramdef>gimage1DArray <parameter>image</parameter></paramdef>
  54                 <paramdef>ivec2 <parameter>P</parameter></paramdef>
  55             </funcprototype>
  56             <funcprototype>
  57                 <funcdef>gvec4 <function>imageLoad</function></funcdef>
  58                 <paramdef>gimage2DArray <parameter>image</parameter></paramdef>
  59                 <paramdef>ivec3 <parameter>P</parameter></paramdef>
  60             </funcprototype>
  61             <funcprototype>
  62                 <funcdef>gvec4 <function>imageLoad</function></funcdef>
  63                 <paramdef>gimageCubeArray <parameter>image</parameter></paramdef>
  64                 <paramdef>ivec3 <parameter>P</parameter></paramdef>
  65             </funcprototype>
  66             <funcprototype>
  67                 <funcdef>gvec4 <function>imageLoad</function></funcdef>
  68                 <paramdef>gimage2DMS <parameter>image</parameter></paramdef>
  69                 <paramdef>ivec2 <parameter>P</parameter></paramdef>
  70                 <paramdef>int <parameter>sample</parameter></paramdef>
  71             </funcprototype>
  72             <funcprototype>
  73                 <funcdef>gvec4 <function>imageLoad</function></funcdef>
  74                 <paramdef>gimage2DMSArray <parameter>image</parameter></paramdef>
  75                 <paramdef>ivec3 <parameter>P</parameter></paramdef>
  76                 <paramdef>int <parameter>sample</parameter></paramdef>
  77             </funcprototype>
  78         </funcsynopsis>
  79     </refsynopsisdiv>
  80     <refsect1 id="parameters"><title>Parameters</title>
  81         <variablelist>
  82         <varlistentry>
  83             <term><parameter>image</parameter></term>
  84             <listitem>
  85                 <para>
  86                     Specify the image unit from which to load a texel.
  87                 </para>
  88             </listitem>
  89         </varlistentry>
  90         <varlistentry>
  91             <term><parameter>P</parameter></term>
  92             <listitem>
  93                 <para>
  94                     Specify the coordinate from which to load the texel.
  95                 </para>
  96             </listitem>
  97         </varlistentry>
  98         <varlistentry>
  99             <term><parameter>sample</parameter></term>
 100             <listitem>
 101                 <para>
 102                     When present, specifies the sample within the image to load
 103                 </para>
 104             </listitem>
 105         </varlistentry>
 106         </variablelist>
 107     </refsect1>
 108     <refsect1 id="description"><title>Description</title>
 109         <para>
 110             <function>imageLoad</function> loads the texel at the coordinate <parameter>P</parameter> from the image
 111             unit <parameter>image</parameter>.  For multi-sample loads, the sample number is given by <parameter>sample</parameter>.  When
 112             <parameter>image</parameter>, <parameter>P</parameter>, <parameter>sample</parameter> identify a valid texel, the bits used
 113             to represent the selected texel in memory are converted to a vec4, ivec4, or uvec4 in the manner described in the OpenGL
 114             Specification and returned.
 115         </para>
 116     </refsect1>
 117     <refsect1 id="versions"><title>Version Support</title>
 118         <informaltable frame="topbot">
 119             #VARTABLECOLS#
 120                 <thead>
 121                     #FUNCTABLEHEADER#
 122                     <row>
 123                         <entry>imageLoad</entry>#newin42#
 124                     </row>
 125                 </thead>
 126             </tgroup>
 127         </informaltable>
 128     </refsect1>
 129     <refsect1 id="seealso"><title>See Also</title>
 130         <para>
 131             <citerefentry><refentrytitle>imageStore</refentrytitle></citerefentry>,
 132             <citerefentry><refentrytitle>imageAtomicAdd</refentrytitle></citerefentry>,
 133             <citerefentry><refentrytitle>imageAtomicMin</refentrytitle></citerefentry>,
 134             <citerefentry><refentrytitle>imageAtomicMax</refentrytitle></citerefentry>,
 135             <citerefentry><refentrytitle>imageAtomicAnd</refentrytitle></citerefentry>,
 136             <citerefentry><refentrytitle>imageAtomicOr</refentrytitle></citerefentry>,
 137             <citerefentry><refentrytitle>imageAtomicXor</refentrytitle></citerefentry>,
 138             <citerefentry><refentrytitle>imageAtomicExchange</refentrytitle></citerefentry>,
 139             <citerefentry><refentrytitle>imageAtomicCompSwap</refentrytitle></citerefentry>
 140         </para>
 141     </refsect1>
 142     <refsect1 id="Copyright"><title>Copyright</title>
 143         <para>
 144             Copyright <trademark class="copyright"></trademark> 2011 Khronos Group.
 145             This material may be distributed subject to the terms and conditions set forth in
 146             the Open Publication License, v 1.0, 8 June 1999.
 147             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 148         </para>
 149     </refsect1>
 150 </refentry>