upstream-doc/manglsl/interpolateAtOffset.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="interpolateAtOffset">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2011</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>interpolateAtOffset</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>interpolateAtOffset</refname>
  17         <refpurpose>sample a varying at specified offset from the center of a pixel</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>Declaration</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>float <function>interpolateAtOffset</function></funcdef>
  23                 <paramdef>float <parameter>interpolant</parameter></paramdef>
  24                 <paramdef>vec2 <parameter>offset</parameter></paramdef>
  25             </funcprototype>
  26             <funcprototype>
  27                 <funcdef>vec2 <function>interpolateAtOffset</function></funcdef>
  28                 <paramdef>vec2 <parameter>interpolant</parameter></paramdef>
  29                 <paramdef>vec2 <parameter>offset</parameter></paramdef>
  30             </funcprototype>
  31             <funcprototype>
  32                 <funcdef>vec3 <function>interpolateAtOffset</function></funcdef>
  33                 <paramdef>vec3 <parameter>interpolant</parameter></paramdef>
  34                 <paramdef>vec2 <parameter>offset</parameter></paramdef>
  35             </funcprototype>
  36             <funcprototype>
  37                 <funcdef>vec4 <function>interpolateAtOffset</function></funcdef>
  38                 <paramdef>vec4 <parameter>interpolant</parameter></paramdef>
  39                 <paramdef>vec2 <parameter>offset</parameter></paramdef>
  40             </funcprototype>
  41         </funcsynopsis>
  42     </refsynopsisdiv>
  43     <refsect1 id="parameters"><title>Parameters</title>
  44         <variablelist>
  45         <varlistentry>
  46             <term><parameter>interpolant</parameter></term>
  47             <listitem>
  48                 <para>
  49                     Specifies the interpolant to be sampled at the specified offset.
  50                 </para>
  51             </listitem>
  52         </varlistentry>
  53         <varlistentry>
  54             <term><parameter>offset</parameter></term>
  55             <listitem>
  56                 <para>
  57                     Specifies the offset from the center of the pixel at which to sample <parameter>interpolant</parameter>.
  58                 </para>
  59             </listitem>
  60         </varlistentry>
  61         </variablelist>
  62     </refsect1>
  63     <refsect1 id="description"><title>Description</title>
  64         <para>
  65             <function>interpolateAtOffset</function> returns the value of the input varying <parameter>interpolant</parameter>
  66             sampled at an offset from the center of the pixel specified by <parameter>offset</parameter>. The two floating-point
  67             components of <parameter>offset</parameter> give the offset in pixels in the <emphasis>x</emphasis> and <emphasis>y</emphasis>
  68             directions from the center of the pixel, respectively. An offset of (0, 0) identifies the center of the pixel. The range and granularity of
  69             offsets supported by this function is implementation-dependent.
  70         </para>
  71     </refsect1>
  72     <refsect1 id="versions"><title>Version Support</title>
  73         <informaltable frame="topbot">
  74             #VARTABLECOLS#
  75                 <thead>
  76                     #FUNCTABLEHEADER#
  77                     <row>
  78                         <entry>interpolateAtoOffset</entry>#newin40#
  79                     </row>
  80                 </thead>
  81             </tgroup>
  82         </informaltable>
  83     </refsect1>
  84     <refsect1 id="seealso"><title>See Also</title>
  85         <para>
  86             <citerefentry><refentrytitle>interpolateAtCentroid</refentrytitle></citerefentry>,
  87             <citerefentry><refentrytitle>interpolateAtSample</refentrytitle></citerefentry>
  88         </para>
  89     </refsect1>
  90     <refsect1 id="Copyright"><title>Copyright</title>
  91         <para>
  92             Copyright <trademark class="copyright"></trademark> 2011 Khronos Group.
  93             This material may be distributed subject to the terms and conditions set forth in
  94             the Open Publication License, v 1.0, 8 June 1999.
  95             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
  96         </para>
  97     </refsect1>
  98 </refentry>