upstream-man-pages/manglsl/textureProjOffset.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="textureProjOffsetOffset">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2011</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>textureProjOffset</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>textureProjOffset</refname>
  17         <refpurpose>perform a texture lookup with projection and offset</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>Declaration</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>gvec4 <function>textureProjOffset</function></funcdef>
  23                 <paramdef>gsampler1D <parameter>sampler</parameter></paramdef>
  24                 <paramdef>vec2 <parameter>P</parameter></paramdef>
  25                 <paramdef>int <parameter>offset</parameter></paramdef>
  26                 <paramdef>[float <parameter>bias</parameter>]</paramdef>
  27             </funcprototype>
  28             <funcprototype>
  29                 <funcdef>gvec4 <function>textureProjOffset</function></funcdef>
  30                 <paramdef>gsampler1D <parameter>sampler</parameter></paramdef>
  31                 <paramdef>vec4 <parameter>P</parameter></paramdef>
  32                 <paramdef>int <parameter>offset</parameter></paramdef>
  33                 <paramdef>[float <parameter>bias</parameter>]</paramdef>
  34             </funcprototype>
  35             <funcprototype>
  36                 <funcdef>gvec4 <function>textureProjOffset</function></funcdef>
  37                 <paramdef>gsampler2D <parameter>sampler</parameter></paramdef>
  38                 <paramdef>vec3 <parameter>P</parameter></paramdef>
  39                 <paramdef>ivec2 <parameter>offset</parameter></paramdef>
  40                 <paramdef>[float <parameter>bias</parameter>]</paramdef>
  41             </funcprototype>
  42             <funcprototype>
  43                 <funcdef>gvec4 <function>textureProjOffset</function></funcdef>
  44                 <paramdef>gsampler2D <parameter>sampler</parameter></paramdef>
  45                 <paramdef>vec4 <parameter>P</parameter></paramdef>
  46                 <paramdef>ivec2 <parameter>offset</parameter></paramdef>
  47                 <paramdef>[float <parameter>bias</parameter>]</paramdef>
  48             </funcprototype>
  49             <funcprototype>
  50                 <funcdef>gvec4 <function>textureProjOffset</function></funcdef>
  51                 <paramdef>gsampler3D <parameter>sampler</parameter></paramdef>
  52                 <paramdef>vec4 <parameter>P</parameter></paramdef>
  53                 <paramdef>ivec3 <parameter>offset</parameter></paramdef>
  54                 <paramdef>[float <parameter>bias</parameter>]</paramdef>
  55             </funcprototype>
  56             <funcprototype>
  57                 <funcdef>float <function>textureProjOffset</function></funcdef>
  58                 <paramdef>sampler1DShadow <parameter>sampler</parameter></paramdef>
  59                 <paramdef>vec4 <parameter>P</parameter></paramdef>
  60                 <paramdef>int <parameter>offset</parameter></paramdef>
  61                 <paramdef>[float <parameter>bias</parameter>]</paramdef>
  62             </funcprototype>
  63             <funcprototype>
  64                 <funcdef>float <function>textureProjOffset</function></funcdef>
  65                 <paramdef>sampler2DShadow <parameter>sampler</parameter></paramdef>
  66                 <paramdef>vec4 <parameter>P</parameter></paramdef>
  67                 <paramdef>ivec2 <parameter>offset</parameter></paramdef>
  68                 <paramdef>[float <parameter>bias</parameter>]</paramdef>
  69             </funcprototype>
  70             <funcprototype>
  71                 <funcdef>gvec4 <function>textureProjOffset</function></funcdef>
  72                 <paramdef>gsampler2DRect <parameter>sampler</parameter></paramdef>
  73                 <paramdef>vec3 <parameter>P</parameter></paramdef>
  74                 <paramdef>ivec2 <parameter>offset</parameter></paramdef>
  75             </funcprototype>
  76             <funcprototype>
  77                 <funcdef>gvec4 <function>textureProjOffset</function></funcdef>
  78                 <paramdef>gsampler2DRect <parameter>sampler</parameter></paramdef>
  79                 <paramdef>vec4 <parameter>P</parameter></paramdef>
  80                 <paramdef>ivec2 <parameter>offset</parameter></paramdef>
  81             </funcprototype>
  82             <funcprototype>
  83                 <funcdef>float <function>textureProjOffset</function></funcdef>
  84                 <paramdef>gsampler2DRectShadow <parameter>sampler</parameter></paramdef>
  85                 <paramdef>vec4 <parameter>P</parameter></paramdef>
  86                 <paramdef>ivec2 <parameter>offset</parameter></paramdef>
  87             </funcprototype>
  88         </funcsynopsis>
  89     </refsynopsisdiv>
  90     <refsect1 id="parameters"><title>Parameters</title>
  91         <variablelist>
  92         <varlistentry>
  93             <term><parameter>sampler</parameter></term>
  94             <listitem>
  95                 <para>
  96                     Specifies the sampler to which the texture from which texels will be retrieved is bound.
  97                 </para>
  98             </listitem>
  99         </varlistentry>
 100         <varlistentry>
 101             <term><parameter>P</parameter></term>
 102             <listitem>
 103                 <para>
 104                     Specifies the texture coordinates at which the texture will be sampled.
 105                 </para>
 106             </listitem>
 107         </varlistentry>
 108         <varlistentry>
 109             <term><parameter>offset</parameter></term>
 110             <listitem>
 111                 <para>
 112                     Specifies the offset that is applied to <parameter>P</parameter> before sampling occurs.
 113                 </para>
 114             </listitem>
 115         </varlistentry>
 116         <varlistentry>
 117             <term><parameter>bias</parameter></term>
 118             <listitem>
 119                 <para>
 120                     Specifies an optional bias to be applied during level-of-detail computation.
 121                 </para>
 122             </listitem>
 123         </varlistentry>
 124         </variablelist>
 125     </refsect1>
 126     <refsect1 id="description"><title>Description</title>
 127         <para>
 128             <function>textureProjOffset</function> performs a texture lookup with projection. The texture coordinates
 129             consumed from <parameter>P</parameter>, not including the last component of <parameter>P</parameter>,
 130             are divided by the last component of <parameter>P</parameter>. The resulting <inlineequation><mml:math><mml:msup><mml:mn>3</mml:mn><mml:mi>rd</mml:mi></mml:msup></mml:math></inlineequation>
 131             component of <parameter>P</parameter> in the shadow forms is used as
 132             <inlineequation><mml:math><mml:msub><mml:mi>D</mml:mi><mml:mi>ref</mml:mi></mml:msub></mml:math></inlineequation>.
 133             After these values are computed, the texture lookup proceeds as in <citerefentry><refentrytitle>textureOffset</refentrytitle></citerefentry>,
 134             with the <parameter>offset</parameter> used to offset the computed texture coordinates.
 135         </para>
 136     </refsect1>
 137     <refsect1 id="versions"><title>Version Support</title>
 138         <informaltable frame="topbot">
 139             #VARTABLECOLS#
 140                 <thead>
 141                     #FUNCTABLEHEADER#
 142                     <row>
 143                         <entry>textureProjOffset</entry>#newin13#
 144                     </row>
 145                     <row>
 146                         <entry>textureProjOffset (gsampler2DRect{Shadow})</entry>#newin14#
 147                     </row>
 148                 </thead>
 149             </tgroup>
 150         </informaltable>
 151     </refsect1>
 152     <refsect1 id="seealso"><title>See Also</title>
 153         <para>
 154             <citerefentry><refentrytitle>texelFetch</refentrytitle></citerefentry>,
 155             <citerefentry><refentrytitle>texelFetchOffset</refentrytitle></citerefentry>,
 156             <citerefentry><refentrytitle>texture</refentrytitle></citerefentry>,
 157             <citerefentry><refentrytitle>textureGather</refentrytitle></citerefentry>,
 158             <citerefentry><refentrytitle>textureGatherOffset</refentrytitle></citerefentry>,
 159             <citerefentry><refentrytitle>textureGatherOffsets</refentrytitle></citerefentry>,
 160             <citerefentry><refentrytitle>textureGrad</refentrytitle></citerefentry>,
 161             <citerefentry><refentrytitle>textureGradOffset</refentrytitle></citerefentry>,
 162             <citerefentry><refentrytitle>textureLod</refentrytitle></citerefentry>,
 163             <citerefentry><refentrytitle>textureLodOffset</refentrytitle></citerefentry>,
 164             <citerefentry><refentrytitle>textureOffset</refentrytitle></citerefentry>,
 165             <citerefentry><refentrytitle>textureProj</refentrytitle></citerefentry>,
 166             <citerefentry><refentrytitle>textureProjGrad</refentrytitle></citerefentry>,
 167             <citerefentry><refentrytitle>textureProjGradOffset</refentrytitle></citerefentry>,
 168             <citerefentry><refentrytitle>textureProjLod</refentrytitle></citerefentry>,
 169             <citerefentry><refentrytitle>textureProjLodOffset</refentrytitle></citerefentry>,
 170             <citerefentry><refentrytitle>textureQueryLod</refentrytitle></citerefentry>,
 171             <citerefentry><refentrytitle>textureSize</refentrytitle></citerefentry>
 172         </para>
 173     </refsect1>
 174     <refsect1 id="Copyright"><title>Copyright</title>
 175         <para>
 176             Copyright <trademark class="copyright"></trademark> 2011 Khronos Group.
 177             This material may be distributed subject to the terms and conditions set forth in
 178             the Open Publication License, v 1.0, 8 June 1999.
 179             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 180         </para>
 181     </refsect1>
 182 </refentry>