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