rename upstream-man-pages to upstream-doc
[clinton/guile-figl.git] / upstream-doc / manglsl / textureOffset.xml
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1<?xml version="1.0" encoding="UTF-8"?>\r
2<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"\r
3 "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">\r
4<refentry id="textureOffset">\r
5 <refmeta>\r
6 <refmetainfo>\r
7 <copyright>\r
8 <year>2012</year>\r
9 <holder>Khronos Group</holder>\r
10 </copyright>\r
11 </refmetainfo>\r
12 <refentrytitle>textureOffset</refentrytitle>\r
13 <manvolnum>3G</manvolnum>\r
14 </refmeta>\r
15 <refnamediv>\r
16 <refname>textureOffset</refname>\r
17 <refpurpose>perform a texture lookup with offset</refpurpose>\r
18 </refnamediv>\r
19 <refsynopsisdiv><title>Declaration</title>\r
20 <funcsynopsis>\r
21 <funcprototype>\r
22 <funcdef>gvec4 <function>textureOffset</function></funcdef>\r
23 <paramdef>gsampler1D <parameter>sampler</parameter></paramdef>\r
24 <paramdef>float <parameter>P</parameter></paramdef>\r
25 <paramdef>int <parameter>offset</parameter></paramdef>\r
26 <paramdef>[float <parameter>bias</parameter>]</paramdef>\r
27 </funcprototype>\r
28 <funcprototype>\r
29 <funcdef>gvec4 <function>textureOffset</function></funcdef>\r
30 <paramdef>gsampler2D <parameter>sampler</parameter></paramdef>\r
31 <paramdef>vec2 <parameter>P</parameter></paramdef>\r
32 <paramdef>ivec2 <parameter>offset</parameter></paramdef>\r
33 <paramdef>[float <parameter>bias</parameter>]</paramdef>\r
34 </funcprototype>\r
35 <funcprototype>\r
36 <funcdef>gvec4 <function>textureOffset</function></funcdef>\r
37 <paramdef>gsampler3D <parameter>sampler</parameter></paramdef>\r
38 <paramdef>vec3 <parameter>P</parameter></paramdef>\r
39 <paramdef>ivec3 <parameter>offset</parameter></paramdef>\r
40 <paramdef>[float <parameter>bias</parameter>]</paramdef>\r
41 </funcprototype>\r
42 <funcprototype>\r
43 <funcdef>gvec4 <function>textureOffset</function></funcdef>\r
44 <paramdef>gsampler2DRect <parameter>sampler</parameter></paramdef>\r
45 <paramdef>vec2 <parameter>P</parameter></paramdef>\r
46 <paramdef>ivec2 <parameter>offset</parameter></paramdef>\r
47 </funcprototype>\r
48 <funcprototype>\r
49 <funcdef>float <function>textureOffset</function></funcdef>\r
50 <paramdef>sampler2DRectShadow <parameter>sampler</parameter></paramdef>\r
51 <paramdef>vec3 <parameter>P</parameter></paramdef>\r
52 <paramdef>ivec2 <parameter>offset</parameter></paramdef>\r
53 </funcprototype>\r
54 <funcprototype>\r
55 <funcdef>float <function>textureOffset</function></funcdef>\r
56 <paramdef>sampler1DShadow <parameter>sampler</parameter></paramdef>\r
57 <paramdef>vec3 <parameter>P</parameter></paramdef>\r
58 <paramdef>int <parameter>offset</parameter></paramdef>\r
59 <paramdef>[float <parameter>bias</parameter>]</paramdef>\r
60 </funcprototype>\r
61 <funcprototype>\r
62 <funcdef>float <function>textureOffset</function></funcdef>\r
63 <paramdef>sampler2DShadow <parameter>sampler</parameter></paramdef>\r
64 <paramdef>vec4 <parameter>P</parameter></paramdef>\r
65 <paramdef>ivec2 <parameter>offset</parameter></paramdef>\r
66 <paramdef>[float <parameter>bias</parameter>]</paramdef>\r
67 </funcprototype>\r
68 <funcprototype>\r
69 <funcdef>gvec4 <function>textureOffset</function></funcdef>\r
70 <paramdef>gsampler1DArray <parameter>sampler</parameter></paramdef>\r
71 <paramdef>vec2 <parameter>P</parameter></paramdef>\r
72 <paramdef>int <parameter>offset</parameter></paramdef>\r
73 <paramdef>[float <parameter>bias</parameter>]</paramdef>\r
74 </funcprototype>\r
75 <funcprototype>\r
76 <funcdef>gvec4 <function>textureOffset</function></funcdef>\r
77 <paramdef>gsampler2DArray <parameter>sampler</parameter></paramdef>\r
78 <paramdef>vec3 <parameter>P</parameter></paramdef>\r
79 <paramdef>ivec2 <parameter>offset</parameter></paramdef>\r
80 <paramdef>[float <parameter>bias</parameter>]</paramdef>\r
81 </funcprototype>\r
82 <funcprototype>\r
83 <funcdef>float <function>textureOffset</function></funcdef>\r
84 <paramdef>sampler1DArrayShadow <parameter>sampler</parameter></paramdef>\r
85 <paramdef>vec3 <parameter>P</parameter></paramdef>\r
86 <paramdef>int <parameter>offset</parameter></paramdef>\r
87 </funcprototype>\r
88 <funcprototype>\r
89 <funcdef>float <function>textureOffset</function></funcdef>\r
90 <paramdef>sampler2DArrayShadow <parameter>sampler</parameter></paramdef>\r
91 <paramdef>vec4 <parameter>P</parameter></paramdef>\r
92 <paramdef>vec2 <parameter>offset</parameter></paramdef>\r
93 </funcprototype>\r
94 </funcsynopsis>\r
95 </refsynopsisdiv>\r
96 <refsect1 id="parameters"><title>Parameters</title>\r
97 <variablelist>\r
98 <varlistentry>\r
99 <term><parameter>sampler</parameter></term>\r
100 <listitem>\r
101 <para>\r
102 Specifies the sampler to which the texture from which texels will be retrieved is bound.\r
103 </para>\r
104 </listitem>\r
105 </varlistentry>\r
106 <varlistentry>\r
107 <term><parameter>P</parameter></term>\r
108 <listitem>\r
109 <para>\r
110 Specifies the texture coordinates at which texture will be sampled.\r
111 </para>\r
112 </listitem>\r
113 </varlistentry>\r
114 <varlistentry>\r
115 <term><parameter>offset</parameter></term>\r
116 <listitem>\r
117 <para>\r
118 Specifies offset, in texels that will be applied to <parameter>P</parameter> before looking up the texel.\r
119 </para>\r
120 </listitem>\r
121 </varlistentry>\r
122 </variablelist>\r
123 </refsect1>\r
124 <refsect1 id="description"><title>Description</title>\r
125 <para>\r
126 <function>textureOffset</function> performs a texture lookup at coordinate <parameter>P</parameter> from the\r
127 texture bound to <parameter>sampler</parameter> with an an additional offset, specified in texels in <parameter>offset</parameter>\r
128 that will be applied to the (u, v, w) texture coordinates before looking up each texel.\r
129 The offset value must be a constant expression. A limited range of offset values are supported;\r
130 the minimum and maximum offset values are implementation-dependent and may be determined\r
131 by querying <constant>GL_MIN_PROGRAM_TEXEL_OFFSET</constant> and <constant>GL_MAX_PROGRAM_TEXEL_OFFSET</constant>,\r
132 respectively.\r
133 </para>\r
134 <para>\r
135 Note that <parameter>offset</parameter> does not apply to the layer coordinate for texture arrays. Also note\r
136 that offsets are not supported for cube maps.\r
137 </para>\r
138 </refsect1>\r
139 <refsect1 id="versions"><title>Version Support</title>\r
140 <informaltable frame="topbot">\r
141 #VARTABLECOLS#\r
142 <thead>\r
143 #FUNCTABLEHEADER#\r
144 <row>\r
145 <entry>textureOffset</entry>#newin13#\r
146 </row>\r
147 <row>\r
148 <entry>textureOffset (gsampler2DRect{Shadow})</entry>#newin14#\r
149 </row>\r
150 </thead>\r
151 </tgroup>\r
152 </informaltable>\r
153 </refsect1>\r
154 <refsect1 id="seealso"><title>See Also</title>\r
155 <para>\r
156 <citerefentry><refentrytitle>texelFetch</refentrytitle></citerefentry>,\r
157 <citerefentry><refentrytitle>texelFetchOffset</refentrytitle></citerefentry>,\r
158 <citerefentry><refentrytitle>texture</refentrytitle></citerefentry>,\r
159 <citerefentry><refentrytitle>textureGather</refentrytitle></citerefentry>,\r
160 <citerefentry><refentrytitle>textureGatherOffset</refentrytitle></citerefentry>,\r
161 <citerefentry><refentrytitle>textureGatherOffsets</refentrytitle></citerefentry>,\r
162 <citerefentry><refentrytitle>textureGrad</refentrytitle></citerefentry>,\r
163 <citerefentry><refentrytitle>textureGradOffset</refentrytitle></citerefentry>,\r
164 <citerefentry><refentrytitle>textureLod</refentrytitle></citerefentry>,\r
165 <citerefentry><refentrytitle>textureLodOffset</refentrytitle></citerefentry>,\r
166 <citerefentry><refentrytitle>textureProj</refentrytitle></citerefentry>,\r
167 <citerefentry><refentrytitle>textureProjGrad</refentrytitle></citerefentry>,\r
168 <citerefentry><refentrytitle>textureProjGradOffset</refentrytitle></citerefentry>,\r
169 <citerefentry><refentrytitle>textureProjLod</refentrytitle></citerefentry>,\r
170 <citerefentry><refentrytitle>textureProjLodOffset</refentrytitle></citerefentry>,\r
171 <citerefentry><refentrytitle>textureProjOffset</refentrytitle></citerefentry>,\r
172 <citerefentry><refentrytitle>textureQueryLod</refentrytitle></citerefentry>,\r
173 <citerefentry><refentrytitle>textureSize</refentrytitle></citerefentry>\r
174 </para>\r
175 </refsect1>\r
176 <refsect1 id="Copyright"><title>Copyright</title>\r
177 <para>\r
178 Copyright <trademark class="copyright"></trademark> 2011-2012 Khronos Group. \r
179 This material may be distributed subject to the terms and conditions set forth in \r
180 the Open Publication License, v 1.0, 8 June 1999.\r
181 <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.\r
182 </para>\r
183 </refsect1>\r
184</refentry>\r