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=
"textureOffset">
9 <holder>Khronos Group
</holder>
12 <refentrytitle>textureOffset
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>textureOffset
</refname>
17 <refpurpose>perform a texture lookup with offset
</refpurpose>
19 <refsynopsisdiv><title>Declaration
</title>
22 <funcdef>gvec4
<function>textureOffset
</function></funcdef>
23 <paramdef>gsampler1D
<parameter>sampler
</parameter></paramdef>
24 <paramdef>float
<parameter>P
</parameter></paramdef>
25 <paramdef>int
<parameter>offset
</parameter></paramdef>
26 <paramdef>[float
<parameter>bias
</parameter>]
</paramdef>
29 <funcdef>gvec4
<function>textureOffset
</function></funcdef>
30 <paramdef>gsampler2D
<parameter>sampler
</parameter></paramdef>
31 <paramdef>vec2
<parameter>P
</parameter></paramdef>
32 <paramdef>ivec2
<parameter>offset
</parameter></paramdef>
33 <paramdef>[float
<parameter>bias
</parameter>]
</paramdef>
36 <funcdef>gvec4
<function>textureOffset
</function></funcdef>
37 <paramdef>gsampler3D
<parameter>sampler
</parameter></paramdef>
38 <paramdef>vec3
<parameter>P
</parameter></paramdef>
39 <paramdef>ivec3
<parameter>offset
</parameter></paramdef>
40 <paramdef>[float
<parameter>bias
</parameter>]
</paramdef>
43 <funcdef>gvec4
<function>textureOffset
</function></funcdef>
44 <paramdef>gsampler2DRect
<parameter>sampler
</parameter></paramdef>
45 <paramdef>vec2
<parameter>P
</parameter></paramdef>
46 <paramdef>ivec2
<parameter>offset
</parameter></paramdef>
49 <funcdef>float
<function>textureOffset
</function></funcdef>
50 <paramdef>sampler2DRectShadow
<parameter>sampler
</parameter></paramdef>
51 <paramdef>vec3
<parameter>P
</parameter></paramdef>
52 <paramdef>ivec2
<parameter>offset
</parameter></paramdef>
55 <funcdef>float
<function>textureOffset
</function></funcdef>
56 <paramdef>sampler1DShadow
<parameter>sampler
</parameter></paramdef>
57 <paramdef>vec3
<parameter>P
</parameter></paramdef>
58 <paramdef>int
<parameter>offset
</parameter></paramdef>
59 <paramdef>[float
<parameter>bias
</parameter>]
</paramdef>
62 <funcdef>float
<function>textureOffset
</function></funcdef>
63 <paramdef>sampler2DShadow
<parameter>sampler
</parameter></paramdef>
64 <paramdef>vec4
<parameter>P
</parameter></paramdef>
65 <paramdef>ivec2
<parameter>offset
</parameter></paramdef>
66 <paramdef>[float
<parameter>bias
</parameter>]
</paramdef>
69 <funcdef>gvec4
<function>textureOffset
</function></funcdef>
70 <paramdef>gsampler1DArray
<parameter>sampler
</parameter></paramdef>
71 <paramdef>vec2
<parameter>P
</parameter></paramdef>
72 <paramdef>int
<parameter>offset
</parameter></paramdef>
73 <paramdef>[float
<parameter>bias
</parameter>]
</paramdef>
76 <funcdef>gvec4
<function>textureOffset
</function></funcdef>
77 <paramdef>gsampler2DArray
<parameter>sampler
</parameter></paramdef>
78 <paramdef>vec3
<parameter>P
</parameter></paramdef>
79 <paramdef>ivec2
<parameter>offset
</parameter></paramdef>
80 <paramdef>[float
<parameter>bias
</parameter>]
</paramdef>
83 <funcdef>float
<function>textureOffset
</function></funcdef>
84 <paramdef>sampler1DArrayShadow
<parameter>sampler
</parameter></paramdef>
85 <paramdef>vec3
<parameter>P
</parameter></paramdef>
86 <paramdef>int
<parameter>offset
</parameter></paramdef>
89 <funcdef>float
<function>textureOffset
</function></funcdef>
90 <paramdef>sampler2DArrayShadow
<parameter>sampler
</parameter></paramdef>
91 <paramdef>vec4
<parameter>P
</parameter></paramdef>
92 <paramdef>vec2
<parameter>offset
</parameter></paramdef>
96 <refsect1 id=
"parameters"><title>Parameters
</title>
99 <term><parameter>sampler
</parameter></term>
102 Specifies the sampler to which the texture from which texels will be retrieved is bound.
107 <term><parameter>P
</parameter></term>
110 Specifies the texture coordinates at which texture will be sampled.
115 <term><parameter>offset
</parameter></term>
118 Specifies offset, in texels that will be applied to
<parameter>P
</parameter> before looking up the texel.
124 <refsect1 id=
"description"><title>Description
</title>
126 <function>textureOffset
</function> performs a texture lookup at coordinate
<parameter>P
</parameter> from the
127 texture bound to
<parameter>sampler
</parameter> with an an additional offset, specified in texels in
<parameter>offset
</parameter>
128 that will be applied to the (u, v, w) texture coordinates before looking up each texel.
129 The offset value must be a constant expression. A limited range of offset values are supported;
130 the minimum and maximum offset values are implementation-dependent and may be determined
131 by querying
<constant>GL_MIN_PROGRAM_TEXEL_OFFSET
</constant> and
<constant>GL_MAX_PROGRAM_TEXEL_OFFSET
</constant>,
135 Note that
<parameter>offset
</parameter> does not apply to the layer coordinate for texture arrays. Also note
136 that offsets are not supported for cube maps.
139 <refsect1 id=
"versions"><title>Version Support
</title>
140 <informaltable frame=
"topbot">
145 <entry>textureOffset
</entry>#newin13#
148 <entry>textureOffset (gsampler2DRect{Shadow})
</entry>#newin14#
154 <refsect1 id=
"seealso"><title>See Also
</title>
156 <citerefentry><refentrytitle>texelFetch
</refentrytitle></citerefentry>,
157 <citerefentry><refentrytitle>texelFetchOffset
</refentrytitle></citerefentry>,
158 <citerefentry><refentrytitle>texture
</refentrytitle></citerefentry>,
159 <citerefentry><refentrytitle>textureGather
</refentrytitle></citerefentry>,
160 <citerefentry><refentrytitle>textureGatherOffset
</refentrytitle></citerefentry>,
161 <citerefentry><refentrytitle>textureGatherOffsets
</refentrytitle></citerefentry>,
162 <citerefentry><refentrytitle>textureGrad
</refentrytitle></citerefentry>,
163 <citerefentry><refentrytitle>textureGradOffset
</refentrytitle></citerefentry>,
164 <citerefentry><refentrytitle>textureLod
</refentrytitle></citerefentry>,
165 <citerefentry><refentrytitle>textureLodOffset
</refentrytitle></citerefentry>,
166 <citerefentry><refentrytitle>textureProj
</refentrytitle></citerefentry>,
167 <citerefentry><refentrytitle>textureProjGrad
</refentrytitle></citerefentry>,
168 <citerefentry><refentrytitle>textureProjGradOffset
</refentrytitle></citerefentry>,
169 <citerefentry><refentrytitle>textureProjLod
</refentrytitle></citerefentry>,
170 <citerefentry><refentrytitle>textureProjLodOffset
</refentrytitle></citerefentry>,
171 <citerefentry><refentrytitle>textureProjOffset
</refentrytitle></citerefentry>,
172 <citerefentry><refentrytitle>textureQueryLod
</refentrytitle></citerefentry>,
173 <citerefentry><refentrytitle>textureSize
</refentrytitle></citerefentry>
176 <refsect1 id=
"Copyright"><title>Copyright
</title>
178 Copyright
<trademark class=
"copyright"></trademark> 2011-
2012 Khronos Group.
179 This material may be distributed subject to the terms and conditions set forth in
180 the Open Publication License, v
1.0,
8 June
1999.
181 <ulink url=
"http://opencontent.org/openpub/">http://opencontent.org/openpub/
</ulink>.