1 <?xml version=
"1.0" encoding=
"UTF-8"?>
2 <!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
3 <!-- saved from url=(0013)about:internet -->
4 <?xml-stylesheet type=
"text/xsl" href=
"mathml.xsl"?><html xmlns=
"http://www.w3.org/1999/xhtml" xmlns:
pref=
"http://www.w3.org/2002/Math/preference" pref:
renderer=
"mathplayer-dl"><head><meta http-equiv=
"Content-Type" content=
"text/html; charset=UTF-8" /><link rel=
"stylesheet" type=
"text/css" href=
"opengl-man.css" /><title>textureGatherOffset - OpenGL Shading Language (GLSL)
</title><meta name=
"generator" content=
"DocBook XSL Stylesheets V1.69.1" /></head><body><div class=
"refentry" lang=
"en" xml:
lang=
"en"><a id=
"textureGatherOffset"></a><div class=
"titlepage"></div><div class=
"refnamediv"><h2>Name
</h2><p>textureGatherOffset — gathers four texels from a texture with offset
</p></div><div class=
"refsynopsisdiv"><h2>Declaration
</h2><div class=
"funcsynopsis"><table border=
"0" summary=
"Function synopsis" cellspacing=
"0" cellpadding=
"0" style=
"padding-bottom: 1em"><tr><td><code class=
"funcdef">gvec4
<b class=
"fsfunc">textureGatherOffset
</b>(
</code></td><td>gsampler2D
</td><td><var class=
"pdparam">sampler
</var>,
</td></tr><tr><td> </td><td>vec2
</td><td><var class=
"pdparam">P
</var>,
</td></tr><tr><td> </td><td>ivec2
</td><td><var class=
"pdparam">offset
</var>,
</td></tr><tr><td> </td><td>[int
</td><td><var class=
"pdparam">comp]
</var><code>)
</code>;
</td></tr></table><table border=
"0" summary=
"Function synopsis" cellspacing=
"0" cellpadding=
"0" style=
"padding-bottom: 1em"><tr><td><code class=
"funcdef">gvec4
<b class=
"fsfunc">textureGatherOffset
</b>(
</code></td><td>gsampler2DArray
</td><td><var class=
"pdparam">sampler
</var>,
</td></tr><tr><td> </td><td>vec3
</td><td><var class=
"pdparam">P
</var>,
</td></tr><tr><td> </td><td>ivec2
</td><td><var class=
"pdparam">offset
</var>,
</td></tr><tr><td> </td><td>[int
</td><td><var class=
"pdparam">comp]
</var><code>)
</code>;
</td></tr></table><table border=
"0" summary=
"Function synopsis" cellspacing=
"0" cellpadding=
"0" style=
"padding-bottom: 1em"><tr><td><code class=
"funcdef">gvec4
<b class=
"fsfunc">textureGatherOffset
</b>(
</code></td><td>gsampler2DRect
</td><td><var class=
"pdparam">sampler
</var>,
</td></tr><tr><td> </td><td>vec3
</td><td><var class=
"pdparam">P
</var>,
</td></tr><tr><td> </td><td>ivec2
</td><td><var class=
"pdparam">offset
</var>,
</td></tr><tr><td> </td><td>[int
</td><td><var class=
"pdparam">comp]
</var><code>)
</code>;
</td></tr></table><table border=
"0" summary=
"Function synopsis" cellspacing=
"0" cellpadding=
"0" style=
"padding-bottom: 1em"><tr><td><code class=
"funcdef">vec4
<b class=
"fsfunc">textureGatherOffset
</b>(
</code></td><td>gsampler2DShadow
</td><td><var class=
"pdparam">sampler
</var>,
</td></tr><tr><td> </td><td>vec2
</td><td><var class=
"pdparam">P
</var>,
</td></tr><tr><td> </td><td>float
</td><td><var class=
"pdparam">refZ
</var>,
</td></tr><tr><td> </td><td>ivec2
</td><td><var class=
"pdparam">offset
</var><code>)
</code>;
</td></tr></table><table border=
"0" summary=
"Function synopsis" cellspacing=
"0" cellpadding=
"0" style=
"padding-bottom: 1em"><tr><td><code class=
"funcdef">vec4
<b class=
"fsfunc">textureGatherOffset
</b>(
</code></td><td>gsampler2DArrayShadow
</td><td><var class=
"pdparam">sampler
</var>,
</td></tr><tr><td> </td><td>vec3
</td><td><var class=
"pdparam">P
</var>,
</td></tr><tr><td> </td><td>float
</td><td><var class=
"pdparam">refZ
</var>,
</td></tr><tr><td> </td><td>ivec2
</td><td><var class=
"pdparam">offset
</var><code>)
</code>;
</td></tr></table><table border=
"0" summary=
"Function synopsis" cellspacing=
"0" cellpadding=
"0"><tr><td><code class=
"funcdef">vec4
<b class=
"fsfunc">textureGatherOffset
</b>(
</code></td><td>gsampler2DRectShadow
</td><td><var class=
"pdparam">sampler
</var>,
</td></tr><tr><td> </td><td>vec3
</td><td><var class=
"pdparam">P
</var>,
</td></tr><tr><td> </td><td>float
</td><td><var class=
"pdparam">refZ
</var>,
</td></tr><tr><td> </td><td>ivec2
</td><td><var class=
"pdparam">offset
</var><code>)
</code>;
</td></tr></table></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"parameters"></a><h2>Parameters
</h2><div class=
"variablelist"><dl><dt><span class=
"term"><em class=
"parameter"><code>sampler
</code></em></span></dt><dd><p>
5 Specifies the sampler to which the texture from which texels will be retrieved is bound.
6 </p></dd><dt><span class=
"term"><em class=
"parameter"><code>P
</code></em></span></dt><dd><p>
7 Specifies the texture coordinates at which texture will be sampled.
8 </p></dd><dt><span class=
"term"><em class=
"parameter"><code>comp
</code></em></span></dt><dd><p>
9 Specifies the component of the source texture that will be used to generate the resulting vector.
10 </p></dd><dt><span class=
"term"><em class=
"parameter"><code>refZ
</code></em></span></dt><dd><p>
11 Specifies the reference Z value used in the comparison for shadow forms.
12 </p></dd><dt><span class=
"term"><em class=
"parameter"><code>offset
</code></em></span></dt><dd><p>
13 Specifies the offset from the specified texture coordinate
<em class=
"parameter"><code>P
</code></em> from which the texels will be gathered.
14 </p></dd></dl></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"description"></a><h2>Description
</h2><p>
15 <code class=
"function">textureGatherOffset
</code> returns the value:
17 </p><pre class=
"programlisting"> vec4(Sample_i0_j1(P + offset, base).comp,
18 Sample_i1_j1(P + offset, base).comp,
19 Sample_i1_j0(P + offset, base).comp,
20 Sample_i0_j9(P + offset, base).comp);
</pre><p>
22 It perfoms as
<a href=
"textureGather.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureGather
</span></span></a> but with
<em class=
"parameter"><code>offset
</code></em>
23 applied as described in
<a href=
"textureOffset.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureOffset
</span></span></a>, except that the
24 implementation-dependent minimum and maximum offset values are given by
<code class=
"constant">GL_MIN_PROGRRAM_TEXTURE_GATHER_OFFSET
</code>
25 and
<code class=
"constant">GL_MAX_PROGRAM_TEXTURE_GATHER_OFFSET
</code>, respectively.
27 If specified, the value of
<em class=
"parameter"><code>comp
</code></em> must ba constant integer expression with a value
28 of
0,
1,
2, or
3, identifying the x, y, z or w component of the four-component vector lookup result for each
29 texel, respectively. If
<em class=
"parameter"><code>comp
</code></em> is not specified, it is treated as
0, selecting the x
30 component of each texel to generate the result.
31 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"versions"></a><h2>Version Support
</h2><div class=
"informaltable"><table border=
"1"><colgroup><col align=
"left" /><col align=
"center" /><col align=
"center" /><col align=
"center" /><col align=
"center" /><col align=
"center" /><col align=
"center" /><col align=
"center" /><col align=
"center" /><col align=
"center" /><col align=
"center" /></colgroup><thead><tr><th align=
"left"><span class=
"bold"><strong>Function
</strong></span></th><th align=
"left"><span class=
"bold"><strong>Version
1.10</strong></span></th><th align=
"left"><span class=
"bold"><strong>Version
1.20</strong></span></th><th align=
"left"><span class=
"bold"><strong>Version
1.30</strong></span></th><th align=
"left"><span class=
"bold"><strong>Version
1.40</strong></span></th><th align=
"left"><span class=
"bold"><strong>Version
1.50</strong></span></th><th align=
"left"><span class=
"bold"><strong>Version
3.30</strong></span></th><th align=
"left"><span class=
"bold"><strong>Version
4.00</strong></span></th><th align=
"left"><span class=
"bold"><strong>Version
4.10</strong></span></th><th align=
"left"><span class=
"bold"><strong>Version
4.20</strong></span></th><th align=
"center"><span class=
"bold"><strong>Version
4.30</strong></span></th></tr><tr><th align=
"left">textureGatherOffset
</th><th align=
"center"><span class=
"emphasis"><em>-
</em></span></th><th align=
"center"><span class=
"emphasis"><em>-
</em></span></th><th align=
"center"><span class=
"emphasis"><em>-
</em></span></th><th align=
"center"><span class=
"emphasis"><em>-
</em></span></th><th align=
"center"><span class=
"emphasis"><em>-
</em></span></th><th align=
"center"><span class=
"emphasis"><em>-
</em></span></th><th align=
"center"><span class=
"emphasis"><em>Y
</em></span></th><th align=
"center"><span class=
"emphasis"><em>Y
</em></span></th><th align=
"center"><span class=
"emphasis"><em>Y
</em></span></th><th align=
"center"><span class=
"emphasis"><em>Y
</em></span></th></tr></thead></table></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"seealso"></a><h2>See Also
</h2><p>
32 <a href=
"texelFetch.xml"><span class=
"citerefentry"><span class=
"refentrytitle">texelFetch
</span></span></a>,
33 <a href=
"texelFetchOffset.xml"><span class=
"citerefentry"><span class=
"refentrytitle">texelFetchOffset
</span></span></a>,
34 <a href=
"texture.xml"><span class=
"citerefentry"><span class=
"refentrytitle">texture
</span></span></a>,
35 <a href=
"textureGather.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureGather
</span></span></a>,
36 <a href=
"textureGatherOffsets.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureGatherOffsets
</span></span></a>,
37 <a href=
"textureGrad.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureGrad
</span></span></a>,
38 <a href=
"textureGradOffset.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureGradOffset
</span></span></a>,
39 <a href=
"textureLod.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureLod
</span></span></a>,
40 <a href=
"textureLodOffset.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureLodOffset
</span></span></a>,
41 <a href=
"textureOffset.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureOffset
</span></span></a>,
42 <a href=
"textureProj.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureProj
</span></span></a>,
43 <a href=
"textureProjGrad.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureProjGrad
</span></span></a>,
44 <a href=
"textureProjGradOffset.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureProjGradOffset
</span></span></a>,
45 <a href=
"textureProjLod.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureProjLod
</span></span></a>,
46 <a href=
"textureProjLodOffset.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureProjLodOffset
</span></span></a>,
47 <a href=
"textureProjOffset.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureProjOffset
</span></span></a>,
48 <a href=
"textureQueryLod.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureQueryLod
</span></span></a>,
49 <a href=
"textureSize.xml"><span class=
"citerefentry"><span class=
"refentrytitle">textureSize
</span></span></a>
50 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"Copyright"></a><h2>Copyright
</h2><p>
51 Copyright
<span class=
"trademark"></span>©
2011 Khronos Group.
52 This material may be distributed subject to the terms and conditions set forth in
53 the Open Publication License, v
1.0,
8 June
1999.
54 <a href=
"http://opencontent.org/openpub/" target=
"_top">http://opencontent.org/openpub/
</a>.
55 </p></div></div></body></html>