'\" t
.\"     Title: textureGather
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 01/03/2018
.\"    Manual: [FIXME: manual]
.\"    Source: [FIXME: source]
.\"  Language: English
.\"
.TH "TEXTUREGATHER" "3G" "01/03/2018" "[FIXME: source]" "[FIXME: manual]"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
textureGather \- gathers four texels from a texture
.SH "DECLARATION"
.HP \w'gvec4\ textureGather('u
.BI "gvec4 textureGather(gsampler2D\ " "sampler" ", vec2\ " "P" ", [int\ " "comp]" ");"
.HP \w'gvec4\ textureGather('u
.BI "gvec4 textureGather(gsampler2DArray\ " "sampler" ", vec3\ " "P" ", [int\ " "comp]" ");"
.HP \w'gvec4\ textureGather('u
.BI "gvec4 textureGather(gsamplerCube\ " "sampler" ", vec3\ " "P" ", [int\ " "comp]" ");"
.HP \w'gvec4\ textureGather('u
.BI "gvec4 textureGather(gsamplerCubeArray\ " "sampler" ", vec4\ " "P" ", [int\ " "comp]" ");"
.HP \w'gvec4\ textureGather('u
.BI "gvec4 textureGather(gsampler2DRect\ " "sampler" ", vec3\ " "P" ", [int\ " "comp]" ");"
.HP \w'vec4\ textureGather('u
.BI "vec4 textureGather(gsampler2DShadow\ " "sampler" ", vec2\ " "P" ", float\ " "refZ" ");"
.HP \w'vec4\ textureGather('u
.BI "vec4 textureGather(gsampler2DArrayShadow\ " "sampler" ", vec3\ " "P" ", float\ " "refZ" ");"
.HP \w'vec4\ textureGather('u
.BI "vec4 textureGather(gsamplerCubeShadow\ " "sampler" ", vec3\ " "P" ", float\ " "refZ" ");"
.HP \w'vec4\ textureGather('u
.BI "vec4 textureGather(gsamplerCubeArrayShadow\ " "sampler" ", vec4\ " "P" ", float\ " "refZ" ");"
.HP \w'vec4\ textureGather('u
.BI "vec4 textureGather(gsampler2DRectShadow\ " "sampler" ", vec3\ " "P" ", float\ " "refZ" ");"
.SH "PARAMETERS"
.PP
\fIsampler\fR
.RS 4
Specifies the sampler to which the texture from which texels will be retrieved is bound\&.
.RE
.PP
\fIP\fR
.RS 4
Specifies the texture coordinates at which texture will be sampled\&.
.RE
.PP
\fIcomp\fR
.RS 4
Specifies the component of the source texture that will be used to generate the resulting vector\&.
.RE
.PP
\fIrefZ\fR
.RS 4
Specifies the reference Z value used in the comparison for shadow forms\&.
.RE
.SH "DESCRIPTION"
.PP
\fBtextureGather\fR
returns the value:
.PP
.if n \{\
.RS 4
.\}
.nf
    vec4(Sample_i0_j1(P, base)\&.comp,
         Sample_i1_j1(P, base)\&.comp,
         Sample_i1_j0(P, base)\&.comp,
         Sample_i0_j1(P, base)\&.comp);
.fi
.if n \{\
.RE
.\}
.PP
If specified, the value of
\fIcomp\fR
must ba constant integer expression with a value of 0, 1, 2, or 3, identifying the x, y, z or w component of the four\-component vector lookup result for each texel, respectively\&. If
\fIcomp\fR
is not specified, it is treated as 0, selecting the x component of each texel to generate the result\&.
.SH "VERSION SUPPORT"
.TS
allbox tab(:);
lB cB s s s s s s s s s s s
lB cB cB cB cB cB cB cB cB cB cB cB cB.
T{

T}:T{
\fBOpenGL Shading Language Version\fR
T}
T{
\fBFunction Name\fR
T}:T{
\fB1\&.10\fR
T}:T{
\fB1\&.20\fR
T}:T{
\fB1\&.30\fR
T}:T{
\fB1\&.40\fR
T}:T{
\fB1\&.50\fR
T}:T{
\fB3\&.30\fR
T}:T{
\fB4\&.00\fR
T}:T{
\fB4\&.10\fR
T}:T{
\fB4\&.20\fR
T}:T{
\fB4\&.30\fR
T}:T{
\fB4\&.40\fR
T}:T{
\fB4\&.50\fR
T}
.T&
l c c c c c c c c c c c c.
T{
textureGather
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
\-
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}:T{
✔
T}
.TE
.sp 1
.SH "SEE ALSO"
.PP
\fBtexelFetch\fR(),
\fBtexelFetchOffset\fR(),
\fBtexture\fR(),
\fBtextureGatherOffset\fR(),
\fBtextureGatherOffsets\fR(),
\fBtextureGrad\fR(),
\fBtextureGradOffset\fR(),
\fBtextureLod\fR(),
\fBtextureLodOffset\fR(),
\fBtextureOffset\fR(),
\fBtextureProj\fR(),
\fBtextureProjGrad\fR(),
\fBtextureProjGradOffset\fR(),
\fBtextureProjLod\fR(),
\fBtextureProjLodOffset\fR(),
\fBtextureProjOffset\fR(),
\fBtextureQueryLod\fR(),
\fBtextureSize\fR()
.SH "COPYRIGHT"
.PP
Copyright
\(co
2011\-2014 Khronos Group\&. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1\&.0, 8 June 1999\&.
\m[blue]\fBhttp://opencontent\&.org/openpub/\fR\m[]\&.
.SH "COPYRIGHT"
.br
Copyright \(co 2011-2014 Khronos Group
.br