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.\"     Title: gl_SampleID
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
.\"      Date: 05/21/2015
.\"    Manual: [FIXME: manual]
.\"    Source: [FIXME: source]
.\"  Language: English
.\"
.TH "GL_SAMPLEID" "3G" "05/21/2015" "[FIXME: source]" "[FIXME: manual]"
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.SH "NAME"
gl_SampleID \- contains the index of the sample currently being processed
.SH "DECLARATION"
in\ \&int\ \&gl_SampleID\ \&;.SH "DESCRIPTION"
.PP
\fIgl_SampleID\fR
is a fragment language input variable that contains the index of the sample currently being processed\&. This variable is in the range 0 to
\fBgl_NumSamples\fR()
\- 1, where
\fBgl_NumSamples\fR()
is the total number of samples in each fragment for the current framebuffer (and thus 1 if rendering to a non\-multisample buffer)\&. Any static use of this variable in a fragment shader causes the entire shader to be evaluated per\-sample rather than per\-fragment\&.
.PP
When rendering to a non\-multisample buffer, or if multisample rasterization is disabled,
\fIgl_SampleID\fR
will always be zero\&.
\fBgl_NumSamples\fR()
is the sample count of the framebuffer regardless of whether multisample rasterization is enabled or not\&.
.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}
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\fBVariable Name\fR
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\fB1\&.10\fR
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\fB4\&.40\fR
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\fB4\&.50\fR
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.T&
l c c c c c c c c c c c c.
T{
gl_SampleID
T}:T{
\-
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\-
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\-
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\-
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\-
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\-
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✔
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✔
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✔
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✔
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✔
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✔
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.TE
.sp
.SH "SEE ALSO"
.PP
\fBgl_SamplePosition\fR(),
\fBgl_NumSamples\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