'\" t .\" Title: gl_SamplePosition .\" Author: [FIXME: author] [see http://docbook.sf.net/el/author] .\" Generator: DocBook XSL Stylesheets v1.79.1 .\" Date: 01/03/2018 .\" Manual: [FIXME: manual] .\" Source: [FIXME: source] .\" Language: English .\" .TH "GL_SAMPLEPOSITION" "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" gl_SamplePosition \- contains the location of the current sample within the current fragment .SH "DECLARATION" in\ \&vec2\ \&gl_SamplePosition\ \&;.SH "DESCRIPTION" .PP \fIgl_SamplePosition\fR is a fragment language input variable that contains the location within a fragment of the sample currently being processed\&. The x and y components of \fIgl_SamplePosition\fR contain the sub\-pixel coordinate of the current sample and will have values in the range 0\&.0 to 1\&.0\&. The sub\-pixel coordinates of the center of the pixel are always (0\&.5, 0\&.5)\&. Any static use of \fIgl_SamplePosition\fR causes the entire fragment shader to be evaluated per\-sample rather than per\-fragment\&. When rendering to a non\-multisample buffer, or if multisample rasterization is disabled, \fIgl_SamplePosition\fR will be (0\&.5, 0\&.5)\&. .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{ gl_SamplePosition 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 \fBgl_SampleID\fR(), \fBgl_SampleMask\fR(), \fBgl_FragCoord\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