'\" t .\" Title: gl_SampleMask .\" 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_SAMPLEMASK" "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_SampleMask \- specifies the sample coverage mask for the current fragment .SH "DECLARATION" out\ \&int\ \&gl_SampleMask[]\ \&;.SH "DESCRIPTION" .PP \fIgl_SampleMask\fR is a fragment language output array that may be used to set the sample mask for the fragment being processed\&. Coverage for the current fragment will become the logical AND of the coverage mask and the output \fIgl_SampleMask\fR\&. That is, setting a bit in \fIgl_SampleMask\fR to zero will cause the corresponding sample to be considered uncovered for the purposes of multisample fragment operations\&. However, setting sample mask bits back to one will never enable samples not covered by the original primitive\&. Bit \fIB\fR of mask \fIgl_SampleMask[M]\fR corresponds to sample 32 * \fIM\fR + \fIB\fR\&. This array must be sized in the fragment shader either implicitly or explicitly to be the same size as the implementation\-dependent maximum sample\-mask (as an array of 32\-bit elements), determined by the maximum number of samples\&. If the fragment shader statically assigns a value to \fIgl_SampleMask\fR, the sample mask will be undefined for any array elements of any fragment shader invocation that fails to assign a value\&. If a shader does not statically assign a value to \fIgl_SampleMask\fR, the sample mask has no effect on the processing of a fragment\&. If the fragment shader is being evaluated at any frequency other than per\-fragment, bits within the sample mask not corresponding to the current fragment shader invocation are ignored\&. .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{ \fBVariable 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_SampleMask 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_SampleMaskIn\fR(), \fBgl_SampleID\fR(), \fBgl_SamplePosition\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