NAME

       gl_SampleMask - specifies the sample coverage mask for the current fragment

DECLARATION

       out int gl_SampleMask[] ;.SH "DESCRIPTION"

       gl_SampleMask 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 gl_SampleMask. That is, setting a bit in gl_SampleMask 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 B of mask gl_SampleMask[M] corresponds to sample 32 * M + B. 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 gl_SampleMask, 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 gl_SampleMask, 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.

VERSION SUPPORT

       ┌──────────────┬───────────────────────────────────────────────────────────────────────────────────┐
       │              │        OpenGL Shading Language Version                                            │
       ├──────────────┼──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────┤
       │Variable      │ 1.10 │ 1.20 │ 1.30 │ 1.40 │ 1.50 │ 3.30 │ 4.00 │ 4.10 │ 4.20 │ 4.30 │ 4.40 │ 4.50 │
       │Name          │      │      │      │      │      │      │      │      │      │      │      │      │
       ├──────────────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────┤
       │gl_SampleMask │  -   │  -   │  -   │  -   │  -   │  -   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │  ✔   │
       └──────────────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────┘

SEE ALSO

       gl_SampleMaskIn(), gl_SampleID(), gl_SamplePosition(), gl_FragCoord()

COPYRIGHT

       Copyright © 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.  http://opencontent.org/openpub/.

COPYRIGHT

       Copyright © 2011-2014 Khronos Group

[FIXME: source]                                    01/03/2018                                  GL_SAMPLEMASK(3G)