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]                             07/22/2015                          GL_SAMPLEMASK(3G)