GL_SAMPLEID

Section: [FIXME: manual] (3G)
Updated: 01/26/2021
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NAME

gl_SampleID - contains the index of the sample currently being processed  

DECLARATION

in int gl_SampleID ;.SH "DESCRIPTION"

gl_SampleID is a fragment language input variable that contains the index of the sample currently being processed. This variable is in the range 0 to gl_NumSamples() - 1, where gl_NumSamples() 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.

When rendering to a non-multisample buffer, or if multisample rasterization is disabled, gl_SampleID will always be zero. gl_NumSamples() is the sample count of the framebuffer regardless of whether multisample rasterization is enabled or not.  

VERSION SUPPORT

OpenGL Shading Language Version
Variable Name 1.10 1.20 1.30 1.40 1.50 3.30 4.00 4.10 4.20 4.30 4.40 4.50
gl_SampleID - - - - - -

 

SEE ALSO

gl_SamplePosition(), gl_NumSamples()  

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. m[blue]http://opencontent.org/openpub/m[].  

COPYRIGHT


Copyright © 2011-2014 Khronos Group


 

Index

NAME
DECLARATION
VERSION SUPPORT
SEE ALSO
COPYRIGHT
COPYRIGHT