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GLSAMPLECOVERAGE(3G)                             OpenGL 3.3                             GLSAMPLECOVERAGE(3G)



NAME
       glSampleCoverage - specify multisample coverage parameters

C SPECIFICATION
       void glSampleCoverage(GLclampf value, GLboolean invert);

PARAMETERS
       value
           Specify a single floating-point sample coverage value. The value is clamped to the range 0 1. The
           initial value is 1.0.

       invert
           Specify a single boolean value representing if the coverage masks should be inverted.  GL_TRUE
           and GL_FALSE are accepted. The initial value is GL_FALSE.

DESCRIPTION
       Multisampling samples a pixel multiple times at various implementation-dependent subpixel locations
       to generate antialiasing effects. Multisampling transparently antialiases points, lines, polygons,
       and images if it is enabled.


       value is used in constructing a temporary mask used in determining which samples will be used in
       resolving the final fragment color. This mask is bitwise-anded with the coverage mask generated from
       the multisampling computation. If the invert flag is set, the temporary mask is inverted (all bits
       flipped) and then the bitwise-and is computed.

       If an implementation does not have any multisample buffers available, or multisampling is disabled,
       rasterization occurs with only a single sample computing a pixel's final RGB color.

       Provided an implementation supports multisample buffers, and multisampling is enabled, then a pixel's
       final color is generated by combining several samples per pixel. Each sample contains color, depth,
       and stencil information, allowing those operations to be performed on each sample.

ASSOCIATED GETS
       glGet() with argument GL_SAMPLE_COVERAGE_VALUE


       glGet() with argument GL_SAMPLE_COVERAGE_INVERT


       glIsEnabled() with argument GL_MULTISAMPLE


       glIsEnabled() with argument GL_SAMPLE_ALPHA_TO_COVERAGE


       glIsEnabled() with argument GL_SAMPLE_ALPHA_TO_ONE


       glIsEnabled() with argument GL_SAMPLE_COVERAGE

SEE ALSO
       glEnable()


COPYRIGHT
       Copyright (C) 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software
       B License. For details, see http://oss.sgi.com/projects/FreeB/.



OpenGL 3.3                                       03/08/2011                             GLSAMPLECOVERAGE(3G)