NAME

       glSampleCoverage - specify multisample coverage parameters

C SPECIFICATION

       void glSampleCoverage(GLfloat 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.

NOTES

       The type of the value parameter was changed from GLclampf to GLfloat. This change is
       transparent to user code and is described in detail on the removedTypes() page.

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(), removedTypes()

COPYRIGHT

       Copyright © 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/.

AUTHORS

       opengl.org