# glSampleCoverage

## 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, and polygons 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_SAMPLE_ALPHA_TO_COVERAGE

glIsEnabled with argument GL_SAMPLE_COVERAGE