WebGLRenderingContext: sampleCoverage() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The WebGLRenderingContext.sampleCoverage() method of the WebGL API specifies multi-sample coverage parameters for anti-aliasing effects.

Syntax

js
sampleCoverage(value, invert)

Parameters

value

A GLclampf which sets a single floating-point coverage value clamped to the range [0,1]. The default value is 1.0.

invert

A GLboolean which sets whether or not the coverage masks should be inverted. The default value is false.

Return value

None (undefined).

Examples

Multi-sampling is disabled by default. To enable or disable multi-sampling, use the enable() and disable() methods with the argument gl.SAMPLE_COVERAGE and gl.SAMPLE_ALPHA_TO_COVERAGE.

js
gl.enable(gl.SAMPLE_COVERAGE);
gl.sampleCoverage(0.5, false);

To check the sample coverage values, query the SAMPLE_COVERAGE_VALUE and SAMPLE_COVERAGE_INVERT constants.

js
gl.getParameter(gl.SAMPLE_COVERAGE_VALUE); // 0.5
gl.getParameter(gl.SAMPLE_COVERAGE_INVERT); // false

Specifications

Specification
WebGL Specification
# 5.14.3

Browser compatibility

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See also