WebGLRenderingContext.sampleCoverage

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

Syntax

void gl.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.

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.

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.

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

Specifications

Specification	Status	Comment
WebGL 1.0 The definition of 'sampleCoverage' in that specification.	Recommendation	Initial definition.
OpenGL ES 2.0 The definition of 'glSampleCoverage' in that specification.	Standard	Man page of the OpenGL API.

Browser compatibility

See also

• HTMLCanvasElement.getContext() – antialias parameter for the context.