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

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.

None (undefined).

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

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