WebGLRenderingContext: sampleCoverage() method

{{APIRef("WebGL")}}{{AvailableInWorkers}}

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

Syntax

sampleCoverage(value, invert)

Parameters

• value
  • : A {{domxref("WebGL_API/Types", "GLclampf")}} which sets a single floating-point coverage value clamped to the range [0,1]. The default value is 1.0.
• invert
  • : A {{domxref("WebGL_API/Types", "GLboolean")}} which sets whether or not the coverage masks should be inverted. The default value is false.

Return value

None ({{jsxref("undefined")}}).

Examples

Multi-sampling is disabled by default. To enable or disable multi-sampling, use the {{domxref("WebGLRenderingContext.enable", "enable()")}} and {{domxref("WebGLRenderingContext.disable", "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

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("HTMLCanvasElement.getContext()")}} – antialias parameter for the context.