WebGLRenderingContext.sampleCoverage()

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

Syntax

JavaScript
void <var>gl</var>.sampleCoverage(<var>value</var>, <var>invert</var>);

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
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.

JavaScript
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.

JavaScript
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

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support 9 12 4.0 (2.0) 11 12 5.1
Feature Android Chrome for Android Edge Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile
Basic support ? 25 (Yes) 4.0 (2.0) 1.0 ? 12 8.0

See also

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/webglrenderingcontext/samplecoverage

API Method Reference WebGL WebGLRenderingContext