WebGLRenderingContext: polygonOffset() 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.

See full compatibility

Note: This feature is available in Web Workers.

The WebGLRenderingContext.polygonOffset() method of the WebGL API specifies the scale factors and units to calculate depth values.

The offset is added before the depth test is performed and before the value is written into the depth buffer.

Syntax

polygonOffset(factor, units)

Parameters

factor: A GLfloat which sets the scale factor for the variable depth offset for each polygon. The default value is 0.
units: A GLfloat which sets the multiplier by which an implementation-specific value is multiplied with to create a constant depth offset. The default value is 0.

Return value

None (undefined).

Examples

The polygon offset fill is disabled by default. To enable or disable polygon offset fill, use the enable() and disable() methods with the argument gl.POLYGON_OFFSET_FILL.

gl.enable(gl.POLYGON_OFFSET_FILL);
gl.polygonOffset(2, 3);

To check the current polygon offset factor or units, query the POLYGON_OFFSET_FACTOR and POLYGON_OFFSET_UNITS constants.

gl.getParameter(gl.POLYGON_OFFSET_FACTOR); // 2
gl.getParameter(gl.POLYGON_OFFSET_UNITS); // 3

Specifications

Specification
WebGL Specification # 5.14.3

Browser compatibility

	desktop					mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS
`polygonOffset`	Chrome – Full support Chrome 9 (Release date: 2011-02-03) footnote Full support	Edge – Full support Edge 12 (Release date: 2015-07-29) footnote Full support	Firefox – Full support Firefox 4 (Release date: 2011-03-22) footnote Full support	Opera – Full support Opera 12 (Release date: 2012-06-14) footnote Full support	Safari – Full support Safari 5.1 (Release date: 2011-07-20) footnote Full support	Chrome Android – Full support Chrome Android 25 (Release date: 2013-02-27) footnote Full support	Firefox for Android – Full support Firefox for Android 4 (Release date: 2011-03-29) footnote Full support	Opera Android – Full support Opera Android 12 (Release date: 2012-02-25) footnote Full support	Safari on iOS – Full support Safari on iOS 8 (Release date: 2014-09-17) footnote Full support	Samsung Internet – Full support Samsung Internet 1.5 (Release date: 2013-09-25) footnote Full support	WebView Android – Full support WebView Android 4.4.3 (Release date: 2014-06-02) footnote Full support	WebView on iOS – Full support WebView on iOS 8 (Release date: 2014-09-17) footnote Full support

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Full support: Full support