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WebGLRenderingContext.polygonOffset

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

void gl.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.

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

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
Basic support 9 12 4 11 12 5.1
Mobile
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support Yes 25 Yes Yes 12 8.1 Yes

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/polygonOffset