OES_draw_buffers_indexed: colorMaskiOES() method

Baseline 2022

Newly available

Since December 2022, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The colorMaskiOES() method of the OES_draw_buffers_indexed WebGL extension sets which color components to enable or to disable when drawing or rendering for a particular draw buffer. It's the indexed version of WebGL 1's WebGLRenderingContext.colorMask() method.

Syntax

js
colorMaskiOES(buf, r, g, b, a)

Parameters

buf

An integer i specifying the draw buffer associated with the constant gl.DRAW_BUFFERi, see WebGL draw buffer constants.

r

A GLboolean specifying whether or not the red color component should be written into the draw buffer.

g

A GLboolean specifying whether or not the green color component should be written into the draw buffer.

b

A GLboolean specifying whether or not the blue color component should be written into the draw buffer.

a

A GLboolean specifying whether or not the red alpha (transparency) component should be written into the draw buffer.

Return value

None (undefined).

Exceptions

  • If buf, r, b, g, or a are not a valid values, a gl.INVALID_VALUE error is thrown.

Examples

Setting and getting color masks

You can set the color masks for the gl.DRAW_BUFFER0 and gl.DRAW_BUFFER1 draw buffers like this:

js
const ext = gl.getExtension("OES_draw_buffers_indexed");

ext.colorMaskiOES(0, 1, 0, 0, 0);
ext.colorMaskiOES(1, 0, 1, 0, 0);

To get the color masks for the gl.DRAW_BUFFER0 and gl.DRAW_BUFFER1 draw buffers, query the COLOR_WRITEMASK constant using WebGL2RenderingContext.getIndexedParameter():

js
gl.getIndexedParameter(gl.COLOR_WRITEMASK, 0);
gl.getIndexedParameter(gl.COLOR_WRITEMASK, 1);

Specifications

Specification
WebGL OES_draw_buffers_indexed Extension Specification

Browser compatibility

BCD tables only load in the browser

See also