Web/API/WEBGL draw buffers/drawBuffersWEBGL

The WEBGL_draw_buffers.drawBuffersWEBGL() method is part of the WebGL API and allows you to define the draw buffers to which all fragment colors are written.

This method is part of the WEBGL_draw_buffers extension.

Note: When using WebGL2, this method is available as gl.drawBuffers() by default and the constants are named gl.COLOR_ATTACHMENT1 etc. without the "WEBGL" suffix.

Syntax

void gl.getExtension('WEBGL_draw_buffers').drawBuffersWEBGL(buffers);

Parameters

buffers: An Array of GLenum constants defining drawing buffers. Possible values:

gl.NONE

The fragment shader is not written to any color buffer.
gl.BACK: The fragment shader is written to the back color buffer.
ext.COLOR_ATTACHMENT0_WEBGL The fragment shader is written the the nth color attachment of the framebuffer.
ext.COLOR_ATTACHMENT1_WEBGL
ext.COLOR_ATTACHMENT2_WEBGL
ext.COLOR_ATTACHMENT3_WEBGL
ext.COLOR_ATTACHMENT4_WEBGL
ext.COLOR_ATTACHMENT5_WEBGL
ext.COLOR_ATTACHMENT6_WEBGL
ext.COLOR_ATTACHMENT7_WEBGL
ext.COLOR_ATTACHMENT8_WEBGL
ext.COLOR_ATTACHMENT9_WEBGL
ext.COLOR_ATTACHMENT10_WEBGL
ext.COLOR_ATTACHMENT11_WEBGL
ext.COLOR_ATTACHMENT12_WEBGL
ext.COLOR_ATTACHMENT13_WEBGL
ext.COLOR_ATTACHMENT14_WEBGL
ext.COLOR_ATTACHMENT15_WEBGL

Return value

None.

Examples

See WEBGL_draw_buffers for more context with this example code.

ext.drawBuffersWEBGL([
  ext.COLOR_ATTACHMENT0_WEBGL, // gl_FragData[0]
  ext.COLOR_ATTACHMENT1_WEBGL, // gl_FragData[1]
  ext.COLOR_ATTACHMENT2_WEBGL, // gl_FragData[2]
  ext.COLOR_ATTACHMENT3_WEBGL  // gl_FragData[3]
]);

Specifications

Specification	Status	Comment
WEBGL_draw_buffersThe definition of 'WEBGL_draw_buffers' in that specification.	Recommendation	Initial definition.
OpenGL ES 3.0The definition of 'glDrawBuffers' in that specification.	Standard	Man page of the (similar) OpenGL API.

Browser compatibility

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`drawBuffersWEBGL`	Chrome Full support Yes	Edge Full support 17	Firefox No support ? — 28 Prefixed' Disabled' No support ? — 28 Prefixed' Disabled' Prefixed' Implemented with the vendor prefix: MOZ_ Disabled' Until version 28 (exclusive): this feature is behind the `webgl.enable-draft-extensions` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config. Full support 28	IE ?	Opera Full support Yes	Safari ?	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android ?	Opera Android Full support Yes	Safari iOS ?	Samsung Internet Android Full support Yes

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown
User must explicitly enable this feature.': User must explicitly enable this feature.
Requires a vendor prefix or different name for use.': Requires a vendor prefix or different name for use.