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ext.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_buffers The definition of 'WEBGL_draw_buffers' in that specification.	Recommendation	Initial definition.
OpenGL ES 3.0 The definition of 'glDrawBuffers' in that specification.	Standard	Man page of the (similar) OpenGL API.

Browser compatibility

Feature	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic support	?	No	Yes — 28 MOZ_ ¹ 28	?	?	?

Feature

Chrome

Edge

Firefox

Internet Explorer

Opera

Safari

Basic support

Yes — 28 MOZ_ ¹

Feature	Android webview	Chrome for Android	Edge mobile	Firefox for Android	IE mobile	Opera Android	iOS Safari
Basic support	?	?	No	?	?	?	?

1. 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.