OES_draw_buffers_indexed: enableiOES() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since December 2022.

The enableiOES() method of the OES_draw_buffers_indexed WebGL extension enables blending for a particular draw buffer.

Syntax

js
enableiOES(target, index)

Parameters

target

Must be gl.BLEND.

index

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

Return value

None (undefined).

Exceptions

  • If target is not gl.BLEND, a gl.INVALID_ENUM error is thrown.
  • If index is not a valid value, a gl.INVALID_VALUE error is thrown.

Examples

Enabling blending for draw buffers

The following two calls enable blending for the draw buffers gl.DRAW_BUFFER0 and gl.DRAW_BUFFER1.

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

ext.enableiOES(gl.BLEND, 0);
ext.enableiOES(gl.BLEND, 1);

You can use WebGLRenderingContext.getParameter() to see how many draw buffers are available.

js
const maxDrawBuffers = gl.getParameter(gl.MAX_DRAW_BUFFERS);

Specifications

Specification
WebGL OES_draw_buffers_indexed Extension Specification

Browser compatibility

See also