HTMLCanvasElement: transferControlToOffscreen() method

The HTMLCanvasElement.transferControlToOffscreen() method transfers control to an OffscreenCanvas object, either on the main thread or on a worker.

Syntax

transferControlToOffscreen()

Parameters

None.

Return value

An OffscreenCanvas object.

Exceptions

InvalidStateError DOMException

Throws if:

the canvas has been set a context mode by calling HTMLCanvasElement.getContext()
the canvas has already transferred its control to offscreen.

Examples

The following example shows how to transfer control to an OffscreenCanvas object on the main thread.

const htmlCanvas = document.createElement("canvas");
const offscreen = htmlCanvas.transferControlToOffscreen();
const gl = offscreen.getContext("webgl");

// Some drawing using the gl context…

The following example shows how to transfer control to an OffscreenCanvas object on a worker.

const offscreen = document.querySelector("canvas").transferControlToOffscreen();
const worker = new Worker("my-worker-url.js");
worker.postMessage({ canvas: offscreen }, [offscreen]);

Specifications

HTML