Web/API/CanvasRenderingContext2D/getTransform

The CanvasRenderingContext2D.getTransform() method of the Canvas 2D API retrieves the current transformation matrix being applied to the context.

Syntax

let storedTransform = ctx.getTransform();

Parameters

None.

Return value

A DOMMatrix object.

The transformation matrix is described by: <math display="inline">\begin{bmatrix} a & c & e \\ b & d & f \\ 0 & 0 & 1 \\ \end{bmatrix}</math>

Note: The returned object is not live, so updating it will not affect the current transformation matrix, and updating the current transformation matrix will not affect an already returned DOMMatrix.

Examples

In the following example, we have two <canvas> elements. We apply a transform to the first one's context using CanvasRenderingContext2D.setTransform() and draw a square on it, then retrieve the matrix from it using getTransform().

We then apply the retrieved matrix directly to the second canvas context by passing the DOMMatrix object directly to setTransform(), and draw a circle on it.

HTML

<canvas width="240"></canvas>
<canvas width="240"></canvas>

CSS

canvas {
  border: 1px solid black;
}

JavaScript

const canvases = document.querySelectorAll('canvas');
const ctx1 = canvases[0].getContext('2d');
const ctx2 = canvases[1].getContext('2d');

ctx1.setTransform(1, .2, .8, 1, 0, 0);
ctx1.fillRect(25, 25, 50, 50);

let storedTransform = ctx1.getTransform();
console.log(storedTransform);

ctx2.setTransform(storedTransform);
ctx2.beginPath();
ctx2.arc(50, 50, 50, 0, 2 * Math.PI);
ctx2.fill();

Result

Specifications

Specification	Status	Comment
HTML Living StandardThe definition of 'CanvasRenderingContext2D.getTransform' in that specification.	Living Standard

Browser compatibility

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
`getTransform`	Chrome Full support 68	Edge Full support 79	Firefox Full support 70	IE No support No	Opera Full support 55	Safari Full support 11	WebView Android Full support 68	Chrome Android Full support 68	Firefox Android No support No	Opera Android Full support 48	Safari iOS Full support 11	Samsung Internet Android Full support 10.0

Legend

Full support: Full support
No support: No support