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: [ a c e b d f 0 0 1 ] \left[ \begin{array}{ccc} a & c & e \ b & d & f \ 0 & 0 & 1 \end{array} \right]

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

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
getTransform
68
79
70
No
55
11
68
68
No
48
11
10.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/getTransform