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:
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 Standard The definition of 'CanvasRenderingContext2D.getTransform' in that specification. |
Living Standard |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
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
See also
- The interface defining this method:
CanvasRenderingContext2D
CanvasRenderingContext2D.transform()