CanvasRenderingContext2D.transform()
The CanvasRenderingContext2D
.transform()
method of the Canvas 2D API multiplies the current transformation with the matrix described by the arguments of this method. You are able to scale, rotate, move and skew the context.
See also the setTransform()
method which resets the current transform to the identity matrix and then invokes transform()
.
Syntax
JavaScript
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void <var>ctx.transform(a, b, c, d, e, f);</var>
The transformation matrix is described by:
Parameters
-
a (m11)
- Horizontal scaling.
-
b (m12)
- Horizontal skewing.
-
c (m21)
- Vertical skewing.
-
d (m22)
- Vertical scaling.
-
e (dx)
- Horizontal moving.
-
f (dy)
- Vertical moving.
Examples
Using the transform
method
This is just a simple code snippet which uses the transform
method.
HTML
HTML
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<canvas id="canvas"></canvas>
JavaScript
JavaScript
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var canvas = document.getElementById("canvas"); var ctx = canvas.getContext("2d"); ctx.transform(1,1,0,1,0,0); ctx.fillRect(0,0,100,100);
Edit the code below and see your changes update live in the canvas:
Playable code
HTML
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<canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas> <div class="playable-buttons"> <input id="edit" type="button" value="Edit" /> <input id="reset" type="button" value="Reset" /> </div> <textarea id="code" class="playable-code"> ctx.transform(1,1,0,1,0,0); ctx.fillRect(0,0,100,100);</textarea>
JavaScript
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var canvas = document.getElementById("canvas"); var ctx = canvas.getContext("2d"); var textarea = document.getElementById("code"); var reset = document.getElementById("reset"); var edit = document.getElementById("edit"); var code = textarea.value; function drawCanvas() { ctx.clearRect(0, 0, canvas.width, canvas.height); eval(textarea.value); } reset.addEventListener("click", function() { textarea.value = code; ctx.setTransform(1, 0, 0, 1, 0, 0); drawCanvas(); }); edit.addEventListener("click", function() { textarea.focus(); }) textarea.addEventListener("input", drawCanvas); window.addEventListener("load", drawCanvas);
Specifications
Specification | Status | Comment |
---|---|---|
WHATWG HTML Living Standard The definition of 'CanvasRenderingContext2D.transform' in that specification. |
Living Standard |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
See also
- The interface defining it,
CanvasRenderingContext2D
CanvasRenderingContext2D.setTransform()
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/canvasrenderingcontext2d/transform