JavaScript canvas2d object method: scale()
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The scale() method of the JavaScript
DOM object
returned by the getContext("2d")
method applied to the HTML <canvas>
element scales the current drawing. It also scales future drawings and the
positioning is also scaled. The parameters are scaling factors, so 1 means stay
at 100% of previous size, 0.5 means adjust to 50% of previous size etc.
It has the following
syntax with the following parameters:
context.scale(scalewidth,scaleheight)
Parameter
|
Required / Optional
|
Description
|
scalewidth
|
Required
|
Scaling factor applied
to width
|
scaleheight
|
Required
|
Scale factor applied to
height (
|
EXAMPLE:
HTML USED IN THIS EXAMPLE:
<!DOCTYPE html>
<html> <!-- Copyright (c) Nematrian Limited 2018 -->
<head></head>
<body>
<span id="element"></span>
<script>
var x2 = document.createElement("CANVAS");
x2.setAttribute("width", "200");
x2.setAttribute("height", "100");
x2.setAttribute("style", "border: 1px solid black");
var c2 = x2.getContext("2d");
c2.strokeStyle = "blue";
c2.strokeRect(10, 10, 40, 30);
c2.scale(3, 1.5);
c2.strokeStyle = "red";
c2.strokeRect(10, 10, 40, 30);
document.getElementById("element").appendChild(x2);
</script>
</body>
</html>
|
FUNCTION THAT MAY ASSIST IN TESTING WHETHER FEATURE IS SUPPORTED:
function isSupportedJavaScriptMethodCanvas2dScale() {
var x = document.createElement("CANVAS"); var c = x.getContext("2d"); return !!c.scale;
} |
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