JavaScript canvas2d object property: data
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The data property of the JavaScript
DOM object returned
by the getContext("2d")
method applied to the HTML <canvas>
element returns an object containing image data for a specific ImageData object.
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", "60");
x2.setAttribute("style", "border: 1px solid black");
var c2 = x2.getContext("2d");
var imgData = c2.createImageData(100,20)
for (var i = 0; i<imgData.data.length; i += 4) {
imgData.data[i+0] = 255; //red channel
imgData.data[i+1] = 0;
imgData.data[i+2] = 0;
imgData.data[i+3] = 255;
}
c2.putImageData(imgData,60,20);
c2.strokeStyle = "rgba(0,0,255,40)"; //so partly transparent
c2.rect(30, 10, 100, 40);
c2.stroke();
document.getElementById("element").appendChild(x2);
</script>
</body>
</html>
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