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<!DOCTYPE html>
<head>
<link rel="match" href="canvas-filter-object-convolve-matrix-expected.html">
<style type="text/css">
canvas {
margin: 5px;
}
</style>
</head>
<body>
</body>
<script>
function makeConvolveFilter(options) {
const KERNEL_MATRIX = [
[3, 0, 0],
[0, 0, 0],
[0, 0, -3],
];
options = Object.assign(options, {
kernelMatrix: KERNEL_MATRIX, name: "convolveMatrix"});
return new CanvasFilter(options);
}
const test_cases = [
{},
{preserveAlpha: true},
{targetX: 2, targetY: 2},
{divisor: 3},
{bias: 0.5},
{edgeMode: "wrap"}
];
function draw(ctx) {
ctx.fillRect(0, 20, 120, 100);
ctx.beginPath();
ctx.arc(150, 70, 50, 0, 2*Math.PI);
ctx.fill();
ctx.beginPath();
ctx.moveTo(220, 20);
ctx.lineTo(170, 120);
ctx.lineTo(270, 120);
ctx.lineTo(220, 20);
ctx.fill();
}
for (tc of test_cases) {
const canvas = document.createElement("canvas");
document.body.prepend(canvas);
const ctx = canvas.getContext("2d");
ctx.filter = "blur(0px)";
ctx.fillStyle = "rgba(0,255,0,0.5)";
draw(ctx);
ctx.fillStyle = "rgba(255,0,255,0.5)";
ctx.filter = makeConvolveFilter(tc);
draw(ctx);
}
</script>
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