97 lines
2.1 KiB
HTML
97 lines
2.1 KiB
HTML
<title>Non Worker</title>
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<article>
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<p>Canvas is running whilst an prime number finder runs - this will cause your browser to hang</p>
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<p>Prime found: <span id="status">0</span></p>
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<div><input type="button" value="start worker" id="toggleWorker" /></div>
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</article>
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<script>
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buildSpinner({ x : 50, y : 50, size : 20, degrees : 30 });
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var running = false;
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var ctr = 0;
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addEvent(document.getElementById('toggleWorker'), 'click', function (event) {
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// doesn't matter what the message is, just toggle the worker
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if (running == false) {
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running = true;
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run();
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} else {
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running = false;
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}
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});
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function run() {
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var n = 1;
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search: while (running) {
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n += 1;
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for (var i = 2; i <= Math.sqrt(n); i += 1)
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if (n % i == 0)
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continue search;
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// found a prime!
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document.querySelector('#status').innerHTML = n;
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}
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}
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function buildSpinner(data) {
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var canvas = document.createElement('canvas');
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canvas.height = 200;
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canvas.width = 300;
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document.querySelector('article').appendChild(canvas);
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var ctx = canvas.getContext("2d"),
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i = 0, degrees = data.degrees, loops = 0, degreesList = [];
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for (i = 0; i < degrees; i++) {
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degreesList.push(i);
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}
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// reset
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i = 0;
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// so I can kill it later
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window.canvasTimer = setInterval(draw, 1000/degrees);
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function reset() {
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ctx.clearRect(0,0,100,100); // clear canvas
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var left = degreesList.slice(0, 1);
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var right = degreesList.slice(1, degreesList.length);
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degreesList = right.concat(left);
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}
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function draw() {
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var c, s, e;
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var d = 0;
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if (i == 0) {
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reset();
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}
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ctx.save();
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d = degreesList[i];
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c = Math.floor(255/degrees*i);
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ctx.strokeStyle = 'rgb(' + c + ', ' + c + ', ' + c + ')';
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ctx.lineWidth = data.size;
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ctx.beginPath();
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s = Math.floor(360/degrees*(d));
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e = Math.floor(360/degrees*(d+1)) - 1;
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ctx.arc(data.x, data.y, data.size, (Math.PI/180)*s, (Math.PI/180)*e, false);
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ctx.stroke();
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ctx.restore();
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i++;
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if (i >= degrees) {
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i = 0;
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}
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}
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}
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</script>
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