140 lines
5.3 KiB
HTML
140 lines
5.3 KiB
HTML
<!--
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This work is licensed under CC BY-NC-ND 4.0
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Link to license: http://creativecommons.org/licenses/by-nc-nd/4.0/
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Attribute to Russell Georgi
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-->
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<html>
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<head>
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<title>
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Problem 3-3
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</title>
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<style>
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html, body {
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width: 100%;
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height: 100%;
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margin: 0px;
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border: 0;
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overflow: hidden;
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display: block;
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}
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canvas {
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position: absolute;
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}
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</style>
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</head>
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<body>
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<canvas id="myCanvas" width="1" height="1" style="border:1px solid #ffffff;">
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Your browser does not support the HTML5 canvas tag.</canvas>
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<script>
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var c = document.getElementById("myCanvas");
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var ctx = c.getContext("2d");
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c.width = window.innerWidth;
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c.height = window.innerHeight;
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//Time step
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var dt = 0.002;
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var t = 0;
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var g = 200;
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var n = 10;
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var positions = new Array(n);
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var velocities = new Array(n);
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var accelerations = new Array(n);
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//Relative position of canvas
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var xPos = 0;
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var yPos = 200;
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var dist = 75;
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//Moves and scales canvas
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ctx.translate(ctx.canvas.width / 2, ctx.canvas.height / 2)
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ctx.scale(1, -1);
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function Reset()
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{
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t = 0;
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for (i = 0; i < n; i++)
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{
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positions[i] = 0;
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velocities[i] = 0;
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accelerations[i] = g * (2 * (2 ** i) - 1) / (2 * (2 ** i));
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}
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}
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Reset();
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function Clear(ctx)
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{
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ctx.clearRect(-c.width, -c.height, c.width * 2, c.height * 2);
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}
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function Update()
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{
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Clear(ctx);
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Draw();
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t += dt;
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if (t > 0.7)
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{
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Reset();
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}
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for (i = 0; i < n; i++)
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{
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velocities[i] += accelerations[i] * dt;
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positions[i] += velocities[i] * dt;
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}
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setTimeout(Update, 1000/60);
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}
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function Draw()
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{
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for (i = 0; i < n; i++)
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{
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if (i == 0)
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{
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ctx.beginPath();
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ctx.arc(xPos + 20 * i, yPos - dist * i, 20, 0, Math.PI * 2);
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ctx.stroke();
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ctx.beginPath();
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ctx.moveTo(xPos + 20 * i - 20, yPos - dist * i);
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ctx.lineTo(xPos + 20 * i - 20, yPos - dist * i - dist + positions[i]);
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ctx.stroke();
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ctx.beginPath();
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ctx.moveTo(xPos + 20 * i + 20, yPos - dist * i);
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ctx.lineTo(xPos + 20 * i + 20, yPos - dist * i - dist - positions[i]);
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ctx.stroke();
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ctx.beginPath();
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ctx.arc(xPos + 20 * i - 20, yPos - dist * i - dist + positions[i], 5, 0, Math.PI * 2);
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ctx.fill();
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} else
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{
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ctx.beginPath();
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ctx.arc(xPos + 20 * i, yPos - dist * i - positions[i - 1], 20, 0, Math.PI * 2);
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ctx.stroke();
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ctx.beginPath();
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ctx.moveTo(xPos + 20 * i - 20, yPos - dist * i - positions[i - 1]);
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ctx.lineTo(xPos + 20 * i - 20, yPos - dist * i - dist - positions[i - 1] + positions[i]);
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ctx.stroke();
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ctx.beginPath();
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ctx.moveTo(xPos + 20 * i + 20, yPos - dist * i - positions[i - 1]);
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ctx.lineTo(xPos + 20 * i + 20, yPos - dist * i - dist - positions[i]);
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ctx.stroke();
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ctx.beginPath();
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ctx.arc(xPos + 20 * i - 20, yPos - dist * i - dist - positions[i - 1] + positions[i], 5, 0, Math.PI * 2);
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ctx.fill();
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}
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}
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}
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window.addEventListener('resize', function(event) {
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c.width = window.innerWidth;
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c.height = window.innerHeight;
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ctx.translate(c.width / 2, c.height / 2);
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ctx.scale(1, -1);
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}, true);
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Update();
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</script>
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</body>
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<p xmlns:cc="http://creativecommons.org/ns#" style="font-size: 1vw; bottom: 0px; position: absolute;">
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This work is licensed under
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<a href="http://creativecommons.org/licenses/by-nc-nd/4.0/?ref=chooser-v1" target="_blank" rel="license noopener noreferrer" style="display:inline-block;">CC BY-NC-ND 4.0<img style="height:22px!important;margin-left:3px;vertical-align:text-bottom;" src="https://mirrors.creativecommons.org/presskit/icons/cc.svg?ref=chooser-v1"><img style="height:22px!important;margin-left:3px;vertical-align:text-bottom;" src="https://mirrors.creativecommons.org/presskit/icons/by.svg?ref=chooser-v1"><img style="height:22px!important;margin-left:3px;vertical-align:text-bottom;" src="https://mirrors.creativecommons.org/presskit/icons/nc.svg?ref=chooser-v1"><img style="height:22px!important;margin-left:3px;vertical-align:text-bottom;" src="https://mirrors.creativecommons.org/presskit/icons/nd.svg?ref=chooser-v1"></a></p>
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</html> |