206 lines
7.5 KiB
HTML
206 lines
7.5 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 5-29
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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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.dropbtn {
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background-color: #04AA6D;
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color: white;
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padding: 16px;
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font-size: 16px;
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border: none;
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}
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.dropbtnm {
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background-color: #04AA6D;
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color: white;
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padding: 16px;
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font-size: 16px;
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border: none;
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}
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.dropdown {
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position: absolute;
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display: inline-block;
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}
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.dropdown-content {
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display: none;
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position: relative;
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background-color: #f1f1f1;
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box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
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z-index: 1;
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}
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.dropdown-content button {
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color: black;
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padding: 12px 16px;
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width: 100px;
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text-decoration: none;
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display: block;
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}
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#m {
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left: 110px;
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}
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.dropdown-content a:hover {background-color: #ddd;}
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.dropdown:hover .dropdown-content {display: block;}
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.dropdown:hover .dropbtn {background-color: #3e8e41;}
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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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class Vector2 {
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constructor (x, y) {
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this.x = x;
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this.y = y;
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}
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scale(n)
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{
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this.x *= n;
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this.y *= n;
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}
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get len()
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{
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return this.calcLen();
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}
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calcLen()
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{
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return (Math.sqrt(this.x * this.x + this.y * this.y));
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}
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}
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var c = document.getElementById("myCanvas");
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var ctx = c.getContext("2d");
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ctx.canvas.width = window.innerWidth;
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ctx.canvas.height = window.innerHeight;
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var l = 100;
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var r = 50;
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var ppl = 2.0;
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var g = 10;
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var n = 500;
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//var f = 1;
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var chainPositions = new Array(1);
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var chainPrevPositions = new Array(1);
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var t = 0;
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var dt = 0.0125;
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var xPos = 0;
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var yPos = 100;
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ctx.translate(ctx.canvas.width / 2, ctx.canvas.height / 2);
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ctx.scale(1.5, -1.5);
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chainPositions[0] = new Vector2(r, 0);
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chainPrevPositions[0] = new Vector2(r, 0);
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for (i = ppl; i < r * Math.PI; i += ppl)
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{
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chainPositions.push(new Vector2(r * Math.cos(i / r), -r * Math.sin(i / r)));
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chainPrevPositions.push(new Vector2(r * Math.cos(i / r), -r * Math.sin(i / r)));
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}
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for (i = 0; i < l; i += ppl)
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{
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chainPositions.push(new Vector2(-r, i));
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chainPrevPositions.push(new Vector2(-r, i));
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}
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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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for (i = 1; i < chainPositions.length; i++)
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{
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positionBeforeUpdate = chainPositions[i];
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chainPositions[i] = new Vector2(2 * chainPositions[i].x - chainPrevPositions[i].x, 2 * chainPositions[i].y - chainPrevPositions[i].y);
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chainPositions[i].y -= g * dt * dt;
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chainPrevPositions[i] = positionBeforeUpdate;
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/*stickCentre = new Vector2((chainPositions[i - 1].x + chainPositions[i].x) / 2, (chainPositions[i - 1].y + chainPositions[i].y) / 2);
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stickDir = new Vector2(chainPositions[i - 1].x - chainPositions[i].x, chainPositions[i - 1].y - chainPositions[i].y);
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stickDir = new Vector2(stickDir.x / stickDir.calcLen(), stickDir.y / stickDir.calcLen());
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if (i != 1)
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{
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chainPositions[i - 1] = new Vector2(stickCentre.x + stickDir.x * ppl / 2, stickCentre.y + stickDir.y * ppl / 2);
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}
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chainPositions[i] = new Vector2(stickCentre.x - stickDir.x * ppl / 2, stickCentre.y - stickDir.y * ppl / 2);*/
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}
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for (j = 0; j < n; j++)
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{
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//i = Math.floor(Math.random()*(chainPositions.length - 1));
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i = j % (chainPositions.length - 1);
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stickCentre = new Vector2((chainPositions[i].x + chainPositions[i + 1].x) / 2, (chainPositions[i].y + chainPositions[i + 1].y) / 2);
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stickDir = new Vector2(chainPositions[i].x - chainPositions[i + 1].x, chainPositions[i].y - chainPositions[i + 1].y);
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stickDir = new Vector2(stickDir.x / stickDir.calcLen(), stickDir.y / stickDir.calcLen());
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if (i != 0)
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{
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chainPositions[i] = new Vector2(stickCentre.x + stickDir.x * ppl / 2, stickCentre.y + stickDir.y * ppl / 2);
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}
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chainPositions[i + 1] = new Vector2(stickCentre.x - stickDir.x * ppl / 2, stickCentre.y - stickDir.y * ppl / 2);
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}
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setTimeout(Update, 500/60);
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}
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function Draw()
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{
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ctx.beginPath();
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ctx.moveTo(chainPositions[0].x + xPos, chainPositions[0].y + yPos);
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for (i = 1; i < chainPositions.length; i++)
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{
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ctx.lineTo(chainPositions[i].x + xPos, chainPositions[i].y + yPos);
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}
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ctx.stroke();
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}
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function vectorAdd(v1, v2)
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{
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return new Vector2(v1.x + v2.x, v1.y + v2.y);
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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(1.5, -1.5);
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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> |