<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<style>html, body {
overflow: hidden;
touch-action: none;
content-zooming: none;
position: absolute;
margin: 0;
padding: 0;
width: 100%;
height: 100%;
background: #000;
}
#screen {
position: absolute;
width: 100vh;
height: 100vh;
max-height: 100vw;
max-width: 100vw;
margin: auto;
top: 0;
bottom: 0;
left: 0;
right: 0;
user-select: none;
}
#screen canvas {
position: relative;
float: left;
display: block;
width: 28.7vmin;
height: 28.7vmin;
background:#222;
margin-left: 3vmin;
margin-top: 3vmin;
border-radius: 3vmin;
}</style>
</HEAD>
<BODY><div id="screen"></div>
<script>"use strict";
{
const Box = class {
constructor(container, i) {
this.canvas = document.createElement("canvas");
container.appendChild(this.canvas);
this.width = this.canvas.width = this.canvas.offsetWidth;
this.height = this.canvas.height = this.canvas.offsetHeight;
this.ctx = this.canvas.getContext("2d");
this.ctx.lineCap = "round";
this.points = Array.from(
{ length: 12 },
_ => new Box.Point(this.width * 0.5, this.width * 0.5)
);
this.constraints = [];
this.color = `hsl(${10 * i}, 70%, 30%)`;
// links p1, p2, length, width
const links = [
[0, 1, 6, 5],
[1, 2, 5, 4],
[3, 7, 10, 6],
[7, 8, 7, 4],
[3, 9, 10, 6],
[9, 10, 7, 4],
[0, 4, 5, 0],
[0, 3, 7, 9],
[0, 5, 6, 5],
[5, 6, 5, 4],
[4, 11, 0.1, 11]
];
// constaints: p1, p2, p3, angle, range
const p2 = Math.PI / 2;
const p3 = Math.PI / 3;
[
[0, 4, 11, 0, 0, 0],
[4, 0, 3, 0, 1, 0.05],
[3, 0, 4, 0, 1, 0.05],
[3, 0, 1, p2, p2 * 4, 0],
[0, 1, 2, -p2, p3, 0.05],
[3, 0, 5, p2, p2 * 4, 0],
[0, 5, 6, -p2, p3, 0.05],
[0, 3, 7, -p3 + 0.5, p2, 0.05],
[0, 3, 9, -p3 + 0.5, p2, 0.05],
[3, 7, 8, p2, p3, 0.05],
[3, 9, 10, p2, p3, 0.05]
].forEach(p => {
this.constraints.push(new Box.Constraint(this, links, p, this.width / 30));
});
}
run() {
this.ctx.setTransform(0, 1, 1, 0, 0, 0);
this.ctx.clearRect(0, 0, this.width + 1, this.height + 1);
this.ctx.globalCompositeOperation = "lighter";
for (const constraint of this.constraints) constraint.solve();
for (const point of this.points) point.integrate();
}
};
Box.Point = class {
constructor(x, y) {
this.x = x;
this.y = y;
this.xb = x;
this.yb = y
this.w = 0;
}
integrate() {
const vx = (this.x - this.xb) * 0.995;
const vy = (this.y - this.yb) * 0.995;
this.xb = this.x;
this.yb = this.y;
this.x += vx;
this.y += vy;
}
};
Box.Constraint = class {
constructor(box, links, p, s) {
this.ctx = box.ctx;
this.p1 = box.points[p[0]];
this.p2 = box.points[p[1]];
this.p3 = box.points[p[2]];
this.m = 0;
this.angle = p[3];
this.range = p[4];
this.force = p[5];
const link1 = this.link(links, p[0], p[1]);
const link2 = this.link(links, p[1], p[2]);
this.len1 = link1[2] * s;
this.len2 = link2[2] * s;
this.width = link2[3] * s * 0.5;
if (this.width * 0.5 > this.p3.w) this.p3.w = this.width * 0.5;
this.shape = document.createElement("canvas");
if (this.width) {
this.shape.width = this.len2 + this.width;
this.shape.height = this.width;
const ict = this.shape.getContext("2d");
ict.lineCap = "round";
ict.strokeStyle = box.color;
ict.beginPath();
ict.lineWidth = this.width * 0.9;
ict.moveTo(this.width * 0.5, this.width * 0.5);
ict.lineTo(this.len2 + this.width * 0.5, this.width * 0.5);
ict.stroke();
}
}
link(links, p0, p1) {
for (const link of links) {
if (
(p0 === link[0] && p1 === link[1]) ||
(p1 === link[0] && p0 === link[1])
)
return link;
}
}
solve() {
const a1 = Math.atan2(this.p2.y - this.p1.y, this.p2.x - this.p1.x);
const b1 = Math.atan2(this.p3.y - this.p2.y, this.p3.x - this.p2.x);
const c = this.angle - (b1 - a1);
const d = c > Math.PI ? c - 2 * Math.PI : c < -Math.PI ? c + 2 * Math.PI : c;
const e = Math.abs(d) > this.range ? (-Math.sign(d) * this.range + d) * this.force : 0;
const cos1 = Math.cos(a1 - e);
const sin1 = Math.sin(a1 - e);
const x1 = this.p1.x + (this.p2.x - this.p1.x) * 0.5;
const y1 = this.p1.y + (this.p2.y - this.p1.y) * 0.5;
this.p1.x = x1 - cos1 * this.len1 * 0.5;
this.p1.y = y1 - sin1 * this.len1 * 0.5;
this.p2.x = x1 + cos1 * this.len1 * 0.5;
this.p2.y = y1 + sin1 * this.len1 * 0.5;
this.m += 0.0005 * (Math.random() - 0.5);
this.m *= 0.99;
const a2 = this.m + Math.atan2(this.p2.y - this.p3.y, this.p2.x - this.p3.x) + e;
const cos2 = Math.cos(a2);
const sin2 = Math.sin(a2);
const x2 = this.p3.x + (this.p2.x - this.p3.x) * 0.5;
const y2 = this.p3.y + (this.p2.y - this.p3.y) * 0.5;
this.p3.x = x2 - cos2 * this.len2 * 0.5;
this.p3.y = y2 - sin2 * this.len2 * 0.5;
this.p2.x = x2 + cos2 * this.len2 * 0.5;
this.p2.y = y2 + sin2 * this.len2 * 0.5;
if (this.width) {
this.ctx.setTransform(cos2, sin2, -sin2, cos2, this.p2.x, this.p2.y);
this.ctx.drawImage(
this.shape,
-this.len2 - this.width * 0.5,
-this.width * 0.5
);
}
}
};
const screen = document.querySelector("#screen");
const boxes = Array.from({ length: 9 }, (v, i) => new Box(screen, i));
const run = () => {
requestAnimationFrame(run);
for (const box of boxes) box.run();
};
run();
}</script>
</BODY>
</HTML>
