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` ````
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/dat-gui/0.5/dat.gui.min.js"></script>
<script src="js/triangles.js"></script>
<canvas id="playground" width="800" height="800"></canvas>
```

` ````
body, html {
margin: 0;
padding: 0;
background: #000;
}
```

` ````
/*
honestly not sure what I was going for here. Still thinking of something cool to do with it
Thanks Ironwallaby for delaunay triangulation implementation
https://github.com/ironwallaby/delaunay
*/
$(function () {
var sim = new Eng();
var gui = new dat.GUI();
//gui.addColor(sim, 'nextLineColor');
gui.add(sim, 'edgeBounce', 0, 1);
gui.add(sim, 'acceleration', 0, 1);
gui.add(sim, 'maxSpeed', 0, 5);
gui.add(sim, 'maxArea', 0, 20000);
});
var Eng = function () {
window.onresize = $.proxy(function(event) {
this.canvas.width = window.innerWidth;
this.canvas.height = window.innerHeight;
}, this);
this.canvas = document.getElementById('playground');
this.c = document.getElementById('playground').getContext('2d');
this.canvas.width = window.innerWidth;
this.canvas.height = window.innerHeight;
this.timestep = 16;
this.updatePositionTimestep = 16;
this.updatePositions = true;
this.getRandomArbitrary = function (min, max) {
return Math.floor(Math.random() * (max - min) + min);
}
this.maxArea = 1000;
this.i = 1000;
this.vertices = new Array(this.i);
this.edgeBounce = 0.4;
this.acceleration = 0.4;
this.maxSpeed = 4;
for(var tr = 0; tr < this.vertices.length; tr++) {
var x, y;
x = this.getRandomArbitrary(-10, this.canvas.width + 10);
y = this.getRandomArbitrary(-10, this.canvas.height + 10);
this.vertices[tr] = {x: x, y: y, velX: 0, velY: 0}
}
this.loop = function () {
this.c.clearRect(0,0, this.canvas.width, this.canvas.height);
if(this.updatePositions) {
this.updatePositions = false;
for(var tr = 0; tr < this.vertices.length; tr++) {
this.vertices[tr].velX = this.vertices[tr].velX + (Math.random() - 0.499999) * this.acceleration;
this.vertices[tr].velY = this.vertices[tr].velY + (Math.random() - 0.499999) * this.acceleration;
if (this.vertices[tr].x > this.canvas.width + 20) {
this.vertices[tr].velX = this.vertices[tr].velX - this.edgeBounce;
} else if(this.vertices[tr].x < -20) {
this.vertices[tr].velX = this.vertices[tr].velX + this.edgeBounce;
}
if (this.vertices[tr].y > this.canvas.height + 20) {
this.vertices[tr].velY = this.vertices[tr].velY - this.edgeBounce;
} else if(this.vertices[tr].y < -20) {
this.vertices[tr].velY = this.vertices[tr].velY + this.edgeBounce;
}
if (this.vertices[tr].velY > this.maxSpeed) {
this.vertices[tr].velY = this.maxSpeed;
}
if (this.vertices[tr].velX > this.maxSpeed) {
this.vertices[tr].velX = this.maxSpeed;
}
this.vertices[tr].x = this.vertices[tr].x + this.vertices[tr].velX;
this.vertices[tr].y = this.vertices[tr].y + this.vertices[tr].velY;
}
setTimeout($.proxy(function () {
this.updatePositions = true;
}, this), this.updatePositionTimestep);
}
var triangles = triangulate(this.vertices)
i = triangles.length
while(i)
triangles[--i].draw(this)
setTimeout($.proxy(function () {
this.loop();
}, this), this.timestep);
}
this.loop();
}
function Triangle(a, b, c) {
this.a = a
this.b = b
this.c = c
var A = b.x - a.x,
B = b.y - a.y,
C = c.x - a.x,
D = c.y - a.y,
E = A * (a.x + b.x) + B * (a.y + b.y),
F = C * (a.x + c.x) + D * (a.y + c.y),
G = 2 * (A * (c.y - b.y) - B * (c.x - b.x)),
minx, miny, dx, dy
/* If the points of the triangle are collinear, then just find the
* extremes and use the midpoint as the center of the circumcircle. */
if(Math.abs(G) < 0.000001) {
minx = Math.min(a.x, b.x, c.x)
miny = Math.min(a.y, b.y, c.y)
dx = (Math.max(a.x, b.x, c.x) - minx) * 0.5
dy = (Math.max(a.y, b.y, c.y) - miny) * 0.5
this.x = minx + dx
this.y = miny + dy
this.r = dx * dx + dy * dy
}
else {
this.x = (D*E - B*F) / G
this.y = (A*F - C*E) / G
dx = this.x - a.x
dy = this.y - a.y
this.r = dx * dx + dy * dy
}
}
Triangle.prototype.draw = function(eng) {
eng.c.beginPath()
var area = Math.abs((this.a.x * (this.b.y - this.c.y) + this.b.x*(this.c.y-this.a.y) + this.c.x * (this.a.y - this.b.y))/2);
eng.c.moveTo(this.a.x, this.a.y)
eng.c.lineTo(this.b.x, this.b.y)
eng.c.lineTo(this.c.x, this.c.y)
//eng.c.fillStyle = 'rgba(0, ' + eng.getRandomArbitrary(150, 200) + ', 0, 1)';
eng.c.fillStyle = 'rgba(22, 141, 217, ' + area/eng.maxArea + ')';
eng.c.fill()
eng.c.closePath()
}
function byX(a, b) {
return b.x - a.x
}
function dedup(edges) {
var j = edges.length,
a, b, i, m, n
outer: while(j) {
b = edges[--j]
a = edges[--j]
i = j
while(i) {
n = edges[--i]
m = edges[--i]
if((a === m && b === n) || (a === n && b === m)) {
edges.splice(j, 2)
edges.splice(i, 2)
j -= 2
continue outer
}
}
}
}
function triangulate(vertices) {
/* Bail if there aren't enough vertices to form any triangles. */
if(vertices.length < 3)
return []
/* Ensure the vertex array is in order of descending X coordinate
* (which is needed to ensure a subquadratic runtime), and then find
* the bounding box around the points. */
vertices.sort(byX)
var i = vertices.length - 1,
xmin = vertices[i].x,
xmax = vertices[0].x,
ymin = vertices[i].y,
ymax = ymin
while(i--) {
if(vertices[i].y < ymin) ymin = vertices[i].y
if(vertices[i].y > ymax) ymax = vertices[i].y
}
/* Find a supertriangle, which is a triangle that surrounds all the
* vertices. This is used like something of a sentinel value to remove
* cases in the main algorithm, and is removed before we return any
* results.
*
* Once found, put it in the "open" list. (The "open" list is for
* triangles who may still need to be considered; the "closed" list is
* for triangles which do not.) */
var dx = xmax - xmin,
dy = ymax - ymin,
dmax = (dx > dy) ? dx : dy,
xmid = (xmax + xmin) * 0.5,
ymid = (ymax + ymin) * 0.5,
open = [
new Triangle(
{x: xmid - 20 * dmax, y: ymid - dmax, __sentinel: true},
{x: xmid , y: ymid + 20 * dmax, __sentinel: true},
{x: xmid + 20 * dmax, y: ymid - dmax, __sentinel: true}
)
],
closed = [],
edges = [],
j, a, b
/* Incrementally add each vertex to the mesh. */
i = vertices.length
while(i--) {
/* For each open triangle, check to see if the current point is
* inside it's circumcircle. If it is, remove the triangle and add
* it's edges to an edge list. */
edges.length = 0
j = open.length
while(j--) {
/* If this point is to the right of this triangle's circumcircle,
* then this triangle should never get checked again. Remove it
* from the open list, add it to the closed list, and skip. */
dx = vertices[i].x - open[j].x
if(dx > 0 && dx * dx > open[j].r) {
closed.push(open[j])
open.splice(j, 1)
continue
}
/* If not, skip this triangle. */
dy = vertices[i].y - open[j].y
if(dx * dx + dy * dy > open[j].r)
continue
/* Remove the triangle and add it's edges to the edge list. */
edges.push(
open[j].a, open[j].b,
open[j].b, open[j].c,
open[j].c, open[j].a
)
open.splice(j, 1)
}
/* Remove any doubled edges. */
dedup(edges)
/* Add a new triangle for each edge. */
j = edges.length
while(j) {
b = edges[--j]
a = edges[--j]
open.push(new Triangle(a, b, vertices[i]))
}
}
/* Copy any remaining open triangles to the closed list, and then
* remove any triangles that share a vertex with the supertriangle. */
Array.prototype.push.apply(closed, open)
i = closed.length
while(i--)
if(closed[i].a.__sentinel ||
closed[i].b.__sentinel ||
closed[i].c.__sentinel)
closed.splice(i, 1)
/* Yay, we're done! */
return closed
}
if (typeof module !== 'undefined') {
module.exports = {
Triangle: Triangle,
triangulate: triangulate
}
}
```

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