Merovius · May 16, 2019 15:09
diff --git a/fdg.js b/fdg.js
 function Graph(div, edges, update) {
  let g = this;
  let c = document.createElement("canvas");
  c.width = '800';
  c.height = '400';
  c.style.background = '#ffffff';
  div.appendChild(c);

  div.appendChild(document.createElement("br"));
  let runSim = document.createElement("input");
  runSim.type = "checkbox";
  div.appendChild(runSim);
  div.appendChild(document.createTextNode("run simulation"));

  div.appendChild(document.createElement("br"));
  let shuffle = document.createElement("input");
  shuffle.type = "button";
  shuffle.onclick = function() {
    g.nodes.forEach(function(n) {
      [n.x, n.y, n.vx, n.vy] = [Math.random()*c.width, Math.random()*c.height, 0, 0];
    })
  }
  shuffle.value = "shuffle";
  div.appendChild(shuffle);

  let ctx = c.getContext("2d");

  let n = -1;
  edges.forEach(function(l) {
    l.forEach(function(i) {
      n = Math.max(i, n);
    })
  });
  n++;
  this.edges = edges;
  this.nodes = [];
  for (let i = 0; i < n; i++) {
    this.nodes.push({
      x: Math.random() * c.width,
      y: Math.random() * c.height,
      vx: 0,
      vy: 0,
      ax: 0,
      ay: 0
    });
  }
  this.width = c.width;
  this.height = c.height;

  this._update = function() {
    if (!runSim.checked) {
      return;
    }
    this.nodes.forEach(function(n) {
      [n.ax, n.ay] = [0, 0];
    })

    update(this);

    for (let i = 0; i < n; i++) {
      let n = this.nodes[i];
      n.vx += n.ax;
      n.vy += n.ay;
      n.x += n.vx;
      n.y += n.vy;

      if (n.x < 0) {
        n.x = 0;
        n.vx = Math.max(n.vx, -n.vx);
      }
      if (n.x > c.width-1) {
        n.x = c.width-1;
        n.vx = Math.min(n.vx, -n.vx);
      }
      if (n.y < 0) {
        n.y = 0;
        n.vy = Math.max(n.vy, -n.vy);
      }
      if (n.y > c.height-1) {
        n.y = c.height-1;
        n.vy = Math.min(n.vy, -n.vy);
      }
    }
  };
  this._draw = function() {
    ctx.clearRect(0, 0, c.width, c.height);
    for (let i = 0; i < n; i++) {
      for (let j = i+1; j < n; j++) {
        if (!this.edges[i].includes(j)) {
          continue;
        }
        let [n, m] = [this.nodes[i], this.nodes[j]];
        ctx.beginPath();
        ctx.moveTo(n.x, n.y);
        ctx.lineTo(m.x, m.y);
        ctx.stroke();
      }
    }

    for (let i = 0; i < n; i++) {
      let n = this.nodes[i];
      ctx.beginPath();
      ctx.arc(n.x, n.y, 10, 0, 2*Math.PI);
      ctx.fill();
    }
  };

  window.setInterval(function() { g._update(); g._draw(); }, 33.33333);
  return this;
 };
diff --git a/index.html b/index.html
 <!DOCTYPE html>
 <head>
  <script src="fdg.js"></script>
 </head>
 <body>
  <div id="graph"></div>
  <script>
    let graph = [
      [1,2,3,7],
      [0,4,5],
      [0,5,6],
      [0,4,10],
      [1,3,8],
      [1,2,8,9],
      [2,7,9],
      [0,6,10],
      [4,5,10],
      [5,6,10],
      [3,7,8,9],
    ];

    let g = new Graph(document.querySelector(".graph#electric"), graph, function(g) {
      const springK = 0.001;
      const drag = 0.1;
      const electricK = 1000;
      for (let i = 0; i < g.nodes.length; i++) {
        let n = g.nodes[i];
        g.edges[i].forEach(function(j) {
          let m = g.nodes[j];
          let [dx, dy] = [n.x-m.x, n.y-m.y];
          n.ax -= springK * dx;
          n.ay -= springK * dy;
        });
        for (let j = 0; j < g.nodes.length; j++) {
          if (i == j) { continue; }
          let m = g.nodes[j];
          let [dx, dy] = [n.x-m.x, n.y-m.y];
          let d = Math.sqrt(dx*dx+dy*dy);
          if (d == 0) { continue; }
          let F = electricK / d**3;
          n.ax += dx * F;
          n.ay += dy * F;
        }
        n.ax -= n.vx * drag;
        n.ay -= n.vy * drag;
      }
    });
  </script>
 </body>
	function Graph(div, edges, update) {
	let g = this;
	let c = document.createElement("canvas");
	c.width = '800';
	c.height = '400';
	c.style.background = '#ffffff';
	div.appendChild(c);

	div.appendChild(document.createElement("br"));
	let runSim = document.createElement("input");
	runSim.type = "checkbox";
	div.appendChild(runSim);
	div.appendChild(document.createTextNode("run simulation"));

	div.appendChild(document.createElement("br"));
	let shuffle = document.createElement("input");
	shuffle.type = "button";
	shuffle.onclick = function() {
	g.nodes.forEach(function(n) {
	[n.x, n.y, n.vx, n.vy] = [Math.random()c.width, Math.random()c.height, 0, 0];
	})
	}
	shuffle.value = "shuffle";
	div.appendChild(shuffle);

	let ctx = c.getContext("2d");

	let n = -1;
	edges.forEach(function(l) {
	l.forEach(function(i) {
	n = Math.max(i, n);
	})
	});
	n++;
	this.edges = edges;
	this.nodes = [];
	for (let i = 0; i < n; i++) {
	this.nodes.push({
	x: Math.random() * c.width,
	y: Math.random() * c.height,
	vx: 0,
	vy: 0,
	ax: 0,
	ay: 0
	});
	}
	this.width = c.width;
	this.height = c.height;

	this._update = function() {
	if (!runSim.checked) {
	return;
	}
	this.nodes.forEach(function(n) {
	[n.ax, n.ay] = [0, 0];
	})

	update(this);

	for (let i = 0; i < n; i++) {
	let n = this.nodes[i];
	n.vx += n.ax;
	n.vy += n.ay;
	n.x += n.vx;
	n.y += n.vy;

	if (n.x < 0) {
	n.x = 0;
	n.vx = Math.max(n.vx, -n.vx);
	}
	if (n.x > c.width-1) {
	n.x = c.width-1;
	n.vx = Math.min(n.vx, -n.vx);
	}
	if (n.y < 0) {
	n.y = 0;
	n.vy = Math.max(n.vy, -n.vy);
	}
	if (n.y > c.height-1) {
	n.y = c.height-1;
	n.vy = Math.min(n.vy, -n.vy);
	}
	}
	};
	this._draw = function() {
	ctx.clearRect(0, 0, c.width, c.height);
	for (let i = 0; i < n; i++) {
	for (let j = i+1; j < n; j++) {
	if (!this.edges[i].includes(j)) {
	continue;
	}
	let [n, m] = [this.nodes[i], this.nodes[j]];
	ctx.beginPath();
	ctx.moveTo(n.x, n.y);
	ctx.lineTo(m.x, m.y);
	ctx.stroke();
	}
	}

	for (let i = 0; i < n; i++) {
	let n = this.nodes[i];
	ctx.beginPath();
	ctx.arc(n.x, n.y, 10, 0, 2*Math.PI);
	ctx.fill();
	}
	};

	window.setInterval(function() { g._update(); g._draw(); }, 33.33333);
	return this;
	};
	<!DOCTYPE html>
	<head>
	<script src="fdg.js"></script>
	</head>
	<body>
	<div id="graph"></div>
	<script>
	let graph = [
	[1,2,3,7],
	[0,4,5],
	[0,5,6],
	[0,4,10],
	[1,3,8],
	[1,2,8,9],
	[2,7,9],
	[0,6,10],
	[4,5,10],
	[5,6,10],
	[3,7,8,9],
	];

	let g = new Graph(document.querySelector(".graph#electric"), graph, function(g) {
	const springK = 0.001;
	const drag = 0.1;
	const electricK = 1000;
	for (let i = 0; i < g.nodes.length; i++) {
	let n = g.nodes[i];
	g.edges[i].forEach(function(j) {
	let m = g.nodes[j];
	let [dx, dy] = [n.x-m.x, n.y-m.y];
	n.ax -= springK * dx;
	n.ay -= springK * dy;
	});
	for (let j = 0; j < g.nodes.length; j++) {
	if (i == j) { continue; }
	let m = g.nodes[j];
	let [dx, dy] = [n.x-m.x, n.y-m.y];
	let d = Math.sqrt(dxdx+dydy);
	if (d == 0) { continue; }
	let F = electricK / d**3;
	n.ax += dx * F;
	n.ay += dy * F;
	}
	n.ax -= n.vx * drag;
	n.ay -= n.vy * drag;
	}
	});
	</script>
	</body>