enjalot/.block

## .block
license: gpl-3.0

## README.md

      
    Raw
  

              README.md
            
          
    Some force-directed points, with the Urquhart graph overlaid. Thanks @enjalot for the idea and time wasted :)
Forked from erlenstar's block: Delaunay Force Mesh II
forked from Fil's block: Urquhart Force Mesh

  
## index.html
<!DOCTYPE html>
<meta charset="utf-8">
<style>
  body {
    margin: 0;
    padding: 0;
  }
</style>
<body>
<script src="//d3js.org/d3.v4.js"></script>
<script>

var width = 960,
    height = 500,
    τ = 2 * Math.PI,
    maxLength = 10000,
    maxLength2 = maxLength * maxLength,
    minDistance = 50,
    maxDistance = 70,
    minDistance2 = minDistance * minDistance,
    maxDistance2 = maxDistance * maxDistance;

var radius = 300;

var randomHue = 0// * Math.random();
var randomSaturation = 0// * Math.random();
var randomLightness = 300// * Math.random();

var nodes = d3.range(300).map(function() {
  return {
    x: Math.random() * width,
    y: Math.random() * height
  };
});

var voronoi = d3.voronoi()
  .x(function(d) { return d.x; })
  .y(function(d) { return d.y; });

var diagram = voronoi(nodes);
var polygons = voronoi.polygons(nodes)

var links = urquhart(diagram);
console.log("POLYGONS", polygons)


var force = d3.forceSimulation()
    .nodes(nodes.slice())
    //.force("link", d3.forceLink().id(function(d) { return d.id; }).distance(40).strength(100))
    .force("charge", d3.forceManyBody().strength(function(d,i){
      return i ? -20 : -1000
    }))
    .force("x", d3.forceX())
    .force("y", d3.forceY())
    .force("center", d3.forceCenter(width / 2, height / 2))
    .on("tick", ticked);


var canvas = d3.select("body").append("canvas")
    .attr("width", width)
    .attr("height", height)
    .on("ontouchstart" in document ? "touchmove" : "mousemove", moved);

var context = canvas.node().getContext("2d");
//context.globalCompositeOperation = "screen";
context.lineJoin = "round"

function moved() {
  var p1 = d3.mouse(this);
  nodes[0].fx = p1[0];
  nodes[0].fy = p1[1];
  force.alpha(0.1).restart();
}


function urquhart(diagram){
    var urquhart = d3.map();
    diagram.links()
    .forEach(function(link) {
      var v = d3.extent([link.source.index, link.target.index]);
      urquhart.set(v, link);
    });
    urquhart._remove = [];
    diagram.triangles()
    .forEach(function(t) {

      var l = 0, length = 0, i="bleh", v;
      for (var j=0; j<3; j++) {
        var a = t[j], b = t[(j+1)%3];
        v = d3.extent([a.index, b.index]);
        length = (a.x-b.x) * (a.x-b.x) + (a.y-b.y) * (a.y-b.y);
        if (length > l) {
          l = length;
          i = v;
        }
      }
      urquhart._remove.push(i);
    });
     //console.log(JSON.stringify(urquhart._remove))
    urquhart._remove.forEach(function(i) {
      if (urquhart.has(i)) urquhart.remove(i);
    });
    return urquhart.values();
  }

function ticked() {
  var diagram = voronoi(nodes);
  var polygons = voronoi.polygons(nodes)
  //var links = diagram.links();
  var links = urquhart(diagram);
  var dlen = links.length
  var plen = polygons.length

  //context.clearRect(0, 0, width, height);
  context.fillStyle="rgba(10,10,10,0.5)";
  context.fillRect(0, 0, width, height);

  var hue = 2;
  var hue1 = (hue + randomHue) % 360;
  var hue2 = (hue + randomHue + 260) % 360;
  var interpolate = d3.interpolateHcl(d3.hcl(hue1, 50, 95), d3.hcl(hue2, 20 + randomSaturation, 20+ randomLightness));

  //context.globalAlpha = 0.5;

  for (var i = 0, n = polygons.length; i < n; ++i) {
    //context.strokeStyle = interpolate(i/plen);
    context.beginPath();
    drawCell(polygons[i]);
    context.strokeStyle = "rgba(255,255,255,0.25)";
    context.lineWidth = 3;
    context.stroke();
  }

  for (var i = 0, n = links.length; i < n; ++i) {
    var link = links[i],
        dx = link.source.x - link.target.x,
        dy = link.source.y - link.target.y;
    var d2 = dx * dx + dy * dy
    if (d2 < maxLength2) {
      //var ratio = d2 > minDistance2 ? (maxDistance2 - d2) / (maxDistance2 - minDistance2) : 0.5;
      //var rease = d3.easeCubic(ratio);
      //context.globalAlpha = rease
      context.beginPath();
      context.moveTo(link.source.x, link.source.y);
      context.lineTo(link.target.x, link.target.y);
      context.lineWidth = 3;
      //context.strokeStyle = interpolate(i/dlen);
      context.strokeStyle = "rgba(250,250,250,0.25)";
      context.stroke();
    }
  }
  context.globalAlpha = 1;


  /*
  context.lineWidth = 2;
  context.beginPath();
  for (var i = 0, n = nodes.length; i < n; ++i) {
    var node = nodes[i];
    context.moveTo(node.x, node.y);
    context.arc(node.x, node.y, 2, 0, τ);
  }


  context.strokeStyle = "#fff";
  context.stroke();
  context.fillStyle = "#000";
  context.fill();
  */
}

function test(x,y) {
  var cx = width/2
  var cy = height/2
  var dx = x - cx
  var dy = y - cy
  var d2 = dx * dx + dy * dy
  var r2 = radius*radius
  if(d2 > r2) {
    x = cx + radius * dx/r2
    y = cy + radius * dy/r2
  }
  return [x,y]
}
function drawCell(cell) {
  if (!cell || !cell[0]) return false;
  var x, y;

  x = cell[0][0];
  y = cell[0][1];
  /*
  if(x > width - 5) x = width-5;
  if(x < 5) x = 5;
  if(y > height - 5) y = height - 5;
  if(y < 5) y = 5;
  */
  var p = test(x,y)
  context.moveTo(p[0], p[1]);

  for (var j = 1, m = cell.length; j < m; ++j) {
    if(!cell[j]) continue;
    x = cell[j][0];
    y = cell[j][1];
    /*
    if(x > width) x = width-5;
    if(x < 5) x = 5;
    if(y > height - 5) y = height - 5;
    if(y < 5) y = 5;
    */
    p = test(x,y)
    context.lineTo(p[0], p[1]);
  }
  context.closePath();
  return true;
}

</script>

## thumbnail.png

      
    Raw
  

              thumbnail.png
	<!DOCTYPE html>
	<meta charset="utf-8">
	<style>
	body {
	margin: 0;
	padding: 0;
	}
	</style>
	<body>
	<script src="//d3js.org/d3.v4.js"></script>
	<script>

	var width = 960,
	height = 500,
	τ = 2 * Math.PI,
	maxLength = 10000,
	maxLength2 = maxLength * maxLength,
	minDistance = 50,
	maxDistance = 70,
	minDistance2 = minDistance * minDistance,
	maxDistance2 = maxDistance * maxDistance;

	var radius = 300;

	var randomHue = 0// * Math.random();
	var randomSaturation = 0// * Math.random();
	var randomLightness = 300// * Math.random();

	var nodes = d3.range(300).map(function() {
	return {
	x: Math.random() * width,
	y: Math.random() * height
	};
	});

	var voronoi = d3.voronoi()
	.x(function(d) { return d.x; })
	.y(function(d) { return d.y; });

	var diagram = voronoi(nodes);
	var polygons = voronoi.polygons(nodes)

	var links = urquhart(diagram);
	console.log("POLYGONS", polygons)


	var force = d3.forceSimulation()
	.nodes(nodes.slice())
	//.force("link", d3.forceLink().id(function(d) { return d.id; }).distance(40).strength(100))
	.force("charge", d3.forceManyBody().strength(function(d,i){
	return i ? -20 : -1000
	}))
	.force("x", d3.forceX())
	.force("y", d3.forceY())
	.force("center", d3.forceCenter(width / 2, height / 2))
	.on("tick", ticked);


	var canvas = d3.select("body").append("canvas")
	.attr("width", width)
	.attr("height", height)
	.on("ontouchstart" in document ? "touchmove" : "mousemove", moved);

	var context = canvas.node().getContext("2d");
	//context.globalCompositeOperation = "screen";
	context.lineJoin = "round"

	function moved() {
	var p1 = d3.mouse(this);
	nodes[0].fx = p1[0];
	nodes[0].fy = p1[1];
	force.alpha(0.1).restart();
	}


	function urquhart(diagram){
	var urquhart = d3.map();
	diagram.links()
	.forEach(function(link) {
	var v = d3.extent([link.source.index, link.target.index]);
	urquhart.set(v, link);
	});
	urquhart._remove = [];
	diagram.triangles()
	.forEach(function(t) {

	var l = 0, length = 0, i="bleh", v;
	for (var j=0; j<3; j++) {
	var a = t[j], b = t[(j+1)%3];
	v = d3.extent([a.index, b.index]);
	length = (a.x-b.x) * (a.x-b.x) + (a.y-b.y) * (a.y-b.y);
	if (length > l) {
	l = length;
	i = v;
	}
	}
	urquhart._remove.push(i);
	});
	//console.log(JSON.stringify(urquhart._remove))
	urquhart._remove.forEach(function(i) {
	if (urquhart.has(i)) urquhart.remove(i);
	});
	return urquhart.values();
	}

	function ticked() {
	var diagram = voronoi(nodes);
	var polygons = voronoi.polygons(nodes)
	//var links = diagram.links();
	var links = urquhart(diagram);
	var dlen = links.length
	var plen = polygons.length

	//context.clearRect(0, 0, width, height);
	context.fillStyle="rgba(10,10,10,0.5)";
	context.fillRect(0, 0, width, height);

	var hue = 2;
	var hue1 = (hue + randomHue) % 360;
	var hue2 = (hue + randomHue + 260) % 360;
	var interpolate = d3.interpolateHcl(d3.hcl(hue1, 50, 95), d3.hcl(hue2, 20 + randomSaturation, 20+ randomLightness));

	//context.globalAlpha = 0.5;

	for (var i = 0, n = polygons.length; i < n; ++i) {
	//context.strokeStyle = interpolate(i/plen);
	context.beginPath();
	drawCell(polygons[i]);
	context.strokeStyle = "rgba(255,255,255,0.25)";
	context.lineWidth = 3;
	context.stroke();
	}

	for (var i = 0, n = links.length; i < n; ++i) {
	var link = links[i],
	dx = link.source.x - link.target.x,
	dy = link.source.y - link.target.y;
	var d2 = dx * dx + dy * dy
	if (d2 < maxLength2) {
	//var ratio = d2 > minDistance2 ? (maxDistance2 - d2) / (maxDistance2 - minDistance2) : 0.5;
	//var rease = d3.easeCubic(ratio);
	//context.globalAlpha = rease
	context.beginPath();
	context.moveTo(link.source.x, link.source.y);
	context.lineTo(link.target.x, link.target.y);
	context.lineWidth = 3;
	//context.strokeStyle = interpolate(i/dlen);
	context.strokeStyle = "rgba(250,250,250,0.25)";
	context.stroke();
	}
	}
	context.globalAlpha = 1;


	/*
	context.lineWidth = 2;
	context.beginPath();
	for (var i = 0, n = nodes.length; i < n; ++i) {
	var node = nodes[i];
	context.moveTo(node.x, node.y);
	context.arc(node.x, node.y, 2, 0, τ);
	}


	context.strokeStyle = "#fff";
	context.stroke();
	context.fillStyle = "#000";
	context.fill();
	*/
	}

	function test(x,y) {
	var cx = width/2
	var cy = height/2
	var dx = x - cx
	var dy = y - cy
	var d2 = dx * dx + dy * dy
	var r2 = radius*radius
	if(d2 > r2) {
	x = cx + radius * dx/r2
	y = cy + radius * dy/r2
	}
	return [x,y]
	}
	function drawCell(cell) {
	if (!cell \|\| !cell[0]) return false;
	var x, y;

	x = cell[0][0];
	y = cell[0][1];
	/*
	if(x > width - 5) x = width-5;
	if(x < 5) x = 5;
	if(y > height - 5) y = height - 5;
	if(y < 5) y = 5;
	*/
	var p = test(x,y)
	context.moveTo(p[0], p[1]);

	for (var j = 1, m = cell.length; j < m; ++j) {
	if(!cell[j]) continue;
	x = cell[j][0];
	y = cell[j][1];
	/*
	if(x > width) x = width-5;
	if(x < 5) x = 5;
	if(y > height - 5) y = height - 5;
	if(y < 5) y = 5;
	*/
	p = test(x,y)
	context.lineTo(p[0], p[1]);
	}
	context.closePath();
	return true;
	}

	</script>