erlenstar/.block

## .block
license: gpl-3.0

## README.md

      
    Raw
  

              README.md
            
          
    Some force-directed points, with a Delaunay mesh overlaid, filtered so that only links less than 100px long are drawn.

  
## index.html
<!DOCTYPE html>
<meta charset="utf-8">
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script>

var width = 960,
    height = 500,
    τ = 2 * Math.PI,
    maxLength = 100,
    maxLength2 = maxLength * maxLength;

var nodes = d3.range(200).map(function() {
  return {
    x: Math.random() * width,
    y: Math.random() * height
  };
});

var force = d3.layout.force()
    .size([width, height])
    .nodes(nodes.slice())
    .charge(function(d, i) { return i ? -30 : -1500; })
    .on("tick", ticked)
    .start();

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

var root = nodes.shift();

root.fixed = true;

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");

function moved() {
  var p1 = d3.mouse(this);
  root.px = p1[0];
  root.py = p1[1];
  force.resume();
}

function ticked() {
  var links = voronoi.links(nodes);

  context.clearRect(0, 0, width, height);

  context.beginPath();
  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;
    if (dx * dx + dy * dy < maxLength2) {
      context.moveTo(link.source.x, link.source.y);
      context.lineTo(link.target.x, link.target.y);
    }
  }
  context.lineWidth = 1;
  context.strokeStyle = "#bbb";
  context.stroke();

  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.lineWidth = 3;
  context.strokeStyle = "#fff";
  context.stroke();
  context.fillStyle = "#000";
  context.fill();
}

</script>

## thumbnail.png

      
    Raw
  

              thumbnail.png
	<!DOCTYPE html>
	<meta charset="utf-8">
	<body>
	<script src="//d3js.org/d3.v3.min.js"></script>
	<script>

	var width = 960,
	height = 500,
	τ = 2 * Math.PI,
	maxLength = 100,
	maxLength2 = maxLength * maxLength;

	var nodes = d3.range(200).map(function() {
	return {
	x: Math.random() * width,
	y: Math.random() * height
	};
	});

	var force = d3.layout.force()
	.size([width, height])
	.nodes(nodes.slice())
	.charge(function(d, i) { return i ? -30 : -1500; })
	.on("tick", ticked)
	.start();

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

	var root = nodes.shift();

	root.fixed = true;

	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");

	function moved() {
	var p1 = d3.mouse(this);
	root.px = p1[0];
	root.py = p1[1];
	force.resume();
	}

	function ticked() {
	var links = voronoi.links(nodes);

	context.clearRect(0, 0, width, height);

	context.beginPath();
	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;
	if (dx * dx + dy * dy < maxLength2) {
	context.moveTo(link.source.x, link.source.y);
	context.lineTo(link.target.x, link.target.y);
	}
	}
	context.lineWidth = 1;
	context.strokeStyle = "#bbb";
	context.stroke();

	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.lineWidth = 3;
	context.strokeStyle = "#fff";
	context.stroke();
	context.fillStyle = "#000";
	context.fill();
	}

	</script>