mbostock/.block

## .block
license: gpl-3.0

## README.md

      
    Raw
  

              README.md
            
          
    Compare to Canvas Swarm.
A response to Trevor Bedford's post, Comparing performance of Processing.js and D3.js.

  
## index.html
<!DOCTYPE html>
<meta charset="utf-8">
<title>SVG Swarm</title>
<style>

svg {
  position: absolute;
  top: 0;
}

circle {
  fill: steelblue;
  stroke: #666;
  stroke-width: 1.5px;
}

</style>
<div id="fps">FPS: <span>?</span></div>
<script src="//d3js.org/d3.v3.min.js"></script>
<script>

var data = d3.range(500).map(function() {
  return {xloc: 0, yloc: 0, xvel: 0, yvel: 0};
});

var width = 960,
    height = 500;

var x = d3.scale.linear()
    .domain([-5, 5])
    .range([0, width]);

var y = d3.scale.linear()
    .domain([-5, 5])
    .range([0, height]);

var time0 = Date.now(),
    time1;

var fps = d3.select("#fps span");

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

var circle = svg.selectAll("circle")
    .data(data)
  .enter().append("circle")
    .attr("cx", 10)
    .attr("cy", 10)
    .attr("r", 1);

d3.timer(function() {

  data.forEach(function(d) {
    d.xloc += d.xvel;
    d.yloc += d.yvel;
    d.xvel += 0.04 * (Math.random() - .5) - 0.05 * d.xvel - 0.0005 * d.xloc;
    d.yvel += 0.04 * (Math.random() - .5) - 0.05 * d.yvel - 0.0005 * d.yloc;
  });

  circle
      .attr("transform", function(d) { return "translate(" + x(d.xloc) + "," + y(d.yloc) + ")"; })
      .attr("r", function(d) { return Math.min(1 + 1000 * Math.abs(d.xvel * d.yvel), 10); });

  time1 = Date.now();
  fps.text(Math.round(1000 / (time1 - time0)));
  time0 = time1;
});

</script>

## thumbnail.png

      
    Raw
  

              thumbnail.png
	<!DOCTYPE html>
	<meta charset="utf-8">
	<title>SVG Swarm</title>
	<style>

	svg {
	position: absolute;
	top: 0;
	}

	circle {
	fill: steelblue;
	stroke: #666;
	stroke-width: 1.5px;
	}

	</style>
	<div id="fps">FPS: <span>?</span></div>
	<script src="//d3js.org/d3.v3.min.js"></script>
	<script>

	var data = d3.range(500).map(function() {
	return {xloc: 0, yloc: 0, xvel: 0, yvel: 0};
	});

	var width = 960,
	height = 500;

	var x = d3.scale.linear()
	.domain([-5, 5])
	.range([0, width]);

	var y = d3.scale.linear()
	.domain([-5, 5])
	.range([0, height]);

	var time0 = Date.now(),
	time1;

	var fps = d3.select("#fps span");

	var svg = d3.select("body").append("svg")
	.attr("width", width)
	.attr("height", height);

	var circle = svg.selectAll("circle")
	.data(data)
	.enter().append("circle")
	.attr("cx", 10)
	.attr("cy", 10)
	.attr("r", 1);

	d3.timer(function() {

	data.forEach(function(d) {
	d.xloc += d.xvel;
	d.yloc += d.yvel;
	d.xvel += 0.04 * (Math.random() - .5) - 0.05 * d.xvel - 0.0005 * d.xloc;
	d.yvel += 0.04 * (Math.random() - .5) - 0.05 * d.yvel - 0.0005 * d.yloc;
	});

	circle
	.attr("transform", function(d) { return "translate(" + x(d.xloc) + "," + y(d.yloc) + ")"; })
	.attr("r", function(d) { return Math.min(1 + 1000 * Math.abs(d.xvel * d.yvel), 10); });

	time1 = Date.now();
	fps.text(Math.round(1000 / (time1 - time0)));
	time0 = time1;
	});

	</script>