dannycochran · February 22, 2016 20:15
diff --git a/index.html b/index.html
 <!DOCTYPE html>
 <meta charset="utf-8">
 <title>Spline Editor</title>
 <style>
 body {
  font: 13px sans-serif;
  position: relative;
  width: 960px;
  height: 500px;
 }
 form {
  position: absolute;
  bottom: 10px;
  left: 10px;
 }
 rect {
  fill: none;
  pointer-events: all;
 }
 circle,
 .line {
  fill: none;
  stroke: steelblue;
  stroke-width: 1.5px;
 }
 circle {
  fill: #fff;
  fill-opacity: .2;
  cursor: move;
 }
 .selected {
  fill: #ff7f0e;
  stroke: #ff7f0e;
 }
 </style>
 <form>
  <label for="interpolate">Interpolate:</label>
  <select id="interpolate"></select><br>
 </form>
 <script src="//d3js.org/d3.v3.min.js"></script>
 <script>
 var width = 960,
    height = 500;
 var points = d3.range(1, 5).map(function(i) {
  return [i * width / 5, 50 + Math.random() * (height - 100)];
 });
 var dragged = null,
    selected = points[0];
 var line = d3.svg.line().interpolate('step-after');
 var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height)
    .attr("tabindex", 1);
 svg.append("rect")
    .attr("width", width)
    .attr("height", height)
    .on("mousedown", mousedown);
 svg.append("path")
    .datum(points)
    .attr("class", "line")
    .call(redraw);
 d3.select(window)
    .on("mousemove", mousemove)
    .on("mouseup", mouseup)
    .on("keydown", keydown);
 d3.select("#interpolate")
    .on("change", change)
  .selectAll("option")
    .data([
      "step-after",
      "linear",
      "step-before",
      "basis",
      "basis-open",
      "basis-closed",
      "cardinal",
      "cardinal-open",
      "cardinal-closed",
      "monotone"
    ])
  .enter().append("option")
    .attr("value", function(d) { return d; })
    .text(function(d) { return d; });
 svg.node().focus();
 function redraw() {
  svg.select("path").attr("d", line);
  var circle = svg.selectAll("circle")
      .data(points, function(d) { return d; });
  circle.enter().append("circle")
      .attr("r", 1e-6)
      .on("mousedown", function(d) { selected = dragged = d; redraw(); })
    .transition()
      .duration(750)
      .ease("elastic")
      .attr("r", 6.5);
  circle
      .classed("selected", function(d) { return d === selected; })
      .attr("cx", function(d) { return d[0]; })
      .attr("cy", function(d) { return d[1]; });
  circle.exit().remove();
  if (d3.event) {
    d3.event.preventDefault();
    d3.event.stopPropagation();
  }
 }
 function change() {
  line.interpolate(this.value);
  redraw();
 }
 function mousedown() {
  points.push(selected = dragged = d3.mouse(svg.node()));
  redraw();
 }
 function mousemove() {
  if (!dragged) return;
  var m = d3.mouse(svg.node());
  dragged[0] = Math.max(0, Math.min(width, m[0]));
  dragged[1] = Math.max(0, Math.min(height, m[1]));
  redraw();
 }
 function mouseup() {
  if (!dragged) return;
  mousemove();
  dragged = null;
 }
 function keydown() {
  if (!selected) return;
  switch (d3.event.keyCode) {
    case 8: // backspace
    case 46: { // delete
      var i = points.indexOf(selected);
      points.splice(i, 1);
      selected = points.length ? points[i > 0 ? i - 1 : 0] : null;
      redraw();
      break;
    }
  }
 }
 </script>
	<!DOCTYPE html>
	<meta charset="utf-8">
	<title>Spline Editor</title>
	<style>
	body {
	font: 13px sans-serif;
	position: relative;
	width: 960px;
	height: 500px;
	}
	form {
	position: absolute;
	bottom: 10px;
	left: 10px;
	}
	rect {
	fill: none;
	pointer-events: all;
	}
	circle,
	.line {
	fill: none;
	stroke: steelblue;
	stroke-width: 1.5px;
	}
	circle {
	fill: #fff;
	fill-opacity: .2;
	cursor: move;
	}
	.selected {
	fill: #ff7f0e;
	stroke: #ff7f0e;
	}
	</style>
	<form>
	<label for="interpolate">Interpolate:</label>
	<select id="interpolate"></select><br>
	</form>
	<script src="//d3js.org/d3.v3.min.js"></script>
	<script>
	var width = 960,
	height = 500;
	var points = d3.range(1, 5).map(function(i) {
	return [i * width / 5, 50 + Math.random() * (height - 100)];
	});
	var dragged = null,
	selected = points[0];
	var line = d3.svg.line().interpolate('step-after');
	var svg = d3.select("body").append("svg")
	.attr("width", width)
	.attr("height", height)
	.attr("tabindex", 1);
	svg.append("rect")
	.attr("width", width)
	.attr("height", height)
	.on("mousedown", mousedown);
	svg.append("path")
	.datum(points)
	.attr("class", "line")
	.call(redraw);
	d3.select(window)
	.on("mousemove", mousemove)
	.on("mouseup", mouseup)
	.on("keydown", keydown);
	d3.select("#interpolate")
	.on("change", change)
	.selectAll("option")
	.data([
	"step-after",
	"linear",
	"step-before",
	"basis",
	"basis-open",
	"basis-closed",
	"cardinal",
	"cardinal-open",
	"cardinal-closed",
	"monotone"
	])
	.enter().append("option")
	.attr("value", function(d) { return d; })
	.text(function(d) { return d; });
	svg.node().focus();
	function redraw() {
	svg.select("path").attr("d", line);
	var circle = svg.selectAll("circle")
	.data(points, function(d) { return d; });
	circle.enter().append("circle")
	.attr("r", 1e-6)
	.on("mousedown", function(d) { selected = dragged = d; redraw(); })
	.transition()
	.duration(750)
	.ease("elastic")
	.attr("r", 6.5);
	circle
	.classed("selected", function(d) { return d === selected; })
	.attr("cx", function(d) { return d[0]; })
	.attr("cy", function(d) { return d[1]; });
	circle.exit().remove();
	if (d3.event) {
	d3.event.preventDefault();
	d3.event.stopPropagation();
	}
	}
	function change() {
	line.interpolate(this.value);
	redraw();
	}
	function mousedown() {
	points.push(selected = dragged = d3.mouse(svg.node()));
	redraw();
	}
	function mousemove() {
	if (!dragged) return;
	var m = d3.mouse(svg.node());
	dragged[0] = Math.max(0, Math.min(width, m[0]));
	dragged[1] = Math.max(0, Math.min(height, m[1]));
	redraw();
	}
	function mouseup() {
	if (!dragged) return;
	mousemove();
	dragged = null;
	}
	function keydown() {
	if (!selected) return;
	switch (d3.event.keyCode) {
	case 8: // backspace
	case 46: { // delete
	var i = points.indexOf(selected);
	points.splice(i, 1);
	selected = points.length ? points[i > 0 ? i - 1 : 0] : null;
	redraw();
	break;
	}
	}
	}
	</script>