cdecker/README.md

## README.md

      
    Raw
  

              README.md
            
          
    A demo of the d3.geo.tile plugin, which determines which 256x256 tiles are visible in the viewport based on a scale and translate. This demo combines the tile plugin with d3.behavior.zoom for panning and zooming, resulting in a a simple slippy map. Based partly on an example by Tom MacWright.

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

body {
  margin: 0;
}

.map {
  position: relative;
  overflow: hidden;
}

.layer {
  position: absolute;
}

.tile {
  position: absolute;
  width: 256px;
  height: 256px;
}

.info {
  position: absolute;
  bottom: 10px;
  left: 10px;
}

</style>
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script src="http://d3js.org/d3.geo.tile.v0.min.js"></script>
<script>

var width = window.innerWidth,
    height = window.innerHeight,
    prefix = prefixMatch(["webkit", "ms", "Moz", "O"]);

var tile = d3.geo.tile()
    .size([width, height]);

var projection = d3.geo.mercator();

var zoom = d3.behavior.zoom()
    .scale(1 << 12)
    .scaleExtent([1 << 9, 1 << 23])
    .translate([width / 2, height / 2])
    .on("zoom", zoomed);

var map = d3.select("body").append("div")
    .attr("class", "map")
    .style("width", width + "px")
    .style("height", height + "px")
    .call(zoom)
    .on("mousemove", mousemoved);

var layer = map.append("div")
    .attr("class", "layer");

var info = map.append("div")
    .attr("class", "info");

zoomed();

function zoomed() {
  var tiles = tile
      .scale(zoom.scale())
      .translate(zoom.translate())
      ();

  projection
      .scale(zoom.scale())
      .translate(zoom.translate());

  var image = layer
      .style(prefix + "transform", matrix3d(tiles.scale, tiles.translate))
    .selectAll(".tile")
      .data(tiles, function(d) { return d; });

  image.exit()
      .remove();

  image.enter().append("img")
      .attr("class", "tile")
      .attr("src", function(d) { return "http://" + ["a", "b", "c", "d"][Math.random() * 4 | 0] + ".tiles.mapbox.com/v3/cdecker.map-wxuc0fyi/" + d[2] + "/" + d[0] + "/" + d[1] + ".png"; })
      .style("left", function(d) { return (d[0] << 8) + "px"; })
      .style("top", function(d) { return (d[1] << 8) + "px"; });
}

function mousemoved() {
  info.text(formatLocation(projection.invert(d3.mouse(this)), zoom.scale()));
}

function matrix3d(scale, translate) {
  var k = scale / 256, r = scale % 1 ? Number : Math.round;
  return "matrix3d(" + [k, 0, 0, 0, 0, k, 0, 0, 0, 0, k, 0, r(translate[0] * scale), r(translate[1] * scale), 0, 1 ] + ")";
}

function prefixMatch(p) {
  var i = -1, n = p.length, s = document.body.style;
  while (++i < n) if (p[i] + "Transform" in s) return "-" + p[i].toLowerCase() + "-";
  return "";
}

function formatLocation(p, k) {
  var format = d3.format("." + Math.floor(Math.log(k) / 2 - 2) + "f");
  return (p[1] < 0 ? format(-p[1]) + "°S" : format(p[1]) + "°N") + " "
       + (p[0] < 0 ? format(-p[0]) + "°W" : format(p[0]) + "°E");
}

</script>

## thumbnail.png

      
    Raw
  

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

	body {
	margin: 0;
	}

	.map {
	position: relative;
	overflow: hidden;
	}

	.layer {
	position: absolute;
	}

	.tile {
	position: absolute;
	width: 256px;
	height: 256px;
	}

	.info {
	position: absolute;
	bottom: 10px;
	left: 10px;
	}

	</style>
	<body>
	<script src="http://d3js.org/d3.v3.min.js"></script>
	<script src="http://d3js.org/d3.geo.tile.v0.min.js"></script>
	<script>

	var width = window.innerWidth,
	height = window.innerHeight,
	prefix = prefixMatch(["webkit", "ms", "Moz", "O"]);

	var tile = d3.geo.tile()
	.size([width, height]);

	var projection = d3.geo.mercator();

	var zoom = d3.behavior.zoom()
	.scale(1 << 12)
	.scaleExtent([1 << 9, 1 << 23])
	.translate([width / 2, height / 2])
	.on("zoom", zoomed);

	var map = d3.select("body").append("div")
	.attr("class", "map")
	.style("width", width + "px")
	.style("height", height + "px")
	.call(zoom)
	.on("mousemove", mousemoved);

	var layer = map.append("div")
	.attr("class", "layer");

	var info = map.append("div")
	.attr("class", "info");

	zoomed();

	function zoomed() {
	var tiles = tile
	.scale(zoom.scale())
	.translate(zoom.translate())
	();

	projection
	.scale(zoom.scale())
	.translate(zoom.translate());

	var image = layer
	.style(prefix + "transform", matrix3d(tiles.scale, tiles.translate))
	.selectAll(".tile")
	.data(tiles, function(d) { return d; });

	image.exit()
	.remove();

	image.enter().append("img")
	.attr("class", "tile")
	.attr("src", function(d) { return "http://" + ["a", "b", "c", "d"][Math.random() * 4 \| 0] + ".tiles.mapbox.com/v3/cdecker.map-wxuc0fyi/" + d[2] + "/" + d[0] + "/" + d[1] + ".png"; })
	.style("left", function(d) { return (d[0] << 8) + "px"; })
	.style("top", function(d) { return (d[1] << 8) + "px"; });
	}

	function mousemoved() {
	info.text(formatLocation(projection.invert(d3.mouse(this)), zoom.scale()));
	}

	function matrix3d(scale, translate) {
	var k = scale / 256, r = scale % 1 ? Number : Math.round;
	return "matrix3d(" + [k, 0, 0, 0, 0, k, 0, 0, 0, 0, k, 0, r(translate[0] * scale), r(translate[1] * scale), 0, 1 ] + ")";
	}

	function prefixMatch(p) {
	var i = -1, n = p.length, s = document.body.style;
	while (++i < n) if (p[i] + "Transform" in s) return "-" + p[i].toLowerCase() + "-";
	return "";
	}

	function formatLocation(p, k) {
	var format = d3.format("." + Math.floor(Math.log(k) / 2 - 2) + "f");
	return (p[1] < 0 ? format(-p[1]) + "°S" : format(p[1]) + "°N") + " "
	+ (p[0] < 0 ? format(-p[0]) + "°W" : format(p[0]) + "°E");
	}

	</script>