larskotthoff/README.md

## readme-blue-marble.jpg

      
    Raw
  

              readme-blue-marble.jpg
            
          
## README.md

      
    Raw
  

              README.md
            
          
    The NASA Blue Marble is reprojected using d3.geo.kavrayskiy7’s invert function. Jason Davies has since done some amazing work on reprojecting raster tiles.

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

body {
  background: #222;
}

</style>
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script src="http://d3js.org/d3.geo.projection.v0.min.js"></script>
<script>
var scale = 1,
    radius = 150;
var width = 960,
    height = 500;

var projection = d3.geo.kavrayskiy7();

var path = d3.geo.path()
    .projection(projection);

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

var context = canvas.node().getContext("2d");

var image = new Image;
image.onload = onload;
image.src = "readme-blue-marble.jpg";

function onload() {
  var dx = image.width,
      dy = image.height;

  context.drawImage(image, 0, 0, dx, dy);

  var sourceData = context.getImageData(0, 0, dx, dy).data,
      target = context.createImageData(width, height),
      targetData = target.data;

  for (var y = 0, i = -1; y < height; ++y) {
    for (var x = 0; x < width; ++x) {
      var p = projection.invert([x, y]), λ = p[0], φ = p[1];
      if (λ > 180 || λ < -180 || φ > 90 || φ < -90) { i += 4; continue; }
      var q = ((90 - φ) / 180 * dy | 0) * dx + ((180 + λ) / 360 * dx | 0) << 2;
      targetData[++i] = sourceData[q];
      targetData[++i] = sourceData[++q];
      targetData[++i] = sourceData[++q];
      targetData[++i] = 255;
    }
  }

  context.clearRect(0, 0, width, height);
  context.putImageData(target, 0, 0);
}

var zoom = d3.behavior.zoom()

    .center([width / 2, height / 2])
    .on("zoomstart", function () {
    m0 = [d3.event.sourceEvent.pageX, d3.event.sourceEvent.pageY];
    var proj = projection.rotate();
    o0 = [-proj[0], -proj[1]];
    d3.event.sourceEvent.stopPropagation();
})
    .on("zoom", function () {
    if (m0) {
        var constant = (scale < 4) ? 4 : scale * 2;
        var m1 = [d3.event.sourceEvent.pageX, d3.event.sourceEvent.pageY],
            o1 = [o0[0] + (m0[0] - m1[0]) / constant, o0[1] + (m1[1] - m0[1]) / constant];
    }
    rotate = [-o1[0], -o1[1]];
    projection.rotate(rotate);
    onload();
});

d3.select('canvas').call(zoom);

</script>

## thumbnail.png

      
    Raw
  

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

	body {
	background: #222;
	}

	</style>
	<body>
	<script src="http://d3js.org/d3.v3.min.js"></script>
	<script src="http://d3js.org/d3.geo.projection.v0.min.js"></script>
	<script>
	var scale = 1,
	radius = 150;
	var width = 960,
	height = 500;

	var projection = d3.geo.kavrayskiy7();

	var path = d3.geo.path()
	.projection(projection);

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

	var context = canvas.node().getContext("2d");

	var image = new Image;
	image.onload = onload;
	image.src = "readme-blue-marble.jpg";

	function onload() {
	var dx = image.width,
	dy = image.height;

	context.drawImage(image, 0, 0, dx, dy);

	var sourceData = context.getImageData(0, 0, dx, dy).data,
	target = context.createImageData(width, height),
	targetData = target.data;

	for (var y = 0, i = -1; y < height; ++y) {
	for (var x = 0; x < width; ++x) {
	var p = projection.invert([x, y]), λ = p[0], φ = p[1];
	if (λ > 180 \|\| λ < -180 \|\| φ > 90 \|\| φ < -90) { i += 4; continue; }
	var q = ((90 - φ) / 180 * dy \| 0) * dx + ((180 + λ) / 360 * dx \| 0) << 2;
	targetData[++i] = sourceData[q];
	targetData[++i] = sourceData[++q];
	targetData[++i] = sourceData[++q];
	targetData[++i] = 255;
	}
	}

	context.clearRect(0, 0, width, height);
	context.putImageData(target, 0, 0);
	}

	var zoom = d3.behavior.zoom()

	.center([width / 2, height / 2])
	.on("zoomstart", function () {
	m0 = [d3.event.sourceEvent.pageX, d3.event.sourceEvent.pageY];
	var proj = projection.rotate();
	o0 = [-proj[0], -proj[1]];
	d3.event.sourceEvent.stopPropagation();
	})
	.on("zoom", function () {
	if (m0) {
	var constant = (scale < 4) ? 4 : scale * 2;
	var m1 = [d3.event.sourceEvent.pageX, d3.event.sourceEvent.pageY],
	o1 = [o0[0] + (m0[0] - m1[0]) / constant, o0[1] + (m1[1] - m0[1]) / constant];
	}
	rotate = [-o1[0], -o1[1]];
	projection.rotate(rotate);
	onload();
	});

	d3.select('canvas').call(zoom);

	</script>