patricksurry/README.md

## README.md

      
    Raw
  

              README.md
            
          
    Adapted from this,
to avoid the second projection and make flying arc height proportional to length.
Because the 'sky' projection is just a scaled up version of the original one,
the projection of a sky point in canvas coords can be easily calculated by scaling
the ground projection point along the vector from the origin.
Another improvement(?) might be to avoid the swoosh/interpolate function by doing
this same trick directly on the stream of points that comes from the normal projection path
function.

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

.land {
  fill: #999;
  stroke-opacity: 1;
}

.graticule {
  fill: none;
  stroke: black;
  stroke-width:.5;
  opacity:.2;
}

.labels {
    font: 8px sans-serif;
    fill: black;
    opacity: .5;

    display:none;
}

.noclicks { pointer-events:none; }

.point {  opacity:.6; }

.arcs {
  opacity:.1;
  stroke: gray;
  stroke-width: 3;
}
.flyers {
  stroke-width:1;
  opacity: .6;
  stroke: darkred;
}
.arc, .flyer {
  stroke-linejoin: round;
  fill:none;
}
  .arc { }
  .flyer { }
  .flyer:hover { }

</style>

<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script src="http://d3js.org/queue.v1.min.js"></script>
<script src="http://d3js.org/topojson.v0.min.js"></script>
<script>

d3.select(window)
    .on("mousemove", mousemove)
    .on("mouseup", mouseup);

var width = 960,
    height = 500;

var proj = d3.geo.orthographic()
    .translate([width / 2, height / 2])
    .clipAngle(90)
    .scale(220);

var path = d3.geo.path().projection(proj).pointRadius(2);

var swoosh = d3.svg.line()
      .x(function(d) { return d[0] })
      .y(function(d) { return d[1] })
      .interpolate("cardinal")
      .tension(.0);

var links = [],
    arcLines = [];

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

queue()
    .defer(d3.json, "world-110m.json")
    .defer(d3.json, "places.json")
    .await(ready);

function ready(error, world, places) {
  var ocean_fill = svg.append("defs").append("radialGradient")
        .attr("id", "ocean_fill")
        .attr("cx", "75%")
        .attr("cy", "25%");
      ocean_fill.append("stop").attr("offset", "5%").attr("stop-color", "#fff");
      ocean_fill.append("stop").attr("offset", "100%").attr("stop-color", "#ababab");

  var globe_highlight = svg.append("defs").append("radialGradient")
        .attr("id", "globe_highlight")
        .attr("cx", "75%")
        .attr("cy", "25%");
      globe_highlight.append("stop")
        .attr("offset", "5%").attr("stop-color", "#ffd")
        .attr("stop-opacity","0.6");
      globe_highlight.append("stop")
        .attr("offset", "100%").attr("stop-color", "#ba9")
        .attr("stop-opacity","0.2");

  var globe_shading = svg.append("defs").append("radialGradient")
        .attr("id", "globe_shading")
        .attr("cx", "55%")
        .attr("cy", "45%");
      globe_shading.append("stop")
        .attr("offset","30%").attr("stop-color", "#fff")
        .attr("stop-opacity","0")
      globe_shading.append("stop")
        .attr("offset","100%").attr("stop-color", "#505962")
        .attr("stop-opacity","0.3")

  var drop_shadow = svg.append("defs").append("radialGradient")
        .attr("id", "drop_shadow")
        .attr("cx", "50%")
        .attr("cy", "50%");
      drop_shadow.append("stop")
        .attr("offset","20%").attr("stop-color", "#000")
        .attr("stop-opacity",".5")
      drop_shadow.append("stop")
        .attr("offset","100%").attr("stop-color", "#000")
        .attr("stop-opacity","0")

  svg.append("ellipse")
    .attr("cx", 440).attr("cy", 450)
    .attr("rx", proj.scale()*.90)
    .attr("ry", proj.scale()*.25)
    .attr("class", "noclicks")
    .style("fill", "url(#drop_shadow)");

  svg.append("circle")
    .attr("cx", width / 2).attr("cy", height / 2)
    .attr("r", proj.scale())
    .attr("class", "noclicks")
    .style("fill", "url(#ocean_fill)");

  svg.append("path")
    .datum(topojson.object(world, world.objects.land))
    .attr("class", "land noclicks")
    .attr("d", path);

  svg.append("circle")
    .attr("cx", width / 2).attr("cy", height / 2)
    .attr("r", proj.scale())
    .attr("class","noclicks")
    .style("fill", "url(#globe_highlight)");

  svg.append("circle")
    .attr("cx", width / 2).attr("cy", height / 2)
    .attr("r", proj.scale())
    .attr("class","noclicks")
    .style("fill", "url(#globe_shading)");

  svg.append("g").attr("class","points")
      .selectAll("text").data(places.features)
    .enter().append("path")
      .attr("class", "point")
      .attr("d", path);

  // spawn links between cities as source/target coord pairs
  places.features.forEach(function(a) {
    places.features.forEach(function(b) {
      if (a !== b) {
        links.push({
          source: a.geometry.coordinates,
          target: b.geometry.coordinates
        });
      }
    });
  });

  // build geoJSON features from links array
  links.forEach(function(e,i,a) {
    var feature =   { "type": "Feature", "geometry": { "type": "LineString", "coordinates": [e.source,e.target] }}
    arcLines.push(feature)
  })

  svg.append("g").attr("class","arcs")
    .selectAll("path").data(arcLines)
    .enter().append("path")
      .attr("class","arc")
      .attr("d",path)

  svg.append("g").attr("class","flyers")
    .selectAll("path").data(links)
    .enter().append("path")
    .attr("class","flyer")
    .attr("d", function(d) { return swoosh(flying_arc(d)) })

  refresh();
}

function flying_arc(pts) {
  var source = pts.source,
      target = pts.target;

  // get canvas coords of arc midpoint and globe center
  var mid = proj(location_along_arc(source, target, .5));
  var ctr = proj.translate();

  // max length of a great circle arc is π,
  // so 0.3 means longest path "flies" 20% of radius above the globe
  var scale = 1 + 0.3 * d3.geo.distance(source,target) / Math.PI;

  mid[0] = ctr[0] + (mid[0]-ctr[0])*scale;
  mid[1] = ctr[1] + (mid[1]-ctr[1])*scale;

  var result = [ proj(source),
                 mid,
                 proj(target) ]
  return result;
}


function refresh() {
  svg.selectAll(".land").attr("d", path);
  svg.selectAll(".point").attr("d", path);

  svg.selectAll(".arc").attr("d", path)
    .attr("opacity", function(d) {
        return fade_at_edge(d)
    })

  svg.selectAll(".flyer")
    .attr("d", function(d) { return swoosh(flying_arc(d)) })
    .attr("opacity", function(d) {
      return fade_at_edge(d)
    })
}

function fade_at_edge(d) {
  var centerPos = proj.invert([width/2,height/2]),
      arc = d3.geo.greatArc(),
      start, end;
  // function is called on 2 different data structures..
  if (d.source) {
    start = d.source,
    end = d.target;
  }
  else {
    start = d.geometry.coordinates[0];
    end = d.geometry.coordinates[1];
  }

  var start_dist = 1.57 - arc.distance({source: start, target: centerPos}),
      end_dist = 1.57 - arc.distance({source: end, target: centerPos});

  var fade = d3.scale.linear().domain([-.1,0]).range([0,.1])
  var dist = start_dist < end_dist ? start_dist : end_dist;

  return fade(dist)
}

function location_along_arc(start, end, loc) {
  var interpolator = d3.geo.interpolate(start,end);
  return interpolator(loc)
}

// modified from http://bl.ocks.org/1392560
var m0, o0;
function mousedown() {
  m0 = [d3.event.pageX, d3.event.pageY];
  o0 = proj.rotate();
  d3.event.preventDefault();
}
function mousemove() {
  if (m0) {
    var m1 = [d3.event.pageX, d3.event.pageY]
      , o1 = [o0[0] + (m1[0] - m0[0]) / 6, o0[1] + (m0[1] - m1[1]) / 6];
    o1[1] = o1[1] > 30  ? 30  :
            o1[1] < -30 ? -30 :
            o1[1];
    proj.rotate(o1);
    refresh();
  }
}
function mouseup() {
  if (m0) {
    mousemove();
    m0 = null;
  }
}
</script>

## places.json

      
Display the source blob

    
Display the rendered blob

    
    Raw
  

              places.json
            
          
      Loading

      Sorry, something went wrong. Reload?
      Sorry, we cannot display this file.
      Sorry, this file is invalid so it cannot be displayed.
      
          Viewer requires iframe.
      
    
## thumbnail.png

      
    Raw
  

              thumbnail.png
            
          
## world-110m.json

      
Display the source blob

    
Display the rendered blob

    
    Raw
  

              world-110m.json
            
          
      Loading

      Sorry, something went wrong. Reload?
      Sorry, we cannot display this file.
      Sorry, this file is invalid so it cannot be displayed.
      
          Viewer requires iframe.
	<!DOCTYPE html>
	<meta charset="utf-8">
	<style>

	.land {
	fill: #999;
	stroke-opacity: 1;
	}

	.graticule {
	fill: none;
	stroke: black;
	stroke-width:.5;
	opacity:.2;
	}

	.labels {
	font: 8px sans-serif;
	fill: black;
	opacity: .5;

	display:none;
	}

	.noclicks { pointer-events:none; }

	.point { opacity:.6; }

	.arcs {
	opacity:.1;
	stroke: gray;
	stroke-width: 3;
	}
	.flyers {
	stroke-width:1;
	opacity: .6;
	stroke: darkred;
	}
	.arc, .flyer {
	stroke-linejoin: round;
	fill:none;
	}
	.arc { }
	.flyer { }
	.flyer:hover { }

	</style>

	<body>
	<script src="http://d3js.org/d3.v3.min.js"></script>
	<script src="http://d3js.org/queue.v1.min.js"></script>
	<script src="http://d3js.org/topojson.v0.min.js"></script>
	<script>

	d3.select(window)
	.on("mousemove", mousemove)
	.on("mouseup", mouseup);

	var width = 960,
	height = 500;

	var proj = d3.geo.orthographic()
	.translate([width / 2, height / 2])
	.clipAngle(90)
	.scale(220);

	var path = d3.geo.path().projection(proj).pointRadius(2);

	var swoosh = d3.svg.line()
	.x(function(d) { return d[0] })
	.y(function(d) { return d[1] })
	.interpolate("cardinal")
	.tension(.0);

	var links = [],
	arcLines = [];

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

	queue()
	.defer(d3.json, "world-110m.json")
	.defer(d3.json, "places.json")
	.await(ready);

	function ready(error, world, places) {
	var ocean_fill = svg.append("defs").append("radialGradient")
	.attr("id", "ocean_fill")
	.attr("cx", "75%")
	.attr("cy", "25%");
	ocean_fill.append("stop").attr("offset", "5%").attr("stop-color", "#fff");
	ocean_fill.append("stop").attr("offset", "100%").attr("stop-color", "#ababab");

	var globe_highlight = svg.append("defs").append("radialGradient")
	.attr("id", "globe_highlight")
	.attr("cx", "75%")
	.attr("cy", "25%");
	globe_highlight.append("stop")
	.attr("offset", "5%").attr("stop-color", "#ffd")
	.attr("stop-opacity","0.6");
	globe_highlight.append("stop")
	.attr("offset", "100%").attr("stop-color", "#ba9")
	.attr("stop-opacity","0.2");

	var globe_shading = svg.append("defs").append("radialGradient")
	.attr("id", "globe_shading")
	.attr("cx", "55%")
	.attr("cy", "45%");
	globe_shading.append("stop")
	.attr("offset","30%").attr("stop-color", "#fff")
	.attr("stop-opacity","0")
	globe_shading.append("stop")
	.attr("offset","100%").attr("stop-color", "#505962")
	.attr("stop-opacity","0.3")

	var drop_shadow = svg.append("defs").append("radialGradient")
	.attr("id", "drop_shadow")
	.attr("cx", "50%")
	.attr("cy", "50%");
	drop_shadow.append("stop")
	.attr("offset","20%").attr("stop-color", "#000")
	.attr("stop-opacity",".5")
	drop_shadow.append("stop")
	.attr("offset","100%").attr("stop-color", "#000")
	.attr("stop-opacity","0")

	svg.append("ellipse")
	.attr("cx", 440).attr("cy", 450)
	.attr("rx", proj.scale()*.90)
	.attr("ry", proj.scale()*.25)
	.attr("class", "noclicks")
	.style("fill", "url(#drop_shadow)");

	svg.append("circle")
	.attr("cx", width / 2).attr("cy", height / 2)
	.attr("r", proj.scale())
	.attr("class", "noclicks")
	.style("fill", "url(#ocean_fill)");

	svg.append("path")
	.datum(topojson.object(world, world.objects.land))
	.attr("class", "land noclicks")
	.attr("d", path);

	svg.append("circle")
	.attr("cx", width / 2).attr("cy", height / 2)
	.attr("r", proj.scale())
	.attr("class","noclicks")
	.style("fill", "url(#globe_highlight)");

	svg.append("circle")
	.attr("cx", width / 2).attr("cy", height / 2)
	.attr("r", proj.scale())
	.attr("class","noclicks")
	.style("fill", "url(#globe_shading)");

	svg.append("g").attr("class","points")
	.selectAll("text").data(places.features)
	.enter().append("path")
	.attr("class", "point")
	.attr("d", path);

	// spawn links between cities as source/target coord pairs
	places.features.forEach(function(a) {
	places.features.forEach(function(b) {
	if (a !== b) {
	links.push({
	source: a.geometry.coordinates,
	target: b.geometry.coordinates
	});
	}
	});
	});

	// build geoJSON features from links array
	links.forEach(function(e,i,a) {
	var feature = { "type": "Feature", "geometry": { "type": "LineString", "coordinates": [e.source,e.target] }}
	arcLines.push(feature)
	})

	svg.append("g").attr("class","arcs")
	.selectAll("path").data(arcLines)
	.enter().append("path")
	.attr("class","arc")
	.attr("d",path)

	svg.append("g").attr("class","flyers")
	.selectAll("path").data(links)
	.enter().append("path")
	.attr("class","flyer")
	.attr("d", function(d) { return swoosh(flying_arc(d)) })

	refresh();
	}

	function flying_arc(pts) {
	var source = pts.source,
	target = pts.target;

	// get canvas coords of arc midpoint and globe center
	var mid = proj(location_along_arc(source, target, .5));
	var ctr = proj.translate();

	// max length of a great circle arc is π,
	// so 0.3 means longest path "flies" 20% of radius above the globe
	var scale = 1 + 0.3 * d3.geo.distance(source,target) / Math.PI;

	mid[0] = ctr[0] + (mid[0]-ctr[0])*scale;
	mid[1] = ctr[1] + (mid[1]-ctr[1])*scale;

	var result = [ proj(source),
	mid,
	proj(target) ]
	return result;
	}



	function refresh() {
	svg.selectAll(".land").attr("d", path);
	svg.selectAll(".point").attr("d", path);

	svg.selectAll(".arc").attr("d", path)
	.attr("opacity", function(d) {
	return fade_at_edge(d)
	})

	svg.selectAll(".flyer")
	.attr("d", function(d) { return swoosh(flying_arc(d)) })
	.attr("opacity", function(d) {
	return fade_at_edge(d)
	})
	}

	function fade_at_edge(d) {
	var centerPos = proj.invert([width/2,height/2]),
	arc = d3.geo.greatArc(),
	start, end;
	// function is called on 2 different data structures..
	if (d.source) {
	start = d.source,
	end = d.target;
	}
	else {
	start = d.geometry.coordinates[0];
	end = d.geometry.coordinates[1];
	}

	var start_dist = 1.57 - arc.distance({source: start, target: centerPos}),
	end_dist = 1.57 - arc.distance({source: end, target: centerPos});

	var fade = d3.scale.linear().domain([-.1,0]).range([0,.1])
	var dist = start_dist < end_dist ? start_dist : end_dist;

	return fade(dist)
	}

	function location_along_arc(start, end, loc) {
	var interpolator = d3.geo.interpolate(start,end);
	return interpolator(loc)
	}

	// modified from http://bl.ocks.org/1392560
	var m0, o0;
	function mousedown() {
	m0 = [d3.event.pageX, d3.event.pageY];
	o0 = proj.rotate();
	d3.event.preventDefault();
	}
	function mousemove() {
	if (m0) {
	var m1 = [d3.event.pageX, d3.event.pageY]
	, o1 = [o0[0] + (m1[0] - m0[0]) / 6, o0[1] + (m0[1] - m1[1]) / 6];
	o1[1] = o1[1] > 30 ? 30 :
	o1[1] < -30 ? -30 :
	o1[1];
	proj.rotate(o1);
	refresh();
	}
	}
	function mouseup() {
	if (m0) {
	mousemove();
	m0 = null;
	}
	}
	</script>