Earthquake Map with fisheye (projected) canvas

Render with canvas instead of SVG for better re-rendering performance. Makes the awesome fisheye effect a little bit smoother.

forked from pnavarrc's block: Earthquake Map

forked from jonpage's block: Earthquake Map

forked from jgondin's block: Earthquake Map

forked from Fil's block: Earthquake Map with fisheye (polar)

forked from Fil's block: Earthquake Map with fisheye (projected) + throttle

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">

<title>Earthquake Map</title>

svg {
    background-color: #111;
    cursor: pointer;
  }

.land {
    fill: #333;
    stroke: #555;
    stroke-width: 1;
  }

.earthquake {
    fill-opacity: 0.6;
  }
  </style>

// Create a selection for the container div and append the svg element
var div = d3.select('#map-container'),
    canvas = div.append('canvas');

var land;
var earthquakes;

// Set the size of the SVG element
canvas.attr('width', width).attr('height', height)
var c = canvas.node();
c.width = width;
c.height = height;
var ctx = c.getContext('2d');
    
ctx.globalCompositeOperation = "lighter"

// Create and configure a geographic projection
var _projection = d3.geo.equirectangular()
    .translate([width / 2, height / 2]);

var fisheye = d3.fisheye();

// to start, unclutter JAPAN
var DEG = 180 / Math.PI,
    JAPAN = [138, 36],
    RADIUS = 90,
    POWER = 2.75;
fisheye.center(JAPAN).radius(RADIUS).power(POWER);

var projection = d3.geo.projection(function (λ, φ) {
        λ *= DEG, φ *= DEG;
        var p = fisheye(_projection([λ, φ]));
        return [p[0], -p[1]];
    })
    .scale(1)
    .translate([width / 2, height / 2]);

// Create and configure a path generator
var pathGenerator = d3.geo.path()
    .projection(projection)
    .context(ctx)

//var land = circles = svg.select('nada');
var movehandle = helpers.throttle(function () {
  ctx.fillStyle = "#111"
  ctx.clearRect(0, 0, width, height)
  ctx.fillRect(0, 0, width, height)
  renderLand();
  renderEarthquakes();
    //land.attr('d', pathGenerator);
  /*
    circles
        .each(function (d) {
            var pos = (projection(d.coords));
            //console.log(pos);
            d3.select(this)
                .attr('cx', function (d) {
                    return pos[0];
                })
                .attr('cy', function (d) {
                    return pos[1];
                });
        });
  */
    //land.attr('d', pathGenerator);
}, 10, this);

canvas.on("mousemove", function () {
    fisheye.center(d3.mouse(this));
    movehandle();
});
    
ctx.fillStyle = "#111"
ctx.fillRect(0, 0, width, height)

// Retrieve the geographic data asynchronously
d3.json('land.geojson', function (err, data) {

// Throw errors on getting or parsing the file
    if (err) {
        throw err;
    }

// Land
    land = data;
  /*
    land = svg.select('g.map').selectAll('path.land').data([data]);

land.enter().append('path').classed('land', true);
    land.attr('d', pathGenerator);
    land.exit().remove();
    */
  renderLand()
});
    
function renderLand() {
  ctx.fillStyle = "#333";
  ctx.strokeStyle = "#555";
  land.features.forEach(function(d) {
    ctx.beginPath();
    pathGenerator(d);
    ctx.fill();
    ctx.stroke();
  })
}

// Load the Earthquake data
// https://earthquake.usgs.gov/earthquakes/search/
// https://earthquake.usgs.gov/earthquakes/map/doc_aboutdata.php
d3.csv('earthquakes.csv', function (err, csvdata) {
  console.log("csv", csvdata)
  if (err) {
      throw err;
  }

// Parse the data
  csvdata.forEach(function (d) {
      d.coords = [+d.longitude, +d.latitude];
      d.magnitude = +d.mag;
  });

csvdata.sort(function (a, b) {
      return a.magnitude > b.magnitude ? -1 : 1;
  });

earthquakes = csvdata;
  renderEarthquakes();
})
function renderEarthquakes() {
  // Radius scale
  var rScale = d3.scale.sqrt()
      .domain(d3.extent(earthquakes, function (d) {
          return d.magnitude;
      }))
      .range([1, 10]);

var cScale = d3.scale.sqrt()
      .domain(rScale.domain())
      .range(['#ECD078', '#C02942']);

earthquakes.forEach(function(d) {
    var p = projection(d.coords)
    var color = d3.rgb(cScale(d.magnitude))

ctx.fillStyle = "rgba(" + [color.r, color.g, color.b, 0.2] + ")"
    ctx.beginPath();
    ctx.arc(p[0], p[1], rScale(d.magnitude), 0, 2 * Math.PI)
    ctx.fill();
  })
}
  	/*
    circles = svg.select('g.dots').selectAll('circle.earthquake').data(csvdata);

circles.enter().append('circle')
        .classed('earthquake', true);

circles
        .attr('r', function (d) {
            return rScale(d.magnitude);
        })
        .attr('cx', function (d) {
            return projection(d.coords)[0];
        })
        .attr('cy', function (d) {
            return projection(d.coords)[1];
        })
        .attr('fill', function (d) {
            return cScale(d.magnitude);
        });

circles.exit().remove();
    */
;

</script>

</body>
</html>

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.6/d3.min.js