willgriffiths/index.html

## index.html
<!DOCTYPE html>
<meta charset="utf-8">
<style>
body {
    margin: 0;
}

svg {
    position: absolute;
}

.tooltip text {
  font: 14px Helvetica, Arial, sans-serif;
}

.tooltip rect {
  fill: rgba(200, 200, 200, 0.8);
}
</style>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.1.0/d3.min.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/topojson/3.0.0/topojson.min.js"></script>
<script type="text/javascript" src="https://d3js.org/d3-scale-chromatic.v1.min.js"></script>
<script>
function init() {
var meteoriteDataURL = 'https://raw.githubusercontent.com/FreeCodeCamp/ProjectReferenceData/master/meteorite-strike-data.json';
var mapURL = 'https://raw.githubusercontent.com/mbostock/topojson/master/examples/world-110m.json';

function getRadius(mass) {
  if (mass < 1000) {
    return 0.5;
  }
  if (mass < 100000) {
    return 1;
  }
  if (mass < 1000000) {
    return 2;
  }
  if (mass < 10000000) {
    return 4;
  }
  return 8;
};

var width = 960,
    height = 500,
    originalProjectionScale = height / 4;

var tooltipWidth = 170,
    tooltipHeight = 74;

var formatTime = d3.timeFormat("%B %d, %Y");

var colors = d3.scaleSequential(d3.interpolateCool);

var projection = d3.geoOrthographic().scale(originalProjectionScale).translate([
    width / 2,
    height / 2
]).rotate([0, 0]).clipAngle(90).precision(1);

var canvas = d3.select("body")
        .append("canvas")
        .attr('width', width)
        .attr('height', height),
    hiddenCanvas = d3.select("body")
        .append("canvas")
        .attr('width', width)
        .attr('height', height)
        .style('display','none'),
    path = d3.geoPath().projection(projection),
    circle = d3.geoCircle(),
    ctx,
    hiddenCtx;

var cachedHiddenCanvas = false;

var svg = d3.select('body')
       .append('svg')
       .attr('width', 200)
       .attr('height', 150)
       .style('top', -200)
       .style('left', -200);

d3.json(mapURL, function(error, world) {
    if (error)
        throw(error);

    hiddenCtx = hiddenCanvas.node().getContext('2d');
    ctx = canvas.node().getContext('2d');

    var land = topojson.feature(world, world.objects.land),
        globe = {
            type: 'Sphere'
        };

    d3.json(meteoriteDataURL, function(error, meteoriteData) {
        if (error)
            throw(error);

        var impacts = [],
            impactsScaleable = [],
            impactScale = 1;

        var nextColor = 1,
            colorKey = {};

        //Remove meteors without mass or coordinates
        //Convert mass to integers and year to time
        //Sort decending by mass so we can draw them from largest to smallest
        var meteorites = meteoriteData.features.filter(function(d) {
            return d.geometry && d.properties.mass;
        }).map(function(d) {
            d.properties.mass = parseFloat(d.properties.mass,10);
            d.properties.year = d3.isoParse(d.properties.year);
            return d;
        }).sort(function(a,b) {
            return b.properties.mass - a.properties.mass;
        });

        //Colour scale for coloring meteorite impacts
        colors.domain([d3.max(meteorites, function(d) {
            return Math.log10(d.properties.mass);
        }),d3.min(meteorites, function(d) {
            return Math.log10(d.properties.mass);
        })]);

        meteorites = meteorites.map(function(d) {
            d.properties.color = colors(Math.log10(d.properties.mass));
            return d;
        });

        meteorites.forEach(function(d,i) {
            var color = d3.hsl(d.properties.color),
                hiddenColor = getColor()
                radius = getRadius(d.properties.mass);

            color.opacity = 0.75;
            color = color + '';

            impacts.push({
                circle: circle.center(d.geometry.coordinates).radius(getRadius(d.properties.mass)).precision(20)(),
                color: color,
                mass: d.properties.mass,
                hiddenColor: hiddenColor
            });
        });

        meteorites.forEach(function(d,i) {
            //Create a d3 color so we can change the opacity of it
            var color = d3.hsl(d.properties.color),
                hiddenColor = getColor();

            color.opacity = 0.75;
            color + '';
            colorKey[hiddenColor] = d;

            impactsScaleable.push({
                circle: circle.precision(20),
                color: color,
                mass: d.properties.mass,
                coordinates: d.geometry.coordinates,
                hiddenColor: hiddenColor
            });
        });

        drawCanvas(ctx, impactsScaleable, impactScale, false);

        var zoomD3 = d3.zoom()
            .scaleExtent([0, 32])
            .on("zoom", zoomed);

        var dragD3 = d3.drag()
        .on("drag", dragged)
        .on("start", dragstarted)
        .on("end", dragended);

        canvas.on('mousemove', mousemove);
        canvas.call(dragD3);
        canvas.call(zoomD3);

        function mousemove() {
            var pickedColor,
                rgb,
                target;
            if (!cachedHiddenCanvas) {
              drawCanvas(hiddenCtx, impactsScaleable, impactScale, true);
              cachedHiddenCanvas = true;
            }
            pickedColor = hiddenCtx.getImageData(d3.event.offsetX, d3.event.offsetY, 1, 1).data;
            rgb = 'rgb(' + pickedColor.slice(0,-1).join(',') + ')';
            target = colorKey[rgb] || '';
            if(target) {
              showTooltip(ctx, target, d3.event.offsetX, d3.event.offsetY);
            } else {
              hideTooltip();
            }
        }

        function zoomed() {
            impactScale = (d3.event.transform.k/3 < 1) ? 1 : d3.event.transform.k/3;
            currentK = d3.event.transform.k;
            projection.scale((d3.event.transform.k * originalProjectionScale));
            drawCanvas(ctx, impactsScaleable, impactScale, false);
            cachedHiddenCanvas = false;
        }

        function dragstarted(d) {
            d3.event.sourceEvent.stopPropagation();
            d3.select(this).classed("dragging", true);
        }

        function dragged(d) {
            var scale = projection.scale(),
                currentRotation = projection.rotate(),
                rotationScale = scale/50,
                newLambda,
                newPhi;

            newLambda = currentRotation[0] + (d3.event.dx/rotationScale);
            newPhi = currentRotation[1] + (-d3.event.dy/rotationScale);

            projection.rotate([newLambda,newPhi]);
            drawCanvas(ctx, impactsScaleable, impactScale, false);
            cachedHiddenCanvas = false;
         }

         function dragended(d) {
             d3.select(this).classed("dragging", false);
         }

         function drawCanvas(canvas, impacts, impactScale, hidden) {
             canvas.save();
             canvas.clearRect(0, 0, width, height);
             //Draw land
             canvas.beginPath(); path.context(canvas)(land);
             canvas.fillStyle='black'; canvas.fill(); canvas.closePath();
             //Draw sphere outline
             canvas.beginPath(); path(globe); canvas.stroke(); canvas.closePath();
             //Draw impacts on canvas normally if shown
             if (!hidden) {
                 impacts.forEach(function(d) {
                     canvas.beginPath();
                     path.context(canvas)(d.circle.center(d.coordinates).radius(getRadius(d.mass)/impactScale)());
                     canvas.fillStyle= d.color;
                     canvas.fill();
                     canvas.closePath;
                 });
             } else {
                 impacts.forEach(function(d) {
                     canvas.beginPath();
                     path.context(canvas)(d.circle.center(d.coordinates).radius(getRadius(d.mass)/impactScale)());
                     canvas.fillStyle= d.hiddenColor;
                     canvas.fill();
                     canvas.closePath;
                 });
             }
             canvas.restore();
         }

         function getColor() {
             var rgb = [];
             rgb.push(nextColor % 256);
             rgb.push(parseInt((nextColor / 256) % 256,10));
             rgb.push(parseInt((nextColor / 65536) % 256,10));
             nextColor++;
             return 'rgb(' + rgb.join(',') + ')';
         }

         function showTooltip(canvas, meteor, mouseX, mouseY) {
           var tooltip;

           svg.selectAll('g').remove();

           tooltip = svg.selectAll('g').data([meteor]).enter().append('g').attr('class', 'tooltip');

           svg.style('top', mouseY + 5)
           .style('left', mouseX + 5);

           tooltip.append('rect')
           .attr('width', tooltipWidth)
           .attr('height', tooltipHeight);

           tooltip.append('text')
                  .attr('transform', 'translate(' + (tooltipWidth/2) + ',21)')
                  .attr('text-anchor', 'middle')
                  .text(function(d) {
                    return 'Name: ' + d.properties.name;
                  });

           tooltip.append('text')
                  .attr('transform', 'translate(' + (tooltipWidth/2) + ',42)')
                  .attr('text-anchor', 'middle')
                  .text(function(d) {
                    return 'Mass: ' + (d.properties.mass / 1000) + ' kg';
                  });

            tooltip.append('text')
                   .attr('transform', 'translate(' + (tooltipWidth/2) + ',63)')
                   .attr('text-anchor', 'middle')
                   .text(function(d) {
                     return 'Year: ' + formatTime(d.properties.year);
                   });
         }

         function hideTooltip() {
           svg.selectAll('g').remove();
           svg.style('top', -200)
           .style('left', -200);
         }
    });
});
};

document.addEventListener("DOMContentLoaded", init, false);
</script>
	<!DOCTYPE html>
	<meta charset="utf-8">
	<style>
	body {
	margin: 0;
	}

	svg {
	position: absolute;
	}

	.tooltip text {
	font: 14px Helvetica, Arial, sans-serif;
	}

	.tooltip rect {
	fill: rgba(200, 200, 200, 0.8);
	}
	</style>
	<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.1.0/d3.min.js"></script>
	<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/topojson/3.0.0/topojson.min.js"></script>
	<script type="text/javascript" src="https://d3js.org/d3-scale-chromatic.v1.min.js"></script>
	<script>
	function init() {
	var meteoriteDataURL = 'https://raw.githubusercontent.com/FreeCodeCamp/ProjectReferenceData/master/meteorite-strike-data.json';
	var mapURL = 'https://raw.githubusercontent.com/mbostock/topojson/master/examples/world-110m.json';

	function getRadius(mass) {
	if (mass < 1000) {
	return 0.5;
	}
	if (mass < 100000) {
	return 1;
	}
	if (mass < 1000000) {
	return 2;
	}
	if (mass < 10000000) {
	return 4;
	}
	return 8;
	};

	var width = 960,
	height = 500,
	originalProjectionScale = height / 4;

	var tooltipWidth = 170,
	tooltipHeight = 74;

	var formatTime = d3.timeFormat("%B %d, %Y");

	var colors = d3.scaleSequential(d3.interpolateCool);

	var projection = d3.geoOrthographic().scale(originalProjectionScale).translate([
	width / 2,
	height / 2
	]).rotate([0, 0]).clipAngle(90).precision(1);

	var canvas = d3.select("body")
	.append("canvas")
	.attr('width', width)
	.attr('height', height),
	hiddenCanvas = d3.select("body")
	.append("canvas")
	.attr('width', width)
	.attr('height', height)
	.style('display','none'),
	path = d3.geoPath().projection(projection),
	circle = d3.geoCircle(),
	ctx,
	hiddenCtx;

	var cachedHiddenCanvas = false;

	var svg = d3.select('body')
	.append('svg')
	.attr('width', 200)
	.attr('height', 150)
	.style('top', -200)
	.style('left', -200);

	d3.json(mapURL, function(error, world) {
	if (error)
	throw(error);

	hiddenCtx = hiddenCanvas.node().getContext('2d');
	ctx = canvas.node().getContext('2d');

	var land = topojson.feature(world, world.objects.land),
	globe = {
	type: 'Sphere'
	};

	d3.json(meteoriteDataURL, function(error, meteoriteData) {
	if (error)
	throw(error);

	var impacts = [],
	impactsScaleable = [],
	impactScale = 1;

	var nextColor = 1,
	colorKey = {};

	//Remove meteors without mass or coordinates
	//Convert mass to integers and year to time
	//Sort decending by mass so we can draw them from largest to smallest
	var meteorites = meteoriteData.features.filter(function(d) {
	return d.geometry && d.properties.mass;
	}).map(function(d) {
	d.properties.mass = parseFloat(d.properties.mass,10);
	d.properties.year = d3.isoParse(d.properties.year);
	return d;
	}).sort(function(a,b) {
	return b.properties.mass - a.properties.mass;
	});

	//Colour scale for coloring meteorite impacts
	colors.domain([d3.max(meteorites, function(d) {
	return Math.log10(d.properties.mass);
	}),d3.min(meteorites, function(d) {
	return Math.log10(d.properties.mass);
	})]);

	meteorites = meteorites.map(function(d) {
	d.properties.color = colors(Math.log10(d.properties.mass));
	return d;
	});

	meteorites.forEach(function(d,i) {
	var color = d3.hsl(d.properties.color),
	hiddenColor = getColor()
	radius = getRadius(d.properties.mass);

	color.opacity = 0.75;
	color = color + '';

	impacts.push({
	circle: circle.center(d.geometry.coordinates).radius(getRadius(d.properties.mass)).precision(20)(),
	color: color,
	mass: d.properties.mass,
	hiddenColor: hiddenColor
	});
	});

	meteorites.forEach(function(d,i) {
	//Create a d3 color so we can change the opacity of it
	var color = d3.hsl(d.properties.color),
	hiddenColor = getColor();

	color.opacity = 0.75;
	color + '';
	colorKey[hiddenColor] = d;

	impactsScaleable.push({
	circle: circle.precision(20),
	color: color,
	mass: d.properties.mass,
	coordinates: d.geometry.coordinates,
	hiddenColor: hiddenColor
	});
	});

	drawCanvas(ctx, impactsScaleable, impactScale, false);

	var zoomD3 = d3.zoom()
	.scaleExtent([0, 32])
	.on("zoom", zoomed);

	var dragD3 = d3.drag()
	.on("drag", dragged)
	.on("start", dragstarted)
	.on("end", dragended);

	canvas.on('mousemove', mousemove);
	canvas.call(dragD3);
	canvas.call(zoomD3);

	function mousemove() {
	var pickedColor,
	rgb,
	target;
	if (!cachedHiddenCanvas) {
	drawCanvas(hiddenCtx, impactsScaleable, impactScale, true);
	cachedHiddenCanvas = true;
	}
	pickedColor = hiddenCtx.getImageData(d3.event.offsetX, d3.event.offsetY, 1, 1).data;
	rgb = 'rgb(' + pickedColor.slice(0,-1).join(',') + ')';
	target = colorKey[rgb] \|\| '';
	if(target) {
	showTooltip(ctx, target, d3.event.offsetX, d3.event.offsetY);
	} else {
	hideTooltip();
	}
	}

	function zoomed() {
	impactScale = (d3.event.transform.k/3 < 1) ? 1 : d3.event.transform.k/3;
	currentK = d3.event.transform.k;
	projection.scale((d3.event.transform.k * originalProjectionScale));
	drawCanvas(ctx, impactsScaleable, impactScale, false);
	cachedHiddenCanvas = false;
	}

	function dragstarted(d) {
	d3.event.sourceEvent.stopPropagation();
	d3.select(this).classed("dragging", true);
	}

	function dragged(d) {
	var scale = projection.scale(),
	currentRotation = projection.rotate(),
	rotationScale = scale/50,
	newLambda,
	newPhi;

	newLambda = currentRotation[0] + (d3.event.dx/rotationScale);
	newPhi = currentRotation[1] + (-d3.event.dy/rotationScale);

	projection.rotate([newLambda,newPhi]);
	drawCanvas(ctx, impactsScaleable, impactScale, false);
	cachedHiddenCanvas = false;
	}

	function dragended(d) {
	d3.select(this).classed("dragging", false);
	}

	function drawCanvas(canvas, impacts, impactScale, hidden) {
	canvas.save();
	canvas.clearRect(0, 0, width, height);
	//Draw land
	canvas.beginPath(); path.context(canvas)(land);
	canvas.fillStyle='black'; canvas.fill(); canvas.closePath();
	//Draw sphere outline
	canvas.beginPath(); path(globe); canvas.stroke(); canvas.closePath();
	//Draw impacts on canvas normally if shown
	if (!hidden) {
	impacts.forEach(function(d) {
	canvas.beginPath();
	path.context(canvas)(d.circle.center(d.coordinates).radius(getRadius(d.mass)/impactScale)());
	canvas.fillStyle= d.color;
	canvas.fill();
	canvas.closePath;
	});
	} else {
	impacts.forEach(function(d) {
	canvas.beginPath();
	path.context(canvas)(d.circle.center(d.coordinates).radius(getRadius(d.mass)/impactScale)());
	canvas.fillStyle= d.hiddenColor;
	canvas.fill();
	canvas.closePath;
	});
	}
	canvas.restore();
	}

	function getColor() {
	var rgb = [];
	rgb.push(nextColor % 256);
	rgb.push(parseInt((nextColor / 256) % 256,10));
	rgb.push(parseInt((nextColor / 65536) % 256,10));
	nextColor++;
	return 'rgb(' + rgb.join(',') + ')';
	}

	function showTooltip(canvas, meteor, mouseX, mouseY) {
	var tooltip;

	svg.selectAll('g').remove();

	tooltip = svg.selectAll('g').data([meteor]).enter().append('g').attr('class', 'tooltip');

	svg.style('top', mouseY + 5)
	.style('left', mouseX + 5);

	tooltip.append('rect')
	.attr('width', tooltipWidth)
	.attr('height', tooltipHeight);

	tooltip.append('text')
	.attr('transform', 'translate(' + (tooltipWidth/2) + ',21)')
	.attr('text-anchor', 'middle')
	.text(function(d) {
	return 'Name: ' + d.properties.name;
	});

	tooltip.append('text')
	.attr('transform', 'translate(' + (tooltipWidth/2) + ',42)')
	.attr('text-anchor', 'middle')
	.text(function(d) {
	return 'Mass: ' + (d.properties.mass / 1000) + ' kg';
	});

	tooltip.append('text')
	.attr('transform', 'translate(' + (tooltipWidth/2) + ',63)')
	.attr('text-anchor', 'middle')
	.text(function(d) {
	return 'Year: ' + formatTime(d.properties.year);
	});
	}

	function hideTooltip() {
	svg.selectAll('g').remove();
	svg.style('top', -200)
	.style('left', -200);
	}
	});
	});
	};

	document.addEventListener("DOMContentLoaded", init, false);
	</script>