Created
September 22, 2015 01:31
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Mapping with canvas
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| <!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>Zoom and Rotating (Reprojecting)</title> | |
| <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.6/d3.min.js"></script> | |
| </head> | |
| <body> | |
| <style> | |
| body { | |
| margin: 0; | |
| } | |
| </style> | |
| <div id="map-container"> | |
| <canvas id='container'></canvas> | |
| </div> | |
| <script> | |
| // Set the dimensions of the map | |
| var width = 960, | |
| height = 480, | |
| speed = 1e-2; | |
| // Create a selection for the container div and append the svg element | |
| var div = d3.select('#map-container'), | |
| canvas = div.select('canvas#container'), | |
| context = canvas.node().getContext("2d"); | |
| canvas | |
| .attr('width', width) | |
| .attr('height', height); | |
| // Create and configure a geographic projection | |
| var projection = d3.geo.orthographic() | |
| .scale(height / 2) | |
| .clipAngle(90) | |
| .translate([width / 2, height / 2]) | |
| .precision(0.1); | |
| // Create and configure a path generator | |
| var pathGenerator = d3.geo.path() | |
| .projection(projection) | |
| .context(context); | |
| // Create and configure the graticule generator (one line every 20 degrees) | |
| var graticule = d3.geo.graticule(); | |
| // Retrieve the geographic data asynchronously | |
| d3.json('land.geojson', function(err, data) { | |
| // Throw errors on getting or parsing the file | |
| if (err) { throw err; } | |
| // Background | |
| context.fillStyle = '#ddd'; | |
| context.fillRect(0, 0, width, height); | |
| // Rotate the globe | |
| d3.timer(function(elapsed) { | |
| projection.rotate([speed * elapsed, 30, 15]); | |
| // Canvas Drawing | |
| context.clearRect(0, 0, width, height); | |
| // Sphere | |
| context.beginPath(); | |
| pathGenerator({type: 'Sphere'}); | |
| context.strokeStyle = "#666"; | |
| context.stroke(); | |
| context.fillStyle = '#eee'; | |
| context.fill(); | |
| // Graticule | |
| context.beginPath(); | |
| pathGenerator(graticule()); | |
| context.strokeStyle = "#666"; | |
| context.stroke(); | |
| // Countries | |
| context.beginPath(); | |
| pathGenerator(data); | |
| context.fillStyle = "#999"; | |
| context.fill(); | |
| }); | |
| }); | |
| </script> | |
| </body> | |
| </html> |
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