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79 lines
1.9 KiB
79 lines
1.9 KiB
<!DOCTYPE html> |
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<meta charset="utf-8"> |
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<canvas width="960" height="500"></canvas> |
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<script src="https://d3js.org/d3.v4.min.js"></script> |
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<script> |
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var canvas = d3.select("canvas").on("touchmove mousemove", moved).node(), |
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context = canvas.getContext("2d"), |
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width = canvas.width, |
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height = canvas.height; |
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var sites = d3.range(100) |
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.map(function(d) { return [Math.random() * width, Math.random() * height]; }); |
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var voronoi = d3.voronoi() |
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.extent([[-1, -1], [width + 1, height + 1]]); |
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redraw(); |
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function moved() { |
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sites[0] = d3.mouse(this); |
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redraw(); |
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} |
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function redraw() { |
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var diagram = voronoi(sites), |
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links = diagram.links(), |
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polygons = diagram.polygons(); |
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context.clearRect(0, 0, width, height); |
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context.beginPath(); |
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drawCell(polygons[0]); |
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context.fillStyle = "#f00"; |
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context.fill(); |
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context.beginPath(); |
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for (var i = 0, n = polygons.length; i < n; ++i) drawCell(polygons[i]); |
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context.strokeStyle = "#000"; |
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context.stroke(); |
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context.beginPath(); |
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for (var i = 0, n = links.length; i < n; ++i) drawLink(links[i]); |
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context.strokeStyle = "rgba(0,0,0,0.2)"; |
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context.stroke(); |
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context.beginPath(); |
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drawSite(sites[0]); |
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context.fillStyle = "#fff"; |
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context.fill(); |
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context.beginPath(); |
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for (var i = 1, n = sites.length; i < n; ++i) drawSite(sites[i]); |
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context.fillStyle = "#000"; |
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context.fill(); |
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context.strokeStyle = "#fff"; |
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context.stroke(); |
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} |
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function drawSite(site) { |
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context.moveTo(site[0] + 2.5, site[1]); |
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context.arc(site[0], site[1], 2.5, 0, 2 * Math.PI, false); |
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} |
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function drawLink(link) { |
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context.moveTo(link.source[0], link.source[1]); |
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context.lineTo(link.target[0], link.target[1]); |
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} |
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function drawCell(cell) { |
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if (!cell) return false; |
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context.moveTo(cell[0][0], cell[0][1]); |
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for (var j = 1, m = cell.length; j < m; ++j) { |
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context.lineTo(cell[j][0], cell[j][1]); |
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} |
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context.closePath(); |
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return true; |
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} |
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</script>
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