Merge branch 'voronoi'

examples/voronoi.js

@@ -0,0 +1,140 @@
+
+/**
+ * Module dependencies.
+ */
+
+var Canvas = require('../lib/canvas')
+  , canvas = new Canvas(1920, 1200)
+  , ctx = canvas.getContext('2d')
+  , http = require('http')
+  , fs = require('fs');
+
+var voronoiFactory = require('./rhill-voronoi-core-min.js');
+
+http.createServer(function (req, res) {
+  var voronoi = voronoiFactory()
+    , start = new Date;
+  var bbox =  { xl: 0, xr: canvas.width, yt: 0, yb: canvas.height };
+  
+  for (var i =0 ;i<340;i++)
+  {
+	var x = Math.random()*canvas.width;
+	var y = Math.random()*canvas.height;
+	voronoi.addSites([{x:x,y:y}]);
+  };
+  var diagram = voronoi.compute(bbox);
+
+	ctx.beginPath();
+	ctx.rect(0,0,canvas.width,canvas.height);
+	ctx.fillStyle = '#fff';
+	ctx.fill();
+	ctx.strokeStyle = 'black';
+	ctx.stroke();
+	// voronoi
+	ctx.strokeStyle='rgba(255,255,255,0.5)';
+	ctx.lineWidth = 4;
+	// edges
+	var edges = diagram.edges;
+	var nEdges = edges.length;
+
+	var sites = diagram.sites;
+	var nSites = sites.length;
+	for (var iSite=nSites-1; iSite>=0; iSite-=1) 
+	{
+		site = sites[iSite];
+			ctx.rect(site.x-0.5,site.y-0.5,1,1);
+
+
+
+//		ctx.stroke();
+		var cell = diagram.cells[diagram.sites[iSite].id];
+		if (cell !== undefined) 
+		{
+			var halfedges = cell.halfedges;
+			var nHalfedges = halfedges.length;
+			if (nHalfedges < 3) {return;}
+			var minx = canvas.width;
+			var miny = canvas.height;
+			var maxx = 0;
+			var maxy = 0;
+
+			var v = halfedges[0].getStartpoint();
+			ctx.beginPath();
+			ctx.moveTo(v.x,v.y);
+
+			for (var iHalfedge=0; iHalfedge<nHalfedges; iHalfedge++) 
+			{
+				v = halfedges[iHalfedge].getEndpoint();
+				ctx.lineTo(v.x,v.y);
+				if (v.x< minx) minx = v.x;
+				if (v.y< miny) miny = v.y;
+				if (v.x> maxx) maxx = v.x;
+				if (v.y> maxy) maxy = v.y;
+			}
+			var C = Math.floor(Math.random()*128 + 127).toString();
+
+
+			var midx = (maxx+minx)/2;
+			var midy = (maxy+miny)/2;
+			var R = 0;
+
+			for (var iHalfedge=0; iHalfedge<nHalfedges; iHalfedge++) 
+			{
+				v = halfedges[iHalfedge].getEndpoint();
+				var dx = v.x - site.x;
+				var dy = v.y - site.y;
+				var newR = Math.sqrt(dx*dx + dy*dy);
+				if (newR >R) R = newR;
+			}
+			midx = site.x;
+			midy = site.y;
+			var radgrad = ctx.createRadialGradient(midx+R*0.3,midy-R*0.3,0,midx,midy,R);
+			radgrad.addColorStop(0, "#09760b");
+			radgrad.addColorStop(1.0, "black");
+
+
+			ctx.fillStyle = radgrad;
+			ctx.fill();
+
+			var radgrad2 = ctx.createRadialGradient(midx-R*0.5,midy+R*0.5,R*0.1,midx,midy,R);
+			radgrad2.addColorStop(0, "rgba(255,255,255,0.5)");
+			radgrad2.addColorStop(0.04, "rgba(255,255,255,0.3)");
+			radgrad2.addColorStop(0.05, "rgba(255,255,255,0)");
+
+
+			ctx.fillStyle = radgrad2;
+			ctx.fill();
+
+			var lingrad = ctx.createLinearGradient(minx, site.y, minx+100, site.y-20);
+			lingrad.addColorStop(0.0, "rgba(255,255,255,0.5)");
+			lingrad.addColorStop(0.2, "rgba(255,255,255,0.2)");
+			lingrad.addColorStop(1.0, "rgba(255,255,255,0)");
+			ctx.fillStyle = lingrad;
+			ctx.fill();
+
+		}
+
+	}
+
+	if (nEdges) 
+	{
+			var edge, v;
+			ctx.beginPath();
+			for (var iEdge=nEdges-1; iEdge>=0; iEdge-=1) {
+				edge = edges[iEdge];
+				v = edge.va;
+				ctx.moveTo(v.x,v.y);
+				v = edge.vb;
+				ctx.lineTo(v.x,v.y);
+				}
+			ctx.stroke();
+			}			
+
+  canvas.toBuffer(function(err, buf){
+    var duration = new Date - start;
+    console.log('Rendered in %dms', duration);
+    res.writeHead(200, { 'Content-Type': 'image/png', 'Content-Length': buf.length });
+    res.end(buf);
+  });
+}).listen(3000);
+console.log('Server running on port 3000');