pacman foo

html/force.js

@@ -176,6 +176,12 @@ vis.append("g").attr("class", "links")
 
 vis.append("g").attr("class", "nodes")
 
+var pm = vis.append("path")
+                .style("fill", "#ff0")
+                .style("stroke", "#000")
+                .style("stroke-width", 2.5)
+                .style("stroke-linejoin", "round")
+
 var linkedByIndex
 
 var force = d3.layout.force()
@@ -199,6 +205,13 @@ var force = d3.layout.force()
                 }
               })
 
+var angle = d3.scale.linear()
+                  .domain([0, 1, 2, 3])
+                  .range([0.01, Math.PI/4, 0.01, Math.PI/4])
+var a = 0
+
+var p = {x: 0, y: 0}
+
 force.on("tick", function() {
   var size = force.size()
   var nodes = force.nodes()
@@ -225,7 +238,45 @@ force.on("tick", function() {
 
   vis.selectAll(".node").attr("transform", function(d) { 
     return "translate(" + d.x + "," + d.y + ")";
-  })
+ })
+ 
+  a = (a + 0.10)%2
+
+  pm.attr("d", d3.svg.arc().innerRadius(0)
+     .outerRadius(24).endAngle(-angle(a) + Math.PI/2 + 2*Math.PI).startAngle(angle(a) + Math.PI/2))
+
+  var closest = null
+  var dd = Infinity;
+  for (i = 0; i < n; i++) {
+    var o = nodes[i]
+    if (o.dead)
+      continue
+
+    var d = Math.pow((o.x - p.x),2) + Math.pow( o.y - p.y, 2)
+    if (d < dd) {
+      dd = d
+      closest = o
+    }
+  }
+
+  var dx = closest.x - p.x
+  var dy = closest.y - p.y
+
+  var d = Math.sqrt(Math.pow(dx,2) +  Math.pow(dy,2))
+
+  dx = dx/d
+  dy = dy/d
+
+  if (d>1) {
+
+    p.x += dx
+    p.y += dy
+  } else {
+    closest.dead = true
+  }
+
+  pm.attr("transform", "matrix(" + [dx, dy, -dy, dx, p.x, p.y].join(",") + ")")
+
 })
 
 var data