Fixed bug in my CC implementation

- Wasn't calculating faces for a give original vert correctly
    - vertices generated by surf.subd.cc.refine look about right
    - still missing edge and face connectivity

surf/geometry.py

@@ -25,6 +25,7 @@ def cross(a, b):
     k = a.x * b.y - a.y * b.x
     return Vertex(i, j, k)
 
+
 def centroid(verts):
     xs = [v.x for v in verts]
     ys = [v.y for v in verts]
@@ -37,6 +38,7 @@ def centroid(verts):
 
     return Vertex(x, y, z)
 
+
 class Vertex(object):
     '''
     A vertex is a position along with other information such as color, normal
@@ -72,6 +74,16 @@ class Vertex(object):
             raise TypeError("{0} has an unexpected type: {1}".format(
                 other, type(other)))
 
+    def __iter__(self):
+        """Added to be able to conveniently convert a Vertex into a list
+
+        >>> v = Vertex(0, 1, 2)
+        >>> assert list(v) == [0, 1, 2]
+        """
+        yield self.x
+        yield self.y
+        yield self.z
+
     def __rmul__(self, other):
         return self.__mul__(other)