From 198a7d7ca89694082b204b94ce24c835c7524d37 Mon Sep 17 00:00:00 2001
From: "Stephen M. McQuay" <smcquay@fusionio.com>
Date: Wed, 9 May 2012 09:24:26 -0600
Subject: [PATCH] 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     | 12 ++++++++++++
 surf/subd/cc.py      | 32 +++++++++++++++++++-------------
 surf/test/subd/cc.py |  3 ++-
 3 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/surf/geometry.py b/surf/geometry.py
index 20f721a..fbd7e83 100644
--- a/surf/geometry.py
+++ b/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)
 
diff --git a/surf/subd/cc.py b/surf/subd/cc.py
index aec6f93..e6dc6f9 100644
--- a/surf/subd/cc.py
+++ b/surf/subd/cc.py
@@ -2,17 +2,18 @@ from collections import defaultdict
 
 from surf.geometry import PolygonMesh, centroid
 
-from pprint import pprint as pp   # XXX
-
 
 def refine(mesh):
     new_vertices = list(mesh.vertices)
     f_vert_offset = len(new_vertices)
 
     edge_vids_for = defaultdict(list)
-    face_vids_for = defaultdict(list)
+    face_ids_for_v = defaultdict(list)
 
+    # TODO: not completely populated yet:
     new_edges = list(mesh.edges)
+
+    # TODO: must be populated:
     new_faces = []
 
     # For each face, add a face point
@@ -26,6 +27,8 @@ def refine(mesh):
         # below
         new_face_point = mesh.centroid(cur_face)
         new_vertices.append(new_face_point)
+        for i in cur_face:
+            face_ids_for_v[i].append(cur_face_id)
 
     e_vert_offset = len(new_vertices)
 
@@ -41,7 +44,7 @@ def refine(mesh):
         # Set each edge point to be the average of the two neighbouring, (very
         # recently calculated) face points ...
         tmp_verts.extend([new_vertices[f + f_vert_offset] for f in face_ids_for_edge])
-        
+
         # ... and its two original endpoints.
         tmp_verts.extend([mesh.vertices[vid] for vid in cur_edge])
 
@@ -55,14 +58,18 @@ def refine(mesh):
         for edge_vid in edge_vids_for[trunc_vid]:
             new_edges.append([edge_vid, overall_vid])
 
-    # pp(new_edges)
+    # v_vert_offset = len(new_vertices)
 
     # For each original point P
-    assert f_vert_offset == len(mesh.vertices)
     for new_vid in xrange(f_vert_offset):
         # take the average F of all n face points for faces touching P ...
-        F = centroid([mesh.vertices[vid] for vid in mesh.faces_for_vert[new_vid]])
-        print ">>>", F
+
+        new_face_ids = face_ids_for_v[new_vid]
+        F_verts = []
+        for fid in new_face_ids:
+            F_verts.append(new_vertices[f_vert_offset + fid])
+
+        F = centroid(F_verts)
 
         # and take the average R of all n edge midpoints for edges touching P
         # wiki is wrong ... it should be the edge points, not midpoints ...
@@ -74,18 +81,17 @@ def refine(mesh):
         R = centroid(e_verts)
         # where each edge midpoint is the average of its two endpoint vertices.
         # Move each original point to the point (or add it to new_verts)
-        v = (F + 2 * R + (len(edges) - 3) * new_vertices[new_vid]) / len(edges)
-
-    return None
+        new_vertex_point = (F + 2 * R + (len(edges) - 3) * new_vertices[new_vid]) / len(edges)
+        new_vertices.append(new_vertex_point)
 
+    return PolygonMesh(vertices=new_vertices, edges=new_edges, faces=new_faces)
 
 
 if __name__ == '__main__':
     import json
-    from surf.geometry import PolygonMesh
     from surf.subd.cc import refine
 
-
     cube = json.load(open('blender/samples/cube.json', 'r'))
     p = PolygonMesh(**cube)
     q = refine(p)
+    print q
diff --git a/surf/test/subd/cc.py b/surf/test/subd/cc.py
index 1b51ecc..76b08c9 100644
--- a/surf/test/subd/cc.py
+++ b/surf/test/subd/cc.py
@@ -18,7 +18,8 @@ class TestCC(unittest.TestCase):
     def test_refine(self):
         p = PolygonMesh(**self.cube)
         p2 = cc.refine(p)
-        print p2
+        # TODO: this test is meaningless ...
+        p2
 
 if __name__ == '__main__':
     unittest.main(verbosity=3)