move everything from c3nav.routing.graph to c3nav.routing

src/c3nav/routing/router.py

@@ -0,0 +1,52 @@
+import numpy as np
+from scipy.sparse import csr_matrix
+from scipy.sparse.csgraph import shortest_path
+
+
+class Router():
+    def __init__(self):
+        self.points = []
+        self.points_pk = None
+
+        self.transfer_points = set()
+        self.shortest_paths = None
+        self.predecessors = None
+
+        self._built = False
+
+    # noinspection PyTypeChecker
+    def build(self, points, global_routing=False):
+        if self._built:
+            raise RuntimeError('already built.')
+        self._built = True
+
+        self.points = points
+        self.points_pk = dict(zip(self.points, range(len(self.points))))
+        matrix = np.zeros((len(self.points), len(self.points)))
+
+        for point, pk in self.points_pk.items():
+            for to_point, connection in point.connections.items():
+                if to_point not in self.points_pk:
+                    if not global_routing:
+                        self.transfer_points.add(point)
+                    continue
+                matrix[pk, self.points_pk[to_point]] = connection.distance
+            if global_routing:
+                for to_point, distance in point.in_room_transfer_distances.items():
+                    matrix[pk, self.points_pk[to_point]] = distance
+
+        g_sparse = csr_matrix(np.ma.masked_values(np.fromstring(matrix).reshape(matrix.shape), 0))
+        self.shortest_paths, self.predecessors = shortest_path(g_sparse, return_predecessors=True)
+
+        if not global_routing:
+            for from_point in self.transfer_points:
+                from_point.in_room_transfer_distances = {}
+                connections = self.shortest_paths[self.points_pk[from_point], ]
+                for to_point_pk in np.argwhere(connections != np.inf).flatten():
+                    to_point = self.points[to_point_pk]
+                    if to_point not in self.transfer_points:
+                        continue
+                    from_point.in_room_transfer_distances[to_point] = connections[to_point_pk]
+
+    def get_distance(self, from_point, to_point):
+        return self.shortest_paths[self.points_pk[from_point], self.points_pk[from_point]]