first commit

helix/models/dxf/graph_direction.py

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+from enum import Enum
+
+
+class GraphDirection(Enum):
+    North = (0, 1)
+    NorthEast = (1, 1)
+    East = (1, 0)
+    SouthEast = (1, -1)
+    South = (0, -1)
+    SouthWest = (-1, -1)
+    West = (-1, 0)
+    NorthWest = (-1, 1)
+
+    @classmethod
+    def values(cls):
+        return [
+            cls.North.value,
+            cls.NorthEast.value,
+            cls.East.value,
+            cls.SouthEast.value,
+            cls.South.value,
+            cls.SouthWest.value,
+            cls.West.value,
+            cls.NorthWest.value
+        ]
+
+    @classmethod
+    def ordinal_directions(cls):
+        return [
+            cls.North,
+            cls.East,
+            cls.South,
+            cls.West
+        ]
+
+    def opposite_direction(self):
+        return {
+            GraphDirection.North: GraphDirection.South,
+            GraphDirection.NorthEast: GraphDirection.SouthWest,
+            GraphDirection.East: GraphDirection.West,
+            GraphDirection.SouthEast: GraphDirection.NorthWest,
+            GraphDirection.South: GraphDirection.North,
+            GraphDirection.SouthWest: GraphDirection.NorthEast,
+            GraphDirection.West: GraphDirection.East,
+            GraphDirection.NorthWest: GraphDirection.SouthEast
+        }[self]
+