Add supply_grid file

compiler/router/supply_grid.py

@@ -0,0 +1,27 @@
+import debug
+from vector3d import vector3d
+import grid
+
+
+class supply_grid(grid.grid):
+    """
+    A two layer routing map. Each cell can be blocked in the vertical
+    or horizontal layer.
+    """
+
+    def __init__(self):
+        """ Create a routing map of width x height cells and 2 in the z-axis. """
+        grid.grid.__init__(self)
+        
+        # list of the vdd/gnd rail cells
+        self.vdd_rails = []
+        self.gnd_rails = []
+
+    def reinit(self):
+        """ Reinitialize everything for a new route. """
+
+        # Reset all the cells in the map
+        for p in self.map.values():
+            p.reset()
+        
+