forgot to commit this for dynamic ray of light in pirates

direct/src/distributed/CartesianGridBase.py

@@ -79,3 +79,47 @@ class CartesianGridBase:
 
         return (x, y, 0)
 
+    #--------------------------------------------------------------------------
+    # Function:   utility function to get all zones in a ring of given radius
+    #               around the given zoneId (so if given a zoneId 34342 and a
+    #               radius of 3, a list of all zones exactly 3 grids away from
+    #               zone 34342 will be returned)
+    # Parameters: zoneId, center zone to find surrounding zones of
+    #             radius, how far from zoneId to find zones of for it them
+    # Changes:
+    # Returns:
+    #--------------------------------------------------------------------------
+    def getConcentricZones(self, zoneId, radius):
+        zones = []
+        #currZone = zoneId + radius
+        #numZones = (2 * radius * 8) + 2
+        # start at upper left
+        zone = zoneId - self.startingZone
+        row = zone // self.gridSize
+        col = zone % self.gridSize
+
+        leftOffset = min(col, radius)
+        rightOffset = min(self.gridSize - (col + 1), radius)
+        topOffset = min(row, radius)
+        bottomOffset = min(self.gridSize - (row + 1), radius)
+
+        #print "starting examination of grid circle of radius %s"%radius
+        ulZone = zoneId - leftOffset - topOffset * self.gridSize
+        #print "left offset is %s and radius is %s"%(leftOffset,radius)
+        for currCol in range(int(rightOffset + leftOffset + 1)):
+            if ((currCol == 0 and leftOffset == radius) or (currCol == rightOffset + leftOffset and rightOffset == radius)):
+                # at either left or right edge of area, look at all rows
+                possibleRows = range(int(bottomOffset + topOffset + 1))
+            else:
+                # in a middle column, only look at top and bottom rows
+                possibleRows = []
+                if (topOffset == radius):
+                    possibleRows.append(0)
+                if (bottomOffset == radius):
+                    possibleRows.append(bottomOffset + topOffset)
+            #print "on column %s and looking at rows %s"%(currCol,possibleRows)
+            for currRow in possibleRows:
+                newZone = ulZone + (currRow * self.gridSize) + currCol
+                zones.append(int(newZone))
+                #print "   examining zone %s"%newZone
+        return zones