diff -r ccbf96145796 -r 89d76549ba6e caugrid.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/caugrid.py	Thu Dec 30 14:22:05 2010 +0100
@@ -0,0 +1,39 @@
+class Grid(object):
+
+	def __init__(self):
+		self.cells = {}
+		self.minx = 0
+		self.maxx = 0
+		self.miny = 0
+		self.maxy = 0
+
+	def set(self, pos, value=1):
+		if not pos in self.cells or value != self.cells[pos]:
+			self.cells[pos] = value
+			self.update(pos)
+		return self
+
+	def clear(self, pos):
+		if pos in self.cells:
+			del self.cells[pos]
+			self.update(pos)
+		return self
+
+	def update(self, (x, y)):
+		self.minx = min(x, self.minx)
+		self.maxx = max(x, self.maxx)
+		self.miny = min(y, self.miny)
+		self.maxy = max(y, self.maxy)
+		return self
+
+	def width(self):
+		return self.maxx - self.minx + 1
+
+	def height(self):
+		return self.maxy - self.miny + 1
+
+	def __len__(self):
+		return len(self.cells)
+
+	def __str__(self):
+		pass