added Point class

code/point.lua

@@ -0,0 +1,30 @@
+Point = {}
+Point.__index = Point
+
+function Point:new(x, y)
+   local o = { x = x, y = y }
+   setmetatable(o, self)
+   return o
+end
+
+function Point:__add(other)
+   return Point:new(self.x+other.x, self.y+other.y)
+end
+
+function Point:__sub(other)
+   return Point:new(self.x-other.x, self.y-other.y)
+end
+
+function Point:__mul(n)
+   return Point:new(self.x*n, self.y*n)
+end
+
+function Point:__div(n)
+   return Point:new(self.x/n, self.y/n)
+end
+
+-- absolute value, or the distance from the origin
+function Point:abs()
+   return math.sqrt(self.x ^ 2 + self.y ^ 2)
+end
+