added a comparison function for cutters

git-svn-id: https://pycam.svn.sourceforge.net/svnroot/pycam/trunk@173 bbaffbd6-741e-11dd-a85d-61de82d9cad9

pycam/Cutters/BaseCutter.py

@@ -24,6 +24,18 @@ class BaseCutter:
     def __repr__(self):
         return "BaseCutter"
 
+    def __cmp__(self, other):
+        """ Compare Cutters by shape and size (ignoring the location)
+        This function should be overridden by subclasses, if they describe
+        cutters with a shape depending on more than just the radius.
+        See the ToroidalCutter for an example.
+        """
+        if isinstance(other, BaseCutter):
+            return cmp(self.radius, other.radius)
+        else:
+            # just return a string comparison
+            return cmp(str(self), str(other))
+
     def moveto(self, location):
         self.location = location
         self.minx = location.x-self.radius

pycam/Cutters/ToroidalCutter.py

@@ -30,6 +30,16 @@ class ToroidalCutter(BaseCutter):
     def __repr__(self):
         return "ToroidalCutter<%s,%f,R=%f,r=%f>" % (self.location,self.radius,self.majorradius,self.minorradius)
 
+    def __cmp__(self, other):
+        """ Compare Cutters by shape and size (ignoring the location) """
+        if isinstance(other, ToroidalCutter):
+            # compare the relevant attributes
+            return cmp((self.radius, self.majorradius, self.minorradius),
+                    (other.radius, other.majorradius, other.minorradius))
+        else:
+            # just return a string comparison
+            return cmp(str(self), str(other))
+
     def get_shape(self, format="ODE", additional_distance=0.0):
         if format == "ODE":
             import ode