Make bodies and constraints in the space ordered to (partially) fix p…

…ickle/copy #181

TODO.txt

@@ -17,7 +17,8 @@ v5.x
 - Type annotations?
 - update example code to be less dependent on the flipy function for pygame. instead flip the gravity.
 - Update docs with collision chapter. ShapeFilter, collision callbacks and such
-- use env variables for pymunkoptions, like pygame https://stackoverflow.com/questions/56258942/is-there-an-environment-variable-to-disable-pymunk-chipmunk-from-printing-loadi   
+- use env variables for pymunkoptions, like pygame https://stackoverflow.com/questions/56258942/is-there-an-environment-variable-to-disable-pymunk-chipmunk-from-printing-loadi
+- make running tests with python -m pymunk.tests, and examples with python -m pymunk.examples... somehow. See pybox2d for inspiration    
 
 v6+ (all potentially breaking changes)
 ---
@@ -34,4 +35,5 @@ v6+ (all potentially breaking changes)
 - Make add_collision_handler(a,b) and add_collision_handler(b,a) return the 
   same handler. Fixes https://github.com/viblo/pymunk/issues/132 
 - make default of positive_y_is_up False
-- use sphinx_autodoc_typehints and type hints when python 2 support is dropped
+- use sphinx_autodoc_typehints and type hints when python 2 support is dropped
+- drop support for python 2

pymunk/space.py

@@ -71,9 +71,9 @@ def __init__(self, threaded=False):
         self._removed_shapes = {}
 
         self._shapes = {}
-        self._bodies = set()
+        self._bodies = {}
         self._static_body = None
-        self._constraints = set()
+        self._constraints = {}
 
         self._in_step = False
         self._add_later = set()
@@ -307,13 +307,13 @@ def _add_body(self, body):
         """Adds a body to the space"""
         assert body not in self._bodies, "body already added to space"
         body._space = weakref.proxy(self)
-        self._bodies.add(body)
+        self._bodies[body] = None
         cp.cpSpaceAddBody(self._space, body._body)
 
     def _add_constraint(self, constraint):
         """Adds a constraint to the space"""
         assert constraint not in self._constraints, "constraint already added to space"
-        self._constraints.add(constraint)
+        self._constraints[constraint] = None
         cp.cpSpaceAddConstraint(self._space, constraint._constraint)
 
     def _remove_shape(self, shape):
@@ -324,11 +324,11 @@ def _remove_shape(self, shape):
     def _remove_body(self, body):
         """Removes a body from the space"""
         body._space = None
-        self._bodies.remove(body)
+        del self._bodies[body]
         cp.cpSpaceRemoveBody(self._space, body._body)
     def _remove_constraint(self, constraint):
         """Removes a constraint from the space"""
-        self._constraints.remove(constraint)
+        del self._constraints[constraint]
         cp.cpSpaceRemoveConstraint(self._space, constraint._constraint)
 
     def reindex_shape(self, shape):

pymunk/tests/test_space.py

@@ -754,10 +754,12 @@ def _testCopyMethod(self, copy_func):
 
         b1 = p.Body(1,2)
         b2 = p.Body(3,4)
+        b3 = p.Body(5,6)
         c1 = p.Circle(b1, 7)
         c2 = p.Circle(b1, 8)
-        c3 = p.Circle(s.static_body, 9)
-        s.add(b1,b2, c1, c2, c3)
+        c3 = p.Circle(b2, 9)
+        c4 = p.Circle(s.static_body, 10)
+        s.add(b1, b2, b3, c1, c2, c3, c4)
 
         s.static_body.custom = "x"
 
@@ -779,6 +781,7 @@ def _testCopyMethod(self, copy_func):
 
         s2 = copy_func(s)
 
+        # Assert properties
         self.assertEqual(s.threaded, s2.threaded)
         self.assertEqual(s.iterations, s2.iterations)
         self.assertEqual(s.gravity, s2.gravity)
@@ -789,13 +792,14 @@ def _testCopyMethod(self, copy_func):
         self.assertEqual(s.collision_bias, s2.collision_bias)
         self.assertEqual(s.collision_persistence, s2.collision_persistence)
         self.assertEqual(s.threads, s2.threads)
-
-        self.assertEqual(sorted([c.radius for c in s2.shapes]), [7,8,9])
-        self.assertEqual(sorted([b.mass for b in s2.bodies]), [1,3])
+        # Assert shapes, bodies and constriants
+        self.assertEqual([c.radius for c in s2.shapes], [7,8,9, 10])
+        self.assertEqual([b.mass for b in s2.bodies], [1, 3, 5])
         self.assertEqual(s.static_body.custom, s2.static_body.custom)
         ja = [j.a for j in s2.constraints]
         self.assertIn(s2.static_body, ja)
 
+        # Assert collision handlers
         h2 = s2.add_default_collision_handler()
         self.assertIsNotNone(h2.begin)
         self.assertIsNone(h2.pre_solve)