def test_non_overlapping(self):
points_0 = [Vec2d(1, 0), Vec2d(0, 0), Vec2d(0, 1), Vec2d(1, 1)]
points_1 = [Vec2d(3, 0), Vec2d(2, 0), Vec2d(2, 1), Vec2d(3, 1)]
separating_vectors, overlaps = calculate_separating_vectors(
points_0, points_1)
self.assertFalse(overlaps)
self.assertSameElements(separating_vectors, [])
def test_non_overlapping(self):
points_0 = [Vec2d(1, 0), Vec2d(0, 0), Vec2d(0, 1), Vec2d(1, 1)]
points_1 = [Vec2d(3, 0), Vec2d(2, 0), Vec2d(2, 1), Vec2d(3, 1)]
separating_vectors, overlaps = calculate_separating_vectors(points_0, points_1)
self.assertFalse(overlaps)
self.assertSameElements(separating_vectors, [])
def update(self, delta):
self.handle_messages()
self.collisions = []
if settings.USE_SPATIAL_PARTITIONING:
quad_tree = QuadTreeNode(0, 0, settings.SCREEN_WIDTH, settings.SCREEN_HEIGHT)
for entity in self.entities:
quad_tree.add_entity(entity)
self.system_manager.send_message({
'message_type': MESSAGE_TYPE.QUAD_TREE,
'quad_tree': quad_tree,
})
for entity in self.entities:
if entity.get(ImmovableComponent):
continue
physics_component = entity[PhysicsComponent]
physics_component.update_forces(delta)
if 'Friction' in physics_component.forces:
friction_force = physics_component.forces['Friction']
velocity_delta_due_to_friction = delta * friction_force.vector / physics_component.mass
non_friction_forces = physics_component.get_net_force(exclude_forces=['Friction'])
non_friction_accel = non_friction_forces / physics_component.mass
velocity_without_friction = delta * non_friction_accel + physics_component.velocity
velocity_with_friction = velocity_without_friction + velocity_delta_due_to_friction
# friction was overly aggressive, time to undo some friction
if ((velocity_without_friction[0] < 0 and velocity_with_friction[0] >= 0) or
(velocity_without_friction[0] > 0 and velocity_with_friction[0] <= 0)):
physics_component.velocity = velocity_with_friction
physics_component.velocity = Vec2d(0, physics_component.velocity[1])
physics_component.forces.pop('Friction')
else:
physics_component.velocity = velocity_with_friction
else:
net_force = physics_component.get_net_force()
physics_component.acceleration = net_force / physics_component.mass
physics_component.velocity += delta * physics_component.acceleration
entity.position += delta * physics_component.get_total_velocity()
for entity_a in self.entities:
overlapping_entities = []
if entity_a.get(ImmovableComponent):
continue
collision_candidates = quad_tree.get_intersections(entity_a) if settings.USE_SPATIAL_PARTITIONING else self.entities
for entity_b in collision_candidates:
if entity_a == entity_b:
continue
if entity_a.get(CharacterComponent) and entity_b.get(CharacterComponent):
continue
shape_a = entity_a.get(ShapeComponent)
shape_b = entity_b.get(ShapeComponent)
if shape_a is None or shape_b is None:
continue
separating_vectors, overlap = calculate_separating_vectors(shape_a.get_points(), shape_b.get_points())
entity_a_total_velocity = entity_a[PhysicsComponent].get_total_velocity()
if overlap and entity_a.collision_mask & entity_b.collision_type:
overlapping_entities.append(entity_b)
self.system_manager.send_message({
'message_type': MESSAGE_TYPE.COLLISION,
'collider': entity_a,
'collidee': entity_b
})
if entity_a.get(SkipCollisionResolutionComponent) or entity_b.get(SkipCollisionResolutionComponent):
continue
resolution_vector = self.find_resolution_vector(separating_vectors)
resolution_vector_normalized = resolution_vector.normalized()
if resolution_vector_normalized == Vec2d(0, -1):
entity_a.send_message({
'message_type': MESSAGE_TYPE.LANDED,
})
entity_a[PhysicsComponent].velocity = Vec2d(entity_a[PhysicsComponent].velocity[0], 0)
if entity_a[PhysicsComponent].velocity[0] > 0:
direction_multiplier = -1
elif entity_a[PhysicsComponent].velocity[0] < 0:
direction_multiplier = 1
else:
direction_multiplier = 0
if direction_multiplier != 0:
entity_a[PhysicsComponent].forces['Friction'] = Force(
self.coefficient_of_friction *
entity_a[PhysicsComponent].mass *
Vec2d(direction_multiplier * entity_a[PhysicsComponent].get_net_force()[1], 0),
source=entity_b
)
elif 'Friction' in entity_a[PhysicsComponent].forces:
entity_a[PhysicsComponent].forces.pop('Friction')
elif resolution_vector_normalized == Vec2d(0, 1):
entity_a[PhysicsComponent].velocity = Vec2d(entity_a[PhysicsComponent].velocity[0], 0)
entity_a.position += resolution_vector
if 'Friction' in entity_a[PhysicsComponent].forces:
friction_force = entity_a[PhysicsComponent].forces['Friction']
if friction_force.source not in overlapping_entities:
entity_a[PhysicsComponent].forces.pop('Friction')
if len(overlapping_entities) == 0:
entity_a.send_message({
'message_type': MESSAGE_TYPE.AIRBORNE,
})
