core.py 文件源码

def get_collision_force(self, entity_a, entity_b):
        if (not entity_a.collide) or (not entity_b.collide):
            return [None, None] # not a collider
        if (entity_a is entity_b):
            return [None, None] # don't collide against itself
        # compute actual distance between entities
        delta_pos = entity_a.state.p_pos - entity_b.state.p_pos
        dist = np.sqrt(np.sum(np.square(delta_pos)))
        # minimum allowable distance
        dist_min = entity_a.size + entity_b.size
        # softmax penetration
        k = self.contact_margin
        penetration = np.logaddexp(0, -(dist - dist_min)/k)*k
        force = self.contact_force * delta_pos / dist * penetration
        force_a = +force if entity_a.movable else None
        force_b = -force if entity_b.movable else None
        return [force_a, force_b]