|
27
|
1 #############################################################################
|
|
|
2 #
|
|
|
3 # Copyright (c) 2010 by Casey Duncan and contributors
|
|
|
4 # All Rights Reserved.
|
|
|
5 #
|
|
|
6 # This software is subject to the provisions of the MIT License
|
|
|
7 # A copy of the license should accompany this distribution.
|
|
|
8 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
|
9 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
|
10 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
|
|
|
11 #
|
|
|
12 #############################################################################
|
|
|
13
|
|
|
14 __version__ = '$Id$'
|
|
|
15
|
|
|
16
|
|
|
17 class EulerMovement(object):
|
|
|
18 """System that applies entity movement to position using Euler's method
|
|
|
19
|
|
|
20 :param position_component: Name of :class:`grease.component.Position`
|
|
|
21 component to update.
|
|
|
22 :param movement_component: Name of :class:`grease.component.Movement`
|
|
|
23 component used to update position.
|
|
|
24 """
|
|
|
25
|
|
|
26 def __init__(self, position_component='position', movement_component='movement'):
|
|
|
27 self.position_component = position_component
|
|
|
28 self.movement_component = movement_component
|
|
|
29
|
|
|
30 def set_world(self, world):
|
|
|
31 """Bind the system to a world"""
|
|
|
32 self.world = world
|
|
|
33
|
|
|
34 def step(self, dt):
|
|
|
35 """Apply movement to position"""
|
|
|
36 assert self.world is not None, "Cannot run with no world set"
|
|
|
37 for position, movement in self.world.components.join(
|
|
|
38 self.position_component, self.movement_component):
|
|
|
39 movement.velocity += movement.accel * dt
|
|
|
40 position.position += movement.velocity * dt
|
|
|
41 position.angle += movement.rotation * dt
|
|
|
42
|
