1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.replica.replicaisland;
18 
19 /** A light-weight physics implementation for use with non-complex characters (enemies, etc). */
20 public class SimplePhysicsComponent extends GameComponent {
21     private static final float DEFAULT_BOUNCINESS = 0.1f;
22     private float mBounciness;
23 
SimplePhysicsComponent()24     public SimplePhysicsComponent() {
25         super();
26         setPhase(GameComponent.ComponentPhases.POST_PHYSICS.ordinal());
27         reset();
28     }
29 
30     @Override
reset()31     public void reset() {
32         mBounciness = DEFAULT_BOUNCINESS;
33     }
34 
setBounciness(float bounciness)35     public void setBounciness(float bounciness) {
36         mBounciness = bounciness;
37     }
38 
39     @Override
update(float timeDelta, BaseObject parent)40     public void update(float timeDelta, BaseObject parent) {
41         GameObject parentObject = (GameObject) parent;
42 
43         final Vector2 impulse = parentObject.getImpulse();
44         float velocityX = parentObject.getVelocity().x + impulse.x;
45         float velocityY = parentObject.getVelocity().y + impulse.y;
46 
47         if ((parentObject.touchingCeiling() && velocityY > 0.0f)
48             || (parentObject.touchingGround() && velocityY < 0.0f)) {
49             velocityY = -velocityY * mBounciness;
50 
51             if (Utils.close(velocityY, 0.0f)) {
52                 velocityY = 0.0f;
53             }
54         }
55 
56         if ((parentObject.touchingRightWall() && velocityX > 0.0f)
57             || (parentObject.touchingLeftWall() && velocityX < 0.0f)){
58             velocityX = -velocityX * mBounciness;
59 
60             if (Utils.close(velocityX, 0.0f)) {
61                 velocityX = 0.0f;
62             }
63         }
64 
65         parentObject.getVelocity().set(velocityX, velocityY);
66         impulse.zero();
67     }
68 }
69