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
17package com.replica.replicaisland;
18
19/** A light-weight physics implementation for use with non-complex characters (enemies, etc). */
20public class SimplePhysicsComponent extends GameComponent {
21    private static final float DEFAULT_BOUNCINESS = 0.1f;
22    private float mBounciness;
23
24    public SimplePhysicsComponent() {
25        super();
26        setPhase(GameComponent.ComponentPhases.POST_PHYSICS.ordinal());
27        reset();
28    }
29
30    @Override
31    public void reset() {
32        mBounciness = DEFAULT_BOUNCINESS;
33    }
34
35    public void setBounciness(float bounciness) {
36        mBounciness = bounciness;
37    }
38
39    @Override
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