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      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 
     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