Home | History | Annotate | Download | only in replicaisland 
      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 /**
     20  * Maintains a canonical time step, in seconds, for the entire game engine.  This time step
     21  * represents real changes in time but is only updated once per frame.
     22  */
     23 // TODO: time distortion effects could go here, or they could go into a special object manager.
     24 public class TimeSystem extends BaseObject {
     25     private float mGameTime;
     26     private float mRealTime;
     27     private float mFreezeDelay;
     28     private float mGameFrameDelta;
     29     private float mRealFrameDelta;
     30 
     31     private float mTargetScale;
     32     private float mScaleDuration;
     33     private float mScaleStartTime;
     34     private boolean mEaseScale;
     35 
     36     private static final float EASE_DURATION = 0.5f;
     37 
     38     public TimeSystem() {
     39         super();
     40         reset();
     41     }
     42 
     43     @Override
     44     public void reset() {
     45         mGameTime = 0.0f;
     46         mRealTime = 0.0f;
     47         mFreezeDelay = 0.0f;
     48         mGameFrameDelta = 0.0f;
     49         mRealFrameDelta = 0.0f;
     50 
     51         mTargetScale = 1.0f;
     52         mScaleDuration = 0.0f;
     53         mScaleStartTime = 0.0f;
     54         mEaseScale = false;
     55     }
     56 
     57     @Override
     58     public void update(float timeDelta, BaseObject parent) {
     59     	mRealTime += timeDelta;
     60     	mRealFrameDelta = timeDelta;
     61 
     62         if (mFreezeDelay > 0.0f) {
     63             mFreezeDelay -= timeDelta;
     64             mGameFrameDelta = 0.0f;
     65         } else {
     66         	float scale = 1.0f;
     67         	if (mScaleStartTime > 0.0f) {
     68         		final float scaleTime = mRealTime - mScaleStartTime;
     69         		if (scaleTime > mScaleDuration) {
     70         			mScaleStartTime = 0;
     71         		} else {
     72         			if (mEaseScale) {
     73         				if (scaleTime <= EASE_DURATION) {
     74         					// ease in
     75         					scale = Lerp.ease(1.0f, mTargetScale, EASE_DURATION, scaleTime);
     76         				} else if (mScaleDuration - scaleTime < EASE_DURATION) {
     77         					// ease out
     78         					final float easeOutTime = EASE_DURATION - (mScaleDuration - scaleTime);
     79         					scale = Lerp.ease(mTargetScale, 1.0f, EASE_DURATION, easeOutTime);
     80         				} else {
     81         					scale = mTargetScale;
     82         				}
     83         			} else {
     84         				scale = mTargetScale;
     85         			}
     86         		}
     87             }
     88 
     89             mGameTime += (timeDelta * scale);
     90             mGameFrameDelta = (timeDelta * scale);
     91         }
     92 
     93 
     94     }
     95 
     96     public float getGameTime() {
     97         return mGameTime;
     98     }
     99 
    100     public float getRealTime() {
    101         return mRealTime;
    102     }
    103 
    104     public float getFrameDelta() {
    105         return mGameFrameDelta;
    106     }
    107 
    108     public float getRealTimeFrameDelta() {
    109         return mRealFrameDelta;
    110     }
    111 
    112     public void freeze(float seconds) {
    113         mFreezeDelay = seconds;
    114     }
    115 
    116     public void appyScale(float scaleFactor, float duration, boolean ease) {
    117     	mTargetScale = scaleFactor;
    118     	mScaleDuration = duration;
    119     	mEaseScale = ease;
    120     	if (mScaleStartTime <= 0.0f) {
    121     		mScaleStartTime = mRealTime;
    122     	}
    123     }
    124 
    125 }
    126