GameController.java

/**
 * Copyright (C) 2013-2014 Project-Vethrfolnir
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.vethrfolnir.game.services;

import java.util.ArrayList;

import com.vethrfolnir.logging.MuLogger;
import com.vethrfolnir.services.threads.CorvusThreadPool;
import com.vethrfolnir.tools.Updatable;

import corvus.corax.Corax;
import corvus.corax.config.Config;
import corvus.corax.inject.Inject;

/**
 * @author Vlad
 *
 */
public class GameController implements Runnable {
	private static final MuLogger log = MuLogger.getLogger(GameController.class);
	
	private final ArrayList<Updatable> subscribers = new ArrayList<>();
	private volatile boolean active = true;
	
	@Config(key = "Game.UpdateTicks", value = "10")
	private long GameTicks = 10;
	
	/**
	 * The time it took to update all subscribers on the previous pass.
	 */
	private float deltaTime = 0;
	
	@Inject
	private void load() {
		GameTicks = 1000 / GameTicks; // XXX Find out what has the best precision.
		log.info("Initialized.");
	}
	
	/* (non-Javadoc)
	 * @see java.lang.Runnable#run()
	 */
	@Override
	public void run() {
		int tick = 0;
		long lastSample = 0;
		
		while(active) {
        	try {

		        long time = System.currentTimeMillis();

		        if(time - lastSample < GameTicks) {
		        	Thread.sleep(GameTicks);
		            continue;
		        }

		        tick++;
		        lastSample = time;
				long start = System.currentTimeMillis();
		        
				for (int i = 0; i < subscribers.size(); i++) {
					Updatable updatable = subscribers.get(i);
					updatable.update(tick, deltaTime);
				}

				long end = System.currentTimeMillis();
				deltaTime = (end - start) / 1000f;
				//System.out.println("Tick: "+tick +" dt: "+deltaTime);
				if(tick == 10) {
		        	tick = 0;
		        	//System.out.println("System DT: "+deltaTime);
				}
			}
			catch (Exception e) {
				log.fatal("Error in GameController loop!", e);
			}

		}
	}
	
	public void subscribe(Updatable updatable) {
		subscribers.add(updatable);
	}
	
	public void unsubscribe(Updatable updatable) {
		subscribers.remove(updatable);
	}

	public void start() {
		active = true;
		Corax.fetch(CorvusThreadPool.class).execute(this);
		log.info("Started.");
	}
	
	public void stop() {
		active = false;
		log.info("Stoped.");
	}
	
	/**
	 * @return the deltaTime
	 */
	public float getDeltaTime() {
		return deltaTime;
	}
	
	/**
	 * @return the subscribers
	 */
	public ArrayList<Updatable> getSubscribers() {
		return subscribers;
	}

}