package com.caplet.manna;

import java.awt.*;

/**
 * Does the evolution, and displays the results, in a separate thread than 
 * the rest of the applet.  One thread evolves both dishes, so their 
 * generations will be exactly in synch. <p>
 *
 * When evolution is paused, the GAPainter thread still exists, but is 
 * paused, waiting to be told to go.  It starts paused.
 *
 * @author Mark S. Miller, markm@caplet.com
 * @author Terry Stanley, tstanley@cocoon.com
 */
public class GAPainter implements Runnable {
	private boolean amRunning = false;
	private GA[] myGAs;
	private Graphics[] theirGfxs;

    /**
     * Give it the array of GAs it should evolve.
     */
	public GAPainter(GA[] gas) {
	    myGAs = gas;
		Thread painter = new Thread(this);
		painter.setPriority(Thread.MIN_PRIORITY);
		painter.start();
	}

    /**
     * This is the "main"-like method for a Thread.
     */
  	public void run() {
		while(true) {
		    Thread.yield();
			synchronized(this) {  // must get the lock each time through the loop
				while(!amRunning) {
					try {
						this.wait();
					} catch(InterruptedException e) {
						System.err.println("interrupted with " + e);
					}
				}
				step(20);
			}
		}
	}

	private synchronized void step(int matings) {
        for (int i = 0; i < matings; i++) {
            for (int j = 0; j < myGAs.length; j++) {
                myGAs[j].step(myGAs[j].getGraphics());
            }
        }
	}

    /**
     * Let the evolution resume (or commence)
     */
	public synchronized void go() {
		amRunning = true;
		this.notify();
	}

    /**
     * Stop the world, I want to play god.
     */
	public void pause() {
		amRunning = false;
	}

    /**
     * Add the same amount of manna at the same place in all GAs.
     */
	public synchronized void addManna(int cx, int cy, int amount) {
	    for (int i = 0; i < myGAs.length; i++) {
    	    myGAs[i].addManna(cx, cy, amount);
    	}
	}
}