debrisfragment.java

用java开发的一个实施策略游戏源码 值得学习一下

/*
	Netwar
	Copyright (C) 2002  Daniel Grund, Kyle Kakligian, Jason Komutrattananon, & Brian Hibler.

	This file is part of Netwar.

	Netwar 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 2 of the License, or
	(at your option) any later version.

	Netwar 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 Netwar; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package netwar.game.projectile;
import netwar.game.*;
import netwar.utils.*;
import netwar.utils.vectorgraphics.*;
import java.awt.Color;

/** Represents a piece of debris from a destroyed object.
 * This projectile arcs through the air while flipping. 
 * When it falls to the ground, it fizzles.
 * If it lasts out its duration, it fizzles.
 * @author Group N2 - Project Netwar
 * @author Daniel Grund
 */
public class DebrisFragment extends Projectile {
	private Point3D axisDir;
	private int flipSpeed;
	/** Creates a new instance of DebrisFragment */
	public DebrisFragment(GraphicThing gt) {
		appearance = gt;
	}
	/** Just fizzle (debris is currently harmless) */
	protected void Explode() {
		Fizzle();
	}
    
	/** Move forward. Accelerate downward. Explode if it hits the ground. */
	protected void Update() {
		center.doSum(velocity);
		appearance.translate(velocity);
		appearance.rotate(center, axisDir, flipSpeed);
		velocity.z -= 1;
		if(center.z < 0) {
			center.z = 0;
			Explode();
		}
	}
   
	/** Projectile default2 will explode if it's life runs out while in the air (doesn't happen)
	 * @return true
	 */
	protected boolean mustExplode() {
		return true;
	}        
	
	/** Make the GraphicThing appearance.  */
	protected void makeGraphics() {
		//Got it in the constructor.
		axisDir = Point3D.unitUp.getCrossProduct(velocity);
		flipSpeed = (int) velocity.getLength();
	}
}