firework.java

JAVA小程序.非常的有趣.一个简单的模拟放烟火的小程序,里面每更新一次,放出的烟火模式就不同

import java.awt.*;
import java.applet.*;
import java.lang.*;
import java.util.*;
import java.net.*;
public class Firework extends Applet implements Runnable{
	public int AnimationSpeed,
	          RocketStyleVariability,
	          MaxRocketNumber,
	          MaxRocketExplosionEnergy,
	           MaxRocketPatchNumber,
	           MaxRocketPatchLength,
	           Gravity;
	public String RocketSoundtrack;
	private int mx,my;
	private Thread thread=null;
	private Rocket rocket[];
	
	public void init()
	{
		int i;
		String p;
		p=getParameter("AnimationSpeed");
		AnimationSpeed=(p==null)?100:Integer.valueOf(p).intValue();
		RocketSoundtrack=getParameter("RocketSoundtrack");
		p=getParameter("RocketStyleVariability");
		RocketStyleVariability=(p==null)?20:Integer.valueOf(p).intValue();
		p=getParameter("MaxRocketNumber");
		MaxRocketNumber=(p==null)?5:Integer.valueOf(p).intValue();
		p=getParameter("MaxRocketExplosionEnergy");
		MaxRocketExplosionEnergy=(p==null)?500:Integer.valueOf(p).intValue();
		p=getParameter("MaxRocketPatchNumber");
		MaxRocketPatchNumber=(p==null)?50:Integer.valueOf(p).intValue();
		p=getParameter("MaxRocketPatchLength");
		MaxRocketPatchLength=(p==null)?100:Integer.valueOf(p).intValue();
		p=getParameter("Gravity");
		Gravity=(p==null)?20:Integer.valueOf(p).intValue();
		mx=size().width-1;
		my=size().height-1;
		rocket=new Rocket[MaxRocketNumber];
		for(i=0;i<MaxRocketNumber;i++)
		rocket[i]=new Rocket(mx,my,Gravity);
	}
	
	public void start()
	{
		if(thread==null)
		{
			thread=new Thread(this);
			thread.start();
		}
	}
	
	public void stop()
	{
		if(thread!=null)
		{
			thread.stop();
			thread=null;
		}
	}
	
	public void run()
	{
		int i,
		e=(int)(Math.random()*MaxRocketExplosionEnergy*3/4)+MaxRocketExplosionEnergy/4+1,
		p=(int)(Math.random()*MaxRocketPatchNumber*3/4)+MaxRocketPatchNumber/4+1,
		l=(int)(Math.random()*MaxRocketPatchLength*3/4)+MaxRocketPatchLength/4+1;
		long s=(long)(Math.random()*10000);
		boolean sleep;
		Graphics g=getGraphics();
		URL u=null;
		while(true)
		{
			try
			{
				thread.sleep(100/AnimationSpeed);
			}
			catch(InterruptedException x)
			{
			}
			sleep=true;
			for(i=0;i<MaxRocketNumber;i++)
			  sleep=sleep&&rocket[i].sleep;
			  if(sleep&&Math.random()*100<RocketStyleVariability)
			  {
			  		e=(int)(Math.random()*MaxRocketExplosionEnergy*3/4)+MaxRocketExplosionEnergy/4+1;
	             	p=(int)(Math.random()*MaxRocketPatchNumber*3/4)+MaxRocketPatchNumber/4+1;
	            	l=(int)(Math.random()*MaxRocketPatchLength*3/4)+MaxRocketPatchLength/4+1;
	        	    s=(long)(Math.random()*10000);
			  }
			  for(i=0;i<MaxRocketNumber;i++)
			  {
			  	if(rocket[i].sleep&&Math.random()*MaxRocketNumber*1<1)
			  	{
			  		try
			  		{
			  			u=new URL(getDocumentBase(),RocketSoundtrack);
			  		}
			  		catch(MalformedURLException x)
			  		{
			  		}
			  		play(u);
			  		rocket[i].init(e,p,l,s);
			  		rocket[i].start();
			  	}
			  	rocket[i].show(g);
			  }
		}
	}
	
	public void paint(Graphics g)
	{
		g.setColor(Color.black);
		g.fillRect(0,0,mx+1,my+1);
	}
}

class Rocket
{
	public boolean sleep=true;
	private int energy,patch,length,
	            mx,my,
	            gravity,
	            ox,oy,
	            vx[],vy[],
	            x,y,
	            red,blue,green,
	            t;
	private Random random;
	
	public Rocket(int a,int b,int g)
	{
		mx=a;
		my=b;
		gravity=g;
	}
	
	public void init(int e,int p,int l,long seed)
	{
		int i;
		energy=e;
		patch=p;
		length=l;
		random=new Random(seed);
		vx=new int[patch];
		vy=new int[patch];
		red=(int)(random.nextDouble()*128)+128;
		blue=(int)(random.nextDouble()*128)+128;
		green=(int)(random.nextDouble()*128)+128;
		ox=(int)(Math.random()*mx/2)+mx/4;
		oy=(int)(Math.random()*my/2)+my/4;
		for(i=0;i<patch;i++)
		{
			vx[i]=(int)(Math.random()*energy)-energy/2;
			vy[i]=(int)(Math.random()*energy*7/8)-energy/8;
		}
		
	}
	
	public void start()
	{
		t=0;
		sleep=false;
	}
	
	public void show(Graphics g)
	{
		if(!sleep)
		if(t<length)
		{
			int i,c;
			double s;
			Color color;
			c=(int)(random.nextDouble()*64)-32+red;
			if(c>=0&&c<256)red=c;
			c=(int)(random.nextDouble()*64)-32+blue;
			if(c>=0&&c<256)blue=c;
			c=(int)(random.nextDouble()*64)-32+green;
			if(c>=0&&c<256)green=c;
			color=new Color(red,blue,green);
			for(i=0;i<patch;i++)
			{
				s=(double)t/100;
				x=(int)(vx[i]*s);
				y=(int)(vy[i]*s-gravity*s*s);
				g.setColor(color);
				g.drawLine(ox+x,oy-y,ox+x,oy-y);
				if(t>=length/2)
				{
					int j;
					for(j=0;j<2;j++)
					{
						s=(double)((t-length/2)*2+j)/100;
						x=(int)(vx[i]*s);
						y=(int)(vy[i]*s-gravity*s*s);
						g.setColor(Color.black);
						g.drawLine(ox+x,oy-y,ox+x,oy-y);
					}
				}
			}
			t++;
			
		}
		else
		{
			sleep=true;
		}
	}
}