/* <applet code=LineArt.class width=500 height=500></applet> */

import java.awt.*;
import java.applet.Applet;

public class LineArt extends Applet implements Runnable {
Graphics off_g;
Image off;
Thread th;
int w, h;
int line_num;
int x[] = new int[2];
int y[] = new int[2];
int lim_x[] = new int[2];
int lim_y[] = new int[2];
Line line[] = new Line[100];
Color color[][][] = new Color[33][33][33];
int color_r, color_g, color_b;
int color_speed;
int color_prog;
int color_mode;

/*********init********/
  public void init(){
    w = getSize().width;
    h = getSize().height;
    off = createImage(w,h);
    off_g = off.getGraphics();
    th = null;
    line_num = 100;
    for (int i = 0; i < 2; i ++){
      x[i] = (int)(Math.random()*(w-1));
      y[i] = (int)(Math.random()*(h-1));
    }
    lim_x[0] = lim_y[0] = 10;
    lim_x[1] = lim_y[1] = 5;
    for (int i = 0; i < line_num; i++)
      line[i] = new Line();

    for (int r = 0; r < 33; r++){
      for (int g = 0; g < 33; g++){
	for (int b = 0; b < 33; b++){
	  color[r][g][b] = new Color(r>0?(r*8)-1:0,
				     g>0?(g*8)-1:0,
				     b>0?(b*8)-1:0);
	}
      }
    }
    color_r = color_g = color_b = 8;
    color_speed = 0;
    color_prog = 0;
    color_mode = 0;
  }
  
  /*********start*******/
  public void start(){
    if (th == null){
      th = new Thread(this);
      th.start();
    }
  }
  
  /*********run********/
  public void run() {
    while (th != null){
      repaint();
      
      try{
	Thread.sleep(50);
      } catch (InterruptedException e){}
    }
  }
  
  /********paint*******/
  public void paint(Graphics g){
    off_g.setColor(Color.white);
    off_g.fillRect(0,0,w,h);
    
    set_Color();
    drawLine();
    
    g.drawImage(off,0,0,this);
  }
  
  /********set_Color********/
  public void set_Color(){
    if (color_prog >= 33)
      color_prog = 0;
    else
      color_prog++;
    
    if (color_prog == 0){
      color_mode = (int)(Math.random()*3);
      color_prog = 1;
    }
    if (color_speed == 0){
      switch (color_mode){
      case 0:
	color_r = changeColor(color_r);
	break;
      case 1:
	color_r = changeColor(color_r);
	color_g = changeColor(color_g);
	break;
      case 2:
	color_r = changeColor(color_r);
	color_g = changeColor(color_g);
	color_b = changeColor(color_b);
	break;
      }
    }
    color_speed++;
    if (color_speed >= 3)
      color_speed = 0;
    
    off_g.setColor(color[convert_Color(color_r)]
		   [convert_Color(color_g)]
		   [convert_Color(color_b)]);
  }
  
  /*****convert_Color******/
  public int convert_Color(int i){
    if (i >= 33)
      return 64-i;
    else
      return i;
  }
  
  /********changeColor********/
  public int changeColor(int c){
    if (c >= 64)
      c = 0;
    else
      c++;
    
    return c;
  }
  
  /*******drawLine******/
  public void drawLine(){
    line[0].draw(x[0],y[0],x[1],y[1],off_g);
    
    for(int i = 1; i < line_num; i++){
      line[i].draw(line[i-1].getold_x1(),line[i-1].getold_y1(),
		   line[i-1].getold_x2(),line[i-1].getold_y2(),off_g);
    }
    for (int i = 0; i < line_num; i++)
      line[i].set_old();
    
    for (int i = 0; i < 2; i++){
      x[i] += lim_x[i];
      y[i] += lim_y[i];
      
      if (x[i] <= 0){
	x[i] = 0;
	lim_x[i] = 2+(int)(Math.random()*10);
      }
      else if (x[i] >= w-1){
	x[i] = w-1;
	lim_x[i] = -(2+(int)(Math.random()*10));
      }
      
      if (y[i] <= 0){
	y[i] = 0;
	lim_y[i] = 2+(int)(Math.random()*10);
      }
      else if (y[i] >= h-1){
	y[i] = h-1;
	lim_y[i] = -(2+(int)(Math.random()*10));
      }
    }

	}

  /*******update********/
  public void update(Graphics g){
    paint(g);
  }
  
  /*******stop********/
  public void stop(){
    if (th != null)
      th = null;
  }
}