import java.util.Date;
import java.applet.*;
import java.awt.Graphics;
import java.awt.event.*;
import java.awt.*;
import Rectangle;
import Line;

public class man_plane extends Applet 
{
    double x1 = 350.0;
    double y1 = 150.;
    int go = 1;
    int lasty;

    double tim = 0;
    double dtim=0.01;

    static double qvalue = 10;
    static double speed = 10.;

    double arrowlength;
    double arrowlength2 = 20;
    double arrowlength3 = 60;
    double angle = 20;
    double radangle = angle*(Math.PI/180);
    double sinangle = Math.sin(radangle);
    double cosangle = Math.cos(radangle);

    double dx1;
    double dx2;
    double dy1;
    double dy2;

    double recenty[];
    double inter[];
    long recentt[];
    double I_loop=0.;

    int max = 40;
    int j;
    int xcoord, ycoord;
    long lastt;

    long red;
    long green;
    long blue;

    double r;

    int maxtim =1;
    int brectcx;
    int brectcy;

    double dist1;
    double dist2;
    double compx, compx1, compx2;
    double compy, compy1, compy2;
    double dummy = 0.;
    double rada = 100.;
    double ang=Math.PI/6.;

    int x2 = 325;
    int y2 = 240;

    int numline = 2;

    Scrollbar speedScroll = new Scrollbar(Scrollbar.HORIZONTAL,(int)speed,10,10,100);

    public Label speedLabel = new Label("Speed of Light =" + speed);

    Rectangle rect;
    Rectangle rectn;
    Line line;

/*
public void Reset()
    {
	x1 = 350.0;
	y1 = 350.;
	go = 1;
	tim = 0;
	repaint();
    }

public void Settvalue(String m)
    {
  	maxtim = new Integer(m).intValue();
    }

public void Setqvalue(String m)
    {
	qvalue = new Double(m).doubleValue();
    }

public void Setbvalue(String m)
    {
	betavalue = new Double(m).doubleValue();
    }

public void SetGo()
    {
	go = 1;
	repaint();
    }
*/
 
public void init()
    {




	setBackground(java.awt.Color.white);
	rect = new Rectangle(0,200,7,(int)x1,(int)y1);
	rectn = new Rectangle(0,200,7,(int)x1+4,(int)y1+90);
	
 	recenty = new double[max+1];
	recentt = new long[max+1];
	inter = new double[10*max+1];
	line=new Line(0.0,0.0,0.0,0.0);
            j = 0; 
          while(j <= max)
                {
                recenty[j] = y1;
                recentt[j] = 0;
                j++;
                }
            j = 0; 
          while(j <= 10*max)
                {
                inter[j] = y1;
                j++;
                }

    speedScroll.setForeground(Color.black);
    speedScroll.setBackground(Color.lightGray);


    setLayout(new BorderLayout());
    Panel t = new Panel();
    t.setLayout(new FlowLayout(FlowLayout.CENTER));
    t.add(speedScroll);
    t.add(speedLabel);

    add("South",t);
    }

public void Setbvalue(String m)
    {
        speed = new Double(m).doubleValue();
    }


public void paint(Graphics g)
    {
		  {    
		   	line.ang = ang;  //the angle of field line measured from horizontal
    			line.emag = 1;

			rect.cx = (int)x1;
			rect.cy = (int)y1;
               double vey,vex;


/*			g.setColor(java.awt.Color.white);
    			g.drawLine(brectcx-rect.rw,brectcy-rect.rh,brectcx-rect.rw,brectcy+rect.rh);
    			g.drawLine(brectcx-rect.rw,brectcy-rect.rh,brectcx+rect.rw,brectcy-rect.rh);
    			g.drawLine(brectcx+rect.rw,brectcy-rect.rh,brectcx+rect.rw,brectcy+rect.rh);
    			g.drawLine(brectcx+rect.rw,brectcy+rect.rh,brectcx-rect.rw,brectcy+rect.rh);
*/
			g.setColor(java.awt.Color.red);
    			g.drawLine(rect.cx-rect.rw,rect.cy-rect.rh,rect.cx-rect.rw,rect.cy+rect.rh);
    			g.drawLine(rect.cx-rect.rw,rect.cy-rect.rh,rect.cx+rect.rw,rect.cy-rect.rh);
    			g.drawLine(rect.cx+rect.rw,rect.cy-rect.rh,rect.cx+rect.rw,rect.cy+rect.rh);
    			g.drawLine(rect.cx+rect.rw,rect.cy+rect.rh,rect.cx-rect.rw,rect.cy+rect.rh);

			g.setColor(java.awt.Color.black);
    			g.drawLine(rectn.cx-rectn.rw,rectn.cy-rectn.rh,rectn.cx-rectn.rw,rectn.cy+rectn.rh);
    			g.drawLine(rectn.cx-rectn.rw,rectn.cy-rectn.rh,rectn.cx+rectn.rw,rectn.cy-rectn.rh);
    			g.drawLine(rectn.cx+rectn.rw,rectn.cy-rectn.rh,rectn.cx+rectn.rw,rectn.cy+rectn.rh);
    			g.drawLine(rectn.cx+rectn.rw,rectn.cy+rectn.rh,rectn.cx-rectn.rw,rectn.cy+rectn.rh);

//  interpolate positions

                   int many;
                   double yfirst, ysecond, rfirst, rsecond;

                   int intmax;
                   int ilinc;
                   intmax=(int)(speed/10.);
       
                   ilinc=0;
               
                   while(ilinc < max)
                       {
                          yfirst=recenty[ilinc];
                          ysecond=recenty[ilinc+1];

                          many=0;
                          while(many < intmax)
                             {
                                 rsecond=(double)many/(double)intmax;
                                 rfirst=1.-rsecond;
                                 inter[ilinc*intmax+many]=rfirst*yfirst + rsecond*ysecond;
                                 many++;
//                        System.out.println("many" +many + "ilinc"+ilinc+"rfirst"+rfirst+"resecond"+rsecond);
                              }
                         ilinc++;
                        }        

//    Now draw lines
	
        	    double delarc = 9.;
                    double intarc;
                    intarc = delarc/3.;
                    double deriv;
                    int ilarrow,ilarrow2;

                   int r1=10;
                   int m1;

                   many=0;

                   while (many < 1)
                      {
        	    line.sx = x1 ;
//      	    line.sy = y1 +(many-4)*40;
        	    line.sy = y1 ;
                    ilinc=0;
                    ilarrow=0;
                    ilarrow2=0;
                    m1=max*intmax;
             	    while(ilinc <= m1 && line.sx < 500 && line.sx > 0 && line.sy < 700 && line.sy > 0 )
                	{


	    g.setColor(java.awt.Color.green);
                	    deriv=intmax*15.*(inter[ilinc+1]-inter[ilinc]);
                            line.ey = inter[ilinc]+(many-4)*40;
                            line.ey = inter[ilinc];
                	    line.ex = line.sx-10;
//  draw moving field line
			    g.drawLine((int)line.sx, (int)line.sy, (int)line.ex, (int)line.ey);
  	                    g.drawLine(700-(int)line.sx, (int)line.sy, 700-(int)line.ex, (int)line.ey);
//  draw stationary field line
			    g.drawLine((int)line.sx, 200, (int)line.ex, 200);
  	                    g.drawLine(700-(int)line.sx, 200, 700-(int)line.ex, 200);


//      draw arrow head on field line every once in awhile
                           ilarrow++;
                           ilarrow2++;

           if (ilarrow>5) {
                 compx=line.ex-line.sx;
                 compy=line.ey-line.sy;
                 line.emag = Math.sqrt(Math.pow(compx,2) + Math.pow(compy,2));
              vey = line.sy ;
              vex = line.sx ;
               dy1 = 1*(arrowlength2*((sinangle*compx-cosangle*compy)/line.emag));
                dx1 = -1*(arrowlength2*((cosangle*compx+sinangle*compy)/line.emag));
                dy2 = 1*(arrowlength2*((-sinangle*compx-cosangle*compy)/line.emag));
                dx2 = -1*(arrowlength2*((cosangle*compx-sinangle*compy)/line.emag));
//   moving field line
               g.drawLine((int)vex, (int)vey, (int)(vex + dx1/2.),(int)(vey + dy1/2.));
                g.drawLine((int)vex, (int)vey, (int)(vex + dx2/2.),(int)(vey + dy2/2.));
               g.drawLine(700-(int)vex, (int)vey,700- (int)(vex + dx1/2.),(int)(vey + dy1/2.));
                g.drawLine(700-(int)vex, (int)vey, 700-(int)(vex + dx2/2.),(int)(vey + dy2/2.));
//   stationary field line
                 vey=200.;
                 compx=-1.;
                 compy=0.;
                 line.emag = Math.sqrt(Math.pow(compx,2) + Math.pow(compy,2));
               dy1 = 1*(arrowlength2*((sinangle*compx-cosangle*compy)/line.emag));
                dx1 = 1*(arrowlength2*((cosangle*compx+sinangle*compy)/line.emag));
                dy2 = 1*(arrowlength2*((-sinangle*compx-cosangle*compy)/line.emag));
                dx2 = 1*(arrowlength2*((cosangle*compx-sinangle*compy)/line.emag));
               g.drawLine((int)vex, (int)vey, (int)(vex + dx1/2.),(int)(vey + dy1/2.));
                g.drawLine((int)vex, (int)vey, (int)(vex + dx2/2.),(int)(vey + dy2/2.));
               g.drawLine(700-(int)vex, (int)vey,700- (int)(vex + dx1/2.),(int)(vey + dy1/2.));
                g.drawLine(700-(int)vex, (int)vey, 700-(int)(vex + dx2/2.),(int)(vey + dy2/2.));
               ilarrow=0;
                       }

//  draw perturbation electric field line
//	    g.drawLine((int)line.ex, (int)y1+50, (int)line.ex, (int)(y1+deriv+50));
//	                    g.drawLine(700-(int)line.ex, (int)y1+50, 700-(int)line.ex, (int)(y1+deriv+50));

  	    g.drawLine((int)line.ex, 350, (int)line.ex, 350+(int)deriv);
  	                    g.drawLine(700-(int)line.ex, 350, 700-(int)line.ex, 350+(int)deriv);
//  draw arrow head on perturbation electric field line every once in a while
                 compx=0.;
                 compy=deriv;
                 line.emag = Math.sqrt(Math.pow(compx,2) + Math.pow(compy,2));

          if ( line.emag > .01)
          {
           if (ilarrow2>0) {
              vex = line.ex ;
              vey = 350.+deriv ;
               dy1 = 1*(arrowlength2*((sinangle*compx-cosangle*compy)/line.emag));
                dx1 = -1*(arrowlength2*((cosangle*compx+sinangle*compy)/line.emag));
                dy2 = 1*(arrowlength2*((-sinangle*compx-cosangle*compy)/line.emag));
                dx2 = -1*(arrowlength2*((cosangle*compx-sinangle*compy)/line.emag));
               g.drawLine((int)vex, (int)vey, (int)(vex + dx1/3.),(int)(vey + dy1/3.));
                g.drawLine((int)vex, (int)vey, (int)(vex + dx2/3.),(int)(vey + dy2/3.));
               g.drawLine(700-(int)vex, (int)vey,700- (int)(vex + dx1/3.),(int)(vey + dy1/3.));
                g.drawLine(700-(int)vex, (int)vey, 700-(int)(vex + dx2/3.),(int)(vey + dy2/3.));
               ilarrow2=0;
                   }

              }
//                        System.out.println("m1"+m1+ " ilinc"+ilinc);
// draw magnetic vectors
                r=3.*java.lang.Math.abs(deriv);
                red = (long)(255-r);
                blue = (long)(255);
                green = (long)(255-r);

                if(red>255)      {red=255;}
                if(green>255)    {green=255;}
                if(blue>255)     {blue=255;}

                if(red<0)      {red=0;}
                if(green<0)    {green=0;}
                if(blue<0)     {blue=0;}
                g.setColor(new Color((int)red,(int)green,(int)blue));

                         if(deriv<0)
                             {
                            g.drawOval((int)line.sx-r1/2,350-r1/2,r1,r1);
                              g.drawLine((int)line.sx-(r1*71/200),350-(r1*71/200),(int)line.sx+(r1*71/200),350+(r1*71/200));
                           g.drawLine((int)line.sx-(r1*71/200),350+(r1*71/200),(int)line.sx+(r1*71/200),350-(r1*71/200));
        }
      else
        {
    g.drawOval((int)line.sx-r1/2,350-r1/2,r1,r1);
    g.fillOval((int)line.sx-r1/6,350-r1/6,r1/3,r1/3);
        }
                         if(deriv>0)
                             {
                            g.drawOval(700-((int)line.sx-r1/2),350-r1/2,r1,r1);
                              g.drawLine(700-((int)line.sx-(r1*71/200)),350-(r1*71/200),700-((int)line.sx+(r1*71/200)),350+(r1*71/200));
                           g.drawLine(700-((int)line.sx-(r1*71/200)),350+(r1*71/200),700-((int)line.sx+(r1*71/200)),350-(r1*71/200));
        }
      else
        {
    g.drawOval(700-(int)line.sx-r1/2,350-r1/2,r1,r1);
    g.fillOval(700-(int)line.sx-r1/6,350-r1/6,r1/3,r1/3);
        }



                	    line.sx = line.ex;
                	    line.sy = line.ey;

                          ilinc++;

                	}
                   many++;
                           }

  	    brectcx = rect.cx;
	    brectcy = rect.cy;

	    tim+=dtim;
//   System.out.println("tim=" +tim);

	    //g.setColor(java.awt.Color.white);
//     g.fillRect(0,0,450,500);
	    g.setColor(java.awt.Color.black);
    	 	    }  	   
 //   	    }
}

/*
public boolean mouseMove(Event e, int x, int y)
    {
 
    xcoord = x;
    ycoord = y;
    return true;
    }
*/
 
public boolean mouseDown(Event e, int x, int y)
    {
    xcoord = x;
    ycoord = y;

    if(xcoord < (int)x1 + rect.rw && xcoord > (int)x1-rect.rw && ycoord < (int)y1+rect.rh && ycoord > (int)y1-rect.rh)
   	{
	rect.hit = 1;
	}
	return true;
    }  
 
public boolean mouseUp(Event e, int x, int y)
    {
    rect.hit = 0;
    return true;
    }
 
public boolean mouseDrag(Event e, int x, int y)
    {
    xcoord = x;
    ycoord = y;
    if (rect.hit == 1)
        {
        lasty = rect.cy;
        lastt = new Date().getTime();
 
            j = 0; 
          while(j < max)
                {
                recenty[max-j] = recenty[(max-j-1)];
                recentt[max-j] = recentt[(max-j-1)];
                j++;
                }
                recenty[0] = lasty;
                recentt[0] = lastt;
                rect.cy = y;
		y1 = rect.cy;

//      System.out.println("Recentx[0] = " + recentx[0] + " Recentx[1] = " + recentx[1] + " Recentx[2] = " + recentx[2]);
//      System.out.println("Recentt[0] = " + recentt[0] + " Recentt[1] = " + recentt[1] + " Recentt[2] = " + recentt[2]);
//System.out.println("x=" + x + " y = " + y+ "I_loop  " + I_loop);
//       I_loop=recentx[max]-recentx[max-1];
         
        repaint();
        }
    return true;
    }  

public boolean handleEvent(Event e)
    {
    Object target=e.target;

    if(target==speedScroll)
        {
        speed = speedScroll.getValue();
        speedLabel.setText("Speed of Light = " + speed);
        }
    return super.handleEvent(e);
    }

}