// stokes1.java  Stokes wave simulation
//       Programed by H.Tasaka  1997/12/2/Tue 

import java.applet.Applet;
import java.awt.*;
import java.io.*;
import java.net.URL;
import java.util.StringTokenizer;

public class stokes1 extends Applet {
   private Wave_Simulate1 wave_sim;
   private double v_inc_r=0.0,v_inc_the=5.0,v_inc_phi=0.0;
   final static int SIZE_X=300; 
   final static int SIZE_Y=225;
   final static double RAD=Math.PI/180.;
   final static int MAX_FI=4;
   private Stokes_Wave stk_wave;
   private String datafile="stokes1.dat"; 
   private Point prev;
   private double w_aa,w_amp[],w_lambda[],w_theta[],w_omega[];

   private Label l_aa; 
   private Label l_lambda [] = new Label[MAX_FI];
   private Label l_theta [] = new Label[MAX_FI];
   private Label l_omega [] = new Label[MAX_FI];
   private Scrollbar s_aa;
   private Scrollbar s_lambda [] = new Scrollbar[MAX_FI];
   private Scrollbar s_theta [] = new Scrollbar[MAX_FI];
   private Scrollbar s_omega [] = new Scrollbar[MAX_FI];
   private Panel subPanel = new Panel();
   private Button b_reset; 

   final static void gbcon(GridBagLayout gridbag, GridBagConstraints c,
                          Component cp, Panel p) {
      gridbag.setConstraints(cp, c);    
      p.add(cp);
   }

   public void init(){
      resize(340,470);
      setBackground(Color.gray);

      w_amp   = new double[MAX_FI];
      w_lambda = new double[MAX_FI];
      w_theta = new double[MAX_FI];
      w_omega = new double[MAX_FI];
      stk_wave = new Stokes_Wave();
      read_stokes();

      wave_sim = new Wave_Simulate1(stk_wave);
      wave_sim.resize(SIZE_X,SIZE_Y); 
      add(wave_sim);

      GridBagLayout gridbag = new GridBagLayout();
      subPanel.setLayout(gridbag);
      GridBagConstraints c = new GridBagConstraints();
      c.fill = GridBagConstraints.HORIZONTAL;
      c.anchor = GridBagConstraints.CENTER;
      c.weightx = 1.0;
      c.ipady = 0;

      c.gridwidth = 2;
      gbcon(gridbag, c, new Label("lambda"), subPanel);
      c.gridwidth = GridBagConstraints.REMAINDER;
      gbcon(gridbag, c, new Label("theta"), subPanel);
      Insets insets1 = new Insets(0, 3, 0, 0);
      Insets insets2 = new Insets(0, 0, 0, 3);

      for(int i=0;i<MAX_FI;i++){
         c.gridwidth = 1;
         l_lambda [i]=new Label("r"+(i+1)+": "+w_lambda[i]); 
         c.ipadx = 10;
         c.insets = insets1;
         gbcon(gridbag, c, add(l_lambda[i]), subPanel);
         s_lambda[i] = new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,1000);
         c.ipadx = 30;
         c.insets = insets2;
         gbcon(gridbag, c, add(s_lambda[i]), subPanel);
         set_s_lambda(i);
         l_theta[i] = new Label("t"+(i+1)+": "+w_theta[i]);
         c.ipadx = 10;
         c.insets = insets1;
         gbcon(gridbag, c, add(l_theta[i]), subPanel);
         s_theta[i] = new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,1000);
         c.gridwidth = GridBagConstraints.REMAINDER;
         c.ipadx = 30;
         c.insets = insets2;
         set_s_theta(i);
         gbcon(gridbag, c, add(s_theta[i]), subPanel);
      }
      c.gridwidth = 2;
      gbcon(gridbag, c, new Label("omega"), subPanel);
      c.gridwidth = GridBagConstraints.REMAINDER;
      gbcon(gridbag, c, new Label("amplitude"), subPanel);
      for(int i=0;i<MAX_FI;i++){
         c.gridwidth = 1;
         l_omega [i]=new Label("o"+(i+1)+": "+w_omega[i]); 
         c.ipadx = 10;
         c.insets = insets1;
         gbcon(gridbag, c, add(l_omega[i]), subPanel);
         s_omega[i] = new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,1000);
         c.ipadx = 30;
         c.insets = insets2;
         set_s_omega(i);
         gbcon(gridbag, c, add(s_omega[i]), subPanel);
         c.gridwidth = GridBagConstraints.REMAINDER;
         if(i == 0){ 
            c.gridwidth = 1;
            l_aa=new Label("aa: "+w_aa); 
            c.ipadx = 10;
            c.insets = insets1;
            gbcon(gridbag, c, add(l_aa), subPanel);
            s_aa = new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,1000);
            c.gridwidth = GridBagConstraints.REMAINDER;
            c.ipadx = 30;
            c.insets = insets2;
            set_s_aa();
            gbcon(gridbag, c, add(s_aa), subPanel);
         } else if(i == 1){
            c.gridwidth = GridBagConstraints.REMAINDER;
            gbcon(gridbag, c, new Label(""), subPanel);
         } else if(i == 2){
            c.gridwidth = 1;
            gbcon(gridbag, c, new Label(""), subPanel);
            c.gridwidth = GridBagConstraints.REMAINDER;
            c.ipadx = 30;
            c.insets = insets1;
            b_reset = new Button("Reset");
            gbcon(gridbag, c,add(b_reset), subPanel);
         } else {
            gbcon(gridbag, c, new Label(""), subPanel);
         }
      }
      subPanel.resize(320,200);
      add(subPanel);

      wave_sim.start();
   }

   public void stop(){
      wave_sim.stop();
   }

   private void read_stokes(){
      double amp,lambda,theta,omega;
      int i;

      try{
         InputStream is = new URL(getDocumentBase(), datafile).openStream();
         DataInputStream dis = new DataInputStream(is);
         try{
            StringTokenizer st;

            st = new StringTokenizer(dis.readLine());
            st = new StringTokenizer(dis.readLine());
            w_aa = Double.valueOf(st.nextToken()).doubleValue();
            stk_wave.set_fi_aa(MAX_FI,w_aa);

            for(i=0;i < MAX_FI;i++){
               st = new StringTokenizer(dis.readLine());
               w_amp[i]   = Double.valueOf(st.nextToken()).doubleValue();
               w_lambda[i] = Double.valueOf(st.nextToken()).doubleValue();
               w_theta[i] = Double.valueOf(st.nextToken()).doubleValue();
               w_omega[i] = Double.valueOf(st.nextToken()).doubleValue();
               stk_wave.set_rad(i,w_amp[i],w_lambda[i],w_theta[i],w_omega[i]);
            }
            stk_wave.set_end();
         } catch (IOException e) {
           System.out.println("Data read err =");
           System.err.println("Data read err : Can't access datafile " + datafile);
           Thread.currentThread().stop();
           System.exit(1);
         } finally {
           is.close(); 
         }
      } catch (FileNotFoundException e){
        System.err.println("File Not Found " + datafile);
        Thread.currentThread().stop();
      } catch (IOException e){
        System.err.println("Closing error");
        System.exit(1);
      } catch (Exception e){
        System.err.println("Load datafile error");
      }
   }

   private void set_s_aa(){
      s_aa.setValue((int)(w_aa*1000.));
   }

   private void set_s_lambda(int i){
      s_lambda[i].setValue((int)(w_lambda[i]*20.)); // 20.=1000./50.
   }

   private void set_s_theta(int i){
      s_theta[i].setValue((int)((w_theta[i]+180.)*2.7777778)); //2.77=1000./360.
   }

   private void set_s_omega(int i){
      s_omega[i].setValue((int)(w_omega[i]*2.7777778)); //2.77=1000./360.
   }

   private void reset_data(){
      read_stokes();
      stk_wave.set_fi_aa(MAX_FI,w_aa);
      l_aa.setText("aa: "+(float)w_aa);
      set_s_aa();
      for(int i=0;i < MAX_FI;i++){
         l_lambda[i].setText("r"+(i+1)+": "+(float)w_lambda[i]); 
         l_theta[i].setText("t"+(i+1)+": "+(float)w_theta[i]);
         l_omega[i].setText("o"+(i+1)+": "+(float)w_omega[i]);
         set_s_lambda(i);set_s_theta(i);set_s_omega(i);
         stk_wave.set_rad(i,w_amp[i],w_lambda[i],w_theta[i],w_omega[i]);
      }
      stk_wave.set_end();
      wave_sim.setView1();
   }

   public boolean mouseDown(Event ev, int x, int y) {
      prev = new Point(x, y);
      return true;
   }

   public boolean handleEvent(Event evt){
      if(evt.target instanceof Scrollbar){
         double value = (double)(((Scrollbar)evt.target).getValue());
         if(value == 0) value=1;
         if(evt.target.equals(s_aa)){
            w_aa=value/1000.;
            l_aa.setText("aa: "+(float)w_aa);
            stk_wave.set_fi_aa(MAX_FI,w_aa);
            stk_wave.set_end();
         } else {
            for(int i=0;i < MAX_FI;i++){
               if(evt.target.equals(s_lambda[i])){
                  w_lambda[i]=0.05*value; //w_lambda = 50.*(value/1000.) 
                  l_lambda[i].setText("r"+(i+1)+": "+(float)w_lambda[i]);
                  stk_wave.set_rad(i,w_amp[i],w_lambda[i],w_theta[i],w_omega[i]);
                  stk_wave.set_end();
                  break;
               } else if(evt.target.equals(s_theta[i])){
                  w_theta[i]=-180.+0.36*value; //w_theta=-180.+(360.*value/1000.)
                  l_theta[i].setText("t"+(i+1)+": "+(float)w_theta[i]);
                  stk_wave.set_rad(i,w_amp[i],w_lambda[i],w_theta[i],w_omega[i]);
                  stk_wave.set_end();
                  break;
               } else if(evt.target.equals(s_omega[i])){
                  w_omega[i]=0.36*value; //w_omega=360.*(value/1000.)
                  l_omega[i].setText("o"+(i+1)+": "+(float)w_omega[i]);
                  stk_wave.set_rad(i,w_amp[i],w_lambda[i],w_theta[i],w_omega[i]);
                  stk_wave.set_end();
                  break;
               }
            }//for(i=0;i < MAX_FI;i 
         } //if(evt.target.equals(s_aa))
         return true;
      } //if(evt.target instanceof Scrollbar)
      return super.handleEvent(evt);
   }

   public boolean action(Event evt,Object obj){
      if(evt.target instanceof Button){
         reset_data();
         return true;
      }
      return super.action(evt,obj);
   } 

   public boolean mouseDrag(Event ev, int x, int y) {
      wave_sim.changeView1(0.0,(double)(x-prev.x),(double)(y-prev.y));
      prev.move(x, y);
      return true;
   }

   public boolean mouseUp(Event ev, int x, int y) {
      prev = null;
      return true;
   }       

}

class Wave_Simulate1 extends Canvas implements Runnable {
   final static double RD=Math.PI/180.;  
   final static int SIZE_X=300; 
   final static int SIZE_Y=225;

   private double px_g,py_g;
   private int    dvx_g,dvy_g,out0_g;

   private double mark_xmin,mark_xmax,mark_xstp,mark_ymin,mark_ymax,mark_ystp,
          mark_zmin,mark_zmax,mark_zstp;
   private double viewp_xf,viewp_yf,viewp_zf,viewp_r,viewp_the,viewp_phi,
          viewp_vthx,viewp_vthy,v_inc_r,v_inc_the,v_inc_phi,rand_vel;
   private int viewp_dwnx,viewp_dwny,v_dispx,v_dispy;
   private byte vmove_sw,mark_sw=1; 
   private double wv_time,wx1,wx2,wy1,wy2,sth,cth,cfi,sfi;
   private Stokes_Wave stk_wave;

   private double wv_xmin,wv_xmax,wv_ymin,wv_ymax;

/* --- time_parm --- */
   private double start_t,play_t,t_div;
   private double end_t,stp_t;
/* ^^^ Parm_time ^^^ */

   private Image doubleBuffer;
   private Graphics myGC;
   private Thread kick=null;   

   Wave_Simulate1(){
   }

   Wave_Simulate1(Stokes_Wave stkw){
      stk_wave = new Stokes_Wave(); 
      stk_wave = stkw;

      mark_xmin=-10.0;mark_xmax=10.0;mark_xstp=2.0;
      mark_ymin=-10.0;mark_ymax=10.0;mark_ystp=2.0;
      mark_zmin= -4.0;mark_zmax= 4.0;mark_zstp=2.0;
      setView1();
      wv_xmin=-10.0;wv_xmax=10.0;wv_ymin=-10.0;wv_ymax=10.0;
      start_t=0.0;play_t=60.0;t_div=60;
      end_t=start_t+play_t;stp_t=play_t/t_div;

      v_dispx=20;
      v_dispy=10;
   }
 
   public void setView1(){
      viewp_xf=0.0;viewp_yf=0.0;viewp_zf=0.0;
      viewp_r=40.0;viewp_the=-30.0;viewp_phi=30.0;
      viewp_vthx=40.0;viewp_vthy=30.0;
      viewp_dwnx=SIZE_X;viewp_dwny=SIZE_Y; 
   }

   public void changeView1(double r,double the,double phi){
      viewp_r+=r;viewp_the+=the;viewp_phi-=phi;
      if(viewp_r   <    0.) viewp_r  =0.0;
      if(viewp_the >= 360.) viewp_the=0.0;
         else if(viewp_the < 0.0) viewp_the=360.0;
      if(viewp_phi >= 360.) viewp_phi=0.0;
         else if(viewp_phi < 0.0) viewp_phi=360.0;
   }

   public void start(){
      if(kick == null){
         doubleBuffer = createImage(SIZE_X,SIZE_Y);
         myGC = doubleBuffer.getGraphics();
         kick = new Thread(this);
         kick.start();
      }    
   }
   
   public void stop(){
      if(kick != null){
         kick.stop();
         kick = null;
      }
   }
   
   public void update(Graphics g){
       g.drawImage(doubleBuffer,0,0,this);
   }
   
   public void paint(Graphics g){
       update(g);
   }

   public void run(){
      int zmin[],zmax[];
      int continue_e,rcol;
      double a,x,y,z,stp_x,stp_y,rng,ox,oy,oz,cmax,cmin;

      zmin = new int[SIZE_X];
      zmax = new int[SIZE_X];

      myGC.setColor(Color.black);
      myGC.fillRect(0,0,SIZE_X,SIZE_Y);
      setscrn_size();
      a=viewp_the*RD;sth=Math.sin(a);cth=Math.cos(a);
      a=viewp_phi*RD;cfi=Math.cos(a);sfi=Math.sin(a);
      write_marking();

      continue_e = 500;
      stp_x=(wv_xmax-wv_xmin)/20.;
      stp_y=(wv_ymax-wv_ymin)/50.;
      for (int continue_n=0;continue_n<continue_e;continue_n++){
         for(wv_time=start_t;wv_time<end_t;wv_time+=stp_t){
            myGC.setColor(Color.black);
            myGC.fillRect(0,0,SIZE_X,SIZE_Y);
            myGC.setColor(Color.white);
            myGC.drawString("view point (r,the,phi) ="+viewp_r+","+viewp_the+
                            ","+viewp_phi,v_dispx,v_dispy);

            cmax=-10000;cmin=10000;
            for(x=wv_xmin;x<wv_xmax;x+=stp_x){
               z = stk_wave.get_z(x,wv_ymin,wv_time);
               if(z>cmax) cmax=z;
               if(z<cmin) cmin=z;
            }
            rng=150./(cmax-cmin);
            //System.out.println("rng ="+cmax+" "+cmin+" "+rng);
            setscrn_size();
            a=viewp_the*RD;sth=Math.sin(a);cth=Math.cos(a);
            a=viewp_phi*RD;cfi=Math.cos(a);sfi=Math.sin(a);

            write_marking();
            for(x=wv_xmin;x<wv_xmax;x+=stp_x){
               z = stk_wave.get_z(x,wv_ymin,wv_time);
               //z=Math.sin(wv_ymin*Math.PI);
               ox=x;oy=wv_ymin;oz=z;
               for(y=wv_ymin;y<wv_ymax;y+=stp_y){
                  z = stk_wave.get_z(x,y,wv_time);
                  //z=Math.sin(y*Math.PI+3.0*wv_time);
                  rcol=(int)((z-cmin)*rng);
                  //System.out.println("rcol= "+rcol);
                  if(rcol > 150) rcol=150;
                     else if(rcol<0) rcol=0;
                  usline3d(ox,oy,oz,x,y,z,(rcol+30),(rcol+30),255);
                  ox=x;oy=y;oz=z;
               } // for(y=
            }    // for(x=
            repaint();

            try{
               Thread.sleep(50);
            } catch (InterruptedException e){}
         } // for(wv_time
      } // for (int continue_n 
      kick=null;
   }

   private void usline3d(double x0,double y0,double z0,double x1,double y1,
      double z1,int col_r,int col_g,int col_b){
      int xx0,yy0,xx1,yy1,out0,out1;
      
      out0_g=0;
      turntrs(x0,y0,z0);
      convert();
      xx0=dvx_g;yy0=dvy_g;out0=out0_g;
      turntrs(x1,y1,z1);
      convert();
      xx1=dvx_g;yy1=dvy_g;out1=out0_g;
      /* if((out0 == 0)&&(out1 == 0)){
         usline(xx0,yy0,xx1,yy1,col_r,col_g,col_b);
      } */ 
      //System.out.println("line "+xx0+" "+(SIZE_Y-yy0)+" "+xx1+" "
      //                  +(SIZE_Y-yy1));
      myGC.setColor(new Color(col_r,col_g,col_b));
      myGC.drawLine(xx0,SIZE_Y-yy0,xx1,SIZE_Y-yy1);
   }

   private void uspset3d(double x0,double y0,double z0,
        int col_r,int col_g,int col_b) {

      out0_g=0;
      turntrs(x0,y0,z0);
      convert();
      if(out0_g == 0){
         myGC.setColor(new Color(col_r,col_g,col_b));
         myGC.drawLine(dvx_g,SIZE_Y-dvy_g,dvx_g,SIZE_Y-dvy_g); 
      }
   }

   private void setscrn_size() { 
      /* -- output viewp_dwny -- */
      double a,b,px,py;

      a=viewp_r*Math.tan(viewp_vthx*.5*RD);
      b=viewp_r*Math.tan(viewp_vthy*.5*RD);
      turntrs_vf0(viewp_xf,viewp_yf,viewp_zf,0.0,0.0,0.0,viewp_r);
      wx1=px_g-a;wx2=py_g+a;wy1=py_g-b;wy2=py_g+b;
      viewp_dwny=(int)((double)viewp_dwnx*b/a);
   }

   private void turntrs(double xx1,double yy1,double zz1) {
      // output px_g,py_g 
      double x,y,z,a,b,c;

      x=xx1-viewp_xf;
      y=yy1-viewp_yf;
      z=zz1-viewp_zf;
      a=x*cth+y*sth;
      b=viewp_r-a*cfi-z*sfi;
      c=viewp_r/b;
      px_g=(y*cth-x*sth)*c;
      py_g=(z*cfi-a*sfi)*c;
   }

   private void turntrs_vf0(double xx1,double yy1,double zz1,
      double xf,double yf,double zf,double r) {
      // output px_g,py_g
      double x,y,z,a,b,c;

      x=xx1-xf;
      y=yy1-yf;
      z=zz1-zf;
      a=x*cth+y*sth;
      b=r-a*cfi-z*sfi;
      c=r/b;
      px_g=(y*cth-x*sth)*c;
      py_g=(z*cfi-a*sfi)*c;
   }

   private void convert() {
      // input px_g,py_g
      // output dvx_g,dvy_g,out0_g
      double a;

      a=(px_g-wx1)/(wx2-wx1);
      dvx_g=(int)(.5+(double)viewp_dwnx*a);
      a=(py_g-wy1)/(wy2-wy1);
      dvy_g=(int)(.5+(double)viewp_dwny*a);
      /* printf("dvx = %d,%d\n",*dvx,*dvy);  */
      out0_g=0;
      if ((dvx_g < 0) || (dvx_g >= viewp_dwnx)) out0_g=1;
      if ((dvy_g < 0) || (dvy_g >= viewp_dwny)) out0_g=1;
   }

   private void write_marking(){
      double memr_x,memr_y,memr_z;
      int col_r,col_g,col_b,isw;

      if(mark_sw > 0){
         if(mark_sw == 1) isw = 1;
            else isw = 3;
         memr_z=0.0;
         for(int i=0;i<isw;i++){
            if(i==0) memr_z=0.0;
               else if(i==1)  memr_z=mark_zmin;
               else if(i==2)  memr_z=mark_zmax;
            for (memr_x=mark_xmin;memr_x<=mark_xmax;memr_x+=mark_xstp){
               if(memr_z == 0.0){col_r=0;col_g=50;col_b=0;
               } else { col_r=50;col_g=0;col_b=50;}
               usline3d(memr_x,mark_ymin,memr_z,memr_x,mark_ymax,memr_z,
                        col_r,col_g,col_b);
            }
            for (memr_y=mark_ymin;memr_y<=mark_ymax;memr_y+=mark_ystp){
               if(memr_z == 0.0){col_r=0;col_g=100;col_b=0;
               } else { col_r=50;col_g=0;col_b=50;}
               usline3d(mark_xmin,memr_y,memr_z,mark_xmax,memr_y,memr_z,
                        col_r,col_g,col_b);
            }
         }
         memr_y=0.0;
         for(int i=0;i<isw;i++){
            if(i==0) memr_y=0.0;
               else if(i==1)  memr_y=mark_ymax;
               else if(i==2)  memr_y=mark_ymin;
            for (memr_x=mark_xmin;memr_x<=mark_xmax;memr_x+=mark_xstp){
               if(memr_y == 0.0){col_r=0;col_g=50;col_b=0;
               } else { col_r=50;col_g=0;col_b=50;}
               usline3d(memr_x,memr_y,mark_zmin,memr_x,memr_y,mark_zmax,
                     col_r,col_g,col_b);
            }
            for (memr_z=mark_zmin;memr_z<=mark_zmax;memr_z+=mark_zstp){
               if(memr_y == 0.0){col_r=0;col_g=100;col_b=0;
               } else { col_r=50;col_g=0;col_b=50;}
               usline3d(mark_xmin,memr_y,memr_z,mark_xmax,memr_y,memr_z,
                     col_r,col_g,col_b);
            }
         } 
         memr_x=0.0;
         for(int i=0;i<isw;i++){
            if(i==0) memr_x=0.0;
               else if(i==1) memr_x=mark_xmax;
               else if(i==2) memr_x=mark_xmin;
            for (memr_y=mark_ymin;memr_y<=mark_ymax;memr_y+=mark_ystp){
               if(memr_x == 0.0){col_r=0;col_g=50;col_b=0;
               } else { col_r=50;col_g=0;col_b=50;}
               usline3d(memr_x,memr_y,mark_zmin,memr_x,memr_y,mark_zmax,
                     col_r,col_g,col_b);
            }
            for (memr_z=mark_zmin;memr_z<=mark_zmax;memr_z+=mark_zstp){
               if(memr_x == 0.0){col_r=0;col_g=50;col_b=0;
               } else { col_r=50;col_g=0;col_b=50;} 
               usline3d(memr_x,mark_ymin,memr_z,memr_x,mark_ymax,memr_z,
                     col_r,col_g,col_b);
            }
         } 
      } //if(mark_sw
      if(mark_sw > 0) {
         usline3d(mark_xmin,0.0,0.0,0.0,0.0,0.0,155,0,0);
         usline3d(0.0,0.0,0.0,mark_xmax,0.0,0.0,255,100,100);
         usline3d(0.0,mark_ymin,0.0,0.0,0.0,0.0,0,100,0);
         usline3d(0.0,0.0,0.0,0.0,mark_ymax,0.0,100,255,100);
         usline3d(0.0,0.0,mark_zmin,0.0,0.0,0.0,100,100,0);
         usline3d(0.0,0.0,0.0,0.0,0.0,mark_zmax,255,255,100);
      }
      myGC.setColor(Color.white);
      turntrs(mark_xmin,0.0,0.0);convert();
      myGC.drawString("-x",dvx_g,SIZE_Y-dvy_g);
      turntrs(mark_xmax,0.0,0.0);convert();
      myGC.drawString("+x",dvx_g,SIZE_Y-dvy_g);
      turntrs(0.0,mark_ymin,0.0);convert();
      myGC.drawString("-y",dvx_g,SIZE_Y-dvy_g);
      turntrs(0.0,mark_ymax,0.0);convert();
      myGC.drawString("+y",dvx_g,SIZE_Y-dvy_g);
      turntrs(0.0,0.0,mark_zmin);convert();
      myGC.drawString("-z",dvx_g,SIZE_Y-dvy_g);
      turntrs(0.0,0.0,mark_zmax);convert();
      myGC.drawString("+z",dvx_g,SIZE_Y-dvy_g);
   }
}

class Stokes_Wave{
   private double sta[][],fk[],fa[],fl[],fm[],fw[];
   private double aa;
   final static double RAD=Math.PI/180.;
   private int fi;

   Stokes_Wave(){
      sta=new double[10][4];
      fk=new double[10];fa=new double[10];fl=new double[10];
      fm=new double[10];fw=new double[10];
   }   

   public void set_fi_aa(int i,double a){
      fi = i;aa=a;
   }

   public void set_rad(int i,double amp,double lambda,double theta,
                       double omega){
      double k;

      k = (2.0*Math.PI)/lambda;
      fk[i]=k;fa[i]=amp;fl[i]=k*Math.cos(theta*RAD);
      fm[i]=k*Math.sin(theta*RAD);fw[i]=RAD*omega;
   }

   public void set_end(){
     double a,b,c;

     for(int i=0;i<fi;i++){
/*
        a=fa[i]*fa[i];
        b=a*fa[i];
        c=a*a;
        sta[i][0]=fa[i]/fk[i];
        sta[i][1]=(a*.5+.70833333333*c)/fk[i];
        sta[i][2]=(.375*b)/fk[i];
        sta[i][3]=(c/3.)/fk[i];
*/
        a=aa*aa;
        b=a*aa;
        c=a*a;
        sta[i][0]=aa/fk[i];
        sta[i][1]=(aa*.5+.70833333333*c)/fk[i];
        sta[i][2]=(.375*b)/fk[i];
        sta[i][3]=(c/3.)/fk[i];
/*
        sta[i][0]=fa[i];
        sta[i][1]=fa[i];
        sta[i][2]=fa[i];
        sta[i][3]=fa[i];
*/
     }
   }

   public double get_z(double x,double y,double t){
      double z;
      
      z=0.0;
      for(int i=0;i<fi;i++){
         z+=wave(i,x,y,t);
         //System.out.println("get_z"+wave(i,x,y));
      }
      z=0.35*z;
      return(z);
   }

   private double wave(int ii,double x,double y,double t){
      double b,z;

      b=fl[ii]*Math.PI*x+fm[ii]*Math.PI*y-fw[ii]*t;
      z=0.0;
      for(int in=0;in<4;in++){
         z+=sta[ii][in]*Math.cos((double)in*b);
         //System.out.println("z "+z+" "+sta[ii][in]+" "+in+" "+b);
      }
      return(z);
   }
}