/* SCCS  @(#)NslAreaCanvas.java	1.5---05/15/99--12:25:35 */

// Copyright: Copyright (c) 1997 University of Southern California Brain Project.
// Copyright: This software may be freely copied provided the toplevel
// Copyright: COPYRIGHT file is included with each such copy.
// Copyright: Email nsl@java.usc.edu.

//--------------------------------------
// $Log: NslAreaCanvas.java,v $
//
// Revision 1.7  1998/01/30 20:02:25  erhan
// ver 5
//
// Revision 1.4  1997/05/09 22:30:23  danjie
// add some comments and Log
//
//--------------------------------------

package nslj.src.display;

import java.awt.*;
import java.util.*;
import java.io.*;
import nslj.src.lang.*;
import nslj.src.system.*;
import java.lang.Math;
 




public class NslAreaCanvas extends NslCanvas
{


 private Vector2 priv=new  Vector2();



    public NslAreaCanvas()
    {
        super();
    }
    public NslAreaCanvas(NslFrame nslDisplayFrame, NslCanvas pre)
    {
    	this(nslDisplayFrame,pre.canvas_name, 
	 ((NslVariable)pre.variable_list.elementAt(0)).info,
	 pre.getC_min_y(),
	 pre.getC_max_y());
    }

    public NslAreaCanvas(NslFrame nslDisplayFrame, String full_name, 
				NslVariableInfo data_info)
    {
        super(nslDisplayFrame, full_name, data_info);
        last_data_pos = ((NslVariable)variable_list.elementAt(0)).last_data_pos;
	//        data = ((NslVariable)variable_list.elementAt(0)).data;
	draw_time = 0;
    }

   public NslAreaCanvas(NslFrame nslDisplayFrame, String full_name, 
			       NslVariableInfo data_info,
			       double dmin, double dmax)
   {
        super(nslDisplayFrame,full_name, data_info);
        last_data_pos = ((NslVariable)variable_list.elementAt(0)).last_data_pos;
	//  data = ((NslVariable)variable_list.elementAt(0)).data;
	draw_time = 0;
        set_min_max(dmin,dmax);
    }

    public void  set_min_max(double dmin,double dmax)
{
    	y_max =(float) dmax;
	y_min =(float) dmin;
        C_max_y = dmax;
        C_min_y = dmin;     
}   

    public void init()
    {
        Graphics g = getGraphics();
       	Rectangle b = getBounds();
        g.clearRect(0, 0, b.width, b.height);
       // last_data_pos = ((NslVariable)variable_list.elementAt(0)).last_data_pos;
        // data = ((NslVariable)variable_list.elementAt(0)).data;
        paint(g);
	// draw_time = -1;

    }

    public void update()
    {
      Graphics g2 = getGraphics(); 
      draw_time = 0; 
      update(g2);
    }

    public void repaint()
    {
        Graphics g2 = getGraphics();
        draw_time =0;
        paint(g2);

    }



    public void paint_partial(Graphics g)

    {
	     
	if(canvas_type.equals("Normal"))
        super.set_draw_size();
        else if(canvas_type.equals("Zoom"))
        super.zoom_draw_size();

        g.setColor(Color.black);

        //draw variable

        NslVariable v = (NslVariable)variable_list.elementAt(0);
        x_dimension = v.info.getDimension(0);
        y_dimension = v.info.getDimension(1);


        last_data_pos = ((NslVariable)variable_list.elementAt(0)).last_data_pos;
        data = ((NslVariable)variable_list.elementAt(0)).data;



	if ((NslSystem.init_run_char == 'B')||
	   (NslSystem.init_run_char == 'D')){ //before or during
	   //System.out.println("debug: NslAreaCanvas bad flag "+ NslSystem.init_run_char);
	   //NslSystem.init_run_char = 'B';
	   last_data_pos = 0;
	}


	draw_time = last_data_pos;

        NslStoringVariables Bez = new NslStoringVariables();
       // for( ; draw_time<=last_data_pos; draw_time++){

 //System.out.println("\n\n\nDRAWTIME = "+draw_time ); 

/*
	//  if (draw_time > 0 && (draw_time % 30 == 0)) 
		//fitting_main(draw_time); // just for testing purposes
//		Bez.fitting_main(draw_time); // just for testing purposes
*/

          for(int i=0; i<x_dimension; i++)
            for(int j=0; j<y_dimension; j++)
              {

                Color color = getBackground();
                g.setColor(color);

                g.fillRect(drawX+j*dx+1, drawY+i*dy+1, dx-1, dy-1);



                //to draw multiple variables

                for(int v_count=0; v_count<variable_list.size(); v_count++)
                {

                  data = ((NslVariable)variable_list.elementAt(v_count)).data;
                
                  if(data[i][j][draw_time]>= y_max)
                  {
                      data_x_size = dx;
                      data_y_size = dy;
                  }
                  else if(data[i][j][draw_time] <= y_min)
                  {
                      data_x_size = dx; //(int)y_min;
                      data_y_size = dy; //(int)y_min;
                  }
                  else
                  {
                     // data_x_size = (int)(dx * (Math.abs(data[i][j][draw_time] - y_min) / (y_max - y_min)));
                     // data_y_size = (int)(dy * (Math.abs(data[i][j][draw_time] - y_min) / (y_max - y_min)));
			double scale=0;
			if (data[i][j][draw_time]>=0) 
				scale = data[i][j][draw_time]/y_max;
			else
				scale = data[i][j][draw_time]/y_min;

			data_x_size = (int)(dx*scale);
			data_y_size = (int)(dy*scale);
                  }


                  boxColor = ((NslVariable) variable_list.elementAt(v_count)).info.getColor();
                  g.setColor(boxColor);

                  //ERH g.setXORMode(getBackground());  // For overlaying the multiple box

    if (data[i][j][draw_time] == 0) {
                  g.fillRect(drawX+j*dx+ dx/2,
                             drawY+i*dy+ dy/2,
                             1, 1);
    }
    else
    if (data[i][j][draw_time] > 0) {
//System.out.println("Filling rectangle " + data_x_size+" "+data[i][j][draw_time]);
                  g.fillRect(drawX+j*dx+ (dx-data_x_size)/2,
                             drawY+i*dy+ (dy-data_y_size)/2,
                             data_x_size, data_y_size);
    }
    else {
//System.out.println(" Drawing rectangle " + data_x_size+" "+data[i][j][draw_time]);
		g.drawRect(drawX+j*dx+ (dx-data_x_size)/2+1,
                           drawY+i*dy+ (dy-data_y_size)/2+1,
                           data_x_size-2,data_y_size-2);
    }
                  g.setPaintMode();

              }
            }
          //}
          super.paint(g, 1);       
   }

    public void paint(Graphics g)

    {
	     
        draw_time =last_data_pos;
        //System.out.println("THE SIZE IS "+variable_list.size()+"\n\n\n\n\n\n\n\n\n");
        paint_partial(g);
     }



    public void collect()
    {
        for(int i=0; i<variable_list.size(); i++)
        ((NslVariable)variable_list.elementAt(i)).collect();
	Graphics gr=getGraphics();
//        paint(gr);
        paint_partial(gr);
    }

    public void set_y_range(float ymin, float ymax)
    {
        y_min = ymin;
        y_max = ymax;
	super.set_min_max((double)ymin,(double)ymax);
    }



    public int get_ymin()
    {
        return (int)y_min;
    }
    
    public int get_ymax()
    {
        return (int)y_max;
    }

    public void set_box_color(Color c)
    {
            NslVariable ndv = (NslVariable)variable_list.elementAt(0);
            ndv.info.setColor(c);          
            boxColor = c;
        
    }


 public Vector2 V2SubII(Vector2 a, Vector2 b)
  {
        Vector2 c=new Vector2();
 
        c.xset( a.xval() - b.xval() );
        c.yset( a.yval() - b.yval() );
        return(c);
 
  }

 
/*
 * ComputeLeftTangent, ComputeRightTangent, ComputeCenterTangent :
 *Approximate unit tangents at endpoints and "center" of digitized curve
 */
public  Vector2 ComputeLeftTangent(Vector2 [] d, int end)
    /* d;   Digitized points*/
    /* end; Index to "left" end of region */
{
    Vector2     tHat1;
    tHat1 = V2SubII(d[end+1], d[end]);
    //tHat1 = V2Normalize(tHat1);
    //System.out.println("end "+end+" d[end+1] "+d[end+1].xval()+" "+d[end+1].yval()+" d[end] "+d[end].xval()+" "+d[end].yval()+" IN LEFT TANGENT:"+tHat1.xval()+" "+tHat1.yval() );
    tHat1.V2Normalize();
    //System.out.println("IN LEFT TANGENT:"+tHat1.xval()+" "+tHat1.yval() );
    return tHat1;
}
 
public Vector2 ComputeRightTangent(Vector2 [] d, int end)
   /* d;                      Digitized points            */
   /* end;          Index to "right" end of region */
{
    Vector2     tHat2;
    tHat2 = V2SubII(d[end-1], d[end]);
    //tHat2 = V2Normalize(tHat2);
    tHat2.V2Normalize();
    //System.out.println("IN RIGHT TANGENT:"+tHat2.xval()+" "+tHat2.yval() );
    return tHat2;
}
 
 
public  Vector2 ComputeCenterTangent(Vector2 [] d, int center)
  /* d;                     Digitized points */

  /*center;          Index to point inside region        */
{
    Vector2     V1, V2, tHatCenter;
 
    V1 = V2SubII(d[center-1], d[center]);
    V2 = V2SubII(d[center], d[center+1]);

    tHatCenter = new Vector2();
    tHatCenter.xset ( (V1.xval()  + V2.xval() )/2.0);
    tHatCenter.yset ( (V1.yval()  + V2.yval() )/2.0);
    tHatCenter.V2Normalize();
    return tHatCenter;
}
 

/*
 *  ChordLengthParameterize :
 *      Assign parameter values to digitized points
 *      using relative distances between points.
 */
public double [] ChordLengthParameterize(Vector2 [] d, int first, int last)
    /*      *d;              Array of digitized points */
    /*     first, last;           Indices defining region     */
{
    int         i;
    double      [] u;                     /*  Parameterization            */
 
 //System.out.println("ENTERING ChordLengthParametrize");
    u = new double [last-first+1];
/*    u = (double *)malloc((unsigned)(last-first+1) * sizeof(double)); */
 
    u[0] = 0.0;
    for (i = first+1; i <= last; i++) {
                u[i-first] = u[i-first-1] +
                                V2DistanceBetween2Points(d[i], d[i-1]);
    }
 
    for (i = first + 1; i <= last; i++) {
                u[i-first] = u[i-first] / u[last-first];

// System.out.print(" "+u[i-first]);
  
    }
 
 
 //System.out.println("\nEXITING ChordLengthParametrize");
    return(u);
}
 
 
 
/*
 *  ComputeMaxError :
 *      Find the maximum squared distance of digitized points
 *      to fitted curve.
*/
public  double ComputeMaxError(Vector2 [] d, int first, int last, 
	    		      Vector2 [] bezCurve, double [] u, int [] splitPoint)
    /* d;     Array of digitized points   */
    /* first, last;   Indices defining region     */
    /* BezierCurve bezCurve  Fitted Bezier curve         */
    /* u;     Parameterization of points  */
    /* splitPoint;  Point of maximum error      */
{
    int         i;
    double      maxDist;                /*  Maximum error               */
    double      dist;           /*  Current error               */
    Vector2      P;                      /*  Point on curve              */
    Vector2     v;                      /*  Vector from point to curve  */
 
//System.out.println("ENTERING MAX ERROR"+splitPoint[0]);
    splitPoint[0] = (last - first + 1)/2;
  /*  *splitPoint = (last - first + 1)/2; */
    maxDist = 0.0;
    for (i = first + 1; i < last; i++) {
                P = BezierII(3, bezCurve, u[i-first]);
                v = V2SubII(P, d[i]);
                dist = v.V2SquaredLength();
               /*  dist = V2SquaredLength(&v); */
                if (dist >= maxDist) {
                maxDist = dist;
                /* *splitPoint = i; */
                splitPoint[0] = i;
                }
    }
//System.out.println("EXITING MAX ERROR"+splitPoint[0]);
//System.out.println("splitPoint "+splitPoint[0]+" and maxDist "+maxDist);
    return (maxDist);
}



/*
 *  Reparameterize:
 *      Given set of points and their parameterization, try to find
 *   a better parameterization.
 *
 */
 public double [] Reparameterize(Vector2 [] d, int first, int last, double [] u, 
			      Vector2 [] bezCurve)
    /* d;  Array of digitized points   */
    /* first, last;   Indices defining region     */
    /* u;   Current parameter values    */
    /* bezCurve;    Current fitted curve        */
{
    int         nPts = last-first+1;
    int         i;
    double      [] uPrime = new double [nPts];  /*  New parameter values     */
 

/*    uPrime = (double *)malloc(nPts * sizeof(double)); */
    for (i = first; i <= last; i++) {
           uPrime[i-first] = NewtonRaphsonRootFind(bezCurve, d[i], u[i-first]);

// System.out.print(" "+uPrime[i-first]);
    }
 //System.out.println();

    return (uPrime);
}
 



/*
 *  NewtonRaphsonRootFind :
 *      Use Newton-Raphson iteration to find better root.
 */
public double NewtonRaphsonRootFind(Vector2 [] Q, Vector2 P, double u)
    /* Q;      Current fitted curve        */
    /* P;      Digitized point             */
    /* u;      Parameter value for "P"     */
{
    double              numerator, denominator;
    Vector2  [] Q1 = new Vector2[3];
    Vector2  [] Q2= new Vector2[2];   /*  Q' and Q''                  */
    Vector2              Q_u, Q1_u, Q2_u; /*u evaluated at Q, Q', & Q''  */
    double              uPrime;         /*  Improved u                  */
    int                 i;
   
    /* Compute Q(u)     */
    Q_u = BezierII(3, Q, u);
   
    /* Generate control vertices for Q' */
    for (i = 0; i <= 2; i++) {
		double x1 = Q[i+1].xval() - Q[i].xval();
		double y1 = Q[i+1].yval() - Q[i].yval();

		Q1[i] = new Vector2();
                Q1[i].xset (x1 * 3.0);
                Q1[i].yset (y1 * 3.0);
    }
   
    /* Generate control vertices for Q'' */
    for (i = 0; i <= 1; i++) {
		double x1 = Q[i+1].xval() - Q[i].xval();
		double y1 = Q[i+1].yval() - Q[i].yval();

		Q2[i] = new Vector2();
                Q2[i].xset ( x1 * 2.0);
                Q2[i].yset ( y1 * 2.0);
    }
   
    /* Compute Q'(u) and Q''(u) */
    Q1_u = BezierII(2, Q1, u);
    Q2_u = BezierII(1, Q2, u);
   
    /* Compute f(u)/f'(u) */
    numerator = (Q_u.xval() - P.xval()) * (Q1_u.xval()) + (Q_u.yval() - P.yval()) * (Q1_u.yval());
    denominator = (Q1_u.xval()) * (Q1_u.xval()) + (Q1_u.yval()) * (Q1_u.yval()) +
                          (Q_u.xval() - P.xval()) * (Q2_u.xval()) + (Q_u.yval() - P.yval()) * (Q2_u.yval());
   
    /* u = u - f(u)/f'(u) */
    uPrime = u - (numerator/denominator);
    return (uPrime);
}




/*
 *  FitCurve :
 *      Fit a Bezier curve to a set of digitized points
 */
//void FitCurve(Vector2 []d, int nPts, double error, PrintStream ps, int i1, int j1)
void FitCurve(Vector2 []d, int nPts, double error, PrintStream ps)
  /*     *d;          Array of digitized points   */
  /*         nPts;   Number of digitized points  */
  /*      error;   User-defined error squared  */
 /*   FILE        *fp; */
{
    Vector2     tHat1, tHat2;   /*  Unit tangent vectors at endpoints */

    int ii, jj;

    //System.out.println("FITTING A CURVE!!!\n\n\n\n");
        //System.out.println("THE SIZE IS "+variable_list.size()+"\n\n\n\n\n\n\n\n\n");
   /* for (ii=0;ii<nPts;ii++)
     System.out.println(" "+d[ii].xval()+" "+d[ii].yval());
    System.out.println("!!!\n\n\n\n");
*/
 
    tHat1 = ComputeLeftTangent(d, 0);
    tHat2 = ComputeRightTangent(d, nPts - 1);
//printf("\n\nThere are %d nPts.\n", nPts);
 //System.out.println("There are "+nPts+" nPts.");
 //System.out.println("tHat1 "+tHat1.xval()+" "+tHat1.yval()+" tHat2 "+tHat2.xval()+" "+tHat2.yval() );
    
    FitCubic(d, 0, nPts - 1, tHat1, tHat2, error, ps);
   // FitCubic(d, 0, nPts - 1, tHat1, tHat2, error, ps, i1, j1);
}

 
/*
 *  FitCubic :
 *      Fit a Bezier curve to a (sub)set of digitized points
 */
public void FitCubic(Vector2 [] d, int first, int last, 
		     Vector2 tHat1, Vector2 tHat2, double error, PrintStream ps)
 //Vector2 tHat1, Vector2 tHat2, double error, PrintStream ps, int i1, int j1)
    /*   d;      Array of digitized points */
    /*   first, last;   Indices of first and last pts in region */
    /*   tHat1, tHat2; Unit tangent vectors at endpoints */
    /*    error;   User-defined error squared     */
/*    FILE        *fp; */
{
    Vector2 [] bezCurve; /*Control points of fitted Bezier curve*/
    double  [] u;             /*  Parameter values for point  */
    double  [] uPrime;        /*  Improved parameter values */
    double      maxError;       /*  Maximum fitting error        */
    int         splitPoint;     /*  Point to split point set at  */
    int         nPts;           /*  Number of points in subset  */
    double      iterationError; /*Error below which you try iterating  */
    int         maxIterations = 4; /*  Max times to try iterating  */
    Vector2     tHatCenter;     /* Unit tangent vector at splitPoint */
    int         i;
 
    iterationError = error * error;
    nPts = last - first + 1;


    splitPoint = nPts; /* MAKE SURE THIS IS CORRECT!! */
 
   //printf("Error is %f (nPts = %d -- last %d first %d)\n", error, nPts, last, f irst);
   //System.out.println("Error is "+error+" (nPts = "+ nPts+" -- last "+last+" first "+first+")");
 
    /*  Use heuristic if region only has two points in it */
    if (nPts == 2) {
            double dist = V2DistanceBetween2Points(d[last], d[first]) / 3.0;
 
                bezCurve = new Vector2 [4];
		for (i=0;i<4; i++) bezCurve[i] = new Vector2();

/*                bezCurve = (Point2 *)malloc(4 * sizeof(Point2)); */
                bezCurve[0] = d[first];
                bezCurve[3] = d[last];
//System.out.println("BEZ CURVE is "+bezCurve[0].xval()+" "+bezCurve[0].yval()+" and "+bezCurve[3].xval()+" "+bezCurve[3].yval());			
//System.out.println("BEZ CURVE is "+bezCurve[1].xval()+" "+bezCurve[1].yval()+" and "+bezCurve[2].xval()+" "+bezCurve[2].yval());			
                V2Add(bezCurve[0], V2Scale(tHat1, dist), bezCurve[1]);
                V2Add(bezCurve[3], V2Scale(tHat2, dist), bezCurve[2]);
//                DrawBezierCurve(3, bezCurve, fp);
                //DrawBezierCurve(3, bezCurve, ps, i1, j1);
                DrawBezierCurve(3, bezCurve, ps );
/*    printf("Returning from nPts=2\n"); */
                return;
    }
 
    /*  Parameterize points, and attempt to fit curve */
    u = ChordLengthParameterize(d, first, last);
    //for (i=1;i<5;i++) System.out.print(" "+u[i]);
    //System.out.print("\n");

    bezCurve = GenerateBezier(d, first, last, u, tHat1, tHat2);
 
//    printf("Value %4.3f\n", sizeof(bezCurve)/sizeof(Point2));
 
    /*  Find max deviation of points to fitted curve */

		int [] split = new int[1];
	//System.out.println("BEFORE: SPLITPOINT "+splitPoint);
		split[0] = splitPoint;
	//maxError=1;	
    maxError = ComputeMaxError(d, first, last, bezCurve, u, split);
		splitPoint = split[0];
	//System.out.println("AFTER: SPLITPOINT "+splitPoint);
    if (maxError < error) {
                //DrawBezierCurve(3, bezCurve, fp);
                //DrawBezierCurve(3, bezCurve, ps, i1, j1);
                DrawBezierCurve(3, bezCurve, ps);
                //free((void *)u);
             //   free(u);
                //free((void *)bezCurve);
             //   free(bezCurve);
//    printf("Returning from maxerror %f\n", maxError);
                return;
    }
    /*  If error not too large, try some reparameterization  */
    /*  and iteration */
    if (maxError < iterationError) {
    //printf("Returning from maxerror %f and iteration error  %f\n", maxError, it erationError);
                for (i = 0; i < maxIterations; i++) {

		/* int [] split = new int[1]; */
	
		split[0] = splitPoint;

                uPrime = Reparameterize(d, first, last, u, bezCurve);
                bezCurve = GenerateBezier(d, first, last, uPrime, tHat1, tHat2)
;
                maxError = ComputeMaxError(d, first, last, bezCurve, uPrime, split);
		splitPoint = split[0];

                if (maxError < error) {
                        //DrawBezierCurve(3, bezCurve, fp);
                        //DrawBezierCurve(3, bezCurve, ps, i1, j1);
                        DrawBezierCurve(3, bezCurve, ps);
                        //free((void *)u);
                      //  free(u);
                        //free((void *)bezCurve);
                      //  free(bezCurve);
                        return;
            }
            //free((void *)u);
          //  free(u);
            u = uPrime;
        }
    }
 
 
    /* Fitting failed -- split at max error point and fit recursively */
    //free((void *)u);
  //  free(u);
    //free((void *)bezCurve);
 //   free(bezCurve);
    tHatCenter = ComputeCenterTangent(d, splitPoint);
   //FitCubic(d, first, splitPoint, tHat1, tHatCenter, error, fp);
   //FitCubic(d, first, splitPoint, tHat1, tHatCenter, error, ps,i1,j1);
//   FitCubic(d, first, splitPoint, tHat1, tHatCenter, error, ps);
    //V2Negate(&tHatCenter);
    tHatCenter.V2Negate();
    //FitCubic(d, splitPoint, last, tHatCenter, tHat2, error, fp);
    //FitCubic(d, splitPoint, last, tHatCenter, tHat2, error, ps,i1,j1);
//    FitCubic(d, splitPoint, last, tHatCenter, tHat2, error, ps);

//System.out.println("EXITING FITCUBIC");
}
 


 
/*
 *  GenerateBezier :
 *  Use least-squares method to find Bezier control points for region.
 *
 */
public Vector2 []  GenerateBezier(Vector2 [] d , int first, int last, 
                                   double uPrime[], 
                                   Vector2 tHat1, Vector2 tHat2)
    /* d:  Array of digitized points   */
    /* first last:  Indices defining region     */
    /* uPrime: Parameter values for region */
    /* tHat1, tHat2:  Unit tangents at endpoints  */
{
    int         i;
    double C[][]  = new double[2][2];     /* Matrix C             */
    double []   X = new double [2];        /* Matrix X                     */
    Vector2 A[][] ;/* Precomputed rhs for eqn      */
    int         nPts;                   /* Number of pts in sub-curve */
    double      det_C0_C1,              /* Determinants of matrices     */
                det_C0_X,
                        det_X_C1;
    double      alpha_l,                /* Alpha values, left and right */
                alpha_r;
    Vector2     tmp;                    /* Utility variable             */
    Vector2 []  bezCurve = new Vector2[4];   /* RETURN bezier curve ctl pts  */


//System.out.println("ENTERING GENERATE BEZIER "+tHat1.xval()+" "+tHat1.yval()+" "+tHat2.xval()+" "+tHat2.yval());
 
    for (i=0; i<4; i++) bezCurve[i] = new Vector2();

    
/*    bezCurve = (Vector2 *)malloc(4 * sizeof(Vector2)); */
    nPts = last - first + 1;
 

    A = new Vector2 [nPts][2];
 
    /* Compute the A's  */
    for (i = 0; i < nPts; i++) {
                Vector2 v1 = new Vector2();
                Vector2 v2 = new Vector2();
		
                v1.xset ( tHat1.xval() );
                v1.yset ( tHat1.yval() );
                v2.xset ( tHat2.xval() );
                v2.yset ( tHat2.yval() );
//System.out.println("PT: "+i);
//System.out.print("that1 length "+tHat1.V2Length()+" "+tHat1.xval()+" "+tHat1.yval() );
//System.out.print("that2 length "+tHat2.V2Length()+" "+tHat2.xval()+" "+tHat2.yval() );
    // System.out.print("Before: "+v1.xval() +" "+v1.yval() );
                V2Scale(v1, B1(uPrime[i]));
     //System.out.println("after : "+v1.xval() +" "+v1.yval() );
     //System.out.print("Before: "+v2.xval() +" "+v2.yval() );
                V2Scale(v2,  B2(uPrime[i]));
     //System.out.println("after : "+v2.xval() +" "+v2.yval() );

                A[i][0] = new Vector2();
                A[i][0].xset( v1.xval() );
                A[i][0].yset( v1.yval() );
                A[i][1] = new Vector2();
                A[i][1].xset ( v2.xval() );
                A[i][1].yset ( v2.yval() );
//	System.out.println("A[i][0] "+A[i][0].xval()+" "+A[i][0].yval());
//	System.out.println("A[i][1] "+A[i][1].xval()+" "+A[i][1].yval());
//	System.out.println("B1 "+B1(uPrime[i])+" B2 "+B2(uPrime[i]));
    }
 
    /* Create the C and X matrices      */
    C[0][0] = 0.0;
    C[0][1] = 0.0;
    C[1][0] = 0.0;
    C[1][1] = 0.0;
    X[0]    = 0.0;
    X[1]    = 0.0;
 
    for (i = 0; i < nPts; i++) {
        C[0][0] += V2Dot(A[i][0], A[i][0]);
                C[0][1] += V2Dot(A[i][0], A[i][1]);
/*                                      C[1][0] += V2Dot(A[i][0], A[i][1]);*/
                C[1][0] = C[0][1];
                C[1][1] += V2Dot(A[i][1], A[i][1]);
 
                tmp = V2SubII(d[first + i],
                V2AddII(
                  V2ScaleIII(d[first], B0(uPrime[i])),
                        V2AddII(
                                V2ScaleIII(d[first], B1(uPrime[i])),
                                                V2AddII(
                                        V2ScaleIII(d[last], B2(uPrime[i])),
                                        V2ScaleIII(d[last], B3(uPrime[i]))))));
 
 
        X[0] += V2Dot(A[i][0], tmp);
        X[1] += V2Dot(A[i][1], tmp);
    }

	System.out.println("C "+C[0][0]+" "+C[0][1]+" "+C[1][0]+" "+C[1][1]);
	System.out.println("X "+X[0]+" "+X[1]);
 
    /* Compute the determinants of C and X      */
    det_C0_C1 = C[0][0] * C[1][1] - C[1][0] * C[0][1];
    det_C0_X  = C[0][0] * X[1]    - C[0][1] * X[0];
    det_X_C1  = X[0]    * C[1][1] - X[1]    * C[0][1];
 
    /* Finally, derive alpha values     */
    if (det_C0_C1 == 0.0) {
                det_C0_C1 = (C[0][0] * C[1][1]) * 10e-12;
    }
    alpha_l = det_X_C1 / det_C0_C1;
    alpha_r = det_C0_X / det_C0_C1;

//System.out.println("\n\n\nalpha_l "+alpha_l+" alpha_r "+alpha_r);
 
 
    /*  If alpha negative, use the Wu/Barsky heuristic (see text) */
 
    if (alpha_l < 0.0 || alpha_r < 0.0) {
	 	int ddd;
                double  dist = V2DistanceBetween2Points(d[last], d[first])/3.0;

		for (ddd=0;ddd<4;ddd++) bezCurve[ddd] = new Vector2();
 
                bezCurve[0] = d[first];
                bezCurve[3] = d[last];
	//System.out.println("HERE!!!!");

                V2Add(bezCurve[0], V2Scale(tHat1, dist), bezCurve[1]);
                V2Add(bezCurve[3], V2Scale(tHat2, dist), bezCurve[2]);
                return (bezCurve);
    }
 
    /*  First and last control points of the Bezier curve are */
    /*  positioned exactly at the first and last data points */
    /*  Control points 1 and 2 are positioned an alpha distance out */
    /*  on the tangent vectors, left and right, respectively */
    bezCurve[0] = new Vector2();
    bezCurve[1] = new Vector2();
    bezCurve[2] = new Vector2();
    bezCurve[3] = new Vector2();
    bezCurve[0].xset( d[first].xval() );
    bezCurve[0].yset( d[first].yval() );
    bezCurve[3].xset( d[last].xval() );
    bezCurve[3].yset( d[last].yval() );
//System.out.println("EDW??? 1");
    V2Add(bezCurve[0], V2Scale(tHat1, alpha_l), bezCurve[1]);

//System.out.println("EDW??? 2");
    V2Add(bezCurve[3], V2Scale(tHat2, alpha_r), bezCurve[2]);

//System.out.println("BEZ_CURVE is "+bezCurve[0].xval()+" "+bezCurve[0].yval()+" and "+bezCurve[3].xval()+" "+bezCurve[3].yval());			
//System.out.println("BEZ_CURVE is "+bezCurve[1].xval()+" "+bezCurve[1].yval()+" and "+bezCurve[2].xval()+" "+bezCurve[2].yval());			

//System.out.println("EXITING GENERATE BEZIER");
    return (bezCurve);
}

 
/*
 *  B0, B1, B2, B3 :
 *      Bezier multipliers
 */
static double B0(double u)
{
    double tmp = 1.0 - u;
    return (tmp * tmp * tmp);
}
 
 
static double B1(double u)
{
    double tmp = 1.0 - u;
    return (3 * u * (tmp * tmp));
}
 
static double B2(double u)
{
    double tmp = 1.0 - u;
    return (3 * u * u * tmp);
}
 
static double B3(double u)
{
    return (u * u * u);
}



 
/*
 *  Bezier :
 *      Evaluate a Bezier curve at a particular parameter value
 *
 */
public  Vector2 BezierII(int degree, Vector2 [] V, double t)
    /*  degree;   The degree of the bezier curve       */
    /*     *V; Array of control points              */
    /*     t;Parametric value to find point for   */
{
    int         i, j;
    Vector2      Q;              /* Point on curve at parameter t        */
    Vector2   [] Vtemp = new Vector2 [degree+1];         /* Local copy of control points         */
 

    /* Copy array       
    Vtemp = (Point2 *)malloc((unsigned)((degree+1)
                                * sizeof (Point2)));
   */
    for (i = 0; i <= degree; i++) {
		Vtemp[i] = new Vector2();
                Vtemp[i].xset( V[i].xval() );
                Vtemp[i].yset( V[i].yval() );
    }
 
    /* Triangle computation     */
    for (i = 1; i <= degree; i++) {
                for (j = 0; j <= degree-i; j++) {
		double x = Vtemp[j].xval();
		double x1 = Vtemp[j+1].xval();
		double y = Vtemp[j].yval();
		double y1 = Vtemp[j+1].yval();
                Vtemp[j].xset (  (1.0 - t) * x + t * x1 );
                Vtemp[j].yset ( (1.0 - t) * y + t * y1 );
//	      System.out.print("("+Vtemp[j].xval()+" "+Vtemp[j].yval()+")" );
                }
    }
 
    Q = Vtemp[0];
	      System.out.print("("+Vtemp[0].xval()+" "+Vtemp[0].yval()+")" );
/*    free((void *)Vtemp); */
    return Q;
}


 
  public Vector2 V2Scale( Vector2 v, double newlen )
  {
        double len = v.V2Length();
        if (len != 0.0) {
                double temp;
 
                temp = v.xval();
                v.xset( temp * newlen/len );
 
                temp = v.yval();
                v.yset( temp * newlen/len );
        }
        return(v);
  }
 
/* return vector sum c = a+b */
  public  Vector2 V2Add(Vector2 a, Vector2 b, Vector2 c)
  {
        //c = new Vector2();
        c.xset(  a.xval() + b.xval() );
        c.yset(  a.yval() + b.yval() );
//System.out.println("V2Add: "+a.xval()+" + "+b.xval()+" = "+c.xval() );
//System.out.println("V2Add: "+a.yval()+" + "+b.yval()+" = "+c.yval()+"\n");
        return(c);
  }

 
 
/* return the dot product of vectors a and b */
  public double V2Dot(Vector2 a, Vector2 b)
  {
        return( a.xval() * b.xval() +  a.yval() * b.yval() );
  }
 
  public Vector2 V2AddII(Vector2 a, Vector2 b)
  {
        Vector2 c=new Vector2();
 
        c.xset( a.xval() + b.xval() );
        c.yset( a.yval() + b.yval() );
        return(c);
  }
 
  public Vector2 V2ScaleIII( Vector2 a, double s )
  {
        Vector2 result = new Vector2();
 
        result.xset( s * a.xval() );
        result.yset( s * a.yval() );
 
        return (result);
  }
 
/* return the distance between two points */
  public double V2DistanceBetween2Points(Vector2 a, Vector2 b)
  {
        double dx = a.xval()  - b.xval();
        double dy = a.yval() - b.yval();
	//System.out.println("Distance: "+Math.sqrt((dx*dx)+(dy*dy))+"\n\n");
        return(Math.sqrt((dx*dx)+(dy*dy)));
  }








//public void DrawBezierCurve(int n, Vector2 [] curve, PrintStream ps, int i1, int j1)
public void DrawBezierCurve(int n, Vector2 [] curve, PrintStream ps)
{
  int i;


   //System.out.println("\n\n\n\n\n\n\n");
  for (i=0; i<n; i++){
   //System.out.println("CtrlPt["+i+"] = ("+curve[i].xval()+","+curve[i].yval());
   //ps.println(curve[i].xval()+" "+curve[i].yval() );
  }
  // System.out.println("\n\n\n\n\n\n\n");
}

/*
 *  fitting_main:
 *      Example of how to use the curve-fitting code.  Given an array
 *   of points and a tolerance (squared error between points and
 *      fitted curve), the algorithm will generate a piecewise
 *      cubic Bezier representation that approximates the points.
 *      When a cubic is generated, the routine "DrawBezierCurve"
 *      is called, which outputs the Bezier curve just created
 *      (arguments are the degree and the control points, respectively).
 *      Users will have to implement this function themselves
 *   ascii output, etc.
 *
 */
public void fitting_main(int drawing_time)
{
     //Vector2 d[][] = new Vector2 [x_dimension][y_dimension];
     //Vector2 [] d = new Vector2 [drawing_time];



     Vector2 d[] = new Vector2 [11];


     
     d[0] = new Vector2();
     d[0].xset(0.0); d[0].yset(0.0);
     d[1] = new Vector2();
     d[1].xset(0.0); d[1].yset(0.5);
     d[2] = new Vector2();
     d[2].xset(1.1); d[2].yset(1.4);
     d[3] = new Vector2();
     d[3].xset(2.1); d[3].yset(1.6);
     d[4] = new Vector2();
     d[4].xset(3.2); d[4].yset(1.1);
     d[5] = new Vector2();
     d[5].xset(3.3); d[5].yset(1.07);
     d[6] = new Vector2();
     d[6].xset(3.6); d[6].yset(0.07);
     d[7] = new Vector2();
     d[7].xset(3.8); d[7].yset(0.29);
     d[8] = new Vector2();
     d[8].xset(3.85); d[8].yset(0.59);
     d[9] = new Vector2();
     d[9].xset(4.0); d[9].yset(0.2);
     d[10] = new Vector2();
     d[10].xset(4.0); d[10].yset(0.0);

/* 
    static Vector2 d[11] = {
        { 0.0, 0.0 },
        { 0.0, 0.5 },
        { 1.1, 1.4 },
        { 2.1, 1.6 },
        { 3.2, 1.1 },
        { 3.3, 1.07 },
        { 3.6, 0.07 },
        { 3.8, 0.29 },
        { 3.85, 0.59 },
        { 4.0, 0.2 },
        { 4.0, 0.0 },
    };
*/
 
//    try {
//     PrintStream ps = new PrintStream ( new FileOutputStream("debug.log"), true );
 
//     double      error = 0.1;          /*  Squared error */
// /*    FILE        *fp; */
//     int pts, i, j,k ;
//     float x,y,z;
//      pts= 11;
// /*
//  System.out.print("Fitting curves at time "+drawing_time+"\n\n\n");

			
			
//     FitCurve(d, pts, error, ps);	*/	 /* Fit the Bezier curves */
 
 
//     //fclose(fp);
//    }
//    catch(IOException e) { }
    try {
    PrintWriter pw = new PrintWriter ( new FileOutputStream("debug.log"), true );
 
    double      error = 0.1;          /*  Squared error */
/*    FILE        *fp; */
    int pts, i, j,k ;
    float x,y,z;
    pts= 11;
/*
 System.out.print("Fitting curves at time "+drawing_time+"\n\n\n");

			
			
    FitCurve(d, pts, error, ps);	*/	 /* Fit the Bezier curves */
 
 
    //fclose(fp);
    }
    catch(IOException e) { }
}
 





    private float y_max=100, y_min=0;

    private int data_x_size, data_y_size, x_dimension, y_dimension;
    private int last_data_pos, draw_time;
    private float [][][] data;
    private Color boxColor=Color.black;
    private int  VCount;


}