/**************************************************************************

              	         S K E L E T O N . C

***************************************************************************/
/*****************************************************************************
FILENAME   : Skeleton.c
PURPOSE    : Extraction of Skeletal Points Algorithm  (EOS Algorithm)
*****************************************************************************/

#include </sys/h/types.h>
#include </usr/include/curses.h>
#include <stdio.h>
#include <math.h>
#include "isthdefs.h"
#include "piece.h"
#include </usr/users/header/arrkey.h>

extern int image[512][512];
extern int border_x[512][512];
extern int border_y[512][512];
extern int dist_image[512][512];

float skel_distance();

int mat_length = 0;
int px[19];
int py[19];
float thetathresh;
char skel_strg[79];

#ifdef ROGER  
#endif  
  
/*****************************************************************************
*****************************************************************************/
overinskeleton (deltax, deltay, minx, miny, maxx, maxy)
  int deltax, deltay, minx, miny, maxx, maxy;
{
  int i,j,e, z;
/*  sprintf (skel_strg, "in overinskel");
  printit(skel_strg); 
  printf ("this is in over in skele\n");
  waitforkey();
  */
  for (i=0;i<500;i++)
    j = i;
}
/*****************************************************************************
                        PAINT_MEDIAL                  
*****************************************************************************/
skel_paint_medial (deltax, deltay, minx, miny, maxx, maxy)
int deltax, deltay, minx, miny, maxx, maxy;
{
  int i,j,e, z;
  int grey = 1;
  float p; /* double */
  
  /*sprintf (skel_strg, "before paint it");
  printit(skel_strg); 
  waitforkey();
 */

  p = tan ( (double)(MEDIAL_THETA  * (M_PI / 360.0) ) );
  thetathresh = (float)(p * p);
  
  j = (maxy - miny) / 2; 
  medial_mode(); 

  for (i=1; i<=deltax; i++)
  { 
    if (image[j][i] != 0) 
    {
       if (check_euclidean (j,i,minx, miny))
       {
         mat_length = 0; 
         medial_mode(); 
	 xxx_follow(j,i, minx, miny);
	 if (mat_length > MEDIAL_LNGTH_THRESH)
	 { 
	   /*printf ("mat_length: %d\n", mat_length);  */
	   return(1); 
         }
	mat_length = 0; 
       }
     }/* endif*/
   } /* end for i*/
 } /* end */

/*****************************************************************************
                             FOLLOW                        
*****************************************************************************/
xxx_follow(j,i,minx, miny)
int j,i, minx, miny;
{
  int x,y,z, t, grey;
  VIS$SET_PIXEL (i + minx/*SUN*/,j + miny, 1);
  /*printf ("follow set_pixel at i %d j %d \n", i + minx,j + miny);  */

  for (z=1;z<=8;z++)
  {
      get_next_neighbor (z, i, j, &x, &y);
      grey = VIS$GET_PIXEL (x + minx, y + miny);
      if (grey != 1  && check_euclidean (y,x, minx, miny))
      {
	mat_length++;
        xxx_follow(y,x, minx, miny);
        /*printf ("out of recursion at x:%d y:%d\n", i,j ); */
      }
  } /* end for z */ 
}  /* end function */

/*****************************************************************************
                             CHECK_EUCLIDEAN               
*****************************************************************************/
check_euclidean (j,i, minx, miny)  
int j,i, minx, miny;
{
  float a,b,c;
  int z,t;
  int theta, denom;
  float dist_ij[8];

  px[1] = border_x[j-1][i+1]; 
  py[1] = border_y[j-1][i+1];
  
  px[2] = border_x[j-1][i]; 
  py[2] = border_y[j-1][i];
 
  px[3] = border_x[j-1][i-1]; 
  py[3] = border_y[j-1][i-1];
  
  px[4] = border_x[j][i-1]; 
  py[4] = border_y[j][i-1];

  px[5] = border_x[j+1][i-1]; 
  py[5] = border_y[j+1][i-1];
  
  px[6] = border_x[j+1][i]; 
  py[6] = border_y[j+1][i];
  
  px[7] = border_x[j+1][i+1]; 
  py[7] = border_y[j+1][i+1];
  
  px[8] = border_x[j][i+1]; 
  py[8] = border_y[j][i+1];
  
  for (z=1;z<=8;z++)
  {
     /*printf ("X: %d Y: %d px[%d]: %d", i, j, z, px[z]); 
     printf (" py[]: %d\n", py[z]); 
     */
     if (px[z] == 0)
       return(0);
  } 
  for (z = 1; z <= 8; z++)
    dist_ij[z] = skel_distance (i,j, px[z], py[z]);
  
  for (z = 1; z <= 8; z++)
  {
   c = dist_ij[z];
   for (t = z+1; t <= 8; t++)
   {
    if (px[t] != px[t-1] || py[t] != py[t-1])
    {
      a = skel_distance (px[z], py[z], px[t], py[t]);
      b = dist_ij[t];

     if (a > A_LENGTH && b > B_LENGTH && c > C_LENGTH 
	     && abs( (int)sqrt(b) - (int)sqrt(c) ) < EPSILON) 
     { 
      denom = abs( (int)(b) - (int)(a) );
      if (denom != 0)
      if ( ( a / (float)denom)  > thetathresh )
      {
	dist_image[j][i] = (int)c; 
	return(1);
      } 
     } /* endif epsilon stuff */
    
    } /* endif not the same as just saw*/ 
   } /* end for t loop */
 } /* end for z loop */
  return(0);
} /* end function */
 
/**************************************************************************
                    SKEL_DISTANCE         
***************************************************************************/
float skel_distance(x1,y1,x2,y2)
int x1,y1,x2,y2;
{
  float a,b;
  float q;
 
  a = (float)(x2 - x1);
  b = (float)(y2 - y1);
  a = a*a;
  b = b*b;
  return ( (float)(a+b) );
}

/*****************************************************************************
                                END      
*****************************************************************************/