/************************************************************************
**
** FILE  : cellkalook.c
**
** ZWECK : 
**
** AUTOR : Michael C. Ancutici
**	   Universitaet Stuttgart, Fakultaet Informatik
**
** DATUM : 14.03.93
**									
*************************************************************************/
#include 	"cellkalook.h"
#include	"cell.H"
#include	"cell.h"


#include <stdio.h>



#define vorzeichen( x) 	((x)>0 ? 1 : ((x) == 0 ? 0 : (-1)))





/*************************************************************************
** FUNKTION:	CellKaLookFor
** ZWECK:	
** EINGABE:	
** AUSGABE:
** RETURN: 	
** ANMERK: 	
*************************************************************************/
char CellKaLookFor( mx1, my1, mx2, my2, nr1, nr2)
  int 	mx1, my1;
  int 	mx2, my2;
  int	nr1, nr2;
{
  OBJECT *c;
  int   x1 = CellXKoord( mx1);
  int   y1 = CellYKoord( my1);
  int   x2 = CellXKoord( mx2);
  int   y2 = CellYKoord( my2);
  int 	dx, dy;
  int	dxabs, dyabs;
  int	i, j;
  int	px, py;
  int	sdx, sdy;
  int	x, y;
  

  dx = x2-x1;			/* Steigung fuer x			*/
  dy = y2-y1;			/* Steigung fuer y			*/
  sdx = vorzeichen( dx);	/* Steigungsrichtung x			*/
  sdy = vorzeichen( dy);	/* Steigungsrichtung y			*/
  dxabs = abs( dx);		/* |Steigung x|				*/
  dyabs = abs( dy);		/* |Steigung y|				*/
  
  x = 0;
  y = 0;
  
  px = x1;
  py = y1;
  
  if (dxabs >= dyabs) 
    for (i=0; i<dxabs; i++) {
      y += dyabs;
      if (y >= dxabs) {
        y -= dxabs;
        py += sdy;
      }
      if ( (c = Cell[ px][ py]) )
        do {
          if ( ((c->typ == CE_STELLE) && (c->Nr1 != nr1)) 	|| 
               ((c->typ == CE_TRANSITION) && (c->Nr1 != nr2)) )
            return (c->typ);
          c = c->next;
        } while (c);
      px += sdx;  
    } 
  else 
    for (i=0; i<dyabs; i++) {
      x += dxabs;
      if (x >= dyabs) {
        x -= dyabs;
        px += sdx;
      }
      if ( (c = Cell[ px][ py]) )
        do {
          if ( ((c->typ == CE_STELLE) && (c->Nr1 != nr1)) 	|| 
               ((c->typ == CE_TRANSITION) && (c->Nr1 != nr2)) )
            return (c->typ);
          c = c->next;
        } while (c);
      py += sdy;  
    } 
    
  return CE_OK;
}