/********************************/
/*				*/
/*   grid is a procedure which	*/
/* draws a single point in on	*/
/* a graph.			*/
/*   It deals with points that	*/
/* exceed the limits of the	*/
/* graph, and also with search	*/
/* windows.			*/
/*				*/
/********************************/
#include <stdio.h>

#include <math.h>

#ifndef irint
#define irint(a) 	(a)
#endif

void 
grid(
  char** matrix,
  int pos_x,
  int pos_y,
  int width,
  int height,
  double winstart,
  double winstop,
  double xscale, 
  double yscale,
  double x,
  double y,
  char ch, 
  char altch)
    {
	extern void put_char_at (char**, int, int, char);
    int tempx, tempy;
    char out;

    out = ch;
    if (((winstart < winstop) && (x < winstart || x > winstop))
     || ((winstart > winstop) && (x > winstop  && x < winstart)))
	out = altch;
    tempx = (int)((width*x)/xscale + 0.5);
    tempy = (int)((height*y)/yscale + 0.5);
    if (tempy > height)
	{
	out = '^';
	tempy = height;
	}
    put_char_at(matrix, pos_x+tempx, pos_y+height-tempy, out);
}