/*
   Chris Rewerts, Agricultural Engineering, Purdue University
   April 1991
*/

#include "edit.h"
int 
draw_grid (void)
{
    double U_start;
    double D_south, D_west ;
    double D_north, D_east ;
    double U_to_D_xconv, U_to_D_yconv ;
    double U_west, U_south ;
    double U_east, U_north ;
    double U_x, U_y ;
    int D_x, D_y;
    double ew_res, ns_res;


  /* draw grid */

    ew_res  = real_window.ew_res;
    ns_res = real_window.ns_res;
    U_west = D_get_u_west() ;
    U_east = D_get_u_east() ;
    U_south = D_get_u_south() ;
    U_north = D_get_u_north() ;
    U_to_D_xconv = D_get_u_to_d_xconv() ;
    U_to_D_yconv = D_get_u_to_d_yconv() ;

    D_south = D_get_d_south() ;
    D_north = D_get_d_north() ;
    D_east =  D_get_d_east() ;
    D_west =  D_get_d_west() ;

    R_standard_color(grid_color);

/* Draw vertical grids */
    U_start = U_east;
    for (U_x=U_start; U_x>=U_west; U_x -= ew_res)
    {
        D_x = (int)( ( U_x - U_west ) * U_to_D_xconv + D_west );
        R_move_abs(D_x, (int)D_south) ;
        R_cont_abs(D_x, (int)D_north) ;
    }

/* Draw horizontal grids */
    U_start = U_north;
    for (U_y=U_start; U_y>=U_south; U_y -= ns_res)
    {
        D_y = (int)( ( U_south - U_y ) * U_to_D_yconv + D_south );
        R_move_abs((int)D_west, D_y) ;
        R_cont_abs((int)D_east, D_y) ;
    }

    R_stabilize();

    return 0;
}