Geografic-Information-System/display/d.path/select.c

#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <math.h>
#include <grass/gis.h>
#include <grass/display.h>
#include <grass/vector.h>
#include <grass/colors.h>
#include <grass/glocale.h>
#include "proto.h"

#define WDTH 5

int display(struct Map_info *Map, struct line_pnts *Points,
	    const struct color_rgb *color, int first, int last, int be_bold)
{
    int from, to;

    D_RGB_color(color->r, color->g, color->b);

    if (first)
	from = 0;
    else
	from = 1;
    if (last)
	to = Points->n_points;
    else
	to = Points->n_points - 1;

    if (be_bold)
	D_line_width(2);

    D_polyline_abs(&Points->x[from], &Points->y[from], to - from);

    if (be_bold)
	D_line_width(0);

    return 0;
}



/* Same as path() but get start/stop from the command line (for non-interactive use)
   Hamish Bowman March 2007 */
int coor_path(struct Map_info *Map, const struct color_rgb *hcolor,
	      int be_bold, double start_x, double start_y,
	      double end_x, double end_y)
{
    int ret;
    double nx, ny, fx, fy, tx, ty, msize, maxdist;
    struct line_pnts *Points;
    int start_node, end_node;
    double fdist, tdist, cost;

    Points = Vect_new_line_struct();

    msize = 10 * (D_d_to_u_col(2.0) - D_d_to_u_col(1.0));	/* do it better */
    G_debug(1, "msize = %f\n", msize);

    /*
       x1 = D_d_to_u_col ((double)(screen_x-WDTH));
       y1 = D_d_to_u_row ((double)(screen_y-WDTH));
       x2 = D_d_to_u_col ((double)(screen_x+WDTH));
       y2 = D_d_to_u_row ((double)(screen_y+WDTH));

       x1 = fabs ( x2 - x1 );
       y1 = fabs ( y2 - y1 );

       if ( x1 > y1 ) maxdist = x1;
       else maxdist = y1;
     */

/**  maxdist = 10 pixels on the display (WDTH*2); ?
 **   ie related to zoom level ??  just use msize ?? **/
    maxdist = msize;

    G_debug(1, "Maximum distance in map units = %f\n", maxdist);


    /* Vect_find_node(): find number of nearest node, 0 if not found */
    start_node = Vect_find_node(Map, start_x, start_y, 0.0, maxdist, 0);
    if (start_node > 0) {
	Vect_get_node_coor(Map, start_node, &nx, &ny, NULL);
	fprintf(stderr, _("Node %d: %f %f\n"), start_node, nx, ny);
    }
    if (start_node > 0) {
	fx = nx;
	fy = ny;
    }
    else {
	fx = start_x;
	fy = start_y;
    }
    D_RGB_color(hcolor->r, hcolor->g, hcolor->b);
    D_plot_icon(fx, fy, G_ICON_BOX, 0.0, msize);


    end_node = Vect_find_node(Map, end_x, end_y, 0.0, maxdist, 0);
    if (end_node > 0) {
	Vect_get_node_coor(Map, end_node, &nx, &ny, NULL);
	fprintf(stderr, _("Node %d: %f %f\n"), end_node, nx, ny);
    }
    if (end_node > 0) {
	tx = nx;
	ty = ny;
    }
    else {
	tx = end_x;
	ty = end_y;
    }
    D_RGB_color(hcolor->r, hcolor->g, hcolor->b);
    D_plot_icon(tx, ty, G_ICON_CROSS, 0.0, msize);


    G_debug(2, "find path %f %f -> %f %f", fx, fy, tx, ty);

    ret =
	Vect_net_shortest_path_coor(Map, fx, fy, 0.0, tx, ty, 0.0,
				    5 * maxdist, 5 * maxdist, &cost, Points,
				    NULL, NULL, NULL, NULL, &fdist, &tdist);
    if (ret == 0) {
	fprintf(stdout, _("Destination unreachable\n"));
    }
    else {
	fprintf(stdout, _("Costs on the network = %f\n"), cost);
	fprintf(stdout, _("  Distance to the network = %f, "
			  "distance from the network = %f\n\n"),
		fdist, tdist);

	display(Map, Points, hcolor, 1, 1, be_bold);
    }

    return 0;
}