lw_dist2d_point_poly()

int lw_dist2d_point_poly	(	LWPOINT *	point,
		LWPOLY *	poly,
		DISTPTS *	dl
	)

1. see if pt in outer boundary. if no, then treat the outer ring like a line
2. if in the boundary, test to see if its in a hole. if so, then return dist to hole, else return 0 (point in polygon)

Definition at line 615 of file measures.c.

{
        const POINT2D *p;
        uint32_t i;
 
        LWDEBUG(2, "lw_dist2d_point_poly called");
 
        p = getPoint2d_cp(point->point, 0);
 
        if (dl->mode == DIST_MAX)
        {
                LWDEBUG(3, "looking for maxdistance");
                return lw_dist2d_pt_ptarray(p, poly->rings[0], dl);
        }
        /* Return distance to outer ring if not inside it */
        if ( ptarray_contains_point(poly->rings[0], p) == LW_OUTSIDE )
        {
                LWDEBUG(3, "first point not inside outer-ring");
                return lw_dist2d_pt_ptarray(p, poly->rings[0], dl);
        }
 
        /*
         * Inside the outer ring.
         * Scan though each of the inner rings looking to
         * see if its inside.  If not, distance==0.
         * Otherwise, distance = pt to ring distance
         */
        for ( i = 1;  i < poly->nrings; i++)
        {
                /* Inside a hole. Distance = pt -> ring */
                if ( ptarray_contains_point(poly->rings[i], p) != LW_OUTSIDE )
                {
                        LWDEBUG(3, " inside an hole");
                        return lw_dist2d_pt_ptarray(p, poly->rings[i], dl);
                }
        }
 
        LWDEBUG(3, " inside the polygon");
        if (dl->mode == DIST_MIN)
        {
                dl->distance = 0.0;
                dl->p1.x = dl->p2.x = p->x;
                dl->p1.y = dl->p2.y = p->y;
        }
        return LW_TRUE; /* Is inside the polygon */
}

References DIST_MAX, DIST_MIN, DISTPTS::distance, getPoint2d_cp(), lw_dist2d_pt_ptarray(), LW_OUTSIDE, LW_TRUE, LWDEBUG, DISTPTS::mode, LWPOLY::nrings, DISTPTS::p1, DISTPTS::p2, LWPOINT::point, ptarray_contains_point(), LWPOLY::rings, POINT2D::x, and POINT2D::y.

Referenced by lw_dist2d_distribute_bruteforce().

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