lw_dist3d_pt_poly()

int lw_dist3d_pt_poly	(	const POINT3DZ *	p,
		const LWPOLY *	poly,
		PLANE3D *	plane,
		POINT3DZ *	projp,
		DISTPTS3D *	dl
	)

Checking if the point projected on the plane of the polygon actually is inside that polygon.

If so the mindistance is between that projected point and our original point. If not we check from original point to the boundary. If the projected point is inside a hole of the polygon we check the distance to the boundary of that hole.

Definition at line 1291 of file measures3d.c.

{
        uint32_t i;
 
        if (pt_in_ring_3d(projp, poly->rings[0], plane))
        {
                for (i = 1; i < poly->nrings; i++)
                {
                        /* Inside a hole. Distance = pt -> ring */
                        if (pt_in_ring_3d(projp, poly->rings[i], plane))
                                return lw_dist3d_pt_ptarray(p, poly->rings[i], dl);
                }
 
                /* if the projected point is inside the polygon the shortest distance is between that point and the
                 * input point */
                return lw_dist3d_pt_pt(p, projp, dl);
        }
        else
                /* if the projected point is outside the polygon we search for the closest distance against the boundary
                 * instead */
                return lw_dist3d_pt_ptarray(p, poly->rings[0], dl);
 
        return LW_TRUE;
}

References lw_dist3d_pt_pt(), lw_dist3d_pt_ptarray(), LW_TRUE, LWPOLY::nrings, pt_in_ring_3d(), and LWPOLY::rings.

Referenced by lw_dist3d_point_poly(), and lw_dist3d_ptarray_poly().

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