gserialized_distance_nd()

Datum gserialized_distance_nd

(

PG_FUNCTION_ARGS

)

Definition at line 644 of file gserialized_gist_nd.c.

{
        /* Feature-to-feature distance */
        GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
        GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
        LWGEOM *lw1 = lwgeom_from_gserialized(geom1);
        LWGEOM *lw2 = lwgeom_from_gserialized(geom2);
        LWGEOM *closest;
        double distance;
 
        /* Find an exact shortest line w/ the dimensions we support */
        if (lwgeom_has_z(lw1) && lwgeom_has_z(lw2))
        {
                closest = lwgeom_closest_line_3d(lw1, lw2);
                distance = lwgeom_length(closest);
        }
        else
        {
                closest = lwgeom_closest_line(lw1, lw2);
                distance = lwgeom_length_2d(closest);
        }
 
        /* Can only add the M term if both objects have M */
        if (lwgeom_has_m(lw1) && lwgeom_has_m(lw2))
        {
                double m1 = 0, m2 = 0;
                int usebox = false;
                /* Un-sqrt the distance so we can add extra terms */
                distance = distance * distance;
 
                if (lwgeom_get_type(lw1) == POINTTYPE)
                {
                        POINT4D p;
                        lwpoint_getPoint4d_p((LWPOINT *)lw1, &p);
                        m1 = p.m;
                }
                else if (lwgeom_get_type(lw1) == LINETYPE)
                {
                        LWPOINT *lwp1 = lwline_get_lwpoint(lwgeom_as_lwline(closest), 0);
                        m1 = lwgeom_interpolate_point(lw1, lwp1);
                        lwpoint_free(lwp1);
                }
                else
                        usebox = true;
 
                if (lwgeom_get_type(lw2) == POINTTYPE)
                {
                        POINT4D p;
                        lwpoint_getPoint4d_p((LWPOINT *)lw2, &p);
                        m2 = p.m;
                }
                else if (lwgeom_get_type(lw2) == LINETYPE)
                {
                        LWPOINT *lwp2 = lwline_get_lwpoint(lwgeom_as_lwline(closest), 1);
                        m2 = lwgeom_interpolate_point(lw2, lwp2);
                        lwpoint_free(lwp2);
                }
                else
                        usebox = true;
 
                if (usebox)
                {
                        GBOX b1, b2;
                        if (gserialized_get_gbox_p(geom1, &b1) && gserialized_get_gbox_p(geom2, &b2))
                        {
                                double d;
                                /* Disjoint left */
                                if (b1.mmin > b2.mmax)
                                        d = b1.mmin - b2.mmax;
                                /* Disjoint right */
                                else if (b2.mmin > b1.mmax)
                                        d = b2.mmin - b1.mmax;
                                /* Not Disjoint */
                                else
                                        d = 0;
                                distance += d * d;
                        }
                }
                else
                        distance += (m2 - m1) * (m2 - m1);
 
                distance = sqrt(distance);
        }
 
        lwgeom_free(closest);
 
        PG_FREE_IF_COPY(geom1, 0);
        PG_FREE_IF_COPY(geom2, 1);
        PG_RETURN_FLOAT8(distance);
}

References distance(), gserialized_get_gbox_p(), LINETYPE, lwgeom_as_lwline(), lwgeom_closest_line(), lwgeom_closest_line_3d(), lwgeom_free(), lwgeom_from_gserialized(), lwgeom_get_type(), lwgeom_has_m(), lwgeom_has_z(), lwgeom_interpolate_point(), lwgeom_length(), lwgeom_length_2d(), lwline_get_lwpoint(), lwpoint_free(), lwpoint_getPoint4d_p(), POINT4D::m, GBOX::mmax, GBOX::mmin, and POINTTYPE.

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