lw_dist3d_distanceline()

LWGEOM* lw_dist3d_distanceline	(	const LWGEOM *	lw1,
		const LWGEOM *	lw2,
		int	srid,
		int	mode
	)

Function initializing 3dshortestline and 3dlongestline calculations.

Definition at line 110 of file measures3d.c.

{
        LWDEBUG(2, "lw_dist3d_distanceline is called");
        double x1,x2,y1,y2, z1, z2, x, y;
        double initdistance = ( mode == DIST_MIN ? FLT_MAX : -1.0);
        DISTPTS3D thedl;
        LWPOINT *lwpoints[2];
        LWGEOM *result;
 
        thedl.mode = mode;
        thedl.distance = initdistance;
        thedl.tolerance = 0.0;
 
        /*Check if we really have 3D geometries*/
        /*If not, send it to 2D-calculations which will give the same result*/
        /*as an infinite z-value at one or two of the geometries*/
        if(!lwgeom_has_z(lw1) || !lwgeom_has_z(lw2))
        {
 
                lwnotice("One or both of the geometries is missing z-value. The unknown z-value will be regarded as \"any value\"");
 
                if(!lwgeom_has_z(lw1) && !lwgeom_has_z(lw2))
                        return lw_dist2d_distanceline(lw1, lw2, srid, mode);
 
                DISTPTS thedl2d;
                thedl2d.mode = mode;
                thedl2d.distance = initdistance;
                thedl2d.tolerance = 0.0;
                if (!lw_dist2d_comp( lw1,lw2,&thedl2d))
                {
                        /*should never get here. all cases ought to be error handled earlier*/
                        lwerror("Some unspecified error.");
                        result = (LWGEOM *)lwcollection_construct_empty(COLLECTIONTYPE, srid, 0, 0);
                }
                LWGEOM *vertical_line;
                if(!lwgeom_has_z(lw1))
                {
                        x=thedl2d.p1.x;
                        y=thedl2d.p1.y;
 
                        vertical_line = create_v_line(lw2,x,y,srid);
                        if (!lw_dist3d_recursive(vertical_line, lw2, &thedl))
                        {
                                /*should never get here. all cases ought to be error handled earlier*/
                                lwfree(vertical_line);
                                lwerror("Some unspecified error.");
                                result = (LWGEOM *)lwcollection_construct_empty(COLLECTIONTYPE, srid, 0, 0);
                        }
                        lwfree(vertical_line);
                }
                if(!lwgeom_has_z(lw2))
                {
                        x=thedl2d.p2.x;
                        y=thedl2d.p2.y;
 
                        vertical_line = create_v_line(lw1,x,y,srid);
                        if (!lw_dist3d_recursive(lw1, vertical_line, &thedl))
                        {
                                /*should never get here. all cases ought to be error handled earlier*/
                                lwfree(vertical_line);
                                lwerror("Some unspecified error.");
                                return (LWGEOM *)lwcollection_construct_empty(COLLECTIONTYPE, srid, 0, 0);
                        }
                        lwfree(vertical_line);
                }
 
        }
        else
        {
                if (!lw_dist3d_recursive(lw1, lw2, &thedl))
                {
                        /*should never get here. all cases ought to be error handled earlier*/
                        lwerror("Some unspecified error.");
                        result = (LWGEOM *)lwcollection_construct_empty(COLLECTIONTYPE, srid, 0, 0);
                }
        }
        /*if thedl.distance is unchanged there where only empty geometries input*/
        if (thedl.distance == initdistance)
        {
                LWDEBUG(3, "didn't find geometries to measure between, returning null");
                result = (LWGEOM *)lwcollection_construct_empty(COLLECTIONTYPE, srid, 0, 0);
        }
        else
        {
                x1=thedl.p1.x;
                y1=thedl.p1.y;
                z1=thedl.p1.z;
                x2=thedl.p2.x;
                y2=thedl.p2.y;
                z2=thedl.p2.z;
 
                lwpoints[0] = lwpoint_make3dz(srid, x1, y1, z1);
                lwpoints[1] = lwpoint_make3dz(srid, x2, y2, z2);
 
                result = (LWGEOM *)lwline_from_ptarray(srid, 2, lwpoints);
        }
 
        return result;
}

References COLLECTIONTYPE, create_v_line(), DIST_MIN, DISTPTS::distance, DISTPTS3D::distance, lw_dist2d_comp(), lw_dist2d_distanceline(), lw_dist3d_recursive(), lwcollection_construct_empty(), LWDEBUG, lwerror(), lwfree(), lwgeom_has_z(), lwline_from_ptarray(), lwnotice(), lwpoint_make3dz(), DISTPTS::mode, DISTPTS3D::mode, DISTPTS::p1, DISTPTS3D::p1, DISTPTS::p2, DISTPTS3D::p2, DISTPTS::tolerance, DISTPTS3D::tolerance, POINT2D::x, POINT3DZ::x, pixval::x, POINT2D::y, POINT3DZ::y, pixval::y, and POINT3DZ::z.

Referenced by lwgeom_closest_line_3d(), and lwgeom_furthest_line_3d().

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