Some incomplete work for moving objects in 3D plater

xs/xsp/Point.xsp

@@ -121,4 +121,10 @@ Point::coincides_with(point_sv)
     void set_z(double val)
         %code{% THIS->z = val; %};
     void translate(double x, double y, double z);
+    double distance_to(Pointf3* point)
+        %code{% RETVAL = THIS->distance_to(*point); %};
+    Clone<Pointf3> negative()
+        %code{% RETVAL = THIS->negative(); %};
+    Clone<Pointf3> vector_to(Pointf3* point)
+        %code{% RETVAL = THIS->vector_to(*point); %};
 };