New/updated 3D box auxiliary/convenience functions (e.g., allow (un)constrained movem...

[inkscape.git] / src / perspective-line.cpp

diff --git a/src/perspective-line.cpp b/src/perspective-line.cpp
index 158ddd47bd2a2b7be83a0c77a51704622d3cc600..e5596cc1b5704a09d024ea58802cccb75a8b54c5 100644 (file)
--- a/src/perspective-line.cpp
+++ b/src/perspective-line.cpp
@@ -19,6 +19,7 @@ PerspectiveLine::PerspectiveLine (NR::Point const &pt, Box3D::Axis const axis, P
         Line (pt, *(perspective->get_vanishing_point(axis)), true)
 {
     g_assert (perspective != NULL);
+    g_assert (Box3D::is_single_axis_direction (axis));
 
     if (perspective->get_vanishing_point(axis)->state == VP_INFINITE) {
         this->set_direction(perspective->get_vanishing_point(axis)->v_dir);