Add Object Tool: support placing objects in orthographic axis views

When an projecting onto a plane that is orthogonal to the views Z axis,
project onto a view aligned axis then map it back to the original plane.
see: ED_view3d_win_to_3d_on_plane_with_fallback

Since the depth can't be properly visualized in 3D, display a 2D so
it's possible to to tell the depth from the cursor motion.

1 files changed, 6 insertions, 0 deletions

diff --git a/source/blender/editors/include/ED_view3d.h b/source/blender/editors/include/ED_view3d.h
index e8aa312f444..596533406c3 100644
--- a/source/blender/editors/include/ED_view3d.h
+++ b/source/blender/editors/include/ED_view3d.h
@@ -364,6 +364,12 @@ bool ED_view3d_win_to_3d_on_plane(const struct ARegion *region,
                                   const float mval[2],
                                   const bool do_clip,
                                   float r_out[3]);
+bool ED_view3d_win_to_3d_on_plane_with_fallback(const struct ARegion *region,
+                                                const float plane[4],
+                                                const float mval[2],
+                                                const bool do_clip,
+                                                const float plane_fallback[4],
+                                                float r_out[3]);
 bool ED_view3d_win_to_3d_on_plane_int(const struct ARegion *region,
                                       const float plane[4],
                                       const int mval[2],