Compute the correct visible front corner (also for 'upended' boxes) and set the z...

[inkscape.git] / src / axis-manip.h

diff --git a/src/axis-manip.h b/src/axis-manip.h
index 5690eedcb79f564739f27cf2007f4af41bab7b70..8574bf3ff522846523dec4c3c3464c3f7f7b3b58 100644 (file)
--- a/src/axis-manip.h
+++ b/src/axis-manip.h
@@ -75,6 +75,16 @@ inline bool is_single_axis_direction (Box3D::Axis dir) {
     return (!(dir & (dir - 1)) && dir);
 }
 
+// Warning: We don't check that axis really unamiguously specifies a plane.
+//          Make sure this is the case when calling this function.
+inline guint face_containing_corner (Box3D::Axis axis, guint corner) {
+    if (!is_single_axis_direction (axis)) {
+        axis = (Box3D::Axis) (axis ^ Box3D::XYZ);
+    }
+    return face_to_int (axis ^ ((corner & axis) ? Box3D::REAR : Box3D::FRONT));
+}
+
+
 /**
  * Given two axis directions out of {X, Y, Z} or the corresponding plane, return the remaining one
  * We don't check if 'plane' really specifies a plane (i.e., if it consists of precisely two directions).