Alignment API update for station and positioning referents. Fixes bug with fallback position.

src/ifcopenshell-python/ifcopenshell/api/alignment/add_stationing_referent.py

@@ -16,35 +16,33 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
-import numpy as np
+from typing import Optional
 
 import ifcopenshell
 import ifcopenshell.api.alignment
 from ifcopenshell.api.alignment.update_fallback_position import update_fallback_position
 import ifcopenshell.api.pset
-import ifcopenshell.geom
 import ifcopenshell.guid
 import ifcopenshell.util.element
-import ifcopenshell.util.unit
-from ifcopenshell import entity_instance, ifcopenshell_wrapper
+from ifcopenshell import entity_instance
 
 
 def add_stationing_referent(
     file: ifcopenshell.file,
+    name: str,
     alignment: entity_instance,
     distance_along: float,
     station: float,
-    name: str,
-    positioned_product: entity_instance,
+    incoming_station: Optional[float] = None,
 ) -> entity_instance:
     """
-    Adds an IfcReferent to the alignment with the Pset_Stationing property set.
+    Adds an IfcReferent to the alignment that defines the stationing system.
 
+    :param name: name to assign to IfcReferent.Name, typically a stringized version of the station value
     :param alignment: the alignment to receive the referent
     :param distance_along: distance along the alignment basis curve
     :param station: station value
-    :param name: name to assign to IfcReferent.Name, typically a stringized version of the station value
-    :param positioned_product: the product whose position is informed by the referent
+    :param incoming_station: station value of the incoming segment, only set to specify a station equation
     :return: referent
 
     Example:
@@ -52,7 +50,7 @@ def add_stationing_referent(
     .. code:: python
 
         alignment = model.by_type("IfcAlignment")[0]
-        ifcopenshell.api.alignment.add_stationing_referent(model,alignment=alignment,distance_along=0.0,station=100.0)
+        ifcopenshell.api.alignment.add_stationing_referent(model,name="1+00.0",alignment=alignment,distance_along=0.0,station=100.0)
     """
 
     basis_curve = ifcopenshell.api.alignment.get_basis_curve(alignment)
@@ -100,8 +98,12 @@ def add_stationing_referent(
         Representation=representation,
         PredefinedType="STATION",
     )
+    properties = {"Station": station}
+    if incoming_station is not None:
+        properties["IncomingStation"] = incoming_station
+
     pset_stationing = ifcopenshell.api.pset.add_pset(file, product=referent, name="Pset_Stationing")
-    ifcopenshell.api.pset.edit_pset(file, pset=pset_stationing, properties={"Station": station})
+    ifcopenshell.api.pset.edit_pset(file, pset=pset_stationing, properties=properties)
 
     nest = ifcopenshell.api.alignment.get_referent_nest(file, alignment)
     if nest is None:
@@ -115,15 +117,4 @@ def add_stationing_referent(
         nest.RelatedObjects, key=lambda x: ifcopenshell.util.element.get_pset(x, name="Pset_Stationing", prop="Station")
     )
 
-    if len(referent.Positions) == 0:
-        rel_positions = file.createIfcRelPositions(
-            GlobalId=ifcopenshell.guid.new(),
-            RelatingPositioningElement=referent,
-            RelatedProducts=[
-                positioned_product,
-            ],
-        )
-    else:
-        referent.Positions[0].RelatedProducts += (positioned_product,)
-
     return referent