From 701635b81c1a25ef4cf160402a4cf1e6828961cc Mon Sep 17 00:00:00 2001
From: Richard Brice <37087370+RickBrice@users.noreply.github.com>
Date: Wed, 25 Feb 2026 07:51:17 -0800
Subject: [PATCH] revises get_mapped_segments

get_mapped_segments now looks for representations attached to alignment segments before using the more complex method of computing the index of segments in the composite curve.
updates segment_vertices to use get_mapped_segments
---
 .../ifcopenshell/api/alignment/get_mapped_segments.py | 11 +++++++++++
 .../ifcopenshell/api/alignment/segment_vertices.py    |  9 +++------
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/ifcopenshell-python/ifcopenshell/api/alignment/get_mapped_segments.py b/src/ifcopenshell-python/ifcopenshell/api/alignment/get_mapped_segments.py
index 0b8a3b65b3..7e51a24543 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/alignment/get_mapped_segments.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/alignment/get_mapped_segments.py
@@ -44,6 +44,17 @@ def get_mapped_segments(layout_segment: entity_instance) -> Sequence[entity_inst
     if not layout_segment.is_a(expected_type):
         raise TypeError(f"Expected to see type '{expected_type}', instead received '{layout_segment.is_a()}'.")
 
+    # if the representation is attached directly to the layout segment, just get the representation curve
+    representations = ifcopenshell.util.representation.get_representations_iter(layout_segment)
+    for representation in representations:
+        if representation.RepresentationIdentifier == "Axis" and representation.RepresentationType == "Segment":
+            if len(representation.Items) == 1:
+                return (representation.Items[0],None)
+            else:
+                return representation.Items
+
+    # representation was not attached directly to the segment, so we have to find
+    # them from the composite curve
     layout = layout_segment.Nests[0].RelatingObject
     curve = ifcopenshell.api.alignment.get_layout_curve(layout)
 
diff --git a/src/ifcopenshell-python/ifcopenshell/api/alignment/segment_vertices.py b/src/ifcopenshell-python/ifcopenshell/api/alignment/segment_vertices.py
index ae1fd86656..8e158eb599 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/alignment/segment_vertices.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/alignment/segment_vertices.py
@@ -66,12 +66,9 @@ def segment_vertices(file: ifcopenshell.file, segment: entity_instance):
     # In the more common case, there is only one IfcCurveSegment geometric representation
     # and start_segment_curve and end_segment_curve are equal
     if segment_type == "IFCALIGNMENTSEGMENT":
-        representations = ifcopenshell.util.representation.get_representations_iter(segment)
-        for representation in representations:
-            if representation.RepresentationIdentifier == "Axis" and representation.RepresentationType == "Segment":
-                start_segment_curve = representation.Items[0]
-                end_segment_curve = representation.Items[-1]
-                break
+        segments = ifcopenshell.api.alignment.get_mapped_segments(segment)
+        start_segment_curve = segments[0]
+        end_segment_curve = start_segment_curve if segments[1] == None else segment[1]
     else:
         start_segment_curve = segment
         end_segment_curve = segment