Updates alignment api. Fixes bugs authoring semantic-only alignment

2026-08-12 02:23:34 +00:00 · 2026-05-25 10:31:57 -07:00
parent 852311279d
commit 3559d23f81
27 changed files with 1086 additions and 373 deletions
@@ -0,0 +1,89 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2025 Thomas Krijnen <thomas@aecgeeks.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# 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 ifcopenshell.api.alignment
+import ifcopenshell.geom
+from ifcopenshell import entity_instance, ifcopenshell_wrapper
+from ifcopenshell.api.alignment._map_alignment_segment import _map_alignment_segment
+from typing import Union
+import math
+import numpy as np
+
+
+def _get_segment_endpoint(file: ifcopenshell.file, segment: entity_instance) -> Union[np.array, None]:
+    """
+    Computes the 4x4 matrix for a segment end point. The segment can be an IfcAlignmentSegment
+    or IfcCurveSegment
+    """
+
+    expected_types = ["IfcAlignmentSegment", "IfcCurveSegment"]
+    if not segment.is_a() in expected_types:
+        raise TypeError(
+            f"Expected entity type to be one of {[_ for _ in expected_types]}, instead received {segment.is_a()}"
+        )
+
+    file.begin_transaction()  # use a transaction so we can discard any temporary IFC entities created
+
+    curve_segment = segment
+    if segment.is_a("IfcAlignmentSegment"):
+        layout = ifcopenshell.api.alignment.get_layout(segment)
+        mapped_segments = _map_alignment_segment(file, layout, segment)
+        curve_segment = mapped_segments[0] if mapped_segments[1] == None else mapped_segments[1]
+
+        # Inside of the IfcOpenShell C++ implementation where the IfcCurveSegment calculations occur,
+        # the composite curve owning the segment is evaluated to determine if a horizontal, vertical, or cant segment is being evaluated.
+        # This is necessary to determine how the end point of the curve segment is calculated.
+        # A temporary curve segment has been created and it needs to be associated with the correct composite curve for the end point to be calculated correctly.
+        # Inside the C++ implementation, if a composite curve isn't associated with the segment the segment is assumed to be horizontal. For this reason
+        # a temporary IfcCompositeCurve for horizontal segments doesn't need to be created.
+        if layout.is_a("IfcAlignmentVertical"):
+            gc = file.createIfcGradientCurve(Segments=[curve_segment])
+        elif layout.is_a("IfcAlignmentCant"):
+            # The evaluation of cant segments depend on the start conditions of the next segment. In the absense of a next segment the
+            # optional EndPoint is used. Since a tempoaryar IfcSegmentReferenceCurve is being used, there is not a next segment.
+            # For this reason the EndPoint must be created from the design parameters of the sementic segment definiton.
+            Dsl = segment.DesignParameters.StartCantLeft
+            Dsr = segment.DesignParameters.StartCantRight
+            Del = segment.DesignParameters.EndCantLeft if segment.DesignParameters.EndCantLeft != None else Dsl
+            Der = segment.DesignParameters.EndCantRight if segment.DesignParameters.EndCantRight != None else Dsr
+            cant = Der - Del
+            rh = layout.RailHeadDistance
+            Ay = cant / rh
+            Az = math.sqrt(rh**2 - cant**2) / rh
+
+            src = file.createIfcSegmentedReferenceCurve(
+                Segments=[curve_segment],
+                EndPoint=file.createIfcAxis2Placement3D(
+                    Location=file.createIfcCartesianPoint((segment.DesignParameters.StartDistAlong, 0.5 * cant, 0.0)),
+                    RefDirection=file.createIfcDirection((1.0, 0.0, 0.0)),
+                    Axis=file.createIfcDirection((0.0, Ay, Az)),
+                ),
+            )
+
+    settings = ifcopenshell.geom.settings()
+
+    segment_fn = ifcopenshell_wrapper.map_shape(settings, curve_segment)
+    segment_evaluator = ifcopenshell_wrapper.function_item_evaluator(settings, segment_fn)
+    x = segment_fn.end()
+    e = segment_evaluator.evaluate(x)
+    end = np.array(e)
+
+    file.discard_transaction()
+
+    return end