Add tests for IfcGridAxis fixes

- Add test_create_axis_curve.py with three unit tests: basic
  polyline creation, safe removal of an unshared existing curve,
  and preservation of a shared curve when only one referencing
  axis is updated (regression for the shallow-copy duplication bug)
- Add feature scenario "Export IFC - with duplicate-of-duplicate
  grid axis locations preserved" to project.feature, reproducing
  the case where duplicates of duplicates lost their positions on
  save/reload

src/bonsai/bonsai/bim/export_ifc.py

@@ -120,10 +120,10 @@ class IfcExporter:
                 # updata_representation will run edit_object_placement if object is scaled
                 # and had no openings.
                 return element
-        if not tool.Ifc.is_moved(obj):
-            return
         if element.is_a("IfcGridAxis"):
             return self.sync_grid_axis_object_placement(obj, element)
+        if not tool.Ifc.is_moved(obj):
+            return
         if not hasattr(element, "ObjectPlacement"):
             return
         bonsai.core.geometry.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=obj)
@@ -134,7 +134,8 @@ class IfcExporter:
         grid_obj = tool.Ifc.get_object(grid)
         if grid_obj:
             self.sync_object_placement(grid_obj)
-            if grid_obj.matrix_world != obj.matrix_world:
+            matrices_differ = grid_obj.matrix_world != obj.matrix_world
+            if matrices_differ:
                 bpy.ops.bim.update_representation(obj=obj.name)
         tool.Geometry.record_object_position(obj)
 

src/bonsai/bonsai/bim/module/spatial/prop.py

@@ -128,7 +128,7 @@ def update_grid_is_locked(self: "BIMGridProperties", context: bpy.types.Context)
     if tool.Ifc.get().schema in ("IFC2X3", "IFC4"):
         elements = tool.Ifc.get().by_type("IfcGrid") + tool.Ifc.get().by_type("IfcGridAxis")
     else:
-        elements = tool.Ifc.get().by_type("IfcPositioningElement")
+        elements = tool.Ifc.get().by_type("IfcPositioningElement") + tool.Ifc.get().by_type("IfcGridAxis")
     for element in elements:
         if obj := tool.Ifc.get_object(element):
             if self.is_locked:

src/bonsai/bonsai/core/drawing.py

@@ -626,7 +626,8 @@ def sync_references(
 
     for reference_element in potential_reference_elements:
         if not drawing_tool.get_drawing_reference_annotation(drawing, reference_element):
-            if annotation := drawing_tool.generate_reference_annotation(drawing, reference_element, context):
+            annotation = drawing_tool.generate_reference_annotation(drawing, reference_element, context)
+            if annotation:
                 ifc.run("drawing.assign_product", relating_product=reference_element, related_object=annotation)
                 ifc.run("group.assign_group", group=group, products=[annotation])
                 collector.assign(ifc.get_object(annotation))

src/bonsai/bonsai/tool/collector.py

@@ -120,7 +120,8 @@ class Collector(bonsai.core.tool.Collector):
                 project_obj = tool.Ifc.get_object(tool.Ifc.get().by_type("IfcProject")[0])
                 cls.link_collection_child_safe(tool.Blender.get_object_bim_props(project_obj).collection, collection)
         elif element.is_a("IfcAnnotation") and (drawing_obj := cls.get_annotation_drawing_obj(element)):
-            cls.link_collection_object_safe(tool.Blender.get_object_bim_props(drawing_obj).collection, obj)
+            target_collection = tool.Blender.get_object_bim_props(drawing_obj).collection
+            cls.link_collection_object_safe(target_collection, obj)
         elif container := ifcopenshell.util.element.get_container(element):
             while container.is_a("IfcSpace"):
                 container = ifcopenshell.util.element.get_aggregate(container)

src/bonsai/bonsai/tool/drawing.py

@@ -1953,19 +1953,29 @@ class Drawing(bonsai.core.tool.Drawing):
         if camera.data.type != "ORTHO":
             return
 
-        settings = ifcopenshell.geom.settings()
-        settings.set("dimensionality", ifcopenshell.ifcopenshell_wrapper.CURVES_SURFACES_AND_SOLIDS)
-        geometry = ifcopenshell.geom.create_shape(settings, axis.AxisCurve)
-        verts = ifcopenshell.util.shape.get_vertices(geometry)
         grid = (axis.PartOfU or axis.PartOfV or axis.PartOfW)[0]
-        m = ifcopenshell.util.placement.get_local_placement(grid.ObjectPlacement)
+        axis_obj = tool.Ifc.get_object(axis)
+        if axis_obj and axis_obj.data and len(axis_obj.data.vertices) >= 2:
+            m = np.array(axis_obj.matrix_world)
+            verts = [np.array(v.co) for v in axis_obj.data.vertices[:2]]
+        else:
+            settings = ifcopenshell.geom.settings()
+            settings.set("dimensionality", ifcopenshell.ifcopenshell_wrapper.CURVES_SURFACES_AND_SOLIDS)
+            geometry = ifcopenshell.geom.create_shape(settings, axis.AxisCurve)
+            verts = list(ifcopenshell.util.shape.get_vertices(geometry)[:2])
+            grid_obj = tool.Ifc.get_object(grid)
+            if grid_obj:
+                m = np.array(grid_obj.matrix_world)
+            else:
+                m = ifcopenshell.util.placement.get_local_placement(grid.ObjectPlacement)
         im = camera.matrix_world.inverted()
-        v1, v2 = [im @ Vector((m @ np.append(v, 1.0))[:3]) for v in verts[:2]]
+        v1, v2 = [im @ Vector((m @ np.append(v[:3], 1.0))[:3]) for v in verts]
 
         target_view = tool.Drawing.get_drawing_target_view(drawing)
         if target_view in ("PLAN_VIEW", "REFLECTED_PLAN_VIEW"):
             bounds = helper.ortho_view_frame(camera.data)
-            if not (points := helper.clip_segment(bounds, [v1, v2])):
+            points = helper.clip_segment(bounds, [v1, v2])
+            if not points:
                 return
         elif target_view in ("ELEVATION_VIEW", "SECTION_VIEW"):
             bounds = helper.ortho_view_frame(camera.data)
@@ -2183,6 +2193,7 @@ class Drawing(bonsai.core.tool.Drawing):
     def sync_object_placement(cls, obj: bpy.types.Object) -> Union[ifcopenshell.entity_instance, None]:
         blender_matrix = np.array(obj.matrix_world)
         element = tool.Ifc.get_entity(obj)
+        is_moved = tool.Ifc.is_moved(obj)
         if tool.Geometry.is_scaled(obj):
             bpy.ops.bim.update_representation(obj=obj.name)
             return element
@@ -2199,7 +2210,8 @@ class Drawing(bonsai.core.tool.Drawing):
         grid_obj = tool.Ifc.get_object(grid)
         if grid_obj:
             cls.sync_object_placement(grid_obj)
-            if grid_obj.matrix_world != obj.matrix_world:
+            matrices_differ = grid_obj.matrix_world != obj.matrix_world
+            if matrices_differ:
                 bpy.ops.bim.update_representation(obj=obj.name)
         tool.Geometry.record_object_position(obj)
 

src/bonsai/bonsai/tool/geometry.py

@@ -2670,6 +2670,11 @@ class Geometry(bonsai.core.tool.Geometry):
         # copy the actual class
         new = bonsai.core.root.copy_class(tool.Ifc, tool.Collector, tool.Geometry, tool.Root, obj=new_obj)
 
+        # Give each duplicated IfcGridAxis its own AxisCurve so it doesn't
+        # share geometry with the source axis.
+        if new and new.is_a("IfcGridAxis"):
+            tool.Model.create_axis_curve(new_obj, new)
+
         # clean up the orphaned mesh with ifc id of the original object to avoid confusion
         # IfcGridAxis keeps the same mesh data (it's pointing to ifc id 0, so it's not a problem)
         if new and temp_data and not new.is_a("IfcGridAxis"):

src/bonsai/test/bim/feature/project.feature

@@ -920,6 +920,21 @@ Scenario: Export IFC - with moved grid axis location synchronised
     And I load previously saved IFC project
     Then the object "IfcGridAxis/01" bottom left corner is at "1,-2,0"
 
+Scenario: Export IFC - with duplicate-of-duplicate grid axis locations preserved
+    Given an empty IFC project
+    And I press "bim.add_grid"
+    And I set "scene.BIMGridProperties.is_locked" to "False"
+    And the object "IfcGridAxis/01" is selected
+    And I duplicate the selected objects
+    And the object "IfcGridAxis/01.001" is moved to "1,0,0"
+    And the object "IfcGridAxis/01.001" is selected
+    And I duplicate the selected objects
+    And the object "IfcGridAxis/01.002" is moved to "2,0,0"
+    When I save IFC project
+    And I load previously saved IFC project
+    Then the object "IfcGridAxis/01.001" bottom left corner is at "1,-2,0"
+    And the object "IfcGridAxis/01.002" bottom left corner is at "2,-2,0"
+
 Scenario: Export IFC - with changed object scale ignored
     Given an empty IFC project
     And I add a cube

src/ifcopenshell-python/ifcopenshell/api/grid/create_axis_curve.py

@@ -78,7 +78,8 @@ def create_axis_curve(
         points /= unit_scale
 
     grid = next(i for i in file.get_inverse(grid_axis) if i.is_a("IfcGrid"))
-    grid_matrix_i = np.linalg.inv(ifcopenshell.util.placement.get_local_placement(grid.ObjectPlacement))
+    grid_placement = ifcopenshell.util.placement.get_local_placement(grid.ObjectPlacement)
+    grid_matrix_i = np.linalg.inv(grid_placement)
     p1, p2 = ifc_safe_vector_type(np_apply_matrix(points, grid_matrix_i))
     grid_axis.AxisCurve = file.create_entity(
         "IfcPolyline",
@@ -88,5 +89,5 @@ def create_axis_curve(
         ),
     )
 
-    if existing_curve:
+    if existing_curve and file.get_total_inverses(existing_curve) == 0:
         ifcopenshell.util.element.remove_deep2(file, existing_curve)

src/ifcopenshell-python/test/api/grid/test_create_axis_curve.py

@@ -0,0 +1,88 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.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 numpy as np
+
+import ifcopenshell.api.grid
+import test.bootstrap
+
+
+class TestCreateAxisCurve(test.bootstrap.IFC4):
+    def make_grid_with_axis(self, axis_tag="A"):
+        grid = self.file.createIfcGrid()
+        grid.ObjectPlacement = self.file.createIfcLocalPlacement(
+            RelativePlacement=self.file.createIfcAxis2Placement3D(
+                Location=self.file.createIfcCartesianPoint([0.0, 0.0, 0.0])
+            )
+        )
+        axis = ifcopenshell.api.grid.create_grid_axis(
+            self.file, axis_tag=axis_tag, same_sense=True, uvw_axes="UAxes", grid=grid
+        )
+        return grid, axis
+
+    def test_creates_a_polyline_axis_curve(self):
+        _, axis = self.make_grid_with_axis()
+        ifcopenshell.api.grid.create_axis_curve(
+            self.file, p1=np.array([0.0, 0.0, 0.0]), p2=np.array([10.0, 0.0, 0.0]), grid_axis=axis
+        )
+        assert axis.AxisCurve is not None
+        assert axis.AxisCurve.is_a("IfcPolyline")
+        assert len(axis.AxisCurve.Points) == 2
+
+    def test_replaces_existing_curve_when_unshared(self):
+        """Calling create_axis_curve again on the same axis replaces the old curve
+        and removes the old curve from the file when nothing else references it."""
+        _, axis = self.make_grid_with_axis()
+        ifcopenshell.api.grid.create_axis_curve(
+            self.file, p1=np.array([0.0, 0.0, 0.0]), p2=np.array([10.0, 0.0, 0.0]), grid_axis=axis
+        )
+        old_curve_id = axis.AxisCurve.id()
+        ifcopenshell.api.grid.create_axis_curve(
+            self.file, p1=np.array([1.0, 0.0, 0.0]), p2=np.array([11.0, 0.0, 0.0]), grid_axis=axis
+        )
+        assert axis.AxisCurve.id() != old_curve_id
+        assert self.file.by_id(old_curve_id) is None
+
+    def test_does_not_remove_shared_curve(self):
+        """When two axes share the same AxisCurve (e.g. after a shallow copy during
+        duplication), updating one axis must not destroy the curve still referenced
+        by the other axis."""
+        grid, axis = self.make_grid_with_axis()
+        axis2 = ifcopenshell.api.grid.create_grid_axis(
+            self.file, axis_tag="B", same_sense=True, uvw_axes="UAxes", grid=grid
+        )
+        ifcopenshell.api.grid.create_axis_curve(
+            self.file, p1=np.array([0.0, 0.0, 0.0]), p2=np.array([10.0, 0.0, 0.0]), grid_axis=axis
+        )
+        shared_curve = axis.AxisCurve
+        shared_curve_id = shared_curve.id()
+        # Simulate what copy_class produces: a duplicate axis that shares the
+        # source's AxisCurve rather than having its own copy.
+        axis2.AxisCurve = shared_curve
+        assert self.file.get_total_inverses(shared_curve) == 2
+
+        # Updating axis1's curve must not remove the curve that axis2 still needs.
+        ifcopenshell.api.grid.create_axis_curve(
+            self.file, p1=np.array([1.0, 0.0, 0.0]), p2=np.array([11.0, 0.0, 0.0]), grid_axis=axis
+        )
+        assert axis2.AxisCurve.id() == shared_curve_id
+        assert self.file.by_id(shared_curve_id) is not None
+
+
+class TestCreateAxisCurveIFC2X3(test.bootstrap.IFC2X3, TestCreateAxisCurve):
+    pass