Move handling legacy mathutils buffer types to separate methods

src/bonsai/bonsai/bim/module/drawing/decoration.py

@@ -1762,40 +1762,34 @@ class CutDecorator:
         shader.uniform_float("color", color)
         batch.draw(shader)
 
-    def cache_camera_matrix(self):
+    def cache_camera_matrix(self) -> None:
+        assert bpy.context.scene and bpy.context.scene.camera
         obj = bpy.context.scene.camera
-        # Explicit `dtype` for Blender <5.0 compatibility.
         DecoratorData.camera_location_checksum = repr(
-            np.array(obj.matrix_world.translation, dtype=np.float32).tobytes()
+            tool.Blender.np_array_legacy(obj.matrix_world.translation).tobytes()
         )
-        DecoratorData.camera_rotation_checksum = repr(np.array(obj.matrix_world.to_3x3(), dtype=np.float32).tobytes())
+        DecoratorData.camera_rotation_checksum = repr(tool.Blender.np_array_legacy(obj.matrix_world.to_3x3()).tobytes())
 
-    def is_camera_moved(self):
+    def is_camera_moved(self) -> bool:
         if not DecoratorData.camera_location_checksum:
             self.cache_camera_matrix()
             return True  # Let's be conservative
+
+        assert bpy.context.scene and bpy.context.scene.camera
         obj = bpy.context.scene.camera
 
         # Handle both old float64 and new float32 checksums for version compatibility
-        loc_checksum_bytes = eval(DecoratorData.camera_location_checksum)
-        if len(loc_checksum_bytes) == 24:  # Old format: 3 * 8 bytes (float64)
-            loc_check = np.frombuffer(loc_checksum_bytes, dtype=np.float64).astype(np.float32)
-        else:  # New format: 3 * 4 bytes (float32)
-            loc_check = np.frombuffer(loc_checksum_bytes, dtype=np.float32)
-
-        loc_real = np.array(obj.matrix_world.translation, dtype=np.float32).flatten()
+        loc_checksum_bytes: bytes = eval(DecoratorData.camera_location_checksum)
+        loc_check = tool.Blender.np_frombuffer_legacy(loc_checksum_bytes, 3)
+        loc_real = tool.Blender.np_array_legacy(obj.matrix_world.translation)
         if not np.allclose(loc_check, loc_real, atol=1e-4):  # 0.1 mm
             self.cache_camera_matrix()
             return True
 
         # Handle both old float64 and new float32 checksums for version compatibility
-        rot_checksum_bytes = eval(DecoratorData.camera_rotation_checksum)
-        if len(rot_checksum_bytes) == 72:  # Old format: 9 * 8 bytes (float64)
-            rot_check = np.frombuffer(rot_checksum_bytes, dtype=np.float64).astype(np.float32).reshape(3, 3)
-        else:  # New format: 9 * 4 bytes (float32)
-            rot_check = np.frombuffer(rot_checksum_bytes, dtype=np.float32).reshape(3, 3)
-
-        rot_real = np.array(obj.matrix_world.to_3x3(), dtype=np.float32)
+        rot_checksum_bytes: bytes = eval(DecoratorData.camera_rotation_checksum)
+        rot_check = tool.Blender.np_frombuffer_legacy(rot_checksum_bytes, 9)
+        rot_real = tool.Blender.np_array_legacy(obj.matrix_world.to_3x3())
         rot_dot = np.dot(rot_check, rot_real.T)
         angle_rad = np.arccos(np.clip((np.trace(rot_dot) - 1) / 2, -1, 1))
         if angle_rad > 0.0017453292519943296:  # 0.1 degrees

src/bonsai/bonsai/tool/blender.py

@@ -49,7 +49,7 @@ import ifcopenshell.util.element
 import numpy as np
 import numpy.typing as npt
 from ifcopenshell import entity_instance
-from mathutils import Vector
+from mathutils import Matrix, Vector
 
 import bonsai.bim
 import bonsai.core.tool
@@ -2127,3 +2127,32 @@ class Blender(bonsai.core.tool.Blender):
         if cls.BLENDER_5:
             return "BLENDER_EEVEE"
         return "BLENDER_EEVEE_NEXT"
+
+    @classmethod
+    def np_frombuffer_legacy(cls, bytedata: bytes, n: int) -> npt.NDArray[np.float32]:
+        """
+        Read ``n`` float values from ``bytedata``, regardless if they are stored as ``float32`` or ``float64``.
+        Needed to support .blend files saved in Blender <5.0.0.
+        Also allows to work with .blend files from 5.0.0+ in older Blender versions.
+
+        In ``bpy.app.version >= 5.0.0`` ``mathutils`` transitioned to use ``float32`` buffer type,
+        while in previous version they were using ``float64``.
+        In some cases we are storing raw bytes (e.g. object transforms cheksums), so old .blend files
+        might still have ``float64`` data stored.
+
+        See https://projects.blender.org/blender/blender/issues/149283
+        """
+        if len(bytedata) == (n * 2):
+            return np.frombuffer(bytedata, dtype=np.float64).astype(np.float32)
+        return np.frombuffer(bytedata, dtype=np.float32)
+
+    @classmethod
+    def np_array_legacy(cls, mathutils_type: Union[Vector, Matrix]) -> npt.NDArray[np.float32]:
+        """
+        Converts ``mathutils`` types to ``np.float32`` arrays, regardless of Blender version.
+
+        See ``np_frombuffer_legacy`` for more details.
+        """
+        if cls.BLENDER_5:
+            return np.array(mathutils_type)
+        return np.array(mathutils_type, dtype=np.float32)

src/bonsai/bonsai/tool/geometry.py

@@ -1152,9 +1152,8 @@ class Geometry(bonsai.core.tool.Geometry):
     def record_object_position(cls, obj: bpy.types.Object) -> None:
         # These are recorded separately because they have different numerical tolerances
         props = tool.Blender.get_object_bim_props(obj)
-        # Explicit dtype for Blender <5.0 compatibility.
-        props.location_checksum = repr(np.array(obj.matrix_world.translation, dtype=np.float32).tobytes())
-        props.rotation_checksum = repr(np.array(obj.matrix_world.to_3x3(), dtype=np.float32).tobytes())
+        props.location_checksum = repr(tool.Blender.np_array_legacy(obj.matrix_world.translation).tobytes())
+        props.rotation_checksum = repr(tool.Blender.np_array_legacy(obj.matrix_world.to_3x3()).tobytes())
 
     @classmethod
     def remove_connection(cls, connection: ifcopenshell.entity_instance) -> None:

src/bonsai/bonsai/tool/ifc.py

@@ -115,24 +115,17 @@ class Ifc(bonsai.core.tool.Ifc):
             return True  # Let's be conservative
 
         # Handle both old float64 and new float32 checksums for version compatibility
-        loc_checksum_bytes = eval(oprops.location_checksum)
-        if len(loc_checksum_bytes) == 24:  # Old format: 3 * 8 bytes (float64)
-            loc_check = np.frombuffer(loc_checksum_bytes, dtype=np.float64).astype(np.float32)
-        else:  # New format: 3 * 4 bytes (float32)
-            loc_check = np.frombuffer(loc_checksum_bytes, dtype=np.float32)
-
-        loc_real = np.array(obj.matrix_world.translation, dtype=np.float32).flatten()
+        loc_checksum_bytes: bytes = eval(oprops.location_checksum)
+        loc_check = tool.Blender.np_frombuffer_legacy(loc_checksum_bytes, 3)
+        loc_real = tool.Blender.np_array_legacy(obj.matrix_world.translation)
         if not np.allclose(loc_check, loc_real, atol=1e-4):  # 0.1 mm
             return True
 
         # Handle both old float64 and new float32 checksums for version compatibility
-        rot_checksum_bytes = eval(oprops.rotation_checksum)
-        if len(rot_checksum_bytes) == 72:  # Old format: 9 * 8 bytes (float64)
-            rot_check = np.frombuffer(rot_checksum_bytes, dtype=np.float64).astype(np.float32).reshape(3, 3)
-        else:  # New format: 9 * 4 bytes (float32)
-            rot_check = np.frombuffer(rot_checksum_bytes, dtype=np.float32).reshape(3, 3)
-
-        rot_real = np.array(obj.matrix_world.to_3x3(), dtype=np.float32)
+        rot_checksum_bytes: bytes = eval(oprops.rotation_checksum)
+        rot_check = tool.Blender.np_frombuffer_legacy(rot_checksum_bytes, 9)
+        rot_check = rot_check.reshape(3, 3)
+        rot_real = tool.Blender.np_array_legacy(obj.matrix_world.to_3x3())
         rot_dot = np.dot(rot_check, rot_real.T)
         angle_rad = np.arccos(np.clip((np.trace(rot_dot) - 1) / 2, -1, 1))
         if angle_rad > 0.0017453292519943296:  # 0.1 degrees

src/bonsai/test/tool/test_geometry.py

@@ -323,8 +323,8 @@ class TestRecordObjectPosition(NewFile):
         obj = bpy.data.objects.new("Object", None)
         props = tool.Blender.get_object_bim_props(obj)
         subject.record_object_position(obj)
-        assert props.location_checksum == repr(np.array(obj.matrix_world.translation, dtype=np.float32).tobytes())
-        assert props.rotation_checksum == repr(np.array(obj.matrix_world.to_3x3(), dtype=np.float32).tobytes())
+        assert props.location_checksum == repr(tool.Blender.np_array_legacy(obj.matrix_world.translation).tobytes())
+        assert props.rotation_checksum == repr(tool.Blender.np_array_legacy(obj.matrix_world.to_3x3()).tobytes())
 
 
 class TestRemoveConnection(NewFile):