Fix #6366. Improve extrusion x_angle and direction handling.

This solution brings new questions to #5938.
Currently, we lack a reliable way to calculate the existing x_angle only based solely on the extrusion direction. For example, a 30 degree angled extrusion with positive direction has the same extrusion direction as a -150 degree angled extrusion with negative direction. The difference lies in the object's rotation.
This means that things can get messy if the user changes the object x angle somehow. We may need to explore alternative approaches.

src/bonsai/bonsai/bim/module/model/slab.py

@@ -297,14 +297,16 @@ class DumbSlabPlaner:
         if representation:
             extrusion = tool.Model.get_extrusion(representation)
             if extrusion:
-                existing_x_angle = tool.Model.get_existing_x_angle(extrusion)
+                # TODO Right now we don't have a reliable way to calculate the existing x_angle only based solely on the extrusion direction.
+                # For instances, a 30 degrees angled extrusion with positive direction has the same extrusion direction as a
+                # -150 degrees angled extrusion with negative direction. The difference lies in the object's rotation.
+                # This means that things can get messy if the user changes the object x angle somehow. We have to figure out an alternative approach.
+                existing_x_angle = obj.rotation_euler.x
                 existing_x_angle = 0 if tool.Cad.is_x(existing_x_angle, 0, tolerance=0.001) else existing_x_angle
                 existing_x_angle = 0 if tool.Cad.is_x(existing_x_angle, pi, tolerance=0.001) else existing_x_angle
                 existing_x_angle = 0 if tool.Cad.is_x(existing_x_angle, 2 * pi, tolerance=0.001) else existing_x_angle
                 direction_ratios = Vector(extrusion.ExtrudedDirection.DirectionRatios)
-                offset_direction = Vector(
+                offset_direction = direction_ratios.copy()
-                    (abs(direction_ratios.x), abs(direction_ratios.y), abs(direction_ratios.z))
-                )  # The offset direction doesn't change with direction sense
                 perpendicular_depth = thickness * abs(1 / cos(existing_x_angle))
                 perpendicular_offset = layer_params["offset"] * abs(1 / cos(existing_x_angle)) / self.unit_scale
 
@@ -320,7 +322,9 @@ class DumbSlabPlaner:
                     abs(existing_x_angle) < (pi / 2) and direction_ratios.z < 0
                 ):
                     # The extrusion direction is negative. If the layer_parameter is set to positive,
-                    # then the we change the extrusion direction.
+                    # then the we change the extrusion direction. And the offset direction should remain positive 
+                    # for either direction sense, so we change it.
+                    offset_direction *= -1
                     if layer_params["direction_sense"] == "POSITIVE":
                         direction_ratios *= -1
 

src/bonsai/bonsai/bim/module/model/wall.py

@@ -307,6 +307,9 @@ class ChangeExtrusionXAngle(bpy.types.Operator, tool.Ifc.Operator):
                 extrusion.Depth = perpendicular_depth
             else:
                 if tool.Model.get_usage_type(element) == "LAYER3":
+                    existing_x_angle = obj.rotation_euler.x
+                    existing_x_angle = 0 if tool.Cad.is_x(existing_x_angle, 0, tolerance=0.001) else existing_x_angle
+                    existing_x_angle = 0 if tool.Cad.is_x(existing_x_angle, pi, tolerance=0.001) else existing_x_angle
                     # Reset the transformation and returns to the original points with 0 degrees
                     extrusion.SweptArea.OuterCurve.Points.CoordList = [
                         (p[0], p[1] * abs(cos(existing_x_angle)))
@@ -325,9 +328,7 @@ class ChangeExtrusionXAngle(bpy.types.Operator, tool.Ifc.Operator):
                     layer_params = tool.Model.get_material_layer_parameters(element)
                     perpendicular_depth = layer_params["thickness"] * abs(1 / cos(x_angle)) / unit_scale
                     perpendicular_offset = layer_params["offset"] * abs(1 / cos(x_angle)) / unit_scale
-                    offset_direction = Vector(
+                    offset_direction = direction_ratios.copy()
-                        (abs(direction_ratios.x), abs(direction_ratios.y), abs(direction_ratios.z))
-                    )  # The offset direction doesn't change with direction sense
 
                     # Check angle and z direction to determine whether the extrusion direction is positive or negative
                     if (abs(x_angle) < (pi / 2) and direction_ratios.z > 0) or (
@@ -342,6 +343,9 @@ class ChangeExtrusionXAngle(bpy.types.Operator, tool.Ifc.Operator):
                     ):
                         # The extrusion direction is negative. If the layer_parameter is set to positive,
                         # then the we change the extrusion direction.
+                        # then the we change the extrusion direction. And the offset direction should remain positive 
+                        # for either direction sense, so we change it.
+                        offset_direction *= -1
                         if layer_params["direction_sense"] == "POSITIVE":
                             direction_ratios *= -1
 
@@ -363,9 +367,10 @@ class ChangeExtrusionXAngle(bpy.types.Operator, tool.Ifc.Operator):
                 )
 
                 # Object rotation
+                current_z_rot = obj.rotation_euler.z
                 rot_mat = mathutils.Matrix.Rotation(x_angle, 4, "X")
-                rot_mat = obj.matrix_world @ rot_mat
                 obj.rotation_euler = rot_mat.to_euler()
+                obj.rotation_euler.z = current_z_rot
 
         if layer2_objs:
             DumbWallRecalculator().recalculate(layer2_objs)

src/bonsai/bonsai/tool/collector.py

@@ -44,6 +44,9 @@ class Collector(bonsai.core.tool.Collector):
         # Note that tool.Geometry.is_locked is only checked within the if
         # statements for efficiency as it is a slow check.
         tool.Geometry.lock_scale(obj)
+        if element.is_a("IfcSlab"):
+            tool.Geometry.lock_rotation(obj, x=True)
+
 
         if element.is_a("IfcGridAxis"):
             if tool.Geometry.is_locked(element):

src/bonsai/bonsai/tool/geometry.py

@@ -177,6 +177,10 @@ class Geometry(bonsai.core.tool.Geometry):
     def unlock_scale(cls, obj: bpy.types.Object) -> None:
         obj.lock_scale = (False, False, False)
 
+    @classmethod
+    def lock_rotation(cls, obj: bpy.types.Object, x: bool=False, y: bool=False, z: bool=False,) -> None:
+        obj.lock_rotation = (x, y, z)
+
     @classmethod
     def unlock_scale_object_with_openings(cls, obj: bpy.types.Object) -> None:
         element = tool.Ifc.get_entity(obj)