From 8aa25fa657ef7d7e082be1ecb1ccdeb65fa1cd41 Mon Sep 17 00:00:00 2001
From: paul <40677073+paullee0@users.noreply.github.com>
Date: Tue, 25 Nov 2025 01:01:38 +0800
Subject: [PATCH] [ArchWall] Fix Bug: Center-Align with Centered Multi-Material
 (#25572)

* [ArchWall] Fix Bug: Center-Align with Centered Multi-Material

Fix #25485

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
 src/Mod/BIM/ArchWall.py | 54 +++++++++++++++++++++++++++++++++++------
 1 file changed, 47 insertions(+), 7 deletions(-)

diff --git a/src/Mod/BIM/ArchWall.py b/src/Mod/BIM/ArchWall.py
index f574e26346..b5b3f108a0 100644
--- a/src/Mod/BIM/ArchWall.py
+++ b/src/Mod/BIM/ArchWall.py
@@ -1397,15 +1397,55 @@ class _Wall(ArchComponent.Component):
                                 )
                             elif curAligns == "Center":
                                 if layers:
+                                    # TODO Current, the order of layers follow
+                                    # "Right" align.  Option for the order of
+                                    # layers follow "Left" align should be
+                                    # provided for users.
+                                    dvec = dvec.negative()
                                     totalwidth = sum([abs(l) for l in layers])
-                                    curWidth = abs(layers[i])
                                     off = totalwidth / 2 - layeroffset
-                                    d1 = Vector(dvec).multiply(off)
-                                    wNe1 = DraftGeomUtils.offsetWire(wire, d1, wireNedge=True)
-                                    layeroffset += curWidth
-                                    off = totalwidth / 2 - layeroffset
-                                    d1 = Vector(dvec).multiply(off)
-                                    wNe2 = DraftGeomUtils.offsetWire(wire, d1, wireNedge=True)
+                                    # TODO To consider offset per edge?
+                                    #
+                                    # Offset follows direction of align "Right".
+                                    # Needs to be reversed in this case.
+                                    off = -off
+                                    # d1 = Vector(dvec).multiply(off)
+                                    curWidth = []
+                                    alignListC = []
+                                    offsetListC = []
+                                    for n in range(edgeNum):
+                                        curWidth.append(abs(layers[i]))
+                                        alignListC.append("Right")  # ("Left")
+                                        offsetListC.append(off)
+                                    # wNe1 = DraftGeomUtils.offsetWire(wire, d1, wireNedge=True)
+                                    # See https://github.com/FreeCAD/FreeCAD/issues/25485#issuecomment-3566734050
+                                    # d1 may be Vector (0,0,0), offsetWire()
+                                    # in draftgeoutils\offsets.py:-
+                                    # v1 = App.Vector(dvec).normalize() return
+                                    # error.  Provide widthList, alignList etc.
+                                    # so no need to run above code to deduce
+                                    # v1 in offsetWire()
+                                    wNe1 = DraftGeomUtils.offsetWire(
+                                        wire,
+                                        dvec,
+                                        widthList=curWidth,
+                                        offsetMode="BasewireMode",
+                                        alignList=alignListC,
+                                        normal=normal,
+                                        basewireOffset=offsetListC,
+                                        wireNedge=True,
+                                    )
+                                    wNe2 = DraftGeomUtils.offsetWire(
+                                        wire,
+                                        dvec,
+                                        widthList=curWidth,
+                                        offsetMode=None,
+                                        alignList=alignListC,
+                                        normal=normal,
+                                        basewireOffset=offsetListC,
+                                        wireNedge=True,
+                                    )
+                                    layeroffset += abs(curWidth[0])
                                 else:
                                     dvec.multiply(width)
                                     wNe2 = DraftGeomUtils.offsetWire(