From 181d3f5536e426f961cc008e5831420001f3b186 Mon Sep 17 00:00:00 2001
From: "Zheng, Lei" <realthunder.dev@gmail.com>
Date: Thu, 7 Jul 2022 12:17:59 +0800
Subject: [PATCH] Gui: fix ViewProviderLink transform with scale

Fixes FreeCAD/FreeCAD#7113
---
 src/Gui/ViewProviderLink.cpp | 28 ++++++++++++++++++++++++++--
 src/Gui/ViewProviderLink.h   |  3 +++
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/Gui/ViewProviderLink.cpp b/src/Gui/ViewProviderLink.cpp
index f007503608..4db16b757b 100644
--- a/src/Gui/ViewProviderLink.cpp
+++ b/src/Gui/ViewProviderLink.cpp
@@ -1819,7 +1819,7 @@ void ViewProviderLink::updateDataPrivate(App::LinkBaseExtension *ext, const App:
             if(canScale(v))
                 pcTransform->scaleFactor.setValue(v.x,v.y,v.z);
             SbMatrix matrix = convert(ext->getTransform(false));
-            linkView->renderDoubleSide(matrix.det3() < 0);
+            linkView->renderDoubleSide(matrix.det3() < 1e-7);
         }
     }else if(prop == ext->getPlacementProperty() || prop == ext->getLinkPlacementProperty()) {
         auto propLinkPlacement = ext->getLinkPlacementProperty();
@@ -1830,7 +1830,7 @@ void ViewProviderLink::updateDataPrivate(App::LinkBaseExtension *ext, const App:
             if(canScale(v))
                 pcTransform->scaleFactor.setValue(v.x,v.y,v.z);
             SbMatrix matrix = convert(ext->getTransform(false));
-            linkView->renderDoubleSide(matrix.det3() < 0);
+            linkView->renderDoubleSide(matrix.det3() < 1e-7);
         }
     }else if(prop == ext->getLinkCopyOnChangeGroupProperty()) {
         if (auto group = ext->getLinkCopyOnChangeGroupValue()) {
@@ -3407,6 +3407,30 @@ ViewProviderDocumentObject *ViewProviderLink::getLinkedViewProvider(
     return self;
 }
 
+void ViewProviderLink::setTransformation(const Base::Matrix4D &rcMatrix)
+{
+    inherited::setTransformation(rcMatrix);
+    auto ext = getLinkExtension();
+    if(ext) {
+        if (ext->getScaleVectorProperty())
+            updateDataPrivate(getLinkExtension(),ext->getScaleVectorProperty());
+        else
+            updateDataPrivate(getLinkExtension(),ext->getScaleProperty());
+    }
+}
+
+void ViewProviderLink::setTransformation(const SbMatrix &rcMatrix)
+{
+    inherited::setTransformation(rcMatrix);
+    auto ext = getLinkExtension();
+    if(ext) {
+        if (ext->getScaleVectorProperty())
+            updateDataPrivate(getLinkExtension(),ext->getScaleVectorProperty());
+        else
+            updateDataPrivate(getLinkExtension(),ext->getScaleProperty());
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////////////
 
 namespace Gui {
diff --git a/src/Gui/ViewProviderLink.h b/src/Gui/ViewProviderLink.h
index 85f9c8a310..c3c34d93af 100644
--- a/src/Gui/ViewProviderLink.h
+++ b/src/Gui/ViewProviderLink.h
@@ -268,6 +268,9 @@ public:
         return true;
     }
 
+    virtual void setTransformation(const Base::Matrix4D &rcMatrix) override;
+    virtual void setTransformation(const SbMatrix &rcMatrix) override;
+
 protected:
     bool setEdit(int ModNum) override;
     void setEditViewer(View3DInventorViewer*, int ModNum) override;