Make E3dScene3D::GetCamera return non-reference

I stumbled over this when Valgrind'ing CppunitTest_sd_filters_test somewhat
erroneously reported

  Source and destination overlap in memcpy(0x2fde4af8, 0x2fde4af8, 96)

for

  aCamera = rNewCamera;

in E3dScene::SetCamera (svx/source/engine3d/scene3d.cxx), where the compiler
chose to use memcpy in the implicit definition of the Viewport3D (being a base
class of Camera3D) copy assignment operator, and the call pattern of
Get/SetCamera in EnhancedCustomShape3d::Create3DObject
(svx/source/customshapes/EnhancedCustomShape3d.cxx) causes that assignment to be
a self-assignment.

Upon closer inspection, some calls of GetCamera already create a copy from the
returned reference, while others modified the returned reference, but then would
also always call SetCamera on it.  An alternative to the given change would have
been to instead change SetCamera(Camera3D&) to UpdateCamera() and require all
call sites of GetCamera/UpdateCamera to modify the reference returned from
GetCamera, but it looks safer overall to go this way.

Change-Id: I578e72db57630dca1b09124a3b11d177005b797d

3 files changed, 10 insertions, 15 deletions

diff --git a/svx/source/customshapes/EnhancedCustomShape3d.cxx b/svx/source/customshapes/EnhancedCustomShape3d.cxx
index 7e2b45ee057a..1f802b8bc49e 100644
--- a/svx/source/customshapes/EnhancedCustomShape3d.cxx
+++ b/svx/source/customshapes/EnhancedCustomShape3d.cxx
@@ -574,7 +574,7 @@ SdrObject* EnhancedCustomShape3d::Create3DObject( const SdrObject* pShape2d, con
             pRet = pScene;
 
             // Camera settings, Perspective ...
-            Camera3D& rCamera = (Camera3D&)pScene->GetCamera();
+            Camera3D rCamera = pScene->GetCamera();
             const basegfx::B3DRange& rVolume = pScene->GetBoundVolume();
             pScene->NbcSetSnapRect( aSnapRect );
 
diff --git a/svx/source/dialog/dlgctl3d.cxx b/svx/source/dialog/dlgctl3d.cxx
index 2dbd53e6f72b..482a89d794ba 100644
--- a/svx/source/dialog/dlgctl3d.cxx
+++ b/svx/source/dialog/dlgctl3d.cxx
@@ -103,7 +103,7 @@ void Svx3DPreviewControl::Construct()
     SetObjectType(SvxPreviewObjectType::SPHERE);
 
     // camera and perspective
-    Camera3D& rCamera  = (Camera3D&) mpScene->GetCamera();
+    Camera3D rCamera  = mpScene->GetCamera();
     const basegfx::B3DRange& rVolume = mpScene->GetBoundVolume();
     double fW = rVolume.getWidth();
     double fH = rVolume.getHeight();
@@ -341,7 +341,7 @@ void Svx3DLightControl::Construct2()
 
     {
         // change camera settings
-        Camera3D& rCamera  = (Camera3D&) mpScene->GetCamera();
+        Camera3D rCamera  = mpScene->GetCamera();
         const basegfx::B3DRange& rVolume = mpScene->GetBoundVolume();
         double fW = rVolume.getWidth();
         double fH = rVolume.getHeight();
diff --git a/svx/source/engine3d/scene3d.cxx b/svx/source/engine3d/scene3d.cxx
index 911aca6e1820..7ca48718a07d 100644
--- a/svx/source/engine3d/scene3d.cxx
+++ b/svx/source/engine3d/scene3d.cxx
@@ -330,31 +330,27 @@ void E3dScene::NbcResize(const Point& rRef, const Fraction& rXFact,
 
 void E3dScene::SetCamera(const Camera3D& rNewCamera)
 {
-    // Set old camera
     aCamera = rNewCamera;
     static_cast<sdr::properties::E3dSceneProperties&>(GetProperties()).SetSceneItemsFromCamera();
 
     SetRectsDirty();
 
-    // Fill new camera from old
-    Camera3D& rCam = (Camera3D&)GetCamera();
-
     // Turn off ratio
-    if(rCam.GetAspectMapping() == AS_NO_MAPPING)
+    if(aCamera.GetAspectMapping() == AS_NO_MAPPING)
         GetCameraSet().SetRatio(0.0);
 
     // Set Imaging geometry
-    basegfx::B3DPoint aVRP(rCam.GetViewPoint());
-    basegfx::B3DVector aVPN(aVRP - rCam.GetVRP());
-    basegfx::B3DVector aVUV(rCam.GetVUV());
+    basegfx::B3DPoint aVRP(aCamera.GetViewPoint());
+    basegfx::B3DVector aVPN(aVRP - aCamera.GetVRP());
+    basegfx::B3DVector aVUV(aCamera.GetVUV());
 
     // use SetViewportValues() to set VRP, VPN and VUV as vectors, too.
     // Else these values would not be exported/imported correctly.
     GetCameraSet().SetViewportValues(aVRP, aVPN, aVUV);
 
     // Set perspective
-    GetCameraSet().SetPerspective(rCam.GetProjection() == PR_PERSPECTIVE);
-    GetCameraSet().SetViewportRectangle((Rectangle&)rCam.GetDeviceWindow());
+    GetCameraSet().SetPerspective(aCamera.GetProjection() == PR_PERSPECTIVE);
+    GetCameraSet().SetViewportRectangle((Rectangle&)aCamera.GetDeviceWindow());
 
     ImpCleanup3DDepthMapper();
 }
@@ -646,8 +642,7 @@ void E3dScene::RecalcSnapRect()
     {
         // The Scene is used as a 2D-Objekt, take the SnapRect from the
         // 2D Display settings
-        Camera3D& rCam = (Camera3D&)pScene->GetCamera();
-        maSnapRect = rCam.GetDeviceWindow();
+        maSnapRect = pScene->aCamera.GetDeviceWindow();
     }
     else
     {