Merge branch 'store_multiview' into 'master'

Avoid calling getMultiview from ~StereoFrustumManager

See merge request OpenMW/openmw!2091

components/stereo/frustum.cpp

@@ -96,8 +96,9 @@ namespace Stereo
         : mCamera(camera)
         , mShadowTechnique(nullptr)
         , mShadowFrustumCallback(nullptr)
+        , mMultiview(Stereo::getMultiview())
     {
-        if (Stereo::getMultiview())
+        if (mMultiview)
         {
 #ifdef OSG_HAS_MULTIVIEW
             mMultiviewFrustumCallback = new MultiviewFrustumCallback(this);
@@ -118,7 +119,7 @@ namespace Stereo
 
     StereoFrustumManager::~StereoFrustumManager()
     {
-        if (Stereo::getMultiview())
+        if (mMultiview)
         {
 #ifdef OSG_HAS_MULTIVIEW
             mCamera->setInitialFrustumCallback(nullptr);

components/stereo/frustum.hpp

@@ -64,6 +64,7 @@ namespace Stereo
         osg::ref_ptr<osg::Camera> mCamera;
         osg::ref_ptr<SceneUtil::MWShadowTechnique> mShadowTechnique;
         osg::ref_ptr<ShadowFrustumCallback> mShadowFrustumCallback;
+        bool mMultiview;
         std::map< osgUtil::CullVisitor*, osgUtil::CullVisitor*> mSharedFrustums;
         osg::BoundingBoxd mBoundingBox;