Stereo now initializes before anything is drawn. Added option to add initial/pre/post draw callbacks to stereo.

apps/openmw/engine.cpp

@@ -721,13 +721,6 @@ void OMW::Engine::prepareEngine (Settings::Manager & settings)
     // Create sound system
     mEnvironment.setSoundManager (new MWSound::SoundManager(mVFS.get(), mUseSound));
 
-    if (!mSkipMenu)
-    {
-        const std::string& logo = Fallback::Map::getString("Movies_Company_Logo");
-        if (!logo.empty())
-            window->playVideo(logo, true);
-    }
-
     // VR mode will override this setting by setting mStereoOverride.
     mStereoEnabled = mStereoOverride || Settings::Manager::getBool("stereo enabled", "Stereo");
 
@@ -736,6 +729,18 @@ void OMW::Engine::prepareEngine (Settings::Manager & settings)
     if (mStereoEnabled)
     {
         mResourceSystem->getSceneManager()->getShaderManager().setStereoGeometryShaderEnabled(Misc::getStereoTechnique() == Misc::StereoView::Technique::GeometryShader_IndexedViewports);
+        // Mask in everything that does not currently use shaders.
+        // Remove that altogether when the sky finally uses them.
+        auto noShaderMask = MWRender::VisMask::Mask_Sky | MWRender::VisMask::Mask_Sun | MWRender::VisMask::Mask_WeatherParticles;
+        auto geometryShaderMask = mViewer->getCamera()->getCullMask() & ~noShaderMask;
+        mStereoView = new Misc::StereoView(mViewer, Misc::getStereoTechnique(), geometryShaderMask, noShaderMask | MWRender::VisMask::Mask_Scene);
+    }
+
+    if (!mSkipMenu)
+    {
+        const std::string& logo = Fallback::Map::getString("Movies_Company_Logo");
+        if (!logo.empty())
+            window->playVideo(logo, true);
     }
 
     // Create the world
@@ -747,11 +752,7 @@ void OMW::Engine::prepareEngine (Settings::Manager & settings)
     // Set up stereo
     if (mStereoEnabled)
     {
-        // Mask in everything that does not currently use shaders.
-        // Remove that altogether when the sky finally uses them.
-        auto noShaderMask = MWRender::VisMask::Mask_Sky | MWRender::VisMask::Mask_Sun | MWRender::VisMask::Mask_WeatherParticles;
-        auto geometryShaderMask = mViewer->getCamera()->getCullMask() & ~noShaderMask;
-        mStereoView = new Misc::StereoView(mViewer, Misc::getStereoTechnique(), geometryShaderMask, noShaderMask | MWRender::VisMask::Mask_Scene);
+        mStereoView->initializeScene();
     }
 
     window->setStore(mEnvironment.getWorld()->getStore());

components/misc/stereo.cpp

@@ -9,6 +9,8 @@
 #include <osgViewer/Viewer>
 
 #include <iostream>
+#include <map>
+#include <string>
 
 #include <components/debug/debuglog.hpp>
 
@@ -225,11 +227,18 @@ namespace Misc
         StereoView* stereoView;
     };
 
+    StereoView* sInstance = nullptr;
+
+    StereoView& StereoView::instance()
+    {
+        return *sInstance;
+    }
+
     StereoView::StereoView(osgViewer::Viewer* viewer, Technique technique, osg::Node::NodeMask geometryShaderMask, osg::Node::NodeMask noShaderMask)
         : osg::Group()
         , mViewer(viewer)
         , mMainCamera(mViewer->getCamera())
-        , mRoot(viewer->getSceneData()->asGroup())
+        , mRoot(mViewer->getSceneData()->asGroup())
         , mTechnique(technique)
         , mGeometryShaderMask(geometryShaderMask)
         , mNoShaderMask(noShaderMask)
@@ -241,19 +250,14 @@ namespace Misc
             // Do nothing
             return;
 
+        mRoot->setDataVariance(osg::Object::STATIC);
+
         mMasterConfig->_id = "STEREO";
         mMasterConfig->_master = true;
         mSlaveConfig->_id = "STEREO";
         mSlaveConfig->_master = false;
 
-        SceneUtil::FindByNameVisitor findScene("Scene Root");
-        mRoot->accept(findScene);
-        mScene = findScene.mFoundNode;
-        if (!mScene)
-            throw std::logic_error("Couldn't find scene root");
-
         setName("Stereo Root");
-        mRoot->setDataVariance(osg::Object::STATIC);
         setDataVariance(osg::Object::STATIC);
         mLeftCamera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
         mLeftCamera->setProjectionResizePolicy(osg::Camera::FIXED);
@@ -287,6 +291,10 @@ namespace Misc
         {
             setupBruteForceTechnique();
         }
+
+        if (sInstance)
+            throw std::logic_error("Double instance og StereoView");
+        sInstance = this;
     }
 
     void StereoView::setupBruteForceTechnique()
@@ -313,8 +321,8 @@ namespace Misc
         mRightCamera->setViewport(width / 2, 0, width / 2, height);
 
         mViewer->stopThreading();
-        mViewer->addSlave(mLeftCamera, true);
         mViewer->addSlave(mRightCamera, true);
+        mViewer->addSlave(mLeftCamera, true);
         mRightCamera->setGraphicsContext(mViewer->getCamera()->getGraphicsContext());
         mLeftCamera->setGraphicsContext(mViewer->getCamera()->getGraphicsContext());
         mViewer->getCamera()->setGraphicsContext(nullptr);
@@ -332,16 +340,14 @@ namespace Misc
         mMainCamera->setCullMask(mGeometryShaderMask);
 
         addChild(mStereoGeometryShaderRoot);
-        mStereoGeometryShaderRoot->addChild(mRoot);
         addChild(mStereoBruteForceRoot);
         mStereoBruteForceRoot->addChild(mLeftCamera);
-        mLeftCamera->addChild(mScene); // Use scene directly to avoid redundant shadow computation.
         mStereoBruteForceRoot->addChild(mRightCamera);
-        mRightCamera->addChild(mScene);
 
         addCullCallback(new StereoStatesetUpdateCallback(this));
 
         // Inject self as the root of the scene graph
+        mStereoGeometryShaderRoot->addChild(mRoot);
         mViewer->setSceneData(this);
     }
 
@@ -494,6 +500,21 @@ namespace Misc
         cb = cb_;
     }
 
+    void StereoView::initializeScene()
+    {
+        SceneUtil::FindByNameVisitor findScene("Scene Root");
+        mRoot->accept(findScene);
+        mScene = findScene.mFoundNode;
+        if (!mScene)
+            throw std::logic_error("Couldn't find scene root");
+
+        if (mTechnique == Technique::GeometryShader_IndexedViewports)
+        {
+            mLeftCamera->addChild(mScene); // Use scene directly to avoid redundant shadow computation.
+            mRightCamera->addChild(mScene);
+        }
+    }
+
     void disableStereoForCamera(osg::Camera* camera)
     {
         auto* viewport = camera->getViewport();
@@ -553,4 +574,33 @@ namespace Misc
         near = 1;
         far = 6656;
     }
+
+    void StereoView::setInitialDrawCallback(osg::ref_ptr<osg::Camera::DrawCallback> cb)
+    {
+        mMainCamera->setInitialDrawCallback(cb);
+    }
+
+    void StereoView::setPredrawCallback(osg::ref_ptr<osg::Camera::DrawCallback> cb)
+    {
+        if (mTechnique == Technique::GeometryShader_IndexedViewports)
+        {
+            mMainCamera->setPreDrawCallback(cb);
+        }
+        else
+        {
+            mLeftCamera->setPreDrawCallback(cb);
+        }
+    }
+
+    void StereoView::setPostdrawCallback(osg::ref_ptr<osg::Camera::DrawCallback> cb)
+    {
+        if (mTechnique == Technique::GeometryShader_IndexedViewports)
+        {
+            mMainCamera->setPostDrawCallback(cb);
+        }
+        else
+        {
+            mRightCamera->setPostDrawCallback(cb);
+        }
+    }
 }

components/misc/stereo.hpp

@@ -89,6 +89,8 @@ namespace Misc
             GeometryShader_IndexedViewports, //!< Frustum camera culls and draws stereo into indexed viewports using an automatically generated geometry shader.
         };
 
+        static StereoView& instance();
+
         //! Adds two cameras in stereo to the mainCamera.
         //! All nodes matching the mask are rendered in stereo using brute force via two camera transforms, the rest are rendered in stereo via a geometry shader.
         //! \param geometryShaderMask should mask in all nodes that use shaders.
@@ -101,9 +103,21 @@ namespace Misc
         void update();
         void updateStateset(osg::StateSet* stateset);
 
+        //! Initialized scene. Call when the "scene root" node has been created
+        void initializeScene();
+
         //! Callback that updates stereo configuration during the update pass
         void setUpdateViewCallback(std::shared_ptr<UpdateViewCallback> cb);
 
+        //! Set the initial draw callback on the appropriate camera object
+        void setInitialDrawCallback(osg::ref_ptr<osg::Camera::DrawCallback> cb);
+
+        //! Set the predraw callback on the appropriate camera object
+        void setPredrawCallback(osg::ref_ptr<osg::Camera::DrawCallback> cb);
+
+        //! Set the postdraw callback on the appropriate camera object
+        void setPostdrawCallback(osg::ref_ptr<osg::Camera::DrawCallback> cb);
+
     private:
         void setupBruteForceTechnique();
         void setupGeometryShaderIndexedViewportTechnique();