Make use of shared shadow maps in the brute force method

components/misc/stereo.cpp

@@ -233,11 +233,19 @@ namespace Misc
         , mTechnique(technique)
         , mGeometryShaderMask(geometryShaderMask)
         , mNoShaderMask(noShaderMask)
+        , mMasterConfig(new SharedShadowMapConfig)
+        , mSlaveConfig(new SharedShadowMapConfig)
+        , mSharedShadowMaps(Settings::Manager::getBool("shared shadow maps", "Stereo"))
     {
         if (technique == Technique::None)
             // Do nothing
             return;
 
+        mMasterConfig->_id = "STEREO";
+        mMasterConfig->_master = true;
+        mSlaveConfig->_id = "STEREO";
+        mSlaveConfig->_master = false;
+
         SceneUtil::FindByNameVisitor findScene("Scene Root");
         mRoot->accept(findScene);
         mScene = findScene.mFoundNode;
@@ -292,6 +300,12 @@ namespace Misc
         mRightCamera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
         mRightCamera->setCullMask(mMainCamera->getCullMask());
 
+        if (mSharedShadowMaps)
+        {
+            mLeftCamera->setUserData(mMasterConfig);
+            mRightCamera->setUserData(mSlaveConfig);
+        }
+
         // Slave cameras must have their viewports defined immediately
         auto width = mMainCamera->getViewport()->width();
         auto height = mMainCamera->getViewport()->height();
@@ -366,8 +380,6 @@ namespace Misc
         auto width = mMainCamera->getViewport()->width();
         auto height = mMainCamera->getViewport()->height();
 
-        if (mTechnique == Technique::GeometryShader_IndexedViewports)
-        {
         // To correctly cull when drawing stereo using the geometry shader, the main camera must
         // draw a fake view+perspective that includes the full frustums of both the left and right eyes.
         // This frustum will be computed as a perspective frustum from a position P slightly behind the eyes L and R
@@ -403,7 +415,7 @@ namespace Misc
             Log(Debug::Error) << "Total FOV exceeds 180 degrees. Case cannot be culled in single-pass VR. Disabling culling to cope. Consider switching to dual-pass VR.";
             mMainCamera->setCullingActive(false);
             return;
-                // TODO: An explicit frustum projection could cope, so implement that later. Guarantee you there will be VR headsets with total fov > 180 in the future. Maybe already.
+            // TODO: An explicit frustum projection could cope, so implement that later. Guarantee you there will be VR headsets with total horizontal fov > 180 in the future. Maybe already.
         }
 
         // Use the law of sines on the triangle spanning PLR to determine P
@@ -426,6 +438,9 @@ namespace Misc
         auto frustumViewMatrix = viewMatrix * frustumView.pose.viewMatrix(true);
         auto frustumProjectionMatrix = frustumView.fov.perspectiveMatrix(near + nearFarOffset, far + nearFarOffset);
 
+        if (mTechnique == Technique::GeometryShader_IndexedViewports)
+        {
+
             // Update camera with frustum matrices
             mMainCamera->setViewMatrix(frustumViewMatrix);
             mMainCamera->setProjectionMatrix(frustumProjectionMatrix);
@@ -439,6 +454,18 @@ namespace Misc
 
             mLeftCamera->setViewport(0, 0, width / 2, height);
             mRightCamera->setViewport(width / 2, 0, width / 2, height);
+
+            if (mMasterConfig->_projection == nullptr)
+                mMasterConfig->_projection = new osg::RefMatrix;
+            if (mMasterConfig->_modelView == nullptr)
+                mMasterConfig->_modelView = new osg::RefMatrix;
+
+            if (mSharedShadowMaps)
+            {
+                mMasterConfig->_referenceFrame = mMainCamera->getReferenceFrame();
+                mMasterConfig->_modelView->set(frustumViewMatrix);
+                mMasterConfig->_projection->set(projectionMatrix);
+            }
         }
     }
 
@@ -462,9 +489,9 @@ namespace Misc
         stereoViewProjectionsUniform->setElement(1, frustumViewMatrixInverse * mRightCamera->getViewMatrix() * mRightCamera->getProjectionMatrix());
     }
 
-    void StereoView::setUpdateViewCallback(std::shared_ptr<UpdateViewCallback> cb)
+    void StereoView::setUpdateViewCallback(std::shared_ptr<UpdateViewCallback> cb_)
     {
-        this->cb = cb;
+        cb = cb_;
     }
 
     void disableStereoForCamera(osg::Camera* camera)

components/misc/stereo.hpp

@@ -8,6 +8,8 @@
 
 #include <memory>
 
+#include <components/sceneutil/mwshadowtechnique.hpp>
+
 // Some cursed headers like to define these
 #if defined(near) || defined(far)
 #undef near
@@ -122,6 +124,11 @@ namespace Misc
         osg::ref_ptr<osg::Camera>   mLeftCamera{ new osg::Camera };
         osg::ref_ptr<osg::Camera>   mRightCamera{ new osg::Camera };
 
+        using SharedShadowMapConfig = SceneUtil::MWShadowTechnique::SharedShadowMapConfig;
+        osg::ref_ptr<SharedShadowMapConfig> mMasterConfig;
+        osg::ref_ptr<SharedShadowMapConfig> mSlaveConfig;
+        bool                                mSharedShadowMaps;
+
         // Camera viewports
         bool flipViewOrder{ true };
 

files/settings-default.cfg

@@ -964,3 +964,6 @@ stereo enabled = false
 # BruteForce: Generates stereo using two cameras and two cull/render passes. Choose this if your game is GPU-bound.
 # GeometryShader: Generates stereo in a single pass using automatically generated geometry shaders. May break custom shaders. Choose this if your game is CPU-bound.
 stereo method = GeometryShader
+
+# May accelerate the BruteForce method when shadows are enabled
+shared shadow maps = true