From 9ec59783bac3dd69f0e0754591842bd733d5fef5 Mon Sep 17 00:00:00 2001
From: AnyOldName3 <krizdjali+github@gmail.com>
Date: Mon, 5 Feb 2018 23:03:18 +0000
Subject: [PATCH] Add basic support for distant terrain CLSB

(cherry picked from commit 0f9dc3e65b72e6fff762f7a0933bae6f861e5fd4)
---
 components/sceneutil/shadow.cpp      | 8 ++++++++
 components/sceneutil/shadow.hpp      | 3 +++
 components/terrain/quadtreeworld.cpp | 7 +++++++
 3 files changed, 18 insertions(+)

diff --git a/components/sceneutil/shadow.cpp b/components/sceneutil/shadow.cpp
index 1e4112971f..cc3eb0be6c 100644
--- a/components/sceneutil/shadow.cpp
+++ b/components/sceneutil/shadow.cpp
@@ -282,6 +282,14 @@ namespace SceneUtil
         popCurrentMask();
     }
 
+    void MWShadow::ComputeLightSpaceBounds::apply(Terrain::QuadTreeWorld & quadTreeWorld)
+    {
+        // For now, just expand the bounds fully as terrain will fill them up and possible ways to detect which terrain definitely won't cast shadows aren't implemented.
+
+        update(osg::Vec3(-1.0, -1.0, 0.0));
+        update(osg::Vec3(1.0, 1.0, 0.0));
+    }
+
     void MWShadow::ComputeLightSpaceBounds::apply(osg::Billboard&)
     {
         OSG_INFO << "Warning Billboards not yet supported" << std::endl;
diff --git a/components/sceneutil/shadow.hpp b/components/sceneutil/shadow.hpp
index b92e8658b2..897b8759da 100644
--- a/components/sceneutil/shadow.hpp
+++ b/components/sceneutil/shadow.hpp
@@ -4,6 +4,7 @@
 #include <osgShadow/ShadowSettings>
 #include <osgShadow/ViewDependentShadowMap>
 
+#include <components/terrain/quadtreeworld.hpp>
 #include <components/shader/shadermanager.hpp>
 
 namespace SceneUtil
@@ -34,6 +35,8 @@ namespace SceneUtil
 
             void apply(osg::Drawable& drawable);
 
+            void apply(Terrain::QuadTreeWorld& quadTreeWorld);
+
             void apply(osg::Billboard&);
 
             void apply(osg::Projection&);
diff --git a/components/terrain/quadtreeworld.cpp b/components/terrain/quadtreeworld.cpp
index f310648050..76baa2f45b 100644
--- a/components/terrain/quadtreeworld.cpp
+++ b/components/terrain/quadtreeworld.cpp
@@ -4,6 +4,8 @@
 
 #include <sstream>
 
+#include <components/sceneutil/shadow.hpp>
+
 #include "quadtreenode.hpp"
 #include "storage.hpp"
 #include "viewdata.hpp"
@@ -344,7 +346,12 @@ void loadRenderingNode(ViewData::Entry& entry, ViewData* vd, ChunkManager* chunk
 void QuadTreeWorld::accept(osg::NodeVisitor &nv)
 {
     if (nv.getVisitorType() != osg::NodeVisitor::CULL_VISITOR && nv.getVisitorType() != osg::NodeVisitor::INTERSECTION_VISITOR)
+    {
+        SceneUtil::MWShadow::ComputeLightSpaceBounds* shadowBoundsVisitor = dynamic_cast<SceneUtil::MWShadow::ComputeLightSpaceBounds *>(&nv);
+        if (shadowBoundsVisitor)
+            shadowBoundsVisitor->apply(*this);
         return;
+    }
 
     ViewData* vd = mRootNode->getView(nv);