From a95d66a587580a92500c2a1237eeae8ac533a2e3 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Wed, 26 Apr 2017 17:10:58 +0100
Subject: [PATCH] Replaced dynamoc_cast<osg::CullStack*> with asCullStack() to
 improve performance of AutoTransform, screen size based LOD and PagedLOD.

---
 include/osg/NodeVisitor     | 8 ++++++++
 include/osgUtil/CullVisitor | 9 +++++++++
 src/osg/AutoTransform.cpp   | 2 +-
 src/osg/LOD.cpp             | 2 +-
 src/osg/PagedLOD.cpp        | 2 +-
 5 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/include/osg/NodeVisitor b/include/osg/NodeVisitor
index bf77ec975..dc6975636 100644
--- a/include/osg/NodeVisitor
+++ b/include/osg/NodeVisitor
@@ -52,6 +52,7 @@ class Camera;
 class CameraView;
 class Drawable;
 class Geometry;
+class CullStack;
 
 
 
@@ -149,6 +150,13 @@ class OSG_EXPORT NodeVisitor : public virtual Object
           * Equivalent to dynamic_cast<const osgUtil::IntersectionVisitor*>(this).*/
         virtual const osgUtil::IntersectionVisitor* asIntersectionVisitor() const { return 0; }
 
+        /** Convert 'this' into a osg::CullStack pointer if Object is a osg::CullStack, otherwise return 0.
+          * Equivalent to dynamic_cast<osg::CullStack*>(this).*/
+        virtual osg::CullStack* asCullStack() { return 0; }
+
+        /** convert 'const this' into a const osg::CullStack pointer if Object is a osg::CullStack, otherwise return 0.
+          * Equivalent to dynamic_cast<const osg::CullStack*>(this).*/
+        virtual const osg::CullStack* asCullStack() const { return 0; }
 
 
 
diff --git a/include/osgUtil/CullVisitor b/include/osgUtil/CullVisitor
index 3fab4f367..2e36bc2e2 100644
--- a/include/osgUtil/CullVisitor
+++ b/include/osgUtil/CullVisitor
@@ -67,6 +67,15 @@ class OSGUTIL_EXPORT CullVisitor : public osg::NodeVisitor, public osg::CullStac
           * Equivalent to dynamic_cast<const osgUtil::CullVisitor*>(this).*/
         virtual const osgUtil::CullVisitor* asCullVisitor() const { return this; }
 
+        /** Convert 'this' into a osg::CullStack pointer if Object is a osg::CullStack, otherwise return 0.
+          * Equivalent to dynamic_cast<osg::CullStack*>(this).*/
+        virtual osg::CullStack* asCullStack() { return static_cast<osg::CullStack*>(this); }
+
+        /** convert 'const this' into a const osg::CullStack pointer if Object is a osg::CullStack, otherwise return 0.
+          * Equivalent to dynamic_cast<const osg::CullStack*>(this).*/
+        virtual const osg::CullStack* asCullStack() const { return static_cast<const osg::CullStack*>(this); }
+
+
         using osg::NodeVisitor::clone;
 
         /** Create a shallow copy of the CullVisitor, used by CullVisitor::create() to clone the prototype. */
diff --git a/src/osg/AutoTransform.cpp b/src/osg/AutoTransform.cpp
index c387131b6..5612db316 100644
--- a/src/osg/AutoTransform.cpp
+++ b/src/osg/AutoTransform.cpp
@@ -140,7 +140,7 @@ osg::Matrixd AutoTransform::computeMatrix(const osg::NodeVisitor* nv) const
     Quat rotation = _rotation;
     osg::Vec3d scale = _scale;
 
-    const CullStack* cs = dynamic_cast<const CullStack*>(nv);
+    const CullStack* cs = nv ? nv->asCullStack() : 0;
     if (cs)
     {
         osg::Vec3d eyePoint = cs->getEyeLocal();
diff --git a/src/osg/LOD.cpp b/src/osg/LOD.cpp
index 679164b78..1ad24cfd6 100644
--- a/src/osg/LOD.cpp
+++ b/src/osg/LOD.cpp
@@ -51,7 +51,7 @@ void LOD::traverse(NodeVisitor& nv)
             }
             else
             {
-                osg::CullStack* cullStack = dynamic_cast<osg::CullStack*>(&nv);
+                osg::CullStack* cullStack = nv.asCullStack();
                 if (cullStack && cullStack->getLODScale())
                 {
                     required_range = cullStack->clampedPixelSize(getBound()) / cullStack->getLODScale();
diff --git a/src/osg/PagedLOD.cpp b/src/osg/PagedLOD.cpp
index 46ea5570c..e2680b2bd 100644
--- a/src/osg/PagedLOD.cpp
+++ b/src/osg/PagedLOD.cpp
@@ -150,7 +150,7 @@ void PagedLOD::traverse(NodeVisitor& nv)
             }
             else
             {
-                osg::CullStack* cullStack = dynamic_cast<osg::CullStack*>(&nv);
+                osg::CullStack* cullStack = nv.asCullStack();
                 if (cullStack && cullStack->getLODScale()>0.0f)
                 {
                     required_range = cullStack->clampedPixelSize(getBound()) / cullStack->getLODScale();