BGE Scenegraph and View frustrum culling improvement.

This commit contains a number of performance improvements for the
BGE in the Scenegraph (parent relation between objects in the
scene) and view frustrum culling.

The scenegraph improvement consists in avoiding position update
if the object has not moved since last update and the removal
of redundant updates and synchronization with the physics engine.

The view frustrum culling improvement consists in using the DBVT
broadphase facility of Bullet to build a tree of graphical objects
in the scene. The elements of the tree are Aabb boxes (Aligned 
Axis Bounding Boxes) enclosing the objects. This provides good
precision in closed and opened scenes. This new culling system
is enabled by default but just in case, it can be disabled with
a button in the World settings. There is no do_version in this
commit but it will be added before the 2.49 release. For now you
must manually enable the DBVT culling option in World settings
when you open an old file.

The above improvements speed up scenegraph and culling up to 5x.
However, this performance improvement is only visible when
you have hundreds or thousands of objects.

The main interest of the DBVT tree is to allow easy occlusion
culling and automatic LOD system. This will be the object of further
improvements.

1 files changed, 16 insertions, 9 deletions

diff --git a/source/gameengine/Ketsji/KX_GameObject.h b/source/gameengine/Ketsji/KX_GameObject.h
index bc6b60102d6..9c7dda5e394 100644
--- a/source/gameengine/Ketsji/KX_GameObject.h
+++ b/source/gameengine/Ketsji/KX_GameObject.h
@@ -57,6 +57,7 @@ struct KX_ClientObjectInfo;
 class KX_RayCast;
 class RAS_MeshObject;
 class KX_IPhysicsController;
+class PHY_IGraphicController;
 class PHY_IPhysicsEnvironment;
 struct Object;
 
@@ -88,6 +89,7 @@ protected:
 	bool       							m_bCulled; 
 
 	KX_IPhysicsController*				m_pPhysicsController1;
+	PHY_IGraphicController*				m_pGraphicController;
 	// used for ray casting
 	PHY_IPhysicsEnvironment*			m_pPhysicsEnvironment;
 	STR_String							m_testPropName;
@@ -351,6 +353,19 @@ public:
 	}
 
 	/**
+	 * @return a pointer to the graphic controller owner by this class 
+	 */
+	PHY_IGraphicController* GetGraphicController()
+	{
+		return m_pGraphicController;
+	}
+
+	void SetGraphicController(PHY_IGraphicController* graphiccontroller) 
+	{ 
+		m_pGraphicController = graphiccontroller;
+	}
+
+	/**
 	 * @section Coordinate system manipulation functions
 	 */
 
@@ -367,8 +382,7 @@ public:
 
 		void						
 	NodeUpdateGS(
-		double time,
-		bool bInitiator
+		double time
 	);
 
 	const 
@@ -525,13 +539,6 @@ public:
 	static void UpdateTransformFunc(SG_IObject* node, void* gameobj, void* scene);
 
 	/**
-	 * Only update the transform if it's a non-dynamic object
-	 */
-		void 
-	UpdateNonDynas(
-	);
-
-	/**
 	 * Function to set IPO option at start of IPO
 	 */ 
 		void