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, 56 insertions, 0 deletions

diff --git a/source/gameengine/Physics/common/PHY_IGraphicController.h b/source/gameengine/Physics/common/PHY_IGraphicController.h
new file mode 100644
index 00000000000..36b8a978e87
--- /dev/null
+++ b/source/gameengine/Physics/common/PHY_IGraphicController.h
@@ -0,0 +1,56 @@
+/**
+ * $Id$
+ *
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): none yet.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+#ifndef PHY_IGRAPHICCONTROLLER_H
+#define PHY_IGRAPHICCONTROLLER_H
+
+#include "PHY_IController.h"
+
+
+
+/**
+	PHY_IPhysicsController is the abstract simplified Interface to a physical object.
+	It contains the IMotionState and IDeformableMesh Interfaces.
+*/
+class PHY_IGraphicController : public PHY_IController
+{
+
+	public:
+		
+		virtual ~PHY_IGraphicController();
+		/**
+			SynchronizeMotionStates ynchronizes dynas, kinematic and deformable entities (and do 'late binding')
+		*/
+		virtual bool SetGraphicTransform()=0;
+
+		virtual PHY_IGraphicController*	GetReplica(class PHY_IMotionState* motionstate) {return 0;}
+
+};
+
+#endif //PHY_IGRAPHICCONTROLLER_H
+