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, 36 insertions, 12 deletions

diff --git a/source/gameengine/Ketsji/KX_KetsjiEngine.cpp b/source/gameengine/Ketsji/KX_KetsjiEngine.cpp
index 97b4213b8bd..70ae0e4b937 100644
--- a/source/gameengine/Ketsji/KX_KetsjiEngine.cpp
+++ b/source/gameengine/Ketsji/KX_KetsjiEngine.cpp
@@ -412,7 +412,7 @@ else
 
 
 	// Compute the number of logic frames to do each update (fixed tic bricks)
-	int frames =int(deltatime*m_ticrate);
+	int frames =int(deltatime*m_ticrate+1e-6);
 //	if (frames>1)
 //		printf("****************************************");
 //	printf("dt = %f, deltatime = %f, frames = %d\n",dt, deltatime,frames);
@@ -465,12 +465,15 @@ else
 
 				
 				m_logger->StartLog(tc_network, m_kxsystem->GetTimeInSeconds(), true);
+				SG_SetActiveStage(SG_STAGE_NETWORK);
 				scene->GetNetworkScene()->proceed(m_frameTime);
 	
-				m_logger->StartLog(tc_scenegraph, m_kxsystem->GetTimeInSeconds(), true);
-				scene->UpdateParents(m_frameTime);
+				//m_logger->StartLog(tc_scenegraph, m_kxsystem->GetTimeInSeconds(), true);
+				//SG_SetActiveStage(SG_STAGE_NETWORK_UPDATE);
+				//scene->UpdateParents(m_frameTime);
 				
 				m_logger->StartLog(tc_physics, m_kxsystem->GetTimeInSeconds(), true);
+				SG_SetActiveStage(SG_STAGE_PHYSICS1);
 				// set Python hooks for each scene
 				PHY_SetActiveEnvironment(scene->GetPhysicsEnvironment());
 				KX_SetActiveScene(scene);
@@ -479,31 +482,37 @@ else
 				
 				// Update scenegraph after physics step. This maps physics calculations
 				// into node positions.		
-				m_logger->StartLog(tc_scenegraph, m_kxsystem->GetTimeInSeconds(), true);
-				scene->UpdateParents(m_frameTime);
+				//m_logger->StartLog(tc_scenegraph, m_kxsystem->GetTimeInSeconds(), true);
+				//SG_SetActiveStage(SG_STAGE_PHYSICS1_UPDATE);
+				//scene->UpdateParents(m_frameTime);
 				
 				// Process sensors, and controllers
 				m_logger->StartLog(tc_logic, m_kxsystem->GetTimeInSeconds(), true);
+				SG_SetActiveStage(SG_STAGE_CONTROLLER);
 				scene->LogicBeginFrame(m_frameTime);
 	
 				// Scenegraph needs to be updated again, because Logic Controllers 
 				// can affect the local matrices.
 				m_logger->StartLog(tc_scenegraph, m_kxsystem->GetTimeInSeconds(), true);
+				SG_SetActiveStage(SG_STAGE_CONTROLLER_UPDATE);
 				scene->UpdateParents(m_frameTime);
 	
 				// Process actuators
 	
 				// Do some cleanup work for this logic frame
 				m_logger->StartLog(tc_logic, m_kxsystem->GetTimeInSeconds(), true);
+				SG_SetActiveStage(SG_STAGE_ACTUATOR);
 				scene->LogicUpdateFrame(m_frameTime, true);
 				
 				scene->LogicEndFrame();
 	
 				// Actuators can affect the scenegraph
 				m_logger->StartLog(tc_scenegraph, m_kxsystem->GetTimeInSeconds(), true);
+				SG_SetActiveStage(SG_STAGE_ACTUATOR_UPDATE);
 				scene->UpdateParents(m_frameTime);
 				
 				m_logger->StartLog(tc_physics, m_kxsystem->GetTimeInSeconds(), true);
+				SG_SetActiveStage(SG_STAGE_PHYSICS2);
 				scene->GetPhysicsEnvironment()->beginFrame();
 		
 				// Perform physics calculations on the scene. This can involve 
@@ -511,6 +520,7 @@ else
 				scene->GetPhysicsEnvironment()->proceedDeltaTime(m_frameTime,1.0/m_ticrate);//m_deltatimerealDeltaTime);
 
 				m_logger->StartLog(tc_scenegraph, m_kxsystem->GetTimeInSeconds(), true);
+				SG_SetActiveStage(SG_STAGE_PHYSICS2_UPDATE);
 				scene->UpdateParents(m_frameTime);
 			
 			
@@ -574,6 +584,7 @@ else
 				KX_SetActiveScene(scene);
 				
 				m_logger->StartLog(tc_scenegraph, m_kxsystem->GetTimeInSeconds(), true);
+				SG_SetActiveStage(SG_STAGE_PHYSICS1);
 				scene->UpdateParents(m_clockTime);
 
 				// Perform physics calculations on the scene. This can involve 
@@ -583,6 +594,7 @@ else
 				// Update scenegraph after physics step. This maps physics calculations
 				// into node positions.		
 				m_logger->StartLog(tc_scenegraph, m_kxsystem->GetTimeInSeconds(), true);
+				SG_SetActiveStage(SG_STAGE_PHYSICS2);
 				scene->UpdateParents(m_clockTime);
 				
 				// Do some cleanup work for this logic frame
@@ -591,6 +603,7 @@ else
 
 				// Actuators can affect the scenegraph
 				m_logger->StartLog(tc_scenegraph, m_kxsystem->GetTimeInSeconds(), true);
+				SG_SetActiveStage(SG_STAGE_ACTUATOR);
 				scene->UpdateParents(m_clockTime);
 				 
  				scene->setSuspendedTime(0.0);
@@ -622,6 +635,7 @@ void KX_KetsjiEngine::Render()
 	const RAS_FrameSettings &framesettings = firstscene->GetFramingType();
 
 	m_logger->StartLog(tc_rasterizer, m_kxsystem->GetTimeInSeconds(), true);
+	SG_SetActiveStage(SG_STAGE_RENDER);
 
 	// hiding mouse cursor each frame
 	// (came back when going out of focus and then back in again)
@@ -1102,14 +1116,22 @@ void KX_KetsjiEngine::RenderFrame(KX_Scene* scene, KX_Camera* cam)
 		cam->GetCameraLocation(), cam->GetCameraOrientation());
 	cam->SetModelviewMatrix(viewmat);
 
-	scene->UpdateMeshTransformations();
+	//redundant, already done in 
+	//scene->UpdateMeshTransformations();
 
 	// The following actually reschedules all vertices to be
 	// redrawn. There is a cache between the actual rescheduling
 	// and this call though. Visibility is imparted when this call
 	// runs through the individual objects.
+
+	m_logger->StartLog(tc_scenegraph, m_kxsystem->GetTimeInSeconds(), true);
+	SG_SetActiveStage(SG_STAGE_CULLING);
+
 	scene->CalculateVisibleMeshes(m_rasterizer,cam);
 
+	m_logger->StartLog(tc_rasterizer, m_kxsystem->GetTimeInSeconds(), true);
+	SG_SetActiveStage(SG_STAGE_RENDER);
+
 	scene->RenderBuckets(camtrans, m_rasterizer, m_rendertools);
 	
 	if (scene->GetPhysicsEnvironment())
@@ -1166,15 +1188,17 @@ void KX_KetsjiEngine::AddScene(KX_Scene* scene)
 void KX_KetsjiEngine::PostProcessScene(KX_Scene* scene)
 {
 	bool override_camera = (m_overrideCam && (scene->GetName() == m_overrideSceneName));
-	
-		// if there is no activecamera, or the camera is being
-		// overridden we need to construct a temporarily camera
+
+	SG_SetActiveStage(SG_STAGE_SCENE);
+
+	// if there is no activecamera, or the camera is being
+	// overridden we need to construct a temporarily camera
 	if (!scene->GetActiveCamera() || override_camera)
 	{
 		KX_Camera* activecam = NULL;
 
 		RAS_CameraData camdata = RAS_CameraData();
-		activecam = new KX_Camera(scene,KX_Scene::m_callbacks,camdata, false);
+		activecam = new KX_Camera(scene,KX_Scene::m_callbacks,camdata);
 		activecam->SetName("__default__cam__");
 	
 			// set transformation
@@ -1186,11 +1210,11 @@ void KX_KetsjiEngine::PostProcessScene(KX_Scene* scene)
 			
 			activecam->NodeSetLocalPosition(camtrans.getOrigin());
 			activecam->NodeSetLocalOrientation(camtrans.getBasis());
-			activecam->NodeUpdateGS(0,true);
+			activecam->NodeUpdateGS(0);
 		} else {
 			activecam->NodeSetLocalPosition(MT_Point3(0.0, 0.0, 0.0));
 			activecam->NodeSetLocalOrientation(MT_Vector3(0.0, 0.0, 0.0));
-			activecam->NodeUpdateGS(0,true);
+			activecam->NodeUpdateGS(0);
 		}
 
 		scene->AddCamera(activecam);