BGE performance: second round of scenegraph improvement.

Use dynamic linked list to handle scenegraph rather than dumb scan
of the whole tree. The performance improvement depends on the fraction
of moving objects. If most objects are static, the speed up is 
considerable. The following table compares the time spent on 
scenegraph before and after this commit on a scene with 10000 objects
in various configuratons:

Scenegraph time (ms)              Before         After
(includes culling)

All objects static,               8.8            1.7  
all visible but small fraction          
in the view frustrum

All objects static,               7,5            0.01
all invisible.

All objects moving,               14.1           8.4
all visible but small fraction
in the view frustrum

This tables shows that static and invisible objects take no CPU at all
for scenegraph and culling. In the general case, this commit will 
speed up the scenegraph between 2x and 5x. Compared to 2.48a, it should
be between 4x and 10x faster. Further speed up is possible by making
the scenegraph cache-friendly.

Next round of performance improvement will be on the rasterizer: use
the same dynamic linked list technique for the mesh slots.

1 files changed, 6 insertions, 141 deletions

diff --git a/source/gameengine/SceneGraph/SG_Spatial.cpp b/source/gameengine/SceneGraph/SG_Spatial.cpp
index 2f3176816c6..97b15bdf376 100644
--- a/source/gameengine/SceneGraph/SG_Spatial.cpp
+++ b/source/gameengine/SceneGraph/SG_Spatial.cpp
@@ -40,7 +40,7 @@ SG_Spatial::
 SG_Spatial(
 	void* clientobj,
 	void* clientinfo,
-	SG_Callbacks callbacks
+	SG_Callbacks& callbacks
 ): 
 
 	SG_IObject(clientobj,clientinfo,callbacks),
@@ -56,8 +56,9 @@ SG_Spatial(
 	
 	m_bbox(MT_Point3(-1.0, -1.0, -1.0), MT_Point3(1.0, 1.0, 1.0)),
 	m_radius(1.0),
-	m_modified(true)
+	m_modified(false)
 {
+	SetModified();
 }
 
 SG_Spatial::
@@ -88,13 +89,6 @@ SG_Spatial::
 	delete (m_parent_relation);
 }
 
-	SG_ParentRelation *
-SG_Spatial::
-GetParentRelation(
-){
-	return m_parent_relation;
-}
-
 	void
 SG_Spatial::
 SetParentRelation(
@@ -102,7 +96,7 @@ SetParentRelation(
 ){
 	delete (m_parent_relation);
 	m_parent_relation = relation;
-	m_modified = true;
+	SetModified();
 }
 
 
@@ -143,11 +137,6 @@ UpdateSpatialData(
 	return bComputesWorldTransform;
 }
 
-bool	SG_Spatial::ComputeWorldTransforms(const SG_Spatial *parent, bool& parentUpdated)
-{
-	return m_parent_relation->UpdateChildCoordinates(this,parent,parentUpdated);
-}
-
 /**
  * Position and translation methods
  */
@@ -169,56 +158,14 @@ RelativeTranslate(
 			m_localPosition += trans;
 		}
 	}
-	m_modified = true;
+	SetModified();
 }	
 	
-	void 
-SG_Spatial::
-SetLocalPosition(
-	const MT_Point3& trans
-){
-	m_localPosition = trans;
-	m_modified = true;
-}
-
-	void				
-SG_Spatial::
-SetWorldPosition(
-	const MT_Point3& trans
-) {
-	m_worldPosition = trans;
-}
 
 /**
  * Scaling methods.
  */ 
 
-	void 
-SG_Spatial::
-RelativeScale(
-	const MT_Vector3& scale
-){
-	m_localScaling = m_localScaling * scale;
-	m_modified = true;
-}
-
-	void 
-SG_Spatial::
-SetLocalScale(
-	const MT_Vector3& scale
-){
-	m_localScaling = scale;
-	m_modified = true;
-}
-
-
-	void				
-SG_Spatial::
-SetWorldScale(
-	const MT_Vector3& scale
-){ 
-	m_worldScaling = scale;
-}
 
 /**
  * Orientation and rotation methods.
@@ -236,93 +183,11 @@ RelativeRotate(
 		rot 
 	:
 	(GetWorldOrientation().inverse() * rot * GetWorldOrientation()));
-	m_modified = true;
-}
-
-	void 
-SG_Spatial::
-SetLocalOrientation(const MT_Matrix3x3& rot)
-{
-	m_localRotation = rot;
-	m_modified = true;
+	SetModified();
 }
 
 
 
-	void				
-SG_Spatial::
-SetWorldOrientation(
-	const MT_Matrix3x3& rot
-) {
-	m_worldRotation = rot;
-}
-
-const 
-	MT_Point3&
-SG_Spatial::
-GetLocalPosition(
-) const	{
-	 return m_localPosition;
-}
-
-const 
-	MT_Matrix3x3&
-SG_Spatial::
-GetLocalOrientation(
-) const	{
-	return m_localRotation;
-}
-
-const 
-	MT_Vector3&	
-SG_Spatial::
-GetLocalScale(
-) const{
-	return m_localScaling;
-}
-
-
-const 
-	MT_Point3&
-SG_Spatial::
-GetWorldPosition(
-) const	{
-	return m_worldPosition;
-}
-
-const 
-	MT_Matrix3x3&	
-SG_Spatial::
-GetWorldOrientation(
-) const	{
-	return m_worldRotation;
-}
-
-const 
-	MT_Vector3&	
-SG_Spatial::
-GetWorldScaling(
-) const	{
-	return m_worldScaling;
-}
-
-void SG_Spatial::SetWorldFromLocalTransform()
-{
-	m_worldPosition= m_localPosition;
-	m_worldScaling= m_localScaling;
-	m_worldRotation= m_localRotation;
-}
-
-SG_BBox& SG_Spatial::BBox()
-{
-	return m_bbox;
-}
-
-void SG_Spatial::SetBBox(SG_BBox& bbox)
-{
-	m_bbox = bbox;
-}
-
 MT_Transform SG_Spatial::GetWorldTransform() const
 {
 	return MT_Transform(m_worldPosition,