osgShadow::ViewDependentShadowTechnique Class Reference

ViewDependentShadowTechnique is a base class for all View Dependent Shadow techniques. More...

Inheritance diagram for osgShadow::ViewDependentShadowTechnique:

Classes
struct	ViewData
	Base container class for view dependent shadow resources. More...

Public Member Functions
	ViewDependentShadowTechnique (void)
	osgShadow::ShadowTechnique equivalent methods for view dependent techniques More...
	ViewDependentShadowTechnique (const ViewDependentShadowTechnique &vdst, const osg::CopyOp &copyop=osg::CopyOp::SHALLOW_COPY)
	Classic OSG cloning constructor. More...
	META_Object (osgShadow, ViewDependentShadowTechnique)
	Declaration of standard OSG object methods. More...
virtual void	dirty ()
	Dirty view data bits and force update of view data resources. More...
virtual void	init ()
	Initialize the ShadowedScene and some data structures. More...
virtual void	update (osg::NodeVisitor &nv)
	Run the update traversal of the ShadowedScene and update any local cached data structures. More...
virtual void	cull (osgUtil::CullVisitor &cv)
	Run the cull traversal of the ShadowedScene and set up the rendering for this ShadowTechnique. More...
virtual void	cleanSceneGraph ()
	Clean scene graph from any shadow technique specific nodes, state and drawables. More...
virtual void	traverse (osg::NodeVisitor &nv)
	Traverse shadow scene graph. More...
Public Member Functions inherited from osgShadow::ShadowTechnique
	ShadowTechnique ()
	ShadowTechnique (const ShadowTechnique &es, const osg::CopyOp &copyop=osg::CopyOp::SHALLOW_COPY)
	META_Object (osgShadow, ShadowTechnique)
ShadowedScene *	getShadowedScene ()
const ShadowedScene *	getShadowedScene () const
Public Member Functions inherited from osg::Object
	Object ()
	Construct an object. More...
	Object (bool threadSafeRefUnref)
	Object (const Object &, const CopyOp &copyop=CopyOp::SHALLOW_COPY)
	Copy constructor, optional CopyOp object can be used to control shallow vs deep copying of dynamic data. More...
virtual Object *	cloneType () const =0
	Clone the type of an object, with Object* return type. More...
virtual Object *	clone (const CopyOp &) const =0
	Clone an object, with Object* return type. More...
virtual bool	isSameKindAs (const Object *) const
virtual const char *	libraryName () const =0
	return the name of the object's library. More...
virtual const char *	className () const =0
	return the name of the object's class type. More...
std::string	getCompoundClassName () const
	return the compound class name that combines the library name and class name. More...
virtual Node *	asNode ()
	Convert 'this' into a Node pointer if Object is a Node, otherwise return 0. More...
virtual const Node *	asNode () const
	convert 'const this' into a const Node pointer if Object is a Node, otherwise return 0. More...
virtual NodeVisitor *	asNodeVisitor ()
	Convert 'this' into a NodeVisitor pointer if Object is a NodeVisitor, otherwise return 0. More...
virtual const NodeVisitor *	asNodeVisitor () const
	convert 'const this' into a const NodeVisitor pointer if Object is a NodeVisitor, otherwise return 0. More...
virtual StateAttribute *	asStateAttribute ()
	Convert 'this' into a StateAttribute pointer if Object is a StateAttribute, otherwise return 0. More...
virtual const StateAttribute *	asStateAttribute () const
	convert 'const this' into a const StateAttribute pointer if Object is a StateAttribute, otherwise return 0. More...
virtual Uniform *	asUniform ()
	Convert 'this' into a Uniform pointer if Object is a Uniform, otherwise return 0. More...
virtual const Uniform *	asUniform () const
	convert 'const this' into a const Uniform pointer if Object is a Uniform, otherwise return 0. More...
virtual void	setThreadSafeRefUnref (bool threadSafe)
	Set whether to use a mutex to ensure ref() and unref() are thread safe. More...
virtual void	setName (const std::string &name)
	Set the name of object using C++ style string. More...
void	setName (const char *name)
	Set the name of object using a C style string. More...
const std::string &	getName () const
	Get the name of object. More...
void	setDataVariance (DataVariance dv)
	Set the data variance of this object. More...
DataVariance	getDataVariance () const
	Get the data variance of this object. More...
virtual void	computeDataVariance ()
	Compute the DataVariance based on an assessment of callback etc. More...
void	setUserDataContainer (osg::UserDataContainer *udc)
	set the UserDataContainer object. More...
template<class T >
void	setUserDataContainer (const ref_ptr< T > &udc)
osg::UserDataContainer *	getUserDataContainer ()
	get the UserDataContainer attached to this object. More...
const osg::UserDataContainer *	getUserDataContainer () const
	get the const UserDataContainer attached to this object. More...
osg::UserDataContainer *	getOrCreateUserDataContainer ()
	Convenience method that returns the UserDataContainer, and if one doesn't already exist creates and assigns a DefaultUserDataContainer to the Object and then return this new UserDataContainer. More...
virtual void	setUserData (Referenced *obj)
	Set user data, data must be subclassed from Referenced to allow automatic memory handling. More...
template<class T >
void	setUserData (const ref_ptr< T > &ud)
virtual Referenced *	getUserData ()
	Get user data. More...
virtual const Referenced *	getUserData () const
	Get const user data. More...
template<typename T >
bool	getUserValue (const std::string &name, T &value) const
	Convenience method that casts the named UserObject to osg::TemplateValueObject<T> and gets the value. More...
template<typename T >
void	setUserValue (const std::string &name, const T &value)
	Convenience method that creates the osg::TemplateValueObject<T> to store the specified value and adds it as a named UserObject. More...
virtual void	resizeGLObjectBuffers (unsigned int)
	Resize any per context GLObject buffers to specified size. More...
virtual void	releaseGLObjects (osg::State *=0) const
	If State is non-zero, this function releases any associated OpenGL objects for the specified graphics context. More...
template<typename T >
BoolValueObject UCharValueObject UShortValueObject UIntValueObject DoubleValueObject Vec3fValueObject Vec2dValueObject Vec4dValueObject PlaneValueObject MatrixdValueObject BoundingBoxdValueObject BoundingSpheredValueObject bool	getUserValue (const std::string &name, T &value) const
	provide implementation of osg::Object::getUserValue(..) template More...
Public Member Functions inherited from osg::Referenced
	Referenced ()
	Referenced (bool threadSafeRefUnref)
	Referenced (const Referenced &)
Referenced &	operator= (const Referenced &)
bool	getThreadSafeRefUnref () const
	Get whether a mutex is used to ensure ref() and unref() are thread safe. More...
OpenThreads::Mutex *	getRefMutex () const
	Get the mutex used to ensure thread safety of ref()/unref(). More...
int	ref () const
	Increment the reference count by one, indicating that this object has another pointer which is referencing it. More...
int	unref () const
	Decrement the reference count by one, indicating that a pointer to this object is no longer referencing it. More...
int	unref_nodelete () const
	Decrement the reference count by one, indicating that a pointer to this object is no longer referencing it. More...
int	referenceCount () const
	Return the number of pointers currently referencing this object. More...
ObserverSet *	getObserverSet () const
	Get the ObserverSet if one is attached, otherwise return NULL. More...
ObserverSet *	getOrCreateObserverSet () const
	Get the ObserverSet if one is attached, otherwise create an ObserverSet, attach it, then return this newly created ObserverSet. More...
void	addObserver (Observer *observer) const
	Add a Observer that is observing this object, notify the Observer when this object gets deleted. More...
void	removeObserver (Observer *observer) const
	Remove Observer that is observing this object. More...

Protected Types
typedef std::map< osg::ref_ptr< osgUtil::CullVisitor >, osg::ref_ptr< ViewData > >	ViewDataMap
	Map of view dependent data per view cull visitor (CVs are used as indices) ViewDependentShadowTechnique uses this map to find VieData for each cull vitior. More...

Protected Member Functions
	~ViewDependentShadowTechnique (void)
	Classic protected OSG destructor. More...
virtual ViewDependentShadowTechnique::ViewData *	getViewDependentData (osgUtil::CullVisitor *cv)
	Return view dependent data for the cull visitor. More...
virtual void	setViewDependentData (osgUtil::CullVisitor *cv, ViewDependentShadowTechnique::ViewData *data)
	Define view dependent data for the cull visitor. More...
Protected Member Functions inherited from osgShadow::ShadowTechnique
osg::Vec3	computeOrthogonalVector (const osg::Vec3 &direction) const
virtual	~ShadowTechnique ()
Protected Member Functions inherited from osg::Object
virtual	~Object ()
	Object destructor. More...
Protected Member Functions inherited from osg::Referenced
virtual	~Referenced ()
void	signalObserversAndDelete (bool signalDelete, bool doDelete) const
void	deleteUsingDeleteHandler () const

Protected Attributes
ViewDataMap	_viewDataMap
OpenThreads::Mutex	_viewDataMapMutex
	Mutex used to serialize accesses to ViewDataMap. More...
Protected Attributes inherited from osgShadow::ShadowTechnique
ShadowedScene *	_shadowedScene
bool	_dirty
Protected Attributes inherited from osg::Object
std::string	_name
DataVariance	_dataVariance
osg::UserDataContainer *	_userDataContainer
Protected Attributes inherited from osg::Referenced
OpenThreads::AtomicPtr	_observerSet
OpenThreads::Atomic	_refCount

Additional Inherited Members
Public Types inherited from osg::Object
enum	DataVariance { DYNAMIC, STATIC, UNSPECIFIED }
Static Public Member Functions inherited from osg::Referenced
static OpenThreads::Mutex *	getGlobalReferencedMutex ()
	Get the optional global Referenced mutex, this can be shared between all osg::Referenced. More...
static void	setThreadSafeReferenceCounting (bool enableThreadSafeReferenceCounting)
	Set whether reference counting should use a mutex for thread safe reference counting. More...
static bool	getThreadSafeReferenceCounting ()
	Get whether reference counting is active. More...
static void	setDeleteHandler (DeleteHandler *handler)
	Set a DeleteHandler to which deletion of all referenced counted objects will be delegated. More...
static DeleteHandler *	getDeleteHandler ()
	Get a DeleteHandler. More...

Detailed Description

ViewDependentShadowTechnique is a base class for all View Dependent Shadow techniques.

It defines fundamental object structure and methods to manage separate shadow resources for each view of the scene. By view we understand osg::View or SceneView instance and their associated Camera. Typical osg application has one or more such views. View Dependent Shadow techniques manage shadow generation for them.

View Dependent Shadow techniques are used to optimize shadow algorithms for part of the scene seen on the view. If rest of the scene is behind view frustum, there is no sense in computing shadows for it. Since in practice we often use 3d databases extending far beyond current camera frustum View Dependent Shadow approach may produce much better shadows.

The other goal is to provide framework for thread safe rendering of the shadows. It allows to use shadows with different OSG threading models.

Conceptually ViewDependentShadowTechnique is similar to osgSim::OverlayNode. Its a container class for number of ViewData (or ViewData derived) objects doing actual shadow work for each of the scene views.

But ViewDependentShadowTechnique is intended as foundation layer for all derived classes so in some way it extends osgSim::OverlayNode approach a bit.

HOW IT WORKS:

ViewDependendentShadowTechnique is derived from osgShadow::ShadowTechnique and as such overrides virtual methods of osgShadow::ShadowTechnique. But most of the shadow dirty work is done by ViewData objects, ViewDependendentShadowTechnique::cull is the only osgShadow::ShadowTechnique method where ViewDependendentShadowTechnique does something significant:

What ViewDependentShadowTechnique::cull( CullVisitor & cv ) does ? It identifies View. CullVisitor ptr is used as View identificator. In practice we do not check and interpret what are actual Views and SceneViews set up by application. We focus on Camera and CullVisitors as a identificators of views. We can safely do this because each such view will have associated unique CullVisitor used to cull the scene in every frame.

Based on CullVisitor ptr passed to cull method, associated Technique::ViewData object is created (if necessary) and then seleced. Then control is passed to this ViewData object. So, each view has its associated unique ViewData (or derived) object performing dirty work of shadow resources management and shadow generation for the view.

To support creation of classes derived from ViewDependentShadowTechnique it was necessary to provide mechanism to override ViewData and allow for initialization of new derived ViewData objects. Creation and initialization is performed when ViewDependendentShadowTechnique::cull gets called with CullVistor ptr which does not yet have associated ViewData object. When it happens, virtual initViewDependentData method is called to give derived techniques a chance to allocate and iniitalize its specific resources as new ViewData derived instance. In practice initViewDependentData in derived techniques should look the same as in base class so as a convenience it was defined as META_ViewDependentShadowTechnique macro. Derived techniques use this macro to override initViewDependentData method for their usage.

After ViewData derived object is construted and selected, control is passed to this object by call to virtual ViewData::cull method. The rest of work is the done by this object. ViewDependentShadowTechnique::ViewData is intended as a base class so it does nothing. In practice the rest of dirty work will do new ViewData classes implemented in derived techniques.

Member Typedef Documentation

typedef std::map< osg::ref_ptr< osgUtil::CullVisitor >, osg::ref_ptr< ViewData > > osgShadow::ViewDependentShadowTechnique::ViewDataMap

protected

Map of view dependent data per view cull visitor (CVs are used as indices) ViewDependentShadowTechnique uses this map to find VieData for each cull vitior.

Constructor & Destructor Documentation

osgShadow::ViewDependentShadowTechnique::ViewDependentShadowTechnique

(

void

)

osgShadow::ShadowTechnique equivalent methods for view dependent techniques

Classic OSG constructor

osgShadow::ViewDependentShadowTechnique::ViewDependentShadowTechnique	(	const ViewDependentShadowTechnique &	vdst,
		const osg::CopyOp &	copyop = osg::CopyOp::SHALLOW_COPY
	)

Classic OSG cloning constructor.

osgShadow::ViewDependentShadowTechnique::~ViewDependentShadowTechnique ( void  )

protected

Classic protected OSG destructor.

Member Function Documentation

virtual void osgShadow::ViewDependentShadowTechnique::cleanSceneGraph ( )

virtual

Clean scene graph from any shadow technique specific nodes, state and drawables.

Reimplemented from osgShadow::ShadowTechnique.

virtual void osgShadow::ViewDependentShadowTechnique::cull ( osgUtil::CullVisitor &  cv )

virtual

Run the cull traversal of the ShadowedScene and set up the rendering for this ShadowTechnique.

Reimplemented from osgShadow::ShadowTechnique.

virtual void osgShadow::ViewDependentShadowTechnique::dirty ( )

virtual

Dirty view data bits and force update of view data resources.

Reimplemented from osgShadow::ShadowTechnique.

virtual ViewDependentShadowTechnique::ViewData* osgShadow::ViewDependentShadowTechnique::getViewDependentData ( osgUtil::CullVisitor *  cv )

protectedvirtual

Return view dependent data for the cull visitor.

virtual void osgShadow::ViewDependentShadowTechnique::init ( )

virtual

Initialize the ShadowedScene and some data structures.

Reimplemented from osgShadow::ShadowTechnique.

osgShadow::ViewDependentShadowTechnique::META_Object	(	osgShadow	,
		ViewDependentShadowTechnique
	)

Declaration of standard OSG object methods.

virtual void osgShadow::ViewDependentShadowTechnique::setViewDependentData ( osgUtil::CullVisitor *  cv, ViewDependentShadowTechnique::ViewData *  data  )

protectedvirtual

Define view dependent data for the cull visitor.

virtual void osgShadow::ViewDependentShadowTechnique::traverse ( osg::NodeVisitor &  nv )

virtual

Traverse shadow scene graph.

Reimplemented from osgShadow::ShadowTechnique.

virtual void osgShadow::ViewDependentShadowTechnique::update ( osg::NodeVisitor &  nv )

virtual

Run the update traversal of the ShadowedScene and update any local cached data structures.

Reimplemented from osgShadow::ShadowTechnique.

Member Data Documentation

ViewDataMap osgShadow::ViewDependentShadowTechnique::_viewDataMap

protected

OpenThreads::Mutex osgShadow::ViewDependentShadowTechnique::_viewDataMapMutex

protected

Mutex used to serialize accesses to ViewDataMap.

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The documentation for this class was generated from the following file:

• osgShadow/ViewDependentShadowTechnique