osgDB::DatabasePager Class Reference

Database paging class which manages the loading of files in a background thread, and syncronizing of loaded models with the main scene graph. More...

Inheritance diagram for osgDB::DatabasePager:

[legend]List of all members.

Public Types
typedef OpenThreads::Thread::ThreadPriority	ThreadPriority
typedef std::list< osg::ref_ptr< osg::PagedLOD > >	PagedLODList
typedef std::set< osg::ref_ptr< osg::StateSet > >	StateSetList
typedef std::vector< osg::ref_ptr< osg::Drawable > >	DrawableList
typedef std::pair< StateSetList, DrawableList >	DataToCompile
typedef std::map< unsigned int, DataToCompile >	DataToCompileMap
typedef std::set< unsigned int >	ActiveGraphicsContexts
enum	DrawablePolicy { DO_NOT_MODIFY_DRAWABLE_SETTINGS, USE_DISPLAY_LISTS, USE_VERTEX_BUFFER_OBJECTS, USE_VERTEX_ARRAYS }
Public Member Functions
	DatabasePager ()
virtual void	requestNodeFile (const std::string &fileName, osg::Group *group, float priority, const osg::FrameStamp *framestamp)
	Add a request to load a node file to end the the database request list.
virtual void	run ()
	Run does the database paging.
virtual int	cancel ()
	Cancel the database pager thread.
virtual void	clear ()
	Clear all internally cached structures.
void	setDatabasePagerThreadPause (bool pause)
	Set whether the database pager thread should be paused or not.
bool	getDatabasePagerThreadPause () const
	Get whether the database pager thread should is paused or not.
void	setAcceptNewDatabaseRequests (bool acceptNewRequests)
	Set whether new database request calls are accepted or ignored.
bool	getAcceptNewDatabaseRequests () const
	Get whether new database request calls are accepted or ignored.
void	setUseFrameBlock (bool useFrameBlock)
	Set the use of the frame block which, if enabled, blocks the DatabasePager from executing which the current frame is being drawn.
bool	getUseFrameBlock () const
	Get the whether UseFrameBlock is on or off.
osg::Block *	getFrameBlock ()
void	setThreadPriorityDuringFrame (ThreadPriority duringFrame)
	Set the priority of the database pager thread during the frame (i.e.
ThreadPriority	getThreadPriorityDuringFrame () const
	Get the priority of the database pager thread during the frame.
void	setThreadPriorityOutwithFrame (ThreadPriority outwithFrame)
	Set the priority of the database pager thread when the frame is not being exectuted (i.e.
ThreadPriority	getThreadPriorityOutwithFrame () const
	Get the priority of the database pager thread when the frame is not being exectuted.
int	getNumFramesActive () const
	Get the number of frames that are currently active.
virtual void	signalBeginFrame (const osg::FrameStamp *framestamp)
	Signal the database thread that the update, cull and draw has begun for a new frame.
virtual void	signalEndFrame ()
	Signal the database thread that the update, cull and draw dispatch has completed.
virtual void	registerPagedLODs (osg::Node *subgraph)
	Find all PagedLOD nodes in a subgraph and register them with the DatabasePager so it can keep track of expired nodes.
void	setDoPreCompile (bool flag)
	Set whether the database pager should pre compile OpenGL objects before allowing them to be merged into the scene graph.
bool	getDoPreCompile () const
	Get whether the database pager should pre compile OpenGL objects before allowing them to be merged into the scene graph.
void	setTargetFrameRate (double tfr)
	Set the target frame rate that the DatabasePager should assume.
double	getTargetFrameRate () const
	Get the target frame rate that the DatabasePager should assume.
void	setMinimumTimeAvailableForGLCompileAndDeletePerFrame (double ta)
	Set the minimum amount of time (in seconds) that should be made available for compiling and delete OpenGL objects per frame.
double	getMinimumTimeAvailableForGLCompileAndDeletePerFrame () const
	Get the minimum amount of time that should be made available for compiling and delete OpenGL objects per frame.
void	setMaximumNumOfObjectsToCompilePerFrame (unsigned int num)
	Set the maximum number of OpenGL objects that the page should attempt to compile per frame.
unsigned int	getMaximumNumOfObjectsToCompilePerFrame () const
	Get the maximum number of OpenGL objects that the page should attempt to compile per frame.
void	setExpiryDelay (double expiryDelay)
	Set the amount of time that a subgraph will be kept without being visited in the cull traversal before being removed.
double	getExpiryDelay () const
	Get the amount of time that a subgraph will be kept without being visited in the cull traversal before being removed.
void	setDeleteRemovedSubgraphsInDatabaseThread (bool flag)
	Set whether the removed subgraphs should be deleted in the database thread or not.
bool	getDeleteRemovedSubgraphsInDatabaseThread () const
	Get whether the removed subgraphs should be deleted in the database thread or not.
void	setDrawablePolicy (DrawablePolicy policy)
	Set how loaded drawables should be handled w.r.t their display list/vertex buffer object/vertex array settings.
DrawablePolicy	getDrawablePolicy () const
	Get how loaded drawables should be handled w.r.t their display list/vertex buffer object/vertex array settings.
void	setUnrefImageDataAfterApplyPolicy (bool changeAutoUnRef, bool valueAutoUnRef)
	Set whether newly loaded textures should have their UnrefImageDataAfterApply set to a specified value.
void	getUnrefImageDataAfterApplyPolicy (bool &changeAutoUnRef, bool &valueAutoUnRef) const
	Get whether newly loaded textures should have their UnrefImageDataAfterApply set to a specified value.
void	setMaxAnisotropyPolicy (bool changeAnisotropy, float valueAnisotropy)
	Set whether newly loaded textures should have their MaxAnisotopy set to a specified value.
void	getMaxAnisotropyPolicy (bool &changeAnisotropy, float &valueAnisotropy) const
	Set whether newly loaded textures should have their MaxAnisotopy set to a specified value.
bool	requiresUpdateSceneGraph () const
	Return true if there are pending updates to the scene graph that require a call to updateSceneGraph(double).
virtual void	updateSceneGraph (double currentFrameTime)
	Merge the changes to the scene graph by calling calling removeExpiredSubgraphs then addLoadedDataToSceneGraph.
void	setCompileGLObjectsForContextID (unsigned int contextID, bool on)
	Turn the compilation of rendering objects for specfied graphics context on (true) or off(false).
bool	getCompileGLObjectsForContextID (unsigned int contextID)
	Get whether the compilation of rendering objects for specfied graphics context on (true) or off(false).
bool	requiresCompileGLObjects () const
	Return true if there are pending compile operations that are required.
virtual void	compileGLObjects (osg::State &state, double &availableTime)
	Compile the rendering objects (display lists,texture objects, VBO's) on loaded subgraph.
Protected Types
typedef std::vector< osg::ref_ptr< DatabaseRequest > >	DatabaseRequestList
typedef std::vector< osg::ref_ptr< osg::Object > >	ObjectList
Protected Member Functions
virtual	~DatabasePager ()
void	updateDatabasePagerThreadBlock ()
void	updateFrameBlock (int delta)
virtual void	removeExpiredSubgraphs (double currentFrameTime)
	Iterate through the active PagedLOD nodes children removing children which havn't been visited since specified expiryTime.
void	addLoadedDataToSceneGraph (double currentFrameTime)
	Add the loaded data to the scene graph.
Protected Attributes
OpenThreads::Mutex	_run_mutex
bool	_startThreadCalled
osg::ref_ptr< osg::Block >	_databasePagerThreadBlock
bool	_done
bool	_acceptNewRequests
bool	_databasePagerThreadPaused
bool	_useFrameBlock
int	_numFramesActive
OpenThreads::Mutex	_numFramesActiveMutex
osg::ref_ptr< osg::Block >	_frameBlock
int	_frameNumber
ThreadPriority	_threadPriorityDuringFrame
ThreadPriority	_threadPriorityOutwithFrame
DatabaseRequestList	_fileRequestList
OpenThreads::Mutex	_fileRequestListMutex
DatabaseRequestList	_dataToCompileList
OpenThreads::Mutex	_dataToCompileListMutex
DrawablePolicy	_drawablePolicy
bool	_changeAutoUnRef
bool	_valueAutoUnRef
bool	_changeAnisotropy
float	_valueAnisotropy
bool	_deleteRemovedSubgraphsInDatabaseThread
ObjectList	_childrenToDeleteList
OpenThreads::Mutex	_childrenToDeleteListMutex
DatabaseRequestList	_dataToMergeList
OpenThreads::Mutex	_dataToMergeListMutex
PagedLODList	_activePagedLODList
PagedLODList	_inactivePagedLODList
double	_expiryDelay
ActiveGraphicsContexts	_activeGraphicsContexts
bool	_doPreCompile
double	_targetFrameRate
double	_minimumTimeAvailableForGLCompileAndDeletePerFrame
unsigned int	_maximumNumOfObjectsToCompilePerFrame

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Detailed Description

Database paging class which manages the loading of files in a background thread, and syncronizing of loaded models with the main scene graph.

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Member Typedef Documentation

typedef std::set<unsigned int> osgDB::DatabasePager::ActiveGraphicsContexts

typedef std::vector< osg::ref_ptr<DatabaseRequest> > osgDB::DatabasePager::DatabaseRequestList [protected]

typedef std::pair<StateSetList,DrawableList> osgDB::DatabasePager::DataToCompile

typedef std::map< unsigned int, DataToCompile > osgDB::DatabasePager::DataToCompileMap

typedef std::vector< osg::ref_ptr<osg::Drawable> > osgDB::DatabasePager::DrawableList

typedef std::vector< osg::ref_ptr<osg::Object> > osgDB::DatabasePager::ObjectList [protected]

typedef std::list< osg::ref_ptr<osg::PagedLOD> > osgDB::DatabasePager::PagedLODList

typedef std::set< osg::ref_ptr<osg::StateSet> > osgDB::DatabasePager::StateSetList

typedef OpenThreads::Thread::ThreadPriority osgDB::DatabasePager::ThreadPriority

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Member Enumeration Documentation

enum osgDB::DatabasePager::DrawablePolicy

Enumeration values: DO_NOT_MODIFY_DRAWABLE_SETTINGS  USE_DISPLAY_LISTS  USE_VERTEX_BUFFER_OBJECTS  USE_VERTEX_ARRAYS

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Constructor & Destructor Documentation

osgDB::DatabasePager::DatabasePager (   )

virtual osgDB::DatabasePager::~DatabasePager (   )  [protected, virtual]

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Member Function Documentation

void osgDB::DatabasePager::addLoadedDataToSceneGraph (  double  currentFrameTime  )  [protected]

Add the loaded data to the scene graph.

virtual int osgDB::DatabasePager::cancel (   )  [virtual]

Cancel the database pager thread.

virtual void osgDB::DatabasePager::clear (   )  [virtual]

Clear all internally cached structures.

virtual void osgDB::DatabasePager::compileGLObjects (  osg::State &  state, double &  availableTime )  [virtual]

Compile the rendering objects (display lists,texture objects, VBO's) on loaded subgraph. note, should only be called from the draw thread. Note, must only be called from a valid graphics context.

bool osgDB::DatabasePager::getAcceptNewDatabaseRequests (   )  const [inline]

Get whether new database request calls are accepted or ignored.

bool osgDB::DatabasePager::getCompileGLObjectsForContextID (  unsigned int  contextID  )

Get whether the compilation of rendering objects for specfied graphics context on (true) or off(false).

bool osgDB::DatabasePager::getDatabasePagerThreadPause (   )  const [inline]

Get whether the database pager thread should is paused or not.

bool osgDB::DatabasePager::getDeleteRemovedSubgraphsInDatabaseThread (   )  const [inline]

Get whether the removed subgraphs should be deleted in the database thread or not.

bool osgDB::DatabasePager::getDoPreCompile (   )  const [inline]

Get whether the database pager should pre compile OpenGL objects before allowing them to be merged into the scene graph.

DrawablePolicy osgDB::DatabasePager::getDrawablePolicy (   )  const [inline]

Get how loaded drawables should be handled w.r.t their display list/vertex buffer object/vertex array settings.

double osgDB::DatabasePager::getExpiryDelay (   )  const [inline]

Get the amount of time that a subgraph will be kept without being visited in the cull traversal before being removed.

osg::Block* osgDB::DatabasePager::getFrameBlock (   )  [inline]

void osgDB::DatabasePager::getMaxAnisotropyPolicy (  bool &  changeAnisotropy, float &  valueAnisotropy )  const [inline]

Set whether newly loaded textures should have their MaxAnisotopy set to a specified value.

unsigned int osgDB::DatabasePager::getMaximumNumOfObjectsToCompilePerFrame (   )  const [inline]

Get the maximum number of OpenGL objects that the page should attempt to compile per frame.

double osgDB::DatabasePager::getMinimumTimeAvailableForGLCompileAndDeletePerFrame (   )  const [inline]

Get the minimum amount of time that should be made available for compiling and delete OpenGL objects per frame. For usage see notes in setTargetFrameRate.

int osgDB::DatabasePager::getNumFramesActive (   )  const [inline]

Get the number of frames that are currently active.

double osgDB::DatabasePager::getTargetFrameRate (   )  const [inline]

Get the target frame rate that the DatabasePager should assume.

ThreadPriority osgDB::DatabasePager::getThreadPriorityDuringFrame (   )  const [inline]

Get the priority of the database pager thread during the frame.

ThreadPriority osgDB::DatabasePager::getThreadPriorityOutwithFrame (   )  const [inline]

Get the priority of the database pager thread when the frame is not being exectuted.

void osgDB::DatabasePager::getUnrefImageDataAfterApplyPolicy (  bool &  changeAutoUnRef, bool &  valueAutoUnRef )  const [inline]

Get whether newly loaded textures should have their UnrefImageDataAfterApply set to a specified value.

bool osgDB::DatabasePager::getUseFrameBlock (   )  const [inline]

Get the whether UseFrameBlock is on or off.

virtual void osgDB::DatabasePager::registerPagedLODs (  osg::Node *  subgraph  )  [virtual]

Find all PagedLOD nodes in a subgraph and register them with the DatabasePager so it can keep track of expired nodes. note, should be only be called from the update thread.

virtual void osgDB::DatabasePager::removeExpiredSubgraphs (  double  currentFrameTime  )  [protected, virtual]

Iterate through the active PagedLOD nodes children removing children which havn't been visited since specified expiryTime. note, should be only be called from the update thread.

virtual void osgDB::DatabasePager::requestNodeFile (  const std::string &  fileName, osg::Group *  group, float  priority, const osg::FrameStamp *  framestamp )  [virtual]

Add a request to load a node file to end the the database request list.

bool osgDB::DatabasePager::requiresCompileGLObjects (   )  const

Return true if there are pending compile operations that are required. If requiresCompileGLObjects() return true the application should call compileGLObjects() .

bool osgDB::DatabasePager::requiresUpdateSceneGraph (   )  const

Return true if there are pending updates to the scene graph that require a call to updateSceneGraph(double).

virtual void osgDB::DatabasePager::run (   )  [virtual]

Run does the database paging.

void osgDB::DatabasePager::setAcceptNewDatabaseRequests (  bool  acceptNewRequests  )  [inline]

Set whether new database request calls are accepted or ignored.

void osgDB::DatabasePager::setCompileGLObjectsForContextID (  unsigned int  contextID, bool  on )

Turn the compilation of rendering objects for specfied graphics context on (true) or off(false).

void osgDB::DatabasePager::setDatabasePagerThreadPause (  bool  pause  )

Set whether the database pager thread should be paused or not.

void osgDB::DatabasePager::setDeleteRemovedSubgraphsInDatabaseThread (  bool  flag  )  [inline]

Set whether the removed subgraphs should be deleted in the database thread or not.

void osgDB::DatabasePager::setDoPreCompile (  bool  flag  )  [inline]

Set whether the database pager should pre compile OpenGL objects before allowing them to be merged into the scene graph. Pre compilation helps reduce the chances of frame drops, but also slows the speed at which tiles are merged as they have to be compiled first.

void osgDB::DatabasePager::setDrawablePolicy (  DrawablePolicy  policy  )  [inline]

Set how loaded drawables should be handled w.r.t their display list/vertex buffer object/vertex array settings.

void osgDB::DatabasePager::setExpiryDelay (  double  expiryDelay  )  [inline]

Set the amount of time that a subgraph will be kept without being visited in the cull traversal before being removed.

void osgDB::DatabasePager::setMaxAnisotropyPolicy (  bool  changeAnisotropy, float  valueAnisotropy )  [inline]

Set whether newly loaded textures should have their MaxAnisotopy set to a specified value.

void osgDB::DatabasePager::setMaximumNumOfObjectsToCompilePerFrame (  unsigned int  num  )  [inline]

Set the maximum number of OpenGL objects that the page should attempt to compile per frame. Note, Lower values reduces chances of a frame drop but lower the rate that database will be paged in at. Default value is 8.

void osgDB::DatabasePager::setMinimumTimeAvailableForGLCompileAndDeletePerFrame (  double  ta  )  [inline]

Set the minimum amount of time (in seconds) that should be made available for compiling and delete OpenGL objects per frame. Default value is 0.001 (1 millisecond). For usage see notes in setTargetFrameRate.

void osgDB::DatabasePager::setTargetFrameRate (  double  tfr  )  [inline]

Set the target frame rate that the DatabasePager should assume. Typically one would set this to the value refresh rate of your display system i.e. 60Hz. Default value is 100. Usage notes. The TargetFrameRate and the MinimumTimeAvailableForGLCompileAndDeletePerFrame parameters are not directly used by DatabasePager, but are should be used as a guide for how long to set aside per frame for compiling and deleting OpenGL objects - ie. the value to use when calling DatabasePager::compileGLObjectgs(state,availableTime,). The longer amount of time to set aside cthe faster databases will be paged in but with increased chance of frame drops, the lower the amount of time the set aside the slower databases will paged it but with better chance of avoid any frame drops. The default values are chosen to achieve the later when running on a modern mid to high end PC. The way to compute the amount of available time use a scheme such as : availableTime = maximum(1.0/targetFrameRate - timeTakenDuringUpdateCullAndDraw, minimumTimeAvailableForGLCompileAndDeletePerFrame).

void osgDB::DatabasePager::setThreadPriorityDuringFrame (  ThreadPriority  duringFrame  )  [inline]

Set the priority of the database pager thread during the frame (i.e. while cull and draw are running.)

void osgDB::DatabasePager::setThreadPriorityOutwithFrame (  ThreadPriority  outwithFrame  )  [inline]

Set the priority of the database pager thread when the frame is not being exectuted (i.e. before or after cull and draw have run.)

void osgDB::DatabasePager::setUnrefImageDataAfterApplyPolicy (  bool  changeAutoUnRef, bool  valueAutoUnRef )  [inline]

Set whether newly loaded textures should have their UnrefImageDataAfterApply set to a specified value.

void osgDB::DatabasePager::setUseFrameBlock (  bool  useFrameBlock  )  [inline]

Set the use of the frame block which, if enabled, blocks the DatabasePager from executing which the current frame is being drawn. When a single processor machine is being used it can be useful to block on frame to help prevent the database paging thread from slowing the cull and draw traversals which in turn can cause frame drops.

virtual void osgDB::DatabasePager::signalBeginFrame (  const osg::FrameStamp *  framestamp  )  [virtual]

Signal the database thread that the update, cull and draw has begun for a new frame. Note, this is called by the application so that the database pager can go to sleep while the CPU is busy on the main rendering threads.

virtual void osgDB::DatabasePager::signalEndFrame (   )  [virtual]

Signal the database thread that the update, cull and draw dispatch has completed. Note, this is called by the application so that the database pager can go to wake back up now the main rendering threads are iddle waiting for the next frame.

void osgDB::DatabasePager::updateDatabasePagerThreadBlock (   )  [inline, protected]

void osgDB::DatabasePager::updateFrameBlock (  int  delta  )  [inline, protected]

virtual void osgDB::DatabasePager::updateSceneGraph (  double  currentFrameTime  )  [inline, virtual]

Merge the changes to the scene graph by calling calling removeExpiredSubgraphs then addLoadedDataToSceneGraph. Note, must only be called from single thread update phase.

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Member Data Documentation

bool osgDB::DatabasePager::_acceptNewRequests [protected]

ActiveGraphicsContexts osgDB::DatabasePager::_activeGraphicsContexts [protected]

PagedLODList osgDB::DatabasePager::_activePagedLODList [protected]

bool osgDB::DatabasePager::_changeAnisotropy [protected]

bool osgDB::DatabasePager::_changeAutoUnRef [protected]

ObjectList osgDB::DatabasePager::_childrenToDeleteList [protected]

OpenThreads::Mutex osgDB::DatabasePager::_childrenToDeleteListMutex [mutable, protected]

osg::ref_ptr<osg::Block> osgDB::DatabasePager::_databasePagerThreadBlock [protected]

bool osgDB::DatabasePager::_databasePagerThreadPaused [protected]

DatabaseRequestList osgDB::DatabasePager::_dataToCompileList [protected]

OpenThreads::Mutex osgDB::DatabasePager::_dataToCompileListMutex [mutable, protected]

DatabaseRequestList osgDB::DatabasePager::_dataToMergeList [protected]

OpenThreads::Mutex osgDB::DatabasePager::_dataToMergeListMutex [mutable, protected]

bool osgDB::DatabasePager::_deleteRemovedSubgraphsInDatabaseThread [protected]

bool osgDB::DatabasePager::_done [protected]

bool osgDB::DatabasePager::_doPreCompile [protected]

DrawablePolicy osgDB::DatabasePager::_drawablePolicy [protected]

double osgDB::DatabasePager::_expiryDelay [protected]

DatabaseRequestList osgDB::DatabasePager::_fileRequestList [protected]

OpenThreads::Mutex osgDB::DatabasePager::_fileRequestListMutex [mutable, protected]

osg::ref_ptr<osg::Block> osgDB::DatabasePager::_frameBlock [protected]

int osgDB::DatabasePager::_frameNumber [protected]

PagedLODList osgDB::DatabasePager::_inactivePagedLODList [protected]

unsigned int osgDB::DatabasePager::_maximumNumOfObjectsToCompilePerFrame [protected]

double osgDB::DatabasePager::_minimumTimeAvailableForGLCompileAndDeletePerFrame [protected]

int osgDB::DatabasePager::_numFramesActive [protected]

OpenThreads::Mutex osgDB::DatabasePager::_numFramesActiveMutex [mutable, protected]

OpenThreads::Mutex osgDB::DatabasePager::_run_mutex [protected]

bool osgDB::DatabasePager::_startThreadCalled [protected]

double osgDB::DatabasePager::_targetFrameRate [protected]

ThreadPriority osgDB::DatabasePager::_threadPriorityDuringFrame [protected]

ThreadPriority osgDB::DatabasePager::_threadPriorityOutwithFrame [protected]

bool osgDB::DatabasePager::_useFrameBlock [protected]

float osgDB::DatabasePager::_valueAnisotropy [protected]

bool osgDB::DatabasePager::_valueAutoUnRef [protected]

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

• DatabasePager

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