OpenSceneGraph  3.0.1
Classes | Public Types | Public Member Functions | Protected Attributes
osg::NodeVisitor Class Reference

Visitor for type safe operations on osg::Nodes. More...

Inheritance diagram for osg::NodeVisitor:
Inheritance graph
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List of all members.

Classes

class  DatabaseRequestHandler
 Callback for managing database paging, such as generated by PagedLOD nodes. More...
class  ImageRequestHandler
 Callback for managing image paging, such as generated by PagedLOD nodes. More...

Public Types

enum  TraversalMode { TRAVERSE_NONE, TRAVERSE_PARENTS, TRAVERSE_ALL_CHILDREN, TRAVERSE_ACTIVE_CHILDREN }
enum  VisitorType {
  NODE_VISITOR = 0, UPDATE_VISITOR, EVENT_VISITOR, COLLECT_OCCLUDER_VISITOR,
  CULL_VISITOR
}

Public Member Functions

 NodeVisitor (TraversalMode tm=TRAVERSE_NONE)
 NodeVisitor (VisitorType type, TraversalMode tm=TRAVERSE_NONE)
virtual ~NodeVisitor ()
virtual const char * libraryName () const
 return the library name/namespapce of the visitor's.
virtual const char * className () const
 return the name of the visitor's class type.
virtual void reset ()
 Method to call to reset visitor.
void setVisitorType (VisitorType type)
 Set the VisitorType, used to distinguish different visitors during traversal of the scene, typically used in the Node::traverse() method to select which behaviour to use for different types of traversal/visitors.
VisitorType getVisitorType () const
 Get the VisitorType.
void setTraversalNumber (unsigned int fn)
 Set the traversal number.
unsigned int getTraversalNumber () const
 Get the traversal number.
void setFrameStamp (FrameStamp *fs)
 Set the FrameStamp that this traversal is associated with.
const FrameStampgetFrameStamp () const
 Get the FrameStamp that this traversal is associated with.
void setTraversalMask (Node::NodeMask mask)
 Set the TraversalMask of this NodeVisitor.
Node::NodeMask getTraversalMask () const
 Get the TraversalMask.
void setNodeMaskOverride (Node::NodeMask mask)
 Set the NodeMaskOverride mask.
Node::NodeMask getNodeMaskOverride () const
 Get the NodeMaskOverride mask.
bool validNodeMask (const osg::Node &node) const
 Method to called by Node and its subclass' Node::accept() method, if the result is true it is used to cull operations of nodes and their subgraphs.
void setTraversalMode (TraversalMode mode)
 Set the traversal mode for Node::traverse() to use when deciding which children of a node to traverse.
TraversalMode getTraversalMode () const
 Get the traversal mode.
void setUserData (Referenced *obj)
 Set user data, data must be subclassed from Referenced to allow automatic memory handling.
ReferencedgetUserData ()
 Get user data.
const ReferencedgetUserData () const
 Get const user data.
void traverse (Node &node)
 Method for handling traversal of a nodes.
void pushOntoNodePath (Node *node)
 Method called by osg::Node::accept() method before a call to the NodeVisitor::apply(..).
void popFromNodePath ()
 Method called by osg::Node::accept() method after a call to NodeVisitor::apply(..).
NodePathgetNodePath ()
 Get the non const NodePath from the top most node applied down to the current Node being visited.
const NodePathgetNodePath () const
 Get the const NodePath from the top most node applied down to the current Node being visited.
virtual osg::Vec3 getEyePoint () const
 Get the eye point in local coordinates.
virtual osg::Vec3 getViewPoint () const
 Get the view point in local coordinates.
virtual float getDistanceToEyePoint (const Vec3 &, bool) const
 Get the distance from a point to the eye point, distance value in local coordinate system.
virtual float getDistanceFromEyePoint (const Vec3 &, bool) const
 Get the distance of a point from the eye point, distance value in the eye coordinate system.
virtual float getDistanceToViewPoint (const Vec3 &, bool) const
 Get the distance from a point to the view point, distance value in local coordinate system.
virtual void apply (Node &node)
virtual void apply (Geode &node)
virtual void apply (Billboard &node)
virtual void apply (Group &node)
virtual void apply (ProxyNode &node)
virtual void apply (Projection &node)
virtual void apply (CoordinateSystemNode &node)
virtual void apply (ClipNode &node)
virtual void apply (TexGenNode &node)
virtual void apply (LightSource &node)
virtual void apply (Transform &node)
virtual void apply (Camera &node)
virtual void apply (CameraView &node)
virtual void apply (MatrixTransform &node)
virtual void apply (PositionAttitudeTransform &node)
virtual void apply (Switch &node)
virtual void apply (Sequence &node)
virtual void apply (LOD &node)
virtual void apply (PagedLOD &node)
virtual void apply (ClearNode &node)
virtual void apply (OccluderNode &node)
virtual void apply (OcclusionQueryNode &node)
void setDatabaseRequestHandler (DatabaseRequestHandler *handler)
 Set the handler for database requests.
DatabaseRequestHandlergetDatabaseRequestHandler ()
 Get the handler for database requests.
const DatabaseRequestHandlergetDatabaseRequestHandler () const
 Get the const handler for database requests.
void setImageRequestHandler (ImageRequestHandler *handler)
 Set the handler for image requests.
ImageRequestHandlergetImageRequestHandler ()
 Get the handler for image requests.
const ImageRequestHandlergetImageRequestHandler () const
 Get the const handler for image requests.

Protected Attributes

VisitorType _visitorType
unsigned int _traversalNumber
ref_ptr< FrameStamp_frameStamp
TraversalMode _traversalMode
Node::NodeMask _traversalMask
Node::NodeMask _nodeMaskOverride
NodePath _nodePath
ref_ptr< Referenced_userData
ref_ptr< DatabaseRequestHandler_databaseRequestHandler
ref_ptr< ImageRequestHandler_imageRequestHandler

Detailed Description

Visitor for type safe operations on osg::Nodes.

Based on GOF's Visitor pattern. The NodeVisitor is useful for developing type safe operations to nodes in the scene graph (as per Visitor pattern), and adds to this support for optional scene graph traversal to allow operations to be applied to whole scenes at once. The Visitor pattern uses a technique of double dispatch as a mechanism to call the appropriate apply(..) method of the NodeVisitor. To use this feature one must use the Node::accept(NodeVisitor) which is extended in each Node subclass, rather than the NodeVisitor apply directly. So use root->accept(myVisitor); instead of myVisitor.apply(*root). The later method will bypass the double dispatch and the appropriate NodeVisitor::apply(..) method will not be called.


Member Enumeration Documentation

Enumerator:
TRAVERSE_NONE 
TRAVERSE_PARENTS 
TRAVERSE_ALL_CHILDREN 
TRAVERSE_ACTIVE_CHILDREN 
Enumerator:
NODE_VISITOR 
UPDATE_VISITOR 
EVENT_VISITOR 
COLLECT_OCCLUDER_VISITOR 
CULL_VISITOR 

Constructor & Destructor Documentation

osg::NodeVisitor::NodeVisitor ( TraversalMode  tm = TRAVERSE_NONE)
osg::NodeVisitor::NodeVisitor ( VisitorType  type,
TraversalMode  tm = TRAVERSE_NONE 
)
virtual osg::NodeVisitor::~NodeVisitor ( ) [virtual]

Member Function Documentation

virtual void osg::NodeVisitor::apply ( Node node) [virtual]
virtual void osg::NodeVisitor::apply ( Geode node) [virtual]
virtual void osg::NodeVisitor::apply ( Billboard node) [virtual]
virtual void osg::NodeVisitor::apply ( Group node) [virtual]
virtual void osg::NodeVisitor::apply ( ProxyNode node) [virtual]
virtual void osg::NodeVisitor::apply ( Projection node) [virtual]
virtual void osg::NodeVisitor::apply ( CoordinateSystemNode node) [virtual]
virtual void osg::NodeVisitor::apply ( ClipNode node) [virtual]

Reimplemented in osgUtil::CullVisitor.

virtual void osg::NodeVisitor::apply ( TexGenNode node) [virtual]

Reimplemented in osgUtil::CullVisitor.

virtual void osg::NodeVisitor::apply ( LightSource node) [virtual]
virtual void osg::NodeVisitor::apply ( Transform node) [virtual]
virtual void osg::NodeVisitor::apply ( Camera node) [virtual]
virtual void osg::NodeVisitor::apply ( CameraView node) [virtual]
virtual void osg::NodeVisitor::apply ( MatrixTransform node) [virtual]
virtual void osg::NodeVisitor::apply ( PositionAttitudeTransform node) [virtual]
virtual void osg::NodeVisitor::apply ( Switch node) [virtual]
virtual void osg::NodeVisitor::apply ( Sequence node) [virtual]
virtual void osg::NodeVisitor::apply ( LOD node) [virtual]
virtual void osg::NodeVisitor::apply ( PagedLOD node) [virtual]
virtual void osg::NodeVisitor::apply ( ClearNode node) [virtual]

Reimplemented in osgUtil::CullVisitor.

virtual void osg::NodeVisitor::apply ( OccluderNode node) [virtual]
virtual void osg::NodeVisitor::apply ( OcclusionQueryNode node) [virtual]

Reimplemented in osgUtil::CullVisitor.

virtual const char* osg::NodeVisitor::className ( ) const [inline, virtual]

return the name of the visitor's class type.

Should be defined by derived classes.

DatabaseRequestHandler* osg::NodeVisitor::getDatabaseRequestHandler ( ) [inline]

Get the handler for database requests.

const DatabaseRequestHandler* osg::NodeVisitor::getDatabaseRequestHandler ( ) const [inline]

Get the const handler for database requests.

virtual float osg::NodeVisitor::getDistanceFromEyePoint ( const Vec3 ,
bool   
) const [inline, virtual]

Get the distance of a point from the eye point, distance value in the eye coordinate system.

Note, not all NodeVisitor implement this method, it is mainly cull visitors which will implement. If the getDistanceFromEyePoint(pos) is not implemented than a default value of 0.0 is returned.

Reimplemented in osgUtil::CullVisitor, and osg::CollectOccludersVisitor.

virtual float osg::NodeVisitor::getDistanceToEyePoint ( const Vec3 ,
bool   
) const [inline, virtual]

Get the distance from a point to the eye point, distance value in local coordinate system.

Note, not all NodeVisitor implement this method, it is mainly cull visitors which will implement. If the getDistanceFromEyePoint(pos) is not implemented then a default value of 0.0 is returned.

Reimplemented in osgUtil::IntersectionVisitor, osgUtil::IntersectVisitor, osgUtil::CullVisitor, and osg::CollectOccludersVisitor.

virtual float osg::NodeVisitor::getDistanceToViewPoint ( const Vec3 ,
bool   
) const [inline, virtual]

Get the distance from a point to the view point, distance value in local coordinate system.

Note, not all NodeVisitor implement this method, it is mainly cull visitors which will implement. If the getDistanceToViewPoint(pos) is not implemented then a default value of 0.0 is returned.

Reimplemented in osgUtil::CullVisitor, and osg::CollectOccludersVisitor.

virtual osg::Vec3 osg::NodeVisitor::getEyePoint ( ) const [inline, virtual]

Get the eye point in local coordinates.

Note, not all NodeVisitor implement this method, it is mainly cull visitors which will implement.

Reimplemented in osgUtil::IntersectionVisitor, osgUtil::IntersectVisitor, and osgUtil::CullVisitor.

const FrameStamp* osg::NodeVisitor::getFrameStamp ( ) const [inline]

Get the FrameStamp that this traversal is associated with.

ImageRequestHandler* osg::NodeVisitor::getImageRequestHandler ( ) [inline]

Get the handler for image requests.

const ImageRequestHandler* osg::NodeVisitor::getImageRequestHandler ( ) const [inline]

Get the const handler for image requests.

Node::NodeMask osg::NodeVisitor::getNodeMaskOverride ( ) const [inline]

Get the NodeMaskOverride mask.

NodePath& osg::NodeVisitor::getNodePath ( ) [inline]

Get the non const NodePath from the top most node applied down to the current Node being visited.

Referenced by osgParticle::ParticleProcessor::getLocalToWorldMatrix(), and osgParticle::ParticleProcessor::getWorldToLocalMatrix().

const NodePath& osg::NodeVisitor::getNodePath ( ) const [inline]

Get the const NodePath from the top most node applied down to the current Node being visited.

Node::NodeMask osg::NodeVisitor::getTraversalMask ( ) const [inline]

Get the TraversalMask.

TraversalMode osg::NodeVisitor::getTraversalMode ( ) const [inline]

Get the traversal mode.

unsigned int osg::NodeVisitor::getTraversalNumber ( ) const [inline]

Get the traversal number.

Typically used to denote the frame count.

Referenced* osg::NodeVisitor::getUserData ( ) [inline]

Get user data.

const Referenced* osg::NodeVisitor::getUserData ( ) const [inline]

Get const user data.

virtual osg::Vec3 osg::NodeVisitor::getViewPoint ( ) const [inline, virtual]

Get the view point in local coordinates.

Note, not all NodeVisitor implement this method, it is mainly cull visitors which will implement.

Reimplemented in osgUtil::CullVisitor.

VisitorType osg::NodeVisitor::getVisitorType ( ) const [inline]

Get the VisitorType.

virtual const char* osg::NodeVisitor::libraryName ( ) const [inline, virtual]

return the library name/namespapce of the visitor's.

Should be defined by derived classes.

void osg::NodeVisitor::popFromNodePath ( ) [inline]

Method called by osg::Node::accept() method after a call to NodeVisitor::apply(..).

Note, the user does not typically call popFromNodePath() as it will be called automatically by the Node::accept() method.

Referenced by osgParticle::Program::accept(), osgParticle::Emitter::accept(), osgParticle::ParticleEffect::accept(), osgParticle::ParticleProcessor::accept(), and osgParticle::PrecipitationEffect::accept().

void osg::NodeVisitor::pushOntoNodePath ( Node node) [inline]

Method called by osg::Node::accept() method before a call to the NodeVisitor::apply(..).

The back of the list will, therefore, be the current node being visited inside the apply(..), and the rest of the list will be the parental sequence of nodes from the top most node applied down the graph to the current node. Note, the user does not typically call pushNodeOnPath() as it will be called automatically by the Node::accept() method.

Referenced by osgParticle::Program::accept(), osgParticle::Emitter::accept(), osgParticle::ParticleEffect::accept(), osgParticle::ParticleProcessor::accept(), and osgParticle::PrecipitationEffect::accept().

virtual void osg::NodeVisitor::reset ( ) [inline, virtual]
void osg::NodeVisitor::setDatabaseRequestHandler ( DatabaseRequestHandler handler) [inline]

Set the handler for database requests.

void osg::NodeVisitor::setFrameStamp ( FrameStamp fs) [inline]

Set the FrameStamp that this traversal is associated with.

void osg::NodeVisitor::setImageRequestHandler ( ImageRequestHandler handler) [inline]

Set the handler for image requests.

void osg::NodeVisitor::setNodeMaskOverride ( Node::NodeMask  mask) [inline]

Set the NodeMaskOverride mask.

Used in validNodeMask() to determine whether to operate on a node or its subgraph, by OR'ing NodeVisitor::_nodeMaskOverride with the Node's own Node::_nodeMask. Typically used to force on nodes which may have been switched off by their own Node::_nodeMask.

void osg::NodeVisitor::setTraversalMask ( Node::NodeMask  mask) [inline]

Set the TraversalMask of this NodeVisitor.

The TraversalMask is used by the NodeVisitor::validNodeMask() method to determine whether to operate on a node and its subgraph. validNodeMask() is called automatically in the Node::accept() method before any call to NodeVisitor::apply(), apply() is only ever called if validNodeMask returns true. Note, if NodeVisitor::_traversalMask is 0 then all operations will be switched off for all nodes. Whereas setting both _traversalMask and _nodeMaskOverride to 0xffffffff will allow a visitor to work on all nodes regardless of their own Node::_nodeMask state.

void osg::NodeVisitor::setTraversalMode ( TraversalMode  mode) [inline]

Set the traversal mode for Node::traverse() to use when deciding which children of a node to traverse.

If a NodeVisitor has been attached via setTraverseVisitor() and the new mode is not TRAVERSE_VISITOR then the attached visitor is detached. Default mode is TRAVERSE_NONE.

void osg::NodeVisitor::setTraversalNumber ( unsigned int  fn) [inline]

Set the traversal number.

Typically used to denote the frame count.

void osg::NodeVisitor::setUserData ( Referenced obj) [inline]

Set user data, data must be subclassed from Referenced to allow automatic memory handling.

If your own data isn't directly subclassed from Referenced then create an adapter object which points to your own objects and handles the memory addressing.

void osg::NodeVisitor::setVisitorType ( VisitorType  type) [inline]

Set the VisitorType, used to distinguish different visitors during traversal of the scene, typically used in the Node::traverse() method to select which behaviour to use for different types of traversal/visitors.

void osg::NodeVisitor::traverse ( Node node) [inline]

Method for handling traversal of a nodes.

If you intend to use the visitor for actively traversing the scene graph then make sure the accept() methods call this method unless they handle traversal directly.

References osg::Node::ascend(), and osg::Node::traverse().

bool osg::NodeVisitor::validNodeMask ( const osg::Node node) const [inline]

Method to called by Node and its subclass' Node::accept() method, if the result is true it is used to cull operations of nodes and their subgraphs.

Return true if the result of a bit wise and of the NodeVisitor::_traversalMask with the bit or between NodeVistor::_nodeMaskOverride and the Node::_nodeMask. default values for _traversalMask is 0xffffffff, _nodeMaskOverride is 0x0, and osg::Node::_nodeMask is 0xffffffff.

References osg::Node::getNodeMask().

Referenced by osgParticle::Program::accept(), osgParticle::Emitter::accept(), osgParticle::ParticleEffect::accept(), osgParticle::ParticleProcessor::accept(), and osgParticle::PrecipitationEffect::accept().


Member Data Documentation

unsigned int osg::NodeVisitor::_traversalNumber [protected]

Reimplemented in osgUtil::CullVisitor.


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

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Generated at Mon Oct 3 2011 12:39:43 for the OpenSceneGraph by doxygen 1.7.5.