300 lines
14 KiB
C++
300 lines
14 KiB
C++
/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2005 Robert Osfield
|
|
*
|
|
* This library is open source and may be redistributed and/or modified under
|
|
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
|
|
* (at your option) any later version. The full license is in LICENSE file
|
|
* included with this distribution, and on the openscenegraph.org website.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* OpenSceneGraph Public License for more details.
|
|
*/
|
|
|
|
#ifndef OSG_NODEVISITOR
|
|
#define OSG_NODEVISITOR 1
|
|
|
|
#include <osg/Node>
|
|
#include <osg/Matrix>
|
|
#include <osg/FrameStamp>
|
|
|
|
namespace osg {
|
|
|
|
class Billboard;
|
|
class ClearNode;
|
|
class ClipNode;
|
|
class CoordinateSystemNode;
|
|
class Geode;
|
|
class Group;
|
|
class LightSource;
|
|
class LOD;
|
|
class MatrixTransform;
|
|
class OccluderNode;
|
|
class PagedLOD;
|
|
class PositionAttitudeTransform;
|
|
class Projection;
|
|
class ProxyNode;
|
|
class Sequence;
|
|
class Switch;
|
|
class TexGenNode;
|
|
class Transform;
|
|
|
|
/** 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. */
|
|
class OSG_EXPORT NodeVisitor : public virtual Referenced
|
|
{
|
|
public:
|
|
|
|
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
|
|
};
|
|
|
|
NodeVisitor(TraversalMode tm=TRAVERSE_NONE);
|
|
|
|
NodeVisitor(VisitorType type,TraversalMode tm=TRAVERSE_NONE);
|
|
|
|
virtual ~NodeVisitor();
|
|
|
|
/** Method to call to reset visitor. Useful if your visitor accumulates
|
|
state during a traversal, and you plan to reuse the visitor.
|
|
To flush that state for the next traversal: call reset() prior
|
|
to each traversal.*/
|
|
virtual void reset() {}
|
|
|
|
|
|
/** 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.*/
|
|
inline void setVisitorType(VisitorType type) { _visitorType = type; }
|
|
|
|
/** Get the VisitorType.*/
|
|
inline VisitorType getVisitorType() const { return _visitorType; }
|
|
|
|
/** Set the traversal number. Typically used to denote the frame count.*/
|
|
inline void setTraversalNumber(int fn) { _traversalNumber = fn; }
|
|
|
|
/** Get the traversal number. Typically used to denote the frame count.*/
|
|
inline int getTraversalNumber() const { return _traversalNumber; }
|
|
|
|
/** Set the FrameStamp that this traversal is associated with.*/
|
|
inline void setFrameStamp(FrameStamp* fs) { _frameStamp = fs; }
|
|
|
|
/** Get the FrameStamp that this traversal is associated with.*/
|
|
inline const FrameStamp* getFrameStamp() const { return _frameStamp.get(); }
|
|
|
|
|
|
/** 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.*/
|
|
inline void setTraversalMask(Node::NodeMask mask) { _traversalMask = mask; }
|
|
|
|
/** Get the TraversalMask.*/
|
|
inline Node::NodeMask getTraversalMask() const { return _traversalMask; }
|
|
|
|
/** 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.*/
|
|
inline void setNodeMaskOverride(Node::NodeMask mask) { _nodeMaskOverride = mask; }
|
|
|
|
/** Get the NodeMaskOverride mask.*/
|
|
inline Node::NodeMask getNodeMaskOverride() const { return _nodeMaskOverride; }
|
|
|
|
/** 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. */
|
|
inline bool validNodeMask(const osg::Node& node) const
|
|
{
|
|
return (getTraversalMask() & (getNodeMaskOverride() | node.getNodeMask()))!=0;
|
|
}
|
|
|
|
/** 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.*/
|
|
inline void setTraversalMode(TraversalMode mode) { _traversalMode = mode; }
|
|
|
|
/** Get the traversal mode.*/
|
|
inline TraversalMode getTraversalMode() const { return _traversalMode; }
|
|
|
|
/**
|
|
* Set user data, data must be subclased 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.
|
|
*/
|
|
inline void setUserData(Referenced* obj) { _userData = obj; }
|
|
|
|
/** Get user data.*/
|
|
inline Referenced* getUserData() { return _userData.get(); }
|
|
|
|
/** Get const user data.*/
|
|
inline const Referenced* getUserData() const { return _userData.get(); }
|
|
|
|
|
|
/** 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.*/
|
|
inline void traverse(Node& node)
|
|
{
|
|
if (_traversalMode==TRAVERSE_PARENTS) node.ascend(*this);
|
|
else if (_traversalMode!=TRAVERSE_NONE) node.traverse(*this);
|
|
}
|
|
|
|
/** 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.*/
|
|
inline void pushOntoNodePath(Node* node) { if (_traversalMode!=TRAVERSE_PARENTS) _nodePath.push_back(node); else _nodePath.insert(_nodePath.begin(),node); }
|
|
|
|
/** 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.*/
|
|
inline void popFromNodePath() { if (_traversalMode!=TRAVERSE_PARENTS) _nodePath.pop_back(); else _nodePath.erase(_nodePath.begin()); }
|
|
|
|
/** Get the non const NodePath from the top most node applied down
|
|
* to the current Node being visited.*/
|
|
NodePath& getNodePath() { return _nodePath; }
|
|
|
|
/** Get the const NodePath from the top most node applied down
|
|
* to the current Node being visited.*/
|
|
const NodePath& getNodePath() const { return _nodePath; }
|
|
|
|
/** Get the eye point in local coordinates.
|
|
* Note, not all NodeVisitor implement this method, it is mainly cull visitors which will implement.*/
|
|
virtual osg::Vec3 getEyePoint() const { return Vec3(0.0f,0.0f,0.0f); }
|
|
|
|
/** 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.*/
|
|
virtual float getDistanceToEyePoint(const Vec3& /*pos*/, bool /*useLODScale*/) const { return 0.0f; }
|
|
|
|
/** 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.*/
|
|
virtual float getDistanceFromEyePoint(const Vec3& /*pos*/, bool /*useLODScale*/) const { return 0.0f; }
|
|
|
|
virtual void apply(Node& node) { traverse(node);}
|
|
|
|
virtual void apply(Geode& node) { apply((Node&)node); }
|
|
virtual void apply(Billboard& node) { apply((Geode&)node); }
|
|
|
|
virtual void apply(Group& node) { apply((Node&)node); }
|
|
|
|
virtual void apply(ProxyNode& node) { apply((Group&)node); }
|
|
|
|
virtual void apply(Projection& node) { apply((Group&)node); }
|
|
|
|
virtual void apply(CoordinateSystemNode& node) { apply((Group&)node); }
|
|
|
|
virtual void apply(ClipNode& node) { apply((Group&)node); }
|
|
virtual void apply(TexGenNode& node) { apply((Group&)node); }
|
|
virtual void apply(LightSource& node) { apply((Group&)node); }
|
|
|
|
virtual void apply(Transform& node) { apply((Group&)node); }
|
|
virtual void apply(MatrixTransform& node) { apply((Transform&)node); }
|
|
virtual void apply(PositionAttitudeTransform& node) { apply((Transform&)node); }
|
|
|
|
virtual void apply(Switch& node) { apply((Group&)node); }
|
|
virtual void apply(Sequence& node) { apply((Group&)node); }
|
|
virtual void apply(LOD& node) { apply((Group&)node); }
|
|
virtual void apply(PagedLOD& node) { apply((LOD&)node); }
|
|
virtual void apply(ClearNode& node) { apply((Group&)node); }
|
|
virtual void apply(OccluderNode& node) { apply((Group&)node); }
|
|
|
|
|
|
/** Callback for managing database paging, such as generated by PagedLOD nodes.*/
|
|
class DatabaseRequestHandler : public osg::Referenced
|
|
{
|
|
public:
|
|
virtual void requestNodeFile(const std::string& fileName,osg::Group* group, float priority, const FrameStamp* framestamp) = 0;
|
|
|
|
protected:
|
|
virtual ~DatabaseRequestHandler() {}
|
|
};
|
|
|
|
/** Set the handler for database requests.*/
|
|
void setDatabaseRequestHandler(DatabaseRequestHandler* handler) { _databaseRequestHandler = handler; }
|
|
|
|
/** Get the handler for database requests.*/
|
|
DatabaseRequestHandler* getDatabaseRequestHandler() { return _databaseRequestHandler.get(); }
|
|
|
|
/** Get the const handler for database requests.*/
|
|
const DatabaseRequestHandler* getDatabaseRequestHandler() const { return _databaseRequestHandler.get(); }
|
|
|
|
|
|
|
|
protected:
|
|
|
|
VisitorType _visitorType;
|
|
int _traversalNumber;
|
|
|
|
ref_ptr<FrameStamp> _frameStamp;
|
|
|
|
TraversalMode _traversalMode;
|
|
Node::NodeMask _traversalMask;
|
|
Node::NodeMask _nodeMaskOverride;
|
|
|
|
NodePath _nodePath;
|
|
|
|
ref_ptr<Referenced> _userData;
|
|
|
|
ref_ptr<DatabaseRequestHandler> _databaseRequestHandler;
|
|
|
|
};
|
|
|
|
|
|
/** Convenience functor for assisting visiting of arrays of osg::Node's.*/
|
|
struct NodeAcceptOp
|
|
{
|
|
NodeVisitor& _nv;
|
|
NodeAcceptOp(NodeVisitor& nv):_nv(nv) {}
|
|
void operator () (Node* node) { node->accept(_nv); }
|
|
void operator () (ref_ptr<Node> node) { node->accept(_nv); }
|
|
};
|
|
|
|
}
|
|
|
|
#endif
|