C++ Portal::intersects方法代码示例

	void DefaultZone::_checkNodeAgainstPortals(PCZSceneNode * pczsn, Portal * ignorePortal)
	{
		if (pczsn == mEnclosureNode ||
			pczsn->allowedToVisit() == false)
		{
			// don't do any checking of enclosure node versus portals
			return;
		}

		PCZone * connectedZone;
        for ( PortalList::iterator it = mPortals.begin(); it != mPortals.end(); ++it )
        {
			Portal * p = *it;
			//Check if the portal intersects the node
			if (p != ignorePortal &&
				p->intersects(pczsn) != Portal::NO_INTERSECT)
			{
				// node is touching this portal
				connectedZone = p->getTargetZone();
				// add zone to the nodes visiting zone list unless it is the home zone of the node
				if (connectedZone != pczsn->getHomeZone() &&
					!pczsn->isVisitingZone(connectedZone))
				{
					pczsn->addZoneToVisitingZonesMap(connectedZone);
					// tell the connected zone that the node is visiting it
					connectedZone->_addNode(pczsn);
					//recurse into the connected zone
					connectedZone->_checkNodeAgainstPortals(pczsn, p->getTargetPortal());
				}
			}
        }
	}

    /* The following function checks if a node has left it's current home zone.
	* This is done by checking each portal in the zone.  If the node has crossed
	* the portal, then the current zone is no longer the home zone of the node.  The
	* function then recurses into the connected zones.  Once a zone is found where
	* the node does NOT cross out through a portal, that zone is the new home zone.
	NOTE: For this function to work, the node must start out in the proper zone to
	      begin with!
	*/
    PCZone* DefaultZone::updateNodeHomeZone( PCZSceneNode * pczsn, bool allowBackTouches )
    {
		// default to newHomeZone being the current home zone
		PCZone * newHomeZone = pczsn->getHomeZone();

		// Check all portals of the start zone for crossings!
		Portal* portal;
		PortalList::iterator pi, piend;
		piend = mPortals.end();
		for (pi = mPortals.begin(); pi != piend; pi++)
		{
			portal = *pi;

			Portal::PortalIntersectResult pir = portal->intersects(pczsn);
			switch (pir)
			{
			default:
			case Portal::NO_INTERSECT: // node does not intersect portal - do nothing
			case Portal::INTERSECT_NO_CROSS:// node intersects but does not cross portal - do nothing				
				break;
			case Portal::INTERSECT_BACK_NO_CROSS:// node intersects but on the back of the portal
				if (allowBackTouches)
				{
					// node is on wrong side of the portal - fix if we're allowing backside touches
					if (portal->getTargetZone() != this &&
						portal->getTargetZone() != pczsn->getHomeZone())
					{
						// set the home zone of the node to the target zone of the portal
						pczsn->setHomeZone(portal->getTargetZone());
						// continue checking for portal crossings in the new zone
						newHomeZone = portal->getTargetZone()->updateNodeHomeZone(pczsn, false);
					}
				}
				break;
			case Portal::INTERSECT_CROSS:
				// node intersects and crosses the portal - recurse into that zone as new home zone
				if (portal->getTargetZone() != this &&
					portal->getTargetZone() != pczsn->getHomeZone())
				{
					// set the home zone of the node to the target zone of the portal
					pczsn->setHomeZone(portal->getTargetZone());
					// continue checking for portal crossings in the new zone
					newHomeZone = portal->getTargetZone()->updateNodeHomeZone(pczsn, true);
				}
				break;
			}
		}

		// return the new home zone
		return newHomeZone;

    }

    void DefaultZone::_findNodes( const Ray &t, 
							      PCZSceneNodeList &list, 
                                  PortalList &visitedPortals,
						 	      bool includeVisitors,
							      bool recurseThruPortals,
							      PCZSceneNode *exclude )
    {
		// if this zone has an enclosure, check against the enclosure AABB first
		if (mEnclosureNode)
		{
			std::pair<bool, Real> nsect = t.intersects(mEnclosureNode->_getWorldAABB());
			if (!nsect.first)
			{
				// AABB of zone does not intersect t, just return.
				return;
			}
		}

		// check nodes at home in this zone
	    PCZSceneNodeList::iterator it = mHomeNodeList.begin();
	    while ( it != mHomeNodeList.end() )
	    {
			PCZSceneNode * pczsn = *it;
			if ( pczsn != exclude )
			{
				// make sure node is not already in the list (might have been added in another
				// zone it was visiting)
				PCZSceneNodeList::iterator it2 = list.find(pczsn);
				if (it2 == list.end())
				{
					std::pair<bool, Real> nsect = t.intersects( pczsn -> _getWorldAABB() );
					if ( nsect.first )
					{
						list.insert( pczsn );
					}
				}
			}
		    ++it;
	    }

		if (includeVisitors)
		{
			// check visitor nodes
			PCZSceneNodeList::iterator iter = mVisitorNodeList.begin();
			while ( iter != mVisitorNodeList.end() )
			{
				PCZSceneNode * pczsn = *iter;
				if ( pczsn != exclude )
				{
					// make sure node is not already in the list (might have been added in another
					// zone it was visiting)
					PCZSceneNodeList::iterator it2 = list.find(pczsn);
					if (it2 == list.end())
					{
						std::pair<bool, Real> nsect = t.intersects( pczsn -> _getWorldAABB() );
						if ( nsect.first )
						{
							list.insert( pczsn );
						}
					}
				}
				++iter;
			}
		}

		// if asked to, recurse through portals
		if (recurseThruPortals)
		{
			PortalList::iterator pit = mPortals.begin();
			while ( pit != mPortals.end() )
			{
				Portal * portal = *pit;
				// check portal versus bounding box
				if (portal->intersects(t))
				{
					// make sure portal hasn't already been recursed through
					PortalList::iterator pit2 = std::find(visitedPortals.begin(), visitedPortals.end(), portal);
					if (pit2 == visitedPortals.end())
					{
						// save portal to the visitedPortals list
						visitedPortals.push_front(portal);
						// recurse into the connected zone 
						portal->getTargetZone()->_findNodes(t, 
															list, 
															visitedPortals,
															includeVisitors, 
															recurseThruPortals, 
															exclude);
					}
				}
				pit++;
			}
		}

	}