#ifndef _PlatformHierarchyInterface_H__
#define _PlatformHierarchyInterface_H__

#include <OgreSceneManager.h>
#include <OgrePrerequisites.h>
#include <OgreCamera.h>
#include <OgreRenderSystem.h>

#include "OgreSolidHalfBoundingBox.h"
#include "HierarchyInterface.h"
#include "OgrePlatformOcclusionQuery.h"

namespace Ogre {

/**	Class which implements a hierarchy interface for a specific type of hierarchy.
	@remark also provides methods for using occlusion queries on the hierarchy nodes
*/

class PlatformHierarchyInterface: public GtpVisibility::HierarchyInterface
{
public:
	/** Construction taking the current scene manager and the current rendersystem as argument
		@param sm current scene manager
		@param rsys current render system 
	*/
	PlatformHierarchyInterface(SceneManager *sm, RenderSystem *rsys);
	~PlatformHierarchyInterface();
		
	/** Returns next available occlusion query or creates new one.
		@return the next occlusion query
	*/
	GtpVisibility::OcclusionQuery *GetNextOcclusionQuery();
		
	/** Sets the current camera.
		@param cam the current camera
	*/
	void SetCamera(Camera *cam);
		
	/** Initialises this scene traverser for the current frame.
	@param root root of the hierarchy
		@param cam current camera
		@remark convenience method wich calls VisibilitySceneTraverser::initFrame,
		sets the current camera, and initialises the distance queue.
	*/
	void InitFrame(GtpVisibility::HierarchyNode *root, Ogre::Camera *cam);
	/** Checks if the node is visible from the current view frustum.
		@param node the current node
		@param intersects returns true if the current node intersects the near plane
	*/
	bool CheckFrustumVisible(GtpVisibility::HierarchyNode *node, bool &intersects);
	/** Sets pointer to the current scene manager.
		@param sm the scene manager 
	*/
	void SetSceneManager(SceneManager *sm);
	/** Sets pointer to the current render system 
		@param rsys the rendersystem 
	*/
	void SetRenderSystem(RenderSystem *rsys);
	/** Returns pointer to bounding box of node.
		@param node current hierarchy node
		@returns bounding box of current node
	*/
	virtual AxisAlignedBox *GetBoundingBox(GtpVisibility::HierarchyNode *node) = 0;
	/** Issue a occlusion query for this node. 
		@param node the current hierarchy node
		@returns occlusion query for this node
	*/
	GtpVisibility::OcclusionQuery *IssueOcclusionQuery(GtpVisibility::HierarchyNode *node);

protected:
	/** Deletes all occlusion queries.
	*/
	void DeleteQueries();
	/** Renders bounding box of specified node.
		@param box the bounding box of the scene node to be rendered 
	*/
	void RenderBoundingBox(AxisAlignedBox *box);
	/** Returns one half of the bounding box.
		@param half the half index of the bouding box (0 or 1)
	*/
	SolidHalfBoundingBox *GetSolidHalfBoundingBox(int half);

	/** two halfes of an aabb. 
	*/
	SolidHalfBoundingBox *mHalfBoundingBox[2];	

	SceneManager *mSceneManager;
	RenderSystem *mRenderSystem;

	Camera *mCamera;
	AxisAlignedBox mBox;

	std::vector<PlatformOcclusionQuery *> mOcclusionQueries;
};

} // namespace Ogre

#endif // PlatformHierarchyInterface_H