/*
-----------------------------------------------------------------------------
This source file is part of the GameTools Project
http://www.gametools.org

Author: Martin Szydlowski
-----------------------------------------------------------------------------
*/

#ifndef _OgreBvhRenderable_H__
#define _OgreBvhRenderable_H__

#include "OgreBvHierarchy.h"

namespace Ogre
{

	// interface which must be implemented by all objects which desire to be
	// placed in the kd-tree
	class BvhRenderable
	{
	public:
		BvhRenderable():mSide(BvhPlaneEvent::PES_BOTH), mClassified(false), mLastQueued(0), mBvHierarchy(0) {};
		virtual ~BvhRenderable()
		{
			if (mBvHierarchy)
				mBvHierarchy->remove(this);
		}

		// gather the information required for the creation of the kd-tree
		virtual void computeScene(BvhPlaneEventList& events, AxisAlignedBox& aabb, int& nObjects, bool includeChildren = true) = 0;

		// put all objects this element holds in the renedering queue
		virtual void queueObjects(Camera* cam, RenderQueue* queue, bool onlyShadowCasters) = 0;

		// place all entities in geometry queue (for CHC)
		virtual void getGeometryList(GeometryVector *geometryList) = 0;

		// return a bounding box enclosing all objects
		virtual AxisAlignedBox getBoundingBox() const = 0;

		// TODO: reconsider getters/setters !!!
		inline bool isClassified()
		{
			return mClassified;
		};
		inline void setClassified(bool q)
		{
			mClassified = q;
		};

		inline BvhPlaneEvent::Side getSide()
		{
			return mSide;
		};
		inline void setSide(BvhPlaneEvent::Side s)
		{
			mSide = s;
		};

		// funcions for attachment/detachment of renderables to/from the kd-tree
		inline bool isAttached()
		{
			return mLeaves.size() != 0;
		};
		// the following functions should work in O(log N)
		inline bool isAttached(BvHierarchy::LeafPtr leaf)
		{
			return mLeaves.find(leaf) != mLeaves.end();
		};
		inline bool attachTo(BvHierarchy::LeafPtr leaf, BvHierarchy * BvHierarchy)
		{
			if (mBvHierarchy == 0 || mBvHierarchy == BvHierarchy)
				mBvHierarchy = BvHierarchy;
			else
				return false;

			BvHierarchy::LeafSet::_Pairib p = mLeaves.insert(leaf);
			return p.second;
		};
		inline bool detachFrom(BvHierarchy::LeafPtr leaf)
		{
			bool success = (mLeaves.erase(leaf) == 1);
			if (mLeaves.size() == 0)
				mBvHierarchy = 0;

			return success;
		};

		inline bool isQueued(unsigned long currentFrame, Camera * currentCam)
		{
			if (mLastQueued == currentFrame && mLastCam == currentCam)
			{
				return true;
			}
			else
			{
				mLastQueued = currentFrame;
				mLastCam = currentCam;
				return false;
			}
		};

		BvHierarchy::LeafSet& getLeaves()
		{
			return mLeaves;
		};

	protected:
		// number of the frame in which this renderable was last queued for rendering
		unsigned long mLastQueued;
		// the camera for which this renderable was last queued for rendering
		Camera * mLastCam;
		
		// BvHierarchy to which this renderable is attached
		BvHierarchy * mBvHierarchy;
		// BvHierarchy leaves which overlap this renderable
		BvHierarchy::LeafSet mLeaves;

		// Flag for the SAH determining the "cheaper" side of the split plane
		BvhPlaneEvent::Side mSide;
		// Flag for the SAH which marks if this renderable was already placed in the list after a split
		bool mClassified;
	}; // class BvhRenderable

} // namespace Ogre

#endif // _OgreBvhRenderable_H__