#ifndef __RENDERQUEUE_H
#define __RENDERQUEUE_H

#include "common.h"
#include "Timer/PerfTimer.h"


namespace CHCDemoEngine 
{

class RenderState;
class Camera;


/** Defines a bucket for scene entities that have the same properties.
*/
struct RenderQueueBucket
{
	/** should test for all texture format parameters, 
	    but we as use the same format for all textures they differ only in size
	*/
	int mTexHeight;
	int mTexWidth;

	bool mHasTexture;
	bool mAlphaTestEnabled;
	bool mCullFaceEnabled;

	/// minimal distance to the camera
	float mMinDistance;

	ShapeContainer mShapes;
};


/** This class implements a render queue that sorts renderable geometry in order
	to minimize state changes while approximately keeping front-to-back order
	The implementation roughly follows the suggested implemenation on Tom Forsyth's article
	on render state changes. It requires sorting only on bucket level and therefore has very
	low overhead
*/
class RenderQueue
{
public:

	/** Default constructor
	*/
	RenderQueue();
	/** Constructor taking a render queue
	*/
	RenderQueue(RenderState *state, Camera *cam);

	~RenderQueue();
	/** Enqueues an entity.
	*/
	void Enqueue(SceneEntity *entity);
	/** Sets the current render state
	*/
	void SetRenderState(RenderState *state);
	/** Sets the current render state
	*/
	void SetCamera(Camera *cam);
	/** Returns the number of entries currently in the queue.
	*/
	inline int GetSize() const { return (int)mNumEntries; }
	/** Renders and clears the queue.
	*/
	void Apply();


protected:

	void Sort();

	void Enqueue(Shape *shape);

	inline bool FitsInBucket(Shape *shape, size_t idx) const;
	/** Clears the render queue
	*/
	void Clear();
	/** Renders the contents of the render queue.
	*/
	void Render();
	/** Prints the current state of the render queue.
	*/
	void Print();


	///////////

	RenderState *mState;
	
	Camera *mCamera;
	//SceneEntityContainer mEntities;
	int mMinSizeForSorting;

	/// each bucket contains objects with similar materials that don't cause a hard state change
	std::vector<RenderQueueBucket *> mBuckets;

	int mNumEntries;
};


}

#endif