//============ Copyright (c) Valve Corporation, All rights reserved. ============

#ifndef VOLUME_CULLER_H
#define VOLUME_CULLER_H

#ifdef _WIN32
#pragma once
#endif

#include "vector.h"
#include "vplane.h"
#include "ssemath.h"

class CVolumeCuller : public CAlignedNewDelete< 16 >
{
public:
	inline CVolumeCuller() { Clear(); }

	inline void Clear() { m_nNumInclusionVolumePlanes = 0; m_bHasExclusionFrustum = false; m_bHasBaseFrustum = false; m_bCullSmallObjects = false; ClearCullCheckStats(); }

	inline bool IsValid() const { return m_bHasExclusionFrustum || ( m_nNumInclusionVolumePlanes != 0 ); }
	
	// Returns false if box is culled.
	bool CheckBox( const VectorAligned &mins, const VectorAligned &maxs ) const;
	bool CheckBox( const Vector &mins, const Vector &maxs ) const;
	bool CheckBoxCenterHalfDiagonal( const VectorAligned &center, const VectorAligned &halfDiagonal ) const;
						
	enum 
	{ 
		cNumBaseFrustumPlanes = 6,

		cNumExclusionFrustumPlanes = 6,
		
		// cMaxInclusionVolumePlanes must at least have enough room to hold the planes output by CSunLightManager::ComputeCullingVolumePlanes().
		cMaxInclusionVolumePlanes = 12 
	};

	// Base frustum
	inline bool HasBaseFrustum() const { return m_bHasBaseFrustum; }
	// Specify NULL to disable the base frustum.
	void SetBaseFrustumPlanes( const VPlane *pPlanes );

	void GetBaseFrustumPlanes( VPlane *pBasePlanes ) const;
	int GetNumBaseFrustumPlanes() const { return cNumBaseFrustumPlanes; }
	
	// Exclusion frustum
	inline bool HasExclusionFrustum() const { return m_bHasExclusionFrustum; }
	// Specify NULL to disable the exclusion frustum.
	void SetExclusionFrustumPlanes( const VPlane *pPlanes );
	
	int GetNumExclusionFrustumPlanes() const { return cNumExclusionFrustumPlanes; }
	const fltx4 *GetExclusionFrustumPlanes() const { return m_ExclusionFrustumPlanes; }
	
	// Inclusion volume
	inline bool HasInclusionVolume() const { return m_nNumInclusionVolumePlanes != 0; }
	// Specify NULL to disable the inclusion volume.
	void SetInclusionVolumePlanes( const VPlane *pPlanes, uint nNumPlanes );
	
	int GetNumInclusionVolumePlanes() const { return m_nNumInclusionVolumePlanes; }
	const fltx4 *GetInclusionVolumePlanes() const { return m_InclusionVolumePlanes; }

	bool GetCullSmallObjects() const { return m_bCullSmallObjects; }
	float GetSmallObjectCullVolumeThreshold() const { return m_flSmallObjectCullVolumeThreshold; }

	void SetCullSmallObjects(bool bCullSmallObjects, float flCullVolumeThreshold ) { m_bCullSmallObjects = bCullSmallObjects; m_flSmallObjectCullVolumeThreshold = flCullVolumeThreshold; }
			
	struct CullCheckStats_t
	{
		uint m_nTotalAABB;
		uint m_nTotalAABBPassed;

		uint m_nTotalCenterHalfDiagonal;
		uint m_nTotalCenterHalfDiagonalPassed;
	};

	inline void ClearCullCheckStats() { memset( &m_Stats, 0, sizeof( m_Stats ) ); }
	inline CullCheckStats_t &GetStats() const { return m_Stats; }
				
private:
	// Objects which are not inside or touch the base planes are culled.
	fourplanes_t	m_baseplanes[2];

	// Objects totally within the exclusion frustum are culled (i.e. anything completely inside the exclusion region must be culled).
	fltx4 m_ExclusionFrustumPlanes[cNumExclusionFrustumPlanes];
	
	// Objects totally outside of the inclusion region are culled (i.e. anything touching or inside the occlusion region cannot be culled).
	fltx4 m_InclusionVolumePlanes[cMaxInclusionVolumePlanes];

	uint m_nNumInclusionVolumePlanes;
		
	bool m_bHasBaseFrustum : 1;
	bool m_bHasExclusionFrustum : 1;

	bool m_bCullSmallObjects : 1;
	float m_flSmallObjectCullVolumeThreshold;

	mutable CullCheckStats_t m_Stats;
};

#endif // VOLUME_CULLER_H