///////////////////////////////////////////////////////////////////////  
//	CSpeedGrassRT Class
//
//	(c) 2003 IDV, Inc.
//
//	*** INTERACTIVE DATA VISUALIZATION (IDV) PROPRIETARY INFORMATION ***
//
//	This software is supplied under the terms of a license agreement or
//	nondisclosure agreement with Interactive Data Visualization and may
//	not be copied or disclosed except in accordance with the terms of
//	that agreement.
//
//      Copyright (c) 2001-2003 IDV, Inc.
//      All Rights Reserved.
//
//		IDV, Inc.
//		1233 Washington St. Suite 610
//		Columbia, SC 29201
//		Voice: (803) 799-1699
//		Fax:   (803) 931-0320
//		Web:   http://www.idvinc.com

#pragma once

#include <vector>
#include <d3dx9.h>


///////////////////////////////////////////////////////////////////////  
///	class CSpeedGrassRT declaration
class CSpeedGrassRT
{
public:
		CSpeedGrassRT( );
		~CSpeedGrassRT( );


        ///////////////////////////////////////////////////////////////////////  
        ///  struct SBlade
		struct SBlade
		{
			SBlade( );

			// geometry
			float				m_afPos[3];
			float				m_afNormal[3];
			float				m_fSize;
			unsigned char		m_ucWhichTexture;

			// wind
			float				m_fNoise;
			float				m_fThrow;

			// color
			float				m_afBottomColor[3];
			float				m_afTopColor[3];
		};


        ///////////////////////////////////////////////////////////////////////  
        ///  struct SRegion
		struct SRegion
		{
			SRegion( );
			~SRegion( );

			// dimensions
			float					m_afCenter[3];
			float					m_afMin[3];
			float					m_afMax[3];
									
			// culling				
			bool					m_bCulled;
			float					m_fCullingRadius;

			// grass/brush blades
			std::vector<SBlade>		m_vBlades;
			LPDIRECT3DVERTEXBUFFER9	m_pVertexBuffer;
		};

		void				DeleteRegions(void);
		const SRegion*		GetRegions(unsigned int& uiNumRegions);
		bool				ParseSffFile(const char* pFilename, unsigned int uiRows, unsigned int uiCols);
		bool				ParseBsfFile(const char* pFilename, unsigned int nNumBlades, unsigned int uiRows, unsigned int uiCols, float fCollisionDistance = 0.0f);
		bool				CustomPlacement(unsigned int uiRows, unsigned int uiCols);


        ///////////////////////////////////////////////////////////////////////  
        //  Geometry

static	const float*		GetUnitBillboard(void)											{ return m_afUnitBillboard; }


        ///////////////////////////////////////////////////////////////////////  
        //  LOD

static  void		        GetLodParams(float& fFarDistance, float& fTransitionLength);
static  void		        SetLodParams(float fFarDistance, float fTransitionLength);


        ///////////////////////////////////////////////////////////////////////  
        //  Culling

		bool				AllRegionsAreCulled(void) const									{ return m_bAllRegionsCulled; }
		void				Cull(void);


        ///////////////////////////////////////////////////////////////////////  
        //  Wind

static	void				SetWindDirection(const float* pWindDir);
static	const float*		GetWindDirection(void);


        ///////////////////////////////////////////////////////////////////////  
        //  Camera

static  const float*		GetCameraPos(void);
//static  void                SetCamera(const float* pPosition, const double* pModelviewMatrix);
static  void                SetCamera(const float* pPosition, const float* pModelviewMatrix);
static	void				SetPerspective(float fAspectRatio, float fFieldOfView);


        ///////////////////////////////////////////////////////////////////////  
        //  Terrain hugging

virtual float				Color(float fX, float fY, const float* pNormal, float* pTopColor, float* pBottomColor) const { return 0.0f; }	
virtual float				Height(float fX, float fY, float* pNormal) const { return 0.0f; }	

protected:

		void				CreateRegions(const std::vector<SBlade>& vSceneBlades, float fCollisionDistance = 0.0f);
static	void				ComputeFrustum(void);
static	void				ComputeUnitBillboard(void);
		void				ConvertCoordsToCell(const float* pCoords, int* pGridCoords) const;
		unsigned int		GetRegionIndex(unsigned int uiRow, unsigned int uiCol) const	{ return uiRow * m_nNumRegionCols + uiCol; }
static	bool				OutsideFrustum(SRegion* pRegion);

		// general
static	float				m_fLodFarDistance;
static	float				m_fLodTransitionLength;
static	float				m_afUnitBillboard[12];
static	float				m_afWindDir[4];

		// regions
		int					m_nNumRegions;
		int					m_nNumRegionCols;
		int					m_nNumRegionRows;
		SRegion*			m_pRegions;

		// camera
static	float				m_afCameraOut[3];
static	float				m_afCameraRight[3];
static	float				m_afCameraUp[3];
static	float				m_afCameraPos[3];
static	float				m_fFieldOfView;
static	float				m_fAspectRatio;

		// culling
static	float				m_afFrustumBox[6];
static	float				m_afFrustumMin[2];
static	float				m_afFrustumMax[2];
static	float				m_afFrustumPlanes[5][4];
		float				m_afBoundingBox[6];
		bool				m_bAllRegionsCulled;
};