// 02/08/02 November235: Particle System
#pragma once

class ParticleType;
class ParticleSystem;

#define COLLISION_NONE 0
#define COLLISION_DIE 1
#define COLLISION_BOUNCE 2

struct particle
{
	particle* nextpart;

	particle* m_pOverlay; // for making multi-layered particles

	ParticleType *pType;

	vec3_t origin;
	vec3_t velocity;
	vec3_t accel;
	vec3_t m_vecWind;

	int m_iEntIndex; // if non-zero, this particle is tied to the given entity

	float m_fRed;
	float m_fGreen;
	float m_fBlue;
	float m_fRedStep;
	float m_fGreenStep;
	float m_fBlueStep;

	float m_fAlpha;
	float m_fAlphaStep;

	float frame;
	float m_fFrameStep;

	float m_fAngle;
	float m_fAngleStep;

	float m_fSize;
	float m_fSizeStep;

	float m_fDrag;

	float age;
	float age_death;
	float age_spray;
};


class RandomRange
{
public:
	RandomRange() { m_fMin = m_fMax = 0; m_bDefined = false; }
	RandomRange(float fValue) { m_fMin = m_fMax = fValue; m_bDefined = true; }
	RandomRange(float fMin, float fMax) { m_fMin = fMin; m_fMax = fMax; m_bDefined = true; }
	RandomRange( char *szToken );

	float m_fMax;
	float m_fMin;
	bool m_bDefined;

	float GetInstance()
	{	return gEngfuncs.pfnRandomFloat(m_fMin, m_fMax);	}

	float GetOffset(float fBasis)
	{	return GetInstance()-fBasis;	}

	bool IsDefined()
	{ return m_bDefined; } //(m_fMin == 0 && m_fMax == 0); }
};

#define MAX_TYPENAME 30

class ParticleType
{
public:
	ParticleType( ParticleType *pNext = NULL );
	ParticleType(char *szFilename);

	bool m_bIsDefined; // is this ParticleType just a placeholder?

	int m_iRenderMode;
	int m_iDrawCond;
//	int m_iCollision;
	RandomRange m_Bounce;
	RandomRange m_BounceFriction;
	bool m_bBouncing;

	RandomRange m_Life;

	RandomRange m_StartAlpha;
	RandomRange m_EndAlpha;
	RandomRange m_StartRed;
	RandomRange m_EndRed;
	RandomRange m_StartGreen;
	RandomRange m_EndGreen;
	RandomRange m_StartBlue;
	RandomRange m_EndBlue;

	RandomRange m_StartSize;
	RandomRange m_SizeDelta;
	RandomRange m_EndSize;

	RandomRange m_StartFrame;
	RandomRange m_EndFrame;
	RandomRange m_FrameRate; // incompatible with EndFrame
	bool m_bEndFrame;

	RandomRange m_StartAngle;
	RandomRange m_AngleDelta;

	RandomRange m_SprayRate;
	RandomRange m_SprayForce;
	RandomRange m_SprayPitch;
	RandomRange m_SprayYaw;
	ParticleType *m_pSprayType;

	RandomRange m_Gravity;
	RandomRange m_WindStrength;
	RandomRange m_WindYaw;

	HSPRITE m_hSprite;
	ParticleType *m_pOverlayType;

	RandomRange m_Drag;

	ParticleType *m_pNext;

	char m_szName[MAX_TYPENAME];

	// here is a particle system. Add a (set of) particles according to this type, and initialise their values.
	particle* CreateParticle(ParticleSystem *pSys);//particle *pPart);

	// initialise this particle. Does not define velocity or age.
	void InitParticle(particle *pPart, ParticleSystem *pSys);
};

class ParticleSystem
{
public:
	ParticleSystem( int entindex, char *szFilename );//int iParticles );
//	ParticleSystem( int iParticles );
	~ParticleSystem( void );
	void AllocateParticles( int iParticles );
	void CalculateDistance();

//	ParticleType *GetMainType() { return GetType(m_szMainType); }
	ParticleType *GetType( const char *szName );
	ParticleType *AddPlaceholderType( const char *szName );
	ParticleType *ParseType( char *&szFile );

	cl_entity_t *GetEntity() { return gEngfuncs.GetEntityByIndex(m_iEntIndex); }

	static float c_fCosTable[360 + 90];
	static bool c_bCosTableInit;

	// General functions
	bool	UpdateSystem( float frametime, /*vec3_t &right, vec3_t &up,*/ int messagenum ); // If this function returns false, the manager deletes the system
	void	DrawSystem();//vec3_t &right, vec3_t &up);
	particle *ActivateParticle(); // adds one of the free particles to the active list, and returns it for initialisation.
								//MUST CHECK WHETHER THIS RESULT IS NULL!

	static float CosLookup(int angle) { return angle < 0? c_fCosTable[angle+360]: c_fCosTable[angle]; }
	static float SinLookup(int angle) { return angle < -90? c_fCosTable[angle+450]: c_fCosTable[angle+90]; }

	// returns false if the particle has died
	bool UpdateParticle( particle *part, float frametime );
	void DrawParticle( particle* part, vec3_t &right, vec3_t &up );

	// Utility functions that have to be public
//	bool ParticleIsVisible( particle* part );

	// Pointer to next system for linked list structure	
	ParticleSystem* m_pNextSystem;

	particle*		m_pActiveParticle;
	float			m_fViewerDist;
	int				m_iEntIndex;

private:
	// the block of allocated particles
	particle*		m_pAllParticles;
	// First particles in the linked list for the active particles and the dead particles
//	particle*		m_pActiveParticle;
	particle*		m_pFreeParticle;
	particle*		m_pMainParticle; // the "source" particle.

	ParticleType *m_pFirstType;

	ParticleType *m_pMainType;
	//char m_szMainType[MAX_TYPENAME]; // name of the main particle type
};