//========= Copyright © 1996-2005, Valve Corporation, All rights reserved. ============//
//
// Purpose: 
//
// $NoKeywords: $
//=============================================================================//
#include "cbase.h"
#include "ivieweffects.h"
#include "shake.h"
#include "hud_macros.h"
#include "isaverestore.h"
#include "view_shared.h"
#include "iviewrender.h"
#include "viewrender.h"
#include "con_nprint.h"
#include "saverestoretypes.h"

// memdbgon must be the last include file in a .cpp file!!!
#include "tier0/memdbgon.h"

extern IntroData_t *g_pIntroData;


// Arbitrary limit so that bad entity logic on the server can't consume tons of memory on the client.
#define MAX_SHAKES		32


//-----------------------------------------------------------------------------
// Purpose: Screen fade variables
//-----------------------------------------------------------------------------
struct screenfade_t
{
	float		Speed;		// How fast to fade (tics / second) (+ fade in, - fade out)
	float		End;		// When the fading hits maximum
	float		Reset;		// When to reset to not fading (for fadeout and hold)
	byte		r, g, b, alpha;	// Fade color
	int			Flags;		// Fading flags

	DECLARE_SIMPLE_DATADESC();
};

BEGIN_SIMPLE_DATADESC( screenfade_t )
	DEFINE_FIELD( Speed,	FIELD_FLOAT ),
	DEFINE_FIELD( End,		FIELD_TIME ),
	DEFINE_FIELD( Reset,	FIELD_TIME ),
	DEFINE_FIELD( r,		FIELD_CHARACTER ),
	DEFINE_FIELD( g,		FIELD_CHARACTER ),
	DEFINE_FIELD( b,		FIELD_CHARACTER ),
	DEFINE_FIELD( alpha,	FIELD_CHARACTER ),
	DEFINE_FIELD( Flags,	FIELD_INTEGER ),
END_DATADESC()


//-----------------------------------------------------------------------------
// Purpose: Screen shake variables
//-----------------------------------------------------------------------------
struct screenshake_t 
{
	float	endtime;
	float	duration;
	float	amplitude;
	float	frequency;
	float	nextShake;
	Vector	offset;
	float	angle;

	DECLARE_SIMPLE_DATADESC();
};

BEGIN_SIMPLE_DATADESC( screenshake_t )
	DEFINE_FIELD( endtime,		FIELD_TIME ),
	DEFINE_FIELD( duration,		FIELD_FLOAT ),
	DEFINE_FIELD( amplitude,	FIELD_FLOAT ),
	DEFINE_FIELD( frequency,	FIELD_FLOAT ),
	DEFINE_FIELD( nextShake,	FIELD_TIME ),
	DEFINE_FIELD( offset,		FIELD_VECTOR ),
	DEFINE_FIELD( angle,		FIELD_FLOAT ),
END_DATADESC()


//-----------------------------------------------------------------------------
// Purpose: Implements the view effects interface for the client .dll
//-----------------------------------------------------------------------------
class CViewEffects : public IViewEffects
{
public:

	~CViewEffects()
	{
		ClearAllFades();
	}

	virtual void	Init( void );
	virtual void	LevelInit( void );
	virtual void	GetFadeParams( int context, byte *r, byte *g, byte *b, byte *a, bool *blend );
	virtual void	CalcShake( void );
	virtual void	ApplyShake( Vector& origin, QAngle& angles, float factor );

	virtual void	Shake( ScreenShake_t &data );
	virtual void	Fade( ScreenFade_t &data );
	virtual void	ClearPermanentFades( void );
	virtual void	FadeCalculate( void );
	virtual void	ClearAllFades( void );

	// Save / Restore
	virtual void	Save( ISave *pSave );
	virtual void	Restore( IRestore *pRestore, bool fCreatePlayers );

private:

	void ClearAllShakes();
	screenshake_t *FindLongestShake();

	CUtlVector<screenfade_t *>	m_FadeList;

	CUtlVector<screenshake_t *>	m_ShakeList;
	Vector m_vecShakeAppliedOffset;
	float m_flShakeAppliedAngle;

	int							m_FadeColorRGBA[4];
	bool						m_bModulate;

	friend void CC_Shake_Stop();
};

static CViewEffects g_ViewEffects;
IViewEffects *vieweffects = ( IViewEffects * )&g_ViewEffects;

// Callback function to call at end of screen m_Fade.
static int s_nCallbackParameter;
static void ( *s_pfnFadeDoneCallback )( int parm1 );


//-----------------------------------------------------------------------------
// Purpose: 
// Input  : *pszName - 
//			iSize - 
//			*pbuf - 
// Output : static int
//-----------------------------------------------------------------------------
void __MsgFunc_Shake( bf_read &msg )
{
	ScreenShake_t shake;

	shake.command	= msg.ReadByte();
	shake.amplitude = msg.ReadFloat();
	shake.frequency = msg.ReadFloat();
	shake.duration	= msg.ReadFloat();

	g_ViewEffects.Shake( shake );
}

//-----------------------------------------------------------------------------
// Purpose: 
// Input  : *pszName - 
//			iSize - 
//			*pbuf - 
// Output : static int
//-----------------------------------------------------------------------------
void __MsgFunc_Fade( bf_read &msg )
{
	ScreenFade_t fade;

	fade.duration = msg.ReadShort(); // fade lasts this long
	fade.holdTime = msg.ReadShort(); // fade lasts this long
	fade.fadeFlags = msg.ReadShort(); // fade type (in / out)
	fade.r = msg.ReadByte(); // fade red
	fade.g = msg.ReadByte(); // fade green
	fade.b = msg.ReadByte(); // fade blue
	fade.a = msg.ReadByte(); // fade blue

	g_ViewEffects.Fade( fade );
}

//-----------------------------------------------------------------------------
// Purpose: 
//-----------------------------------------------------------------------------
void CViewEffects::Init( void )
{
	HOOK_MESSAGE( Shake );
	HOOK_MESSAGE( Fade );
}

//-----------------------------------------------------------------------------
// Purpose: 
//-----------------------------------------------------------------------------
void CViewEffects::LevelInit( void )
{
	ClearAllShakes();
	ClearAllFades();
}


static ConVar shake_show( "shake_show", "0", 0, "Displays a list of the active screen shakes." );
static ConCommand shake_stop("shake_stop", CC_Shake_Stop, "Stops all active screen shakes.\n", FCVAR_CHEAT );

//-----------------------------------------------------------------------------
// Purpose: Stops all active screen shakes.
//-----------------------------------------------------------------------------
void CC_Shake_Stop()
{
	g_ViewEffects.ClearAllShakes();
}


//-----------------------------------------------------------------------------
// Purpose: Apply noise to the eye position.
// UNDONE: Feedback a bit of this into the view model position.  It shakes too much
//-----------------------------------------------------------------------------
void CViewEffects::CalcShake( void )
{
	float	fraction, freq;

	// We'll accumulate the aggregate shake for this frame into these data members.
	m_vecShakeAppliedOffset.Init(0, 0, 0);
	m_flShakeAppliedAngle = 0;

	bool bShow = shake_show.GetBool();

	int nShakeCount = m_ShakeList.Count();
	for ( int nShake = nShakeCount - 1; nShake >= 0; nShake-- )
	{
		screenshake_t *pShake = m_ShakeList.Element( nShake );

		if ( pShake->endtime == 0 )
		{
			// Shouldn't be any such shakes in the list.
			Assert( false );
			continue;
		}

		if ( ( gpGlobals->curtime > pShake->endtime ) || 
			pShake->duration <= 0 || 
			pShake->amplitude <= 0 || 
			pShake->frequency <= 0 )
		{
			// Retire this shake.
			delete m_ShakeList.Element( nShake );
			m_ShakeList.FastRemove( nShake );
			continue;
		}

		if ( bShow )
		{
			con_nprint_t np;
			np.time_to_live = 2.0f;
			np.fixed_width_font = true;
			np.color[0] = 1.0;
			np.color[1] = 0.8;
			np.color[2] = 0.1;
			np.index = nShake + 2;

			engine->Con_NXPrintf( &np, "%02d: dur(%8.2f) amp(%8.2f) freq(%8.2f)", nShake + 1, (double)pShake->duration, (double)pShake->amplitude, (double)pShake->frequency );
		}

		if ( gpGlobals->curtime > pShake->nextShake )
		{
			// Higher frequency means we recalc the extents more often and perturb the display again
			pShake->nextShake = gpGlobals->curtime + (1.0f / pShake->frequency);

			// Compute random shake extents (the shake will settle down from this)
			for (int i = 0; i < 3; i++ )
			{
				pShake->offset[i] = random->RandomFloat( -pShake->amplitude, pShake->amplitude );
			}

			pShake->angle = random->RandomFloat( -pShake->amplitude*0.25, pShake->amplitude*0.25 );
		}

		// Ramp down amplitude over duration (fraction goes from 1 to 0 linearly with slope 1/duration)
		fraction = ( pShake->endtime - gpGlobals->curtime ) / pShake->duration;

		// Ramp up frequency over duration
		if ( fraction )
		{
			freq = (pShake->frequency / fraction);
		}
		else
		{
			freq = 0;
		}

		// square fraction to approach zero more quickly
		fraction *= fraction;

		// Sine wave that slowly settles to zero
		fraction = fraction * sin( gpGlobals->curtime * freq );
		
		// Add to view origin
		m_vecShakeAppliedOffset += pShake->offset * fraction;
		
		// Add to roll
		m_flShakeAppliedAngle += pShake->angle * fraction;

		// Drop amplitude a bit, less for higher frequency shakes
		pShake->amplitude -= pShake->amplitude * ( gpGlobals->frametime / (pShake->duration * pShake->frequency) );
	}
}


//-----------------------------------------------------------------------------
// Purpose: Apply the current screen shake to this origin/angles.  Factor is the amount to apply
//  This is so you can blend in part of the shake
// Input  : origin - 
//			angles - 
//			factor - 
//-----------------------------------------------------------------------------
void CViewEffects::ApplyShake( Vector& origin, QAngle& angles, float factor )
{
	VectorMA( origin, factor, m_vecShakeAppliedOffset, origin );
	angles.z += m_flShakeAppliedAngle * factor;
}


//-----------------------------------------------------------------------------
// Purpose: Zeros out all active screen shakes.
//-----------------------------------------------------------------------------
void CViewEffects::ClearAllShakes()
{
	int nShakeCount = m_ShakeList.Count();
	for ( int i = 0; i < nShakeCount; i++ )
	{
		delete m_ShakeList.Element( i );
	}

	m_ShakeList.Purge();
}


//-----------------------------------------------------------------------------
// Purpose: Returns the shake with the longest duration. This is the shake we
//			use anytime we get an amplitude or frequency command, because the
//			most likely case is that we're modifying a shake with a long
//			duration rather than a brief shake caused by an explosion, etc.
//-----------------------------------------------------------------------------
screenshake_t *CViewEffects::FindLongestShake()
{
	screenshake_t *pLongestShake = NULL;

	int nShakeCount = m_ShakeList.Count();
	for ( int i = 0; i < nShakeCount; i++ )
	{
		screenshake_t *pShake = m_ShakeList.Element( i );
		if ( pShake && ( !pLongestShake || ( pShake->duration > pLongestShake->duration ) ) )
		{
			pLongestShake = pShake;
		}
	}

	return pLongestShake;
}


//-----------------------------------------------------------------------------
// Purpose: Message hook to parse ScreenShake messages
// Input  : pszName - 
//			iSize - 
//			pbuf - 
// Output : 
//-----------------------------------------------------------------------------
void CViewEffects::Shake( ScreenShake_t &data )
{
	if ( ( data.command == SHAKE_START ) && ( m_ShakeList.Count() < MAX_SHAKES ) )
	{
		screenshake_t *pNewShake = new screenshake_t;
			
		pNewShake->amplitude = data.amplitude;
		pNewShake->frequency = data.frequency;
		pNewShake->duration = data.duration;
		pNewShake->nextShake = 0;
		pNewShake->endtime = gpGlobals->curtime + data.duration;

		m_ShakeList.AddToTail( pNewShake );
	}
	else if ( data.command == SHAKE_STOP)
	{
		ClearAllShakes();
	}
	else if ( data.command == SHAKE_AMPLITUDE )
	{
		// Look for the most likely shake to modify.
		screenshake_t *pShake = FindLongestShake();
		if ( pShake )
		{
			pShake->amplitude = data.amplitude;
		}
	}
	else if ( data.command == SHAKE_FREQUENCY )
	{
		// Look for the most likely shake to modify.
		screenshake_t *pShake = FindLongestShake();
		if ( pShake )
		{
			pShake->frequency = data.frequency;
		}
	}
}


//-----------------------------------------------------------------------------
// Purpose: Message hook to parse ScreenFade messages
// Input  : *pszName - 
//			iSize - 
//			*pbuf - 
// Output : int
//-----------------------------------------------------------------------------
void CViewEffects::Fade( ScreenFade_t &data )
{
	// Create a new fade and append it to the list
	screenfade_t *pNewFade = new screenfade_t;
	pNewFade->End	= data.duration * (1.0f/(float)(1<<SCREENFADE_FRACBITS));
	pNewFade->Reset	= data.holdTime * (1.0f/(float)(1<<SCREENFADE_FRACBITS));
	pNewFade->r		= data.r;
	pNewFade->g		= data.g;
	pNewFade->b		= data.b;
	pNewFade->alpha	= data.a;
	pNewFade->Flags	= data.fadeFlags;
	pNewFade->Speed	= 0;

	// Calc fade speed
	if ( data.duration > 0 )
	{
		if ( data.fadeFlags & FFADE_OUT )
		{
			if ( pNewFade->End )
			{
				pNewFade->Speed = -(float)pNewFade->alpha / pNewFade->End;
			}

			pNewFade->End	+= gpGlobals->curtime;
			pNewFade->Reset	+= pNewFade->End;
		}
		else
		{
			if ( pNewFade->End )
			{
				pNewFade->Speed = (float)pNewFade->alpha / pNewFade->End;
			}

			pNewFade->Reset	+= gpGlobals->curtime;
			pNewFade->End	+= pNewFade->Reset;
		}
	}

	if ( data.fadeFlags & FFADE_PURGE )
	{
		ClearAllFades();
	}

	m_FadeList.AddToTail( pNewFade );
}

//-----------------------------------------------------------------------------
// Purpose: Compute the overall color & alpha of the fades
//-----------------------------------------------------------------------------
void CViewEffects::FadeCalculate( void )
{
	// Cycle through all fades and remove any that have finished (work backwards)
	int i;
	int iSize = m_FadeList.Size();
	for (i = iSize-1; i >= 0; i-- )
	{
		screenfade_t *pFade = m_FadeList[i];

		// Keep pushing reset time out indefinitely
		if ( pFade->Flags & FFADE_STAYOUT )
		{
			pFade->Reset = gpGlobals->curtime + 0.1;
		}

		// All done?
		if ( ( gpGlobals->curtime > pFade->Reset ) && ( gpGlobals->curtime > pFade->End ) )
		{
			// User passed in a callback function, call it now
			if ( s_pfnFadeDoneCallback )
			{
				s_pfnFadeDoneCallback( s_nCallbackParameter );
				s_pfnFadeDoneCallback = NULL;
				s_nCallbackParameter = 0;
			}

			// Remove this Fade from the list
			m_FadeList.FindAndRemove( pFade );
			delete pFade;
		}
	}

	m_bModulate = false;
	m_FadeColorRGBA[0] = m_FadeColorRGBA[1] = m_FadeColorRGBA[2] = m_FadeColorRGBA[3] = 0;

	// Cycle through all fades in the list and calculate the overall color/alpha
	for ( i = 0; i < m_FadeList.Size(); i++ )
	{
		screenfade_t *pFade = m_FadeList[i];

		// Color
		m_FadeColorRGBA[0] += pFade->r;
		m_FadeColorRGBA[1] += pFade->g;
		m_FadeColorRGBA[2] += pFade->b;

		// Fading...
		int iFadeAlpha;
		if ( pFade->Flags & (FFADE_OUT|FFADE_IN) )
		{
			iFadeAlpha = pFade->Speed * ( pFade->End - gpGlobals->curtime );
			if ( pFade->Flags & FFADE_OUT )
			{
				iFadeAlpha += pFade->alpha;
			}
			iFadeAlpha = min( iFadeAlpha, pFade->alpha );
			iFadeAlpha = max( 0, iFadeAlpha );
		}
		else
		{
			iFadeAlpha = pFade->alpha;
		}

		// Use highest alpha
		if ( iFadeAlpha > m_FadeColorRGBA[3] )
		{
			m_FadeColorRGBA[3] = iFadeAlpha;
		}

		// Modulate?
		if ( pFade->Flags & FFADE_MODULATE )
		{
			m_bModulate = true;
		}
	}

	// Divide colors
	if ( m_FadeList.Size() )
	{
		m_FadeColorRGBA[0] /= m_FadeList.Size();
		m_FadeColorRGBA[1] /= m_FadeList.Size();
		m_FadeColorRGBA[2] /= m_FadeList.Size();
	}
}

//-----------------------------------------------------------------------------
// Purpose: Clear only the permanent fades in our fade list
//-----------------------------------------------------------------------------
void CViewEffects::ClearPermanentFades( void )
{
	int iSize = m_FadeList.Size();
	for (int i =  iSize-1; i >= 0; i-- )
	{
		screenfade_t *pFade = m_FadeList[i];

		if ( pFade->Flags & FFADE_STAYOUT )
		{
			// Destroy this fade
			m_FadeList.FindAndRemove( pFade );
			delete pFade;
		}
	}
}

//-----------------------------------------------------------------------------
// Purpose: Purge & delete all fades in the queue
//-----------------------------------------------------------------------------
void CViewEffects::ClearAllFades( void )
{
	int iSize = m_FadeList.Size();
	for (int i =  iSize-1; i >= 0; i-- )
	{
		delete m_FadeList[i];
	}
	m_FadeList.Purge();
}

//-----------------------------------------------------------------------------
// Purpose: 
// Input  : context - Which call to Render is this ( CViewSetup::context )
//			*r - 
//			*g - 
//			*b - 
//			*a - 
//			*blend - 
//-----------------------------------------------------------------------------
void CViewEffects::GetFadeParams( int context, byte *r, byte *g, byte *b, byte *a, bool *blend )
{
	// If the intro is overriding our fade, use that instead
	if ( g_pIntroData && g_pIntroData->m_flCurrentFadeColor[3] )
	{
		*r = g_pIntroData->m_flCurrentFadeColor[0];
		*g = g_pIntroData->m_flCurrentFadeColor[1];
		*b = g_pIntroData->m_flCurrentFadeColor[2];
		*a = g_pIntroData->m_flCurrentFadeColor[3];
		*blend = false;
		return;
	}

	FadeCalculate();

	*r = m_FadeColorRGBA[0];
	*g = m_FadeColorRGBA[1];
	*b = m_FadeColorRGBA[2];
	*a = m_FadeColorRGBA[3];
	*blend = m_bModulate;
}

//-----------------------------------------------------------------------------
// Purpose: 
// Input  : *pSave - 
//-----------------------------------------------------------------------------
void CViewEffects::Save( ISave *pSave )
{
	// Save the view fades
	int iCount = m_FadeList.Count();
	pSave->WriteInt( &iCount );
	for ( int i = 0; i < iCount; i++ )
	{
		pSave->StartBlock();
		pSave->WriteAll( m_FadeList[i] );
		pSave->EndBlock();
	}

	// Save the view shakes
	iCount = m_ShakeList.Count();
	pSave->WriteInt( &iCount );
	for ( i = 0; i < iCount; i++ )
	{
		pSave->StartBlock();
		pSave->WriteAll( m_ShakeList[i] );
		pSave->EndBlock();
	}
}

//-----------------------------------------------------------------------------
// Purpose: 
// Input  : *pRestore - 
//			fCreatePlayers - 
//-----------------------------------------------------------------------------
void CViewEffects::Restore( IRestore *pRestore, bool fCreatePlayers )
{
	CGameSaveRestoreInfo *pSaveData = pRestore->GetGameSaveRestoreInfo();

	// View effects is a singleton so we only need to restore it once,
	// from the level that we are going into.
	if( !pSaveData->levelInfo.fUseLandmark )
	{
		ClearAllFades();
		ClearAllShakes();

		// Read in the view fades
		int iCount = pRestore->ReadInt();
		for ( int i = 0; i < iCount; i++ )
		{
			screenfade_t *pNewFade = new screenfade_t;

			pRestore->StartBlock();
			pRestore->ReadAll( pNewFade );
			pRestore->EndBlock();

			m_FadeList.AddToTail( pNewFade );
		}

		// Read in the view shakes
		iCount = pRestore->ReadInt();
		for ( i = 0; i < iCount; i++ )
		{
			screenshake_t *pNewShake = new screenshake_t;

			pRestore->StartBlock();
			pRestore->ReadAll( pNewShake );
			pRestore->EndBlock();

			m_ShakeList.AddToTail( pNewShake );
		}
	}	
}

//====================================================================================================
// CLIENTSIDE VIEW EFFECTS SAVE/RESTORE 
//====================================================================================================
static short VIEWEFFECTS_SAVE_RESTORE_VERSION = 2;

class CViewEffectsSaveRestoreBlockHandler :	public CDefSaveRestoreBlockHandler
{
	struct QueuedItem_t;
public:
	CViewEffectsSaveRestoreBlockHandler()
	{
	}

	const char *GetBlockName()
	{
		return "ViewEffects";
	}

	//---------------------------------

	virtual void PreSave( CSaveRestoreData * ) 
	{
	}
	
	//---------------------------------

	virtual void Save( ISave *pSave ) 
	{
		vieweffects->Save( pSave );
	}
	
	//---------------------------------

	virtual void WriteSaveHeaders( ISave *pSave )
	{
		pSave->WriteShort( &VIEWEFFECTS_SAVE_RESTORE_VERSION );
	}
	
	//---------------------------------

	virtual void PostSave() 
	{
	}
	
	//---------------------------------

	virtual void PreRestore() 
	{
	}
	
	//---------------------------------

	virtual void ReadRestoreHeaders( IRestore *pRestore )
	{
		// No reason why any future version shouldn't try to retain backward compatability. The default here is to not do so.
		short version = pRestore->ReadShort();
		m_bDoLoad = ( version == VIEWEFFECTS_SAVE_RESTORE_VERSION );
	}

	//---------------------------------
	
	virtual void Restore( IRestore *pRestore, bool fCreatePlayers ) 
	{
		if ( m_bDoLoad )
		{
			vieweffects->Restore( pRestore, fCreatePlayers );
		}
	}
	
	//---------------------------------
	
	virtual void PostRestore() 
	{
	}
	
private:
	bool	m_bDoLoad;
};

//-----------------------------------------------------------------------------

CViewEffectsSaveRestoreBlockHandler g_ViewEffectsSaveRestoreBlockHandler;

ISaveRestoreBlockHandler *GetViewEffectsRestoreBlockHandler()
{
	return &g_ViewEffectsSaveRestoreBlockHandler;
}
