Interpolate.h

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/*
===========================================================================

Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company. 

This file is part of the Doom 3 GPL Source Code (?Doom 3 Source Code?).  

Doom 3 Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Doom 3 Source Code is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Doom 3 Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.

===========================================================================
*/

#ifndef __MATH_INTERPOLATE_H__
#define __MATH_INTERPOLATE_H__

/*
==============================================================================================

        Linear interpolation.

==============================================================================================
*/

template< class type >
class idInterpolate {
public:
                                                idInterpolate();

        void                            Init( const float startTime, const float duration, const type &startValue, const type &endValue );
        void                            SetStartTime( float time ) { this->startTime = time; }
        void                            SetDuration( float duration ) { this->duration = duration; }
        void                            SetStartValue( const type &startValue ) { this->startValue = startValue; }
        void                            SetEndValue( const type &endValue ) { this->endValue = endValue; }

        type                            GetCurrentValue( float time ) const;
        bool                            IsDone( float time ) const { return ( time >= startTime + duration ); }

        float                           GetStartTime( void ) const { return startTime; }
        float                           GetEndTime( void ) const { return startTime + duration; }
        float                           GetDuration( void ) const { return duration; }
        const type &            GetStartValue( void ) const { return startValue; }
        const type &            GetEndValue( void ) const { return endValue; }

private:
        float                           startTime;
        float                           duration;
        type                            startValue;
        type                            endValue;
        mutable float           currentTime;
        mutable type            currentValue;
};

/*
====================
idInterpolate::idInterpolate
====================
*/
template< class type >
ID_INLINE idInterpolate<type>::idInterpolate() {
        currentTime = startTime = duration = 0;
        memset( &currentValue, 0, sizeof( currentValue ) );
        startValue = endValue = currentValue;
}

/*
====================
idInterpolate::Init
====================
*/
template< class type >
ID_INLINE void idInterpolate<type>::Init( const float startTime, const float duration, const type &startValue, const type &endValue ) {
        this->startTime = startTime;
        this->duration = duration;
        this->startValue = startValue;
        this->endValue = endValue;
        this->currentTime = startTime - 1;
        this->currentValue = startValue;
}

/*
====================
idInterpolate::GetCurrentValue
====================
*/
template< class type >
ID_INLINE type idInterpolate<type>::GetCurrentValue( float time ) const {
        float deltaTime;

        deltaTime = time - startTime;
        if ( time != currentTime ) {
                currentTime = time;
                if ( deltaTime <= 0 ) {
                        currentValue = startValue;
                } else if ( deltaTime >= duration ) {
                        currentValue = endValue;
                } else {
                        currentValue = startValue + ( endValue - startValue ) * ( (float) deltaTime / duration );
                }
        }
        return currentValue;
}


/*
==============================================================================================

        Continuous interpolation with linear acceleration and deceleration phase.
        The velocity is continuous but the acceleration is not.

==============================================================================================
*/

template< class type >
class idInterpolateAccelDecelLinear  {
public:
                                                idInterpolateAccelDecelLinear();

        void                            Init( const float startTime, const float accelTime, const float decelTime, const float duration, const type &startValue, const type &endValue );
        void                            SetStartTime( float time ) { startTime = time; Invalidate(); }
        void                            SetStartValue( const type &startValue ) { this->startValue = startValue; Invalidate(); }
        void                            SetEndValue( const type &endValue ) { this->endValue = endValue; Invalidate(); }

        type                            GetCurrentValue( float time ) const;
        type                            GetCurrentSpeed( float time ) const;
        bool                            IsDone( float time ) const { return ( time >= startTime + accelTime + linearTime + decelTime ); }

        float                           GetStartTime( void ) const { return startTime; }
        float                           GetEndTime( void ) const { return startTime + accelTime + linearTime + decelTime; }
        float                           GetDuration( void ) const { return accelTime + linearTime + decelTime; }
        float                           GetAcceleration( void ) const { return accelTime; }
        float                           GetDeceleration( void ) const { return decelTime; }
        const type &            GetStartValue( void ) const { return startValue; }
        const type &            GetEndValue( void ) const { return endValue; }

private:
        float                           startTime;
        float                           accelTime;
        float                           linearTime;
        float                           decelTime;
        type                            startValue;
        type                            endValue;
        mutable idExtrapolate<type> extrapolate;

        void                            Invalidate( void );
        void                            SetPhase( float time ) const;
};

/*
====================
idInterpolateAccelDecelLinear::idInterpolateAccelDecelLinear
====================
*/
template< class type >
ID_INLINE idInterpolateAccelDecelLinear<type>::idInterpolateAccelDecelLinear() {
        startTime = accelTime = linearTime = decelTime = 0;
        memset( &startValue, 0, sizeof( startValue ) );
        endValue = startValue;
}

/*
====================
idInterpolateAccelDecelLinear::Init
====================
*/
template< class type >
ID_INLINE void idInterpolateAccelDecelLinear<type>::Init( const float startTime, const float accelTime, const float decelTime, const float duration, const type &startValue, const type &endValue ) {
        type speed;

        this->startTime = startTime;
        this->accelTime = accelTime;
        this->decelTime = decelTime;
        this->startValue = startValue;
        this->endValue = endValue;

        if ( duration <= 0.0f ) {
                return;
        }

        if ( this->accelTime + this->decelTime > duration ) {
                this->accelTime = this->accelTime * duration / ( this->accelTime + this->decelTime );
                this->decelTime = duration - this->accelTime;
        }
        this->linearTime = duration - this->accelTime - this->decelTime;
        speed = ( endValue - startValue ) * ( 1000.0f / ( (float) this->linearTime + ( this->accelTime + this->decelTime ) * 0.5f ) );

        if ( this->accelTime ) {
                extrapolate.Init( startTime, this->accelTime, startValue, ( startValue - startValue ), speed, EXTRAPOLATION_ACCELLINEAR );
        } else if ( this->linearTime ) {
                extrapolate.Init( startTime, this->linearTime, startValue, ( startValue - startValue ), speed, EXTRAPOLATION_LINEAR );
        } else {
                extrapolate.Init( startTime, this->decelTime, startValue, ( startValue - startValue ), speed, EXTRAPOLATION_DECELLINEAR );
        }
}

/*
====================
idInterpolateAccelDecelLinear::Invalidate
====================
*/
template< class type >
ID_INLINE void idInterpolateAccelDecelLinear<type>::Invalidate( void ) {
        extrapolate.Init( 0, 0, extrapolate.GetStartValue(), extrapolate.GetBaseSpeed(), extrapolate.GetSpeed(), EXTRAPOLATION_NONE );
}

/*
====================
idInterpolateAccelDecelLinear::SetPhase
====================
*/
template< class type >
ID_INLINE void idInterpolateAccelDecelLinear<type>::SetPhase( float time ) const {
        float deltaTime;

        deltaTime = time - startTime;
        if ( deltaTime < accelTime ) {
                if ( extrapolate.GetExtrapolationType() != EXTRAPOLATION_ACCELLINEAR ) {
                        extrapolate.Init( startTime, accelTime, startValue, extrapolate.GetBaseSpeed(), extrapolate.GetSpeed(), EXTRAPOLATION_ACCELLINEAR );
                }
        } else if ( deltaTime < accelTime + linearTime ) {
                if ( extrapolate.GetExtrapolationType() != EXTRAPOLATION_LINEAR ) {
                        extrapolate.Init( startTime + accelTime, linearTime, startValue + extrapolate.GetSpeed() * ( accelTime * 0.001f * 0.5f ), extrapolate.GetBaseSpeed(), extrapolate.GetSpeed(), EXTRAPOLATION_LINEAR );
                }
        } else {
                if ( extrapolate.GetExtrapolationType() != EXTRAPOLATION_DECELLINEAR ) {
                        extrapolate.Init( startTime + accelTime + linearTime, decelTime, endValue - ( extrapolate.GetSpeed() * ( decelTime * 0.001f * 0.5f ) ), extrapolate.GetBaseSpeed(), extrapolate.GetSpeed(), EXTRAPOLATION_DECELLINEAR );
                }
        }
}

/*
====================
idInterpolateAccelDecelLinear::GetCurrentValue
====================
*/
template< class type >
ID_INLINE type idInterpolateAccelDecelLinear<type>::GetCurrentValue( float time ) const {
        SetPhase( time );
        return extrapolate.GetCurrentValue( time );
}

/*
====================
idInterpolateAccelDecelLinear::GetCurrentSpeed
====================
*/
template< class type >
ID_INLINE type idInterpolateAccelDecelLinear<type>::GetCurrentSpeed( float time ) const {
        SetPhase( time );
        return extrapolate.GetCurrentSpeed( time );
}


/*
==============================================================================================

        Continuous interpolation with sinusoidal acceleration and deceleration phase.
        Both the velocity and acceleration are continuous.

==============================================================================================
*/

template< class type >
class idInterpolateAccelDecelSine  {
public:
                                                idInterpolateAccelDecelSine();

        void                            Init( const float startTime, const float accelTime, const float decelTime, const float duration, const type &startValue, const type &endValue );
        void                            SetStartTime( float time ) { startTime = time; Invalidate(); }
        void                            SetStartValue( const type &startValue ) { this->startValue = startValue; Invalidate(); }
        void                            SetEndValue( const type &endValue ) { this->endValue = endValue; Invalidate(); }

        type                            GetCurrentValue( float time ) const;
        type                            GetCurrentSpeed( float time ) const;
        bool                            IsDone( float time ) const { return ( time >= startTime + accelTime + linearTime + decelTime ); }

        float                           GetStartTime( void ) const { return startTime; }
        float                           GetEndTime( void ) const { return startTime + accelTime + linearTime + decelTime; }
        float                           GetDuration( void ) const { return accelTime + linearTime + decelTime; }
        float                           GetAcceleration( void ) const { return accelTime; }
        float                           GetDeceleration( void ) const { return decelTime; }
        const type &            GetStartValue( void ) const { return startValue; }
        const type &            GetEndValue( void ) const { return endValue; }

private:
        float                           startTime;
        float                           accelTime;
        float                           linearTime;
        float                           decelTime;
        type                            startValue;
        type                            endValue;
        mutable idExtrapolate<type> extrapolate;

        void                            Invalidate( void );
        void                            SetPhase( float time ) const;
};

/*
====================
idInterpolateAccelDecelSine::idInterpolateAccelDecelSine
====================
*/
template< class type >
ID_INLINE idInterpolateAccelDecelSine<type>::idInterpolateAccelDecelSine() {
        startTime = accelTime = linearTime = decelTime = 0;
        memset( &startValue, 0, sizeof( startValue ) );
        endValue = startValue;
}

/*
====================
idInterpolateAccelDecelSine::Init
====================
*/
template< class type >
ID_INLINE void idInterpolateAccelDecelSine<type>::Init( const float startTime, const float accelTime, const float decelTime, const float duration, const type &startValue, const type &endValue ) {
        type speed;

        this->startTime = startTime;
        this->accelTime = accelTime;
        this->decelTime = decelTime;
        this->startValue = startValue;
        this->endValue = endValue;

        if ( duration <= 0.0f ) {
                return;
        }

        if ( this->accelTime + this->decelTime > duration ) {
                this->accelTime = this->accelTime * duration / ( this->accelTime + this->decelTime );
                this->decelTime = duration - this->accelTime;
        }
        this->linearTime = duration - this->accelTime - this->decelTime;
        speed = ( endValue - startValue ) * ( 1000.0f / ( (float) this->linearTime + ( this->accelTime + this->decelTime ) * idMath::SQRT_1OVER2 ) );

        if ( this->accelTime ) {
                extrapolate.Init( startTime, this->accelTime, startValue, ( startValue - startValue ), speed, EXTRAPOLATION_ACCELSINE );
        } else if ( this->linearTime ) {
                extrapolate.Init( startTime, this->linearTime, startValue, ( startValue - startValue ), speed, EXTRAPOLATION_LINEAR );
        } else {
                extrapolate.Init( startTime, this->decelTime, startValue, ( startValue - startValue ), speed, EXTRAPOLATION_DECELSINE );
        }
}

/*
====================
idInterpolateAccelDecelSine::Invalidate
====================
*/
template< class type >
ID_INLINE void idInterpolateAccelDecelSine<type>::Invalidate( void ) {
        extrapolate.Init( 0, 0, extrapolate.GetStartValue(), extrapolate.GetBaseSpeed(), extrapolate.GetSpeed(), EXTRAPOLATION_NONE );
}

/*
====================
idInterpolateAccelDecelSine::SetPhase
====================
*/
template< class type >
ID_INLINE void idInterpolateAccelDecelSine<type>::SetPhase( float time ) const {
        float deltaTime;

        deltaTime = time - startTime;
        if ( deltaTime < accelTime ) {
                if ( extrapolate.GetExtrapolationType() != EXTRAPOLATION_ACCELSINE ) {
                        extrapolate.Init( startTime, accelTime, startValue, extrapolate.GetBaseSpeed(), extrapolate.GetSpeed(), EXTRAPOLATION_ACCELSINE );
                }
        } else if ( deltaTime < accelTime + linearTime ) {
                if ( extrapolate.GetExtrapolationType() != EXTRAPOLATION_LINEAR ) {
                        extrapolate.Init( startTime + accelTime, linearTime, startValue + extrapolate.GetSpeed() * ( accelTime * 0.001f * idMath::SQRT_1OVER2 ), extrapolate.GetBaseSpeed(), extrapolate.GetSpeed(), EXTRAPOLATION_LINEAR );
                }
        } else {
                if ( extrapolate.GetExtrapolationType() != EXTRAPOLATION_DECELSINE ) {
                        extrapolate.Init( startTime + accelTime + linearTime, decelTime, endValue - ( extrapolate.GetSpeed() * ( decelTime * 0.001f * idMath::SQRT_1OVER2 ) ), extrapolate.GetBaseSpeed(), extrapolate.GetSpeed(), EXTRAPOLATION_DECELSINE );
                }
        }
}

/*
====================
idInterpolateAccelDecelSine::GetCurrentValue
====================
*/
template< class type >
ID_INLINE type idInterpolateAccelDecelSine<type>::GetCurrentValue( float time ) const {
        SetPhase( time );
        return extrapolate.GetCurrentValue( time );
}

/*
====================
idInterpolateAccelDecelSine::GetCurrentSpeed
====================
*/
template< class type >
ID_INLINE type idInterpolateAccelDecelSine<type>::GetCurrentSpeed( float time ) const {
        SetPhase( time );
        return extrapolate.GetCurrentSpeed( time );
}

#endif /* !__MATH_INTERPOLATE_H__ */