CWE-ou-minkata/Sources/Plasma/NucleusLib/pnTimer/plTimedValue.h

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*==LICENSE==*/

#ifndef plTimedValue_inc
#define plTimedValue_inc

#include "hsTimer.h"

class hsStream;

// plTimedValue
// To use, replace your member var of type T with plTimedValue<T>.
// You can then pretty much treat it as normal. To set it to interpolate
// to a new value over secs seconds, use Set(newVal, secs).
// For I/O, see plTimedSimple and plTimedCompound.
template <class T> class plTimedValue
{
protected:
	T			fGoal;
	T			fInit;
	double		fStart;
	hsScalar	fInvSecs;

public:
	plTimedValue() {}
	plTimedValue(const plTimedValue<T>& o) { Set(o, 0.f); }
	plTimedValue(const T& v) { Set(v, 0.f); }

	plTimedValue<T>& operator=(const plTimedValue<T>& o) { return Set(o, 0.f); }
	plTimedValue<T>& operator=(const T& v) { return Set(v, 0.f); }

	plTimedValue<T>& Set(const T& v, hsScalar secs=0);

	operator T () const { return Value(); }

	T Value() const;

};

// Read/Writable version of plTimedValue, for intrinsic types (e.g. int, float, bool).
// Must be a type that hsStream has an overloaded ReadSwap/WriteSwap defined.
template <class T> class plTimedSimple : public plTimedValue<T>
{
public:
	plTimedSimple<T>& operator=(const plTimedValue<T>& o) { return Set(o, 0.f); }
	plTimedSimple<T>& operator=(const T& v) { return Set(v, 0.f); }

	plTimedSimple<T>& Set(const T& v, hsScalar secs=0) { plTimedValue<T>::Set(v, secs); return *this; }

	void Read(hsStream* s);
	void Write(hsStream* s) const;
};

// Read/Writable version of plTimedValue, for compound types (e.g. hsVector3, hsColorRGBA).
// May be any type that has Read(hsStream*)/Write(hsStream*) defined.
template <class T> class plTimedCompound : public plTimedValue<T>
{
public:
	plTimedCompound<T>& operator=(const plTimedValue<T>& o) { return Set(o, 0.f); }
	plTimedCompound<T>& operator=(const T& v) { return Set(v, 0.f); }

	plTimedCompound<T>& Set(const T& v, hsScalar secs=0) { plTimedValue<T>::Set(v, secs); return *this; }

	void Read(hsStream* s);
	void Write(hsStream* s) const;
};

template <class T> 
plTimedValue<T>& plTimedValue<T>::Set(const T& v, hsScalar secs)
{
	if( secs <= 0 )
	{
		fGoal = fInit = v;
		fInvSecs = 0;
	}
	else
	{
		fInit = Value();
		fStart = hsTimer::GetSysSeconds();
		fInvSecs = 1.f / secs;
		fGoal = v;
	}
	return *this;
}

template <class T> 
T plTimedValue<T>::Value() const
{
	if( fInvSecs > 0 )
	{
		hsScalar t = (hsScalar)((hsTimer::GetSysSeconds() - fStart) * fInvSecs);
		hsAssert(t >= 0, "Moving back in time");

		if( t < 1.f )
			return fGoal * t + fInit * (1.f - t);

	}
	return fGoal;
}


template <class T> 
void plTimedSimple<T>::Read(hsStream* s)
{
	T val;
	s->ReadSwap(&val);
	Set(val, 0.f);
}

template <class T> 
void plTimedSimple<T>::Write(hsStream* s) const
{
	T val = Value();
	s->WriteSwap(val);
}

template <class T> 
void plTimedCompound<T>::Read(hsStream* s)
{
	T val;
	val.Read(s);
	Set(val, 0.f);
}

template <class T> 
void plTimedCompound<T>::Write(hsStream* s) const
{
	T val = Value();
	val.Write(s);
}

#endif // plTimedValue_inc