//
//  AttractorKernel.hpp
//  AwesomeAttractorND
//
//  Created by Joshua Moerman on 11/4/11.
//  Copyright 2011 Vadovas. All rights reserved.
//

#ifndef AwesomeAttractorND_AttractorKernel_hpp
#define AwesomeAttractorND_AttractorKernel_hpp

#include "Vectors.hpp"

class AttractorKernel {
public:
	virtual void iterate(VectorIterator begin, VectorIterator end, VectorIterator begin2) = 0;
};

template <typename T>
class StaticAttractorKernel : public AttractorKernel, public T {
public:
	virtual void iterate(VectorIterator begin, VectorIterator end, VectorIterator begin2){
		while (begin != end) {
			T::calculate(*begin2, *begin);
			++begin;
			++begin2;
		}
	}
};

struct Unravel {
	Unravel()
	: parameters()
	{
		parameters[0] = 0.761090;
		parameters[1] = 1.426758;
		parameters[2] = 1.516635;
		parameters[3] = -0.02366;
		parameters[4] = 2.398894;
		parameters[5] = -0.32422;
		parameters[6] = -2.12839;
	}
	
	void calculate(VectorConstRef vectorOld, VectorRef vectorNew){
		vectorNew[0] = parameters[0]*(vectorOld[2] + parameters[1]);
		vectorNew[1] = parameters[2]*(vectorOld[0] + parameters[3]);
		vectorNew[2] = parameters[4]*(vectorOld[1] + parameters[5]);
		
		const double dist = vectorNew[0]*vectorNew[0] + vectorNew[1]*vectorNew[1] + vectorNew[2]*vectorNew[2];
		
		if(dist > parameters[6]*parameters[6]) {
			const double sqrtDist = std::sqrt(dist);
			const double p = 1.0 - parameters[6] * (static_cast<int>(sqrtDist / parameters[6]) + 1.0) / sqrtDist;
			vectorNew[0] *= p;
			vectorNew[1] *= p;
			vectorNew[2] *= p;
		}
	}

protected:
	std::array<double, 7> parameters;
	static const size_t dimension = 3;
};

struct Lorenz {
	void calculate(VectorConstRef o, VectorRef n);
};

/*
 IDEA: explicitly instantiate StaticAttractorKernel<Unravel>, StaticAttractorKernel<Lorenz>, ...
 Thereby we have very little Unravel and Lorenz classes, which do only one thing.
 And an abstract base-class. And only iterate() is virtual, thus calculate() can be inlined!
 */

#endif