// This code is in the public domain -- castanyo@yahoo.es

#ifndef NV_MATH_KAHANSUM_H
#define NV_MATH_KAHANSUM_H

#include <nvmath/nvmath.h>

namespace nv
{

	class KahanSum
	{
	public:
		KahanSum() : accum(0.0f), err(0) {};
		
		void add(float f)
		{
			float compensated = f + err;
			float tmp = accum + compensated;
			err = accum - tmp;
			err += compensated;
			accum = tmp;
		}
		
		float sum() const
		{
			return accum;
		}
		
	private:
		float accum;
		float err;
	};
	
} // nv namespace


#endif // NV_MATH_KAHANSUM_H