#ifndef DIRECT_POSITION_BASED_SOLVER_FOR_STIFF_RODS_INTERFACE
#define DIRECT_POSITION_BASED_SOLVER_FOR_STIFF_RODS_INTERFACE

#include "Common/Common.h"

namespace PBD{
	// Implementation of "Direct Position-Based Solver for Stiff Rods" paper
	// (https://animation.rwth-aachen.de/publication/0557/)
	//
	//	Implemented by:
	//
	//	Crispin Deul
	//	Graduate School CE
	//	Technische Universitt Darmstadt
	//
	//  deul[at] gsc.tu-darmstadt.de
	//


	class RodSegment
	{
	public:
		virtual bool isDynamic() = 0;
		virtual Real Mass() = 0;
		virtual const Vector3r & InertiaTensor() = 0;
		virtual const Vector3r & Position() = 0;
		virtual const Quaternionr & Rotation() = 0;
	};

	class RodConstraint
	{
	public:
		using Vector6r = Eigen::Matrix<Real, 6, 1, Eigen::DontAlign>;
		virtual unsigned int segmentIndex(unsigned int i) = 0;
		virtual Eigen::Matrix<Real, 3, 4, Eigen::DontAlign> & getConstraintInfo() = 0;
		virtual Real getAverageSegmentLength() = 0;
		virtual Vector3r &getRestDarbouxVector() = 0;
		virtual Vector3r &getStiffnessCoefficientK() = 0;
		virtual Vector3r & getStretchCompliance() = 0;
		virtual Vector3r & getBendingAndTorsionCompliance() = 0;
	};
}
#endif