/*! \file piquaternion.h
 * \ingroup Math
 * \~\brief
 * \~english Quaternion
 * \~russian Кватернион
 */
/*
	PIP - Platform Independent Primitives
	Class for quaternions
	Ivan Pelipenko peri4ko@yandex.ru, Andrey Bychkov work.a.b@yandex.ru

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

	This program 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 Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef PIQUATERNION_H
#define PIQUATERNION_H

#include "pimathmatrix.h"

class PIP_EXPORT PIQuaternion {
	friend PIP_EXPORT PIQuaternion operator*(const PIQuaternion & q0, const PIQuaternion & q1);
	friend PIP_EXPORT PIQuaternion operator*(const double & a, const PIQuaternion & q);

public:
	PIQuaternion(const PIMathVectorT3d & u = PIMathVectorT3d(), double a = 0.);

	PIQuaternion conjugate() const { return PIQuaternion(-vector(), scalar()); }
	PIQuaternion rotated(const PIMathVectorT3d & u, double a) const;
	void rotate(const PIMathVectorT3d & u, double a);
	void normalize();

	double & scalar() { return q[0]; }
	double scalar() const { return q[0]; }
	PIMathVectorT3d vector() const { return PIMathVectorT3d({q[1], q[2], q[3]}); }

	PIMathVectorT3d eyler() const;
	PIMathMatrixT33d rotationMatrix() const;
	void axis(PIMathVectorT3d * ret) const;

	static PIQuaternion fromEyler(double ax, double ay, double az);
	static PIQuaternion fromRotationMatrix(const PIMathMatrixT33d & m);
	static PIQuaternion fromAngles(double ax, double ay, double az);
	static PIQuaternion fromAngles2(double ax, double ay, double az);

protected:
	double q[4];
};

PIP_EXPORT PIQuaternion operator*(const double & a, const PIQuaternion & q);
PIP_EXPORT PIQuaternion operator*(const PIQuaternion & q0, const PIQuaternion & q1);
inline PIQuaternion operator+(const PIQuaternion & q0, const PIQuaternion & q1) {
	return PIQuaternion(q0.vector() + q1.vector(), q0.scalar() + q1.scalar());
}
inline PIQuaternion operator-(const PIQuaternion & q0, const PIQuaternion & q1) {
	return PIQuaternion(q0.vector() - q1.vector(), q0.scalar() - q1.scalar());
}
inline PIQuaternion operator-(const PIQuaternion & q0) {
	return PIQuaternion(-q0.vector(), -q0.scalar());
}

#endif // PIQUATERNION_H