/*

* This file is part of the GreasePad distribution (https://github.com/FraunhoferIOSB/GreasePad).

* Copyright (c) 2022-2025 Jochen Meidow, Fraunhofer IOSB

*

* This program is free software: you can redistribute it and/or modify

* it under the terms of the GNU 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 General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program. If not, see <https://www.gnu.org/licenses/>.

*/

#ifndef CONICS_H

#define CONICS_H

#include <Eigen/Core>

#include <utility>

//! Namespace Conic

namespace Conic {

using Eigen::Matrix3d;

using Eigen::Vector3d;

//! Base class for conics

class ConicBase

{

public:

explicit ConicBase(Matrix3d other); //!< Value constructor

[[nodiscard]] Matrix3d C() const { return CC;} //!< getter

[[nodiscard]] bool isCentral() const; //!< Check if conic has a central point

[[nodiscard]] std::pair<Vector3d,Vector3d> intersect( const Vector3d & l ) const; //!< Two intersection points with a straight line

private:

static Matrix3d skew(const Vector3d &x);

Matrix3d CC;

};

//! Ellipse

class Ellipse : public ConicBase

{

public:

explicit Ellipse(const Matrix3d &C ); //!< Value constructor (uncertain point)

[[nodiscard]] std::pair<Eigen::VectorXd,Eigen::VectorXd> poly( int N ) const; //!< Get N points on ellipse

[[nodiscard]] Vector3d polar( const Vector3d & x ) const { return C()*x; } //!< Compute polar l (straight line) for point x, i.e., l=C*x

};

//! Hyperbola

class Hyperbola : public ConicBase

{

public:

explicit Hyperbola(const Matrix3d &C); //!< Value constructor (uncertain straight line)

[[nodiscard]] Vector3d centerline() const; //!< Get straight line

[[nodiscard]] std::pair<double,double> lengthsSemiAxes() const; //!< Get lengths/2 of axes

[[nodiscard]] double angle_rad() const; //!< Get angle between straight line and x-axis in radians.

[[nodiscard]] double angle_deg() const; //!< Get angle between straight line and x-axis in degerees.

[[nodiscard]] Vector3d center() const; //!< Get center point of conic

private:

[[nodiscard]] std::pair<double,double> eigenvalues() const;

};

} // namespace Conic

#endif // CONICS_H