LinEquation.h

 
#ifndef ACTIVE_GEOMETRY_LINEAR_EQUATION
#define ACTIVE_GEOMETRY_LINEAR_EQUATION
 
#include "Active/Geometry/Point.h"
#include "Active/Geometry/XPoint.h"
 
#include <memory>
 
namespace active::geometry {
    
    class Line;
    
    class LinEquation {
    public:
        
        // MARK: - Types
        
        using Unique = std::unique_ptr<LinEquation>;
        using Shared = std::shared_ptr<LinEquation>;
        using Option = std::optional<LinEquation>;
        
        // MARK: - Factory functions
        
        static Option create(const Point& source);
        static Option create(const Point& start, const Point& end);
        static Option create(const Line& source);
        
        // MARK: - Constructors
        
        LinEquation();
        LinEquation(double angle, const Point& source = Point());
        LinEquation(const LinEquation& source);
        
        // MARK: - Operators
        
        LinEquation& operator= (const LinEquation& source);
        bool operator== (const LinEquation& ref) const;
        bool operator== (const Point& ref) const;
        bool operator!= (const LinEquation& ref) const { return !(*this == ref); }
        bool operator< (const LinEquation& ref) const;
        
        // MARK: - Functions (const)
        
        bool isXAxis(double prec = math::eps) const { return math::isZero(m_a, prec); }
        bool isYAxis(double prec = math::eps) const { return math::isZero(m_b, prec); }
        bool isPerpendicularTo(const LinEquation& ref, double prec = math::eps) const;
        bool isParallelTo(const LinEquation& ref, double prec = math::eps) const;
        double azimuthAngle() const;
        Option getFlipped() const;
        Option getPerpendicular(const Point& ref) const;
        Option getParallel(const Point& ref) const;
        double angleTo(const LinEquation& ref) const;
        XPoint::Option intersectionWith(const LinEquation& ref) const;
        Position positionOf(const Point& ref, double prec = math::eps) const;
        bool xAtY(double y, double& x) const;
        bool yAtX(double x, double& y) const;
        Point closestPointTo(const Point& ref) const;
        double lengthTo(const Point& ref) const;
            
    private:
        
        void calculate(const Point& start = Point(), double dx = 1.0, double dy = 0.0);
        static Option getEquation(const Point& start, const Point& end);
        
        double m_a;
        double m_b;
        double m_c;
    };
 
}
 
#endif  //ACTIVE_GEOMETRY_LINEAR_EQUATION