struct mrpt::math::TLine2D

2D line without bounds, represented by its equation \(Ax+By+C=0\).

See also:

TLine3D, TSegment2D, TPolygon2D, TPoint2D

#include <mrpt/math/TLine2D.h>

struct TLine2D

    std::array<double, 3> coefs {{0, 0, 0}};

    // construction

    TLine2D(const TPoint2D& p1, const TPoint2D& p2);
    TLine2D(const TSegment2D& s);
    TLine2D(double A, double B, double C);
    TLine2D(const TLine3D& l);


    double evaluatePoint(const TPoint2D& point) const;
    bool contains(const TPoint2D& point) const;
    double distance(const TPoint2D& point) const;
    double signedDistance(const TPoint2D& point) const;
    void getNormalVector(double(&) vector [2]) const;
    void unitarize();
    void getUnitaryNormalVector(double(&) vector [2]);
    void getDirectorVector(double(&) vector [2]) const;
    void getUnitaryDirectorVector(double(&) vector [2]);
    void generate3DObject(TLine3D& l) const;
    void getAsPose2D(TPose2D& outPose) const;

    void getAsPose2DForcingOrigin(
        const TPoint2D& origin,
        TPose2D& outPose
        ) const;

    std::string asString() const;
    static TLine2D FromCoefficientsABC(double A, double B, double C);
    static TLine2D FromTwoPoints(const TPoint2D& p1, const TPoint2D& p2);


std::array<double, 3> coefs {{0, 0, 0}}

Line coefficients, stored as an array: \(\left[A,B,C\right]\).


TLine2D(const TPoint2D& p1, const TPoint2D& p2)

Constructor from two points, through which the line will pass.



if both points are the same

See also:


TLine2D(const TSegment2D& s)

Constructor from a segment.


Fast default constructor.

Initializes to undefined values.

TLine2D(double A, double B, double C)

Constructor from line’s coefficients.

TLine2D(const TLine3D& l)

Construction from 3D object, discarding the Z.



if the line is normal to the XY plane.


double evaluatePoint(const TPoint2D& point) const

Evaluate point in the line’s equation.

bool contains(const TPoint2D& point) const

Check whether a point is inside the line.

double distance(const TPoint2D& point) const

Distance from a given point.

double signedDistance(const TPoint2D& point) const

Distance with sign from a given point (sign indicates side).

void getNormalVector(double(&) vector [2]) const

Get line’s normal vector.

void unitarize()

Unitarize line’s normal vector.

void getUnitaryNormalVector(double(&) vector [2])

Get line’s normal vector after unitarizing line.

void getDirectorVector(double(&) vector [2]) const

Get line’s director vector.

void getUnitaryDirectorVector(double(&) vector [2])

Unitarize line and then get director vector.

void generate3DObject(TLine3D& l) const

Project into 3D space, setting the z to 0.

std::string asString() const

Returns “[A, B, C]”.

[New in MRPT 2.1.0]

Do not inherit from mrpt::Stringifyable to avoid virtual class table and keeping the class trivially-copiable.

static TLine2D FromCoefficientsABC(double A, double B, double C)

Static constructor from Ax+By+C=0 coefficients.

[New in MRPT 2.0.4]

static TLine2D FromTwoPoints(const TPoint2D& p1, const TPoint2D& p2)

Static constructor from two points.

[New in MRPT 2.0.4]