mxvk::paramLine2D Struct Reference

Parametric 2D line segment represented by a start point, end point, and direction. More...

#include <mxvk/include/mxvk/mxvk_math.h>

Public Member Functions
vec2D	ComputePoint (float t) const
	Compute the point p0 + v * t.
vec2D	ComputePoint (float t) const
	Compute the point p0 + v * t.
vec2D	ComputePoint (float t, vec2D &out) const
	Compute the point p0 + v * t and write it to out.
vec2D	ComputePoint (float t, vec2D &out) const
	Compute the point p0 + v * t and write it to out.
void	Init (const vec2D &start, const vec2D &end)
	Initialize from endpoints and derive the direction vector.
void	Init (const vec2D &start, const vec2D &end)
	Initialize from endpoints and derive the direction vector.
int	Intersect (const paramLine2D &line, float &t_this, float &t_other) const
	Intersect this segment with another parametric segment.
int	Intersect (const paramLine2D &line, float &t_this, float &t_other) const
	Intersect this segment with another parametric segment.
int	Intersect (const paramLine2D &line, vec2D &out) const
	Intersect this segment with another segment and compute the point.
int	Intersect (const paramLine2D &line, vec2D &out) const
	Intersect this segment with another segment and compute the point.
	paramLine2D ()=default
	Construct an uninitialized line segment.
	paramLine2D ()=default
	Construct an uninitialized line segment.
	paramLine2D (const vec2D &start, const vec2D &end, const vec2D &dir)
	Construct from explicit endpoints and direction.
	paramLine2D (const vec2D &start, const vec2D &end, const vec2D &dir)
	Construct from explicit endpoints and direction.
void	Set (const vec2D &start, const vec2D &end, const vec2D &dir)
	Set explicit endpoints and direction.
void	Set (const vec2D &start, const vec2D &end, const vec2D &dir)
	Set explicit endpoints and direction.

Public Attributes
vec2D	p0
	Segment start point.
vec2D	p1
	Segment end point.
vec2D	v
	Direction vector, commonly p1 - p0.

Detailed Description

Parametric 2D line segment represented by a start point, end point, and direction.

Definition at line 875 of file mxvk_math.h.

Constructor & Destructor Documentation

paramLine2D() [1/4]

mxvk::paramLine2D::paramLine2D ( )

default

Construct an uninitialized line segment.

paramLine2D() [2/4]

mxvk::paramLine2D::paramLine2D ( const vec2D & start, const vec2D & end, const vec2D & dir )

inline

Construct from explicit endpoints and direction.

Definition at line 889 of file mxvk_math.h.

{ Set(start, end, dir); }

paramLine2D() [3/4]

mxvk::paramLine2D::paramLine2D ( )

default

Construct an uninitialized line segment.

paramLine2D() [4/4]

mxvk::paramLine2D::paramLine2D ( const vec2D & start, const vec2D & end, const vec2D & dir )

inline

Construct from explicit endpoints and direction.

Definition at line 852 of file mxvk_math_eigen.hpp.

{ Set(start, end, dir); }

Member Function Documentation

ComputePoint() [1/4]

vec2D mxvk::paramLine2D::ComputePoint ( float t ) const

inlinenodiscard

Compute the point p0 + v * t.

Definition at line 906 of file mxvk_math.h.

{ return p0 + v * t; }

ComputePoint() [2/4]

vec2D mxvk::paramLine2D::ComputePoint ( float t ) const

inlinenodiscard

Compute the point p0 + v * t.

Definition at line 869 of file mxvk_math_eigen.hpp.

{ return p0 + v * t; }

ComputePoint() [3/4]

vec2D mxvk::paramLine2D::ComputePoint ( float t, vec2D & out ) const

inline

Compute the point p0 + v * t and write it to out.

Definition at line 909 of file mxvk_math.h.

                                                      {
            out = ComputePoint(t);
            return out;
        }

ComputePoint() [4/4]

vec2D mxvk::paramLine2D::ComputePoint ( float t, vec2D & out ) const

inline

Compute the point p0 + v * t and write it to out.

Definition at line 872 of file mxvk_math_eigen.hpp.

                                                      {
            out = ComputePoint(t);
            return out;
        }

Init() [1/2]

void mxvk::paramLine2D::Init ( const vec2D & start, const vec2D & end )

inline

Initialize from endpoints and derive the direction vector.

Definition at line 899 of file mxvk_math.h.

                                                        {
            p0 = start;
            p1 = end;
            v = end - start;
        }

Init() [2/2]

void mxvk::paramLine2D::Init ( const vec2D & start, const vec2D & end )

inline

Initialize from endpoints and derive the direction vector.

Definition at line 862 of file mxvk_math_eigen.hpp.

                                                        {
            p0 = start;
            p1 = end;
            v = end - start;
        }

Intersect() [1/4]

int mxvk::paramLine2D::Intersect ( const paramLine2D & line, float & t_this, float & t_other ) const

inline

Intersect this segment with another parametric segment.

Parameters

line	Segment to intersect with.
t_this	Receives this segment's intersection parameter.
t_other	Receives the other segment's intersection parameter.

Returns

0 for parallel lines, 1 for segment intersection, 2 for line intersection outside one or both segments.

Definition at line 921 of file mxvk_math.h.

                                                                                    {
            const float det = v.x * line.v.y - v.y * line.v.x;
            if (std::fabs(det) <= EPSILON) {
                return 0;
            }
            const vec2D delta = line.p0 - p0;
            t_this = (delta.x * line.v.y - delta.y * line.v.x) / det;
            t_other = (delta.x * v.y - delta.y * v.x) / det;
            return (t_this >= 0.0f && t_this <= 1.0f && t_other >= 0.0f && t_other <= 1.0f) ? 1 : 2;
        }

Intersect() [2/4]

int mxvk::paramLine2D::Intersect ( const paramLine2D & line, float & t_this, float & t_other ) const

inline

Intersect this segment with another parametric segment.

Parameters

line	Segment to intersect with.
t_this	Receives this segment's intersection parameter.
t_other	Receives the other segment's intersection parameter.

Returns

0 for parallel lines, 1 for segment intersection, 2 for line intersection outside one or both segments.

Definition at line 884 of file mxvk_math_eigen.hpp.

                                                                                    {
            Eigen::Matrix2f directions;
            directions << v.x, line.v.x, v.y, line.v.y;
            const float det = directions.determinant();
            if (std::fabs(det) <= EPSILON) {
                return 0;
            }
            const Eigen::Vector2f delta(line.p0.x - p0.x, line.p0.y - p0.y);
            const Eigen::Vector2f parameters = directions.partialPivLu().solve(delta);
            t_this = parameters.x();
            t_other = -parameters.y();
            return (t_this >= 0.0f && t_this <= 1.0f && t_other >= 0.0f && t_other <= 1.0f) ? 1 : 2;
        }

Intersect() [3/4]

int mxvk::paramLine2D::Intersect ( const paramLine2D & line, vec2D & out ) const

inline

Intersect this segment with another segment and compute the point.

Parameters

line	Segment to intersect with.
out	Receives the intersection point when the lines are not parallel.

Returns

0 for parallel lines, 1 for segment intersection, 2 for line intersection outside one or both segments.

Definition at line 938 of file mxvk_math.h.

                                                                 {
            float t_this = 0.0f;
            float t_other = 0.0f;
            const int result = Intersect(line, t_this, t_other);
            if (result != 0) {
                out = ComputePoint(t_this);
            }
            return result;
        }

Intersect() [4/4]

int mxvk::paramLine2D::Intersect ( const paramLine2D & line, vec2D & out ) const

inline

Intersect this segment with another segment and compute the point.

Parameters

line	Segment to intersect with.
out	Receives the intersection point when the lines are not parallel.

Returns

0 for parallel lines, 1 for segment intersection, 2 for line intersection outside one or both segments.

Definition at line 904 of file mxvk_math_eigen.hpp.

                                                                 {
            float t_this = 0.0f;
            float t_other = 0.0f;
            const int result = Intersect(line, t_this, t_other);
            if (result != 0) {
                out = ComputePoint(t_this);
            }
            return result;
        }

Set() [1/2]

void mxvk::paramLine2D::Set ( const vec2D & start, const vec2D & end, const vec2D & dir )

inline

Set explicit endpoints and direction.

Definition at line 892 of file mxvk_math.h.

                                                                         {
            p0 = start;
            p1 = end;
            v = dir;
        }

Set() [2/2]

void mxvk::paramLine2D::Set ( const vec2D & start, const vec2D & end, const vec2D & dir )

inline

Set explicit endpoints and direction.

Definition at line 855 of file mxvk_math_eigen.hpp.

                                                                         {
            p0 = start;
            p1 = end;
            v = dir;
        }

Member Data Documentation

p0

vec2D mxvk::paramLine2D::p0

Segment start point.

Definition at line 877 of file mxvk_math.h.

p1

vec2D mxvk::paramLine2D::p1

Segment end point.

Definition at line 880 of file mxvk_math.h.

v

vec2D mxvk::paramLine2D::v

Direction vector, commonly p1 - p0.

Definition at line 883 of file mxvk_math.h.

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The documentation for this struct was generated from the following files:

• mxvk/include/mxvk/mxvk_math.h
• mxvk/include/mxvk/mxvk_math_eigen.hpp