G3D::LineSegment Class Reference

#include <LineSegment.h>

Public Member Functions
	LineSegment ()
	LineSegment (class BinaryInput &b)
void	serialize (class BinaryOutput &b) const
void	deserialize (class BinaryInput &b)
virtual	~LineSegment ()
Point3	point (int i) const
Point3	midpoint () const
float	length () const
Point3	closestPoint (const Point3 &point) const
double	distance (const Point3 &p) const
double	distanceSquared (const Point3 &p) const
bool	intersectsSolidSphere (const class Sphere &s) const
Point3	randomPoint () const

Static Public Member Functions
static LineSegment	fromTwoPoints (const Point3 &point1, const Point3 &point2)

Protected Member Functions
	LineSegment (const Point3 &__point, const Vector3 &_direction)

Protected Attributes
Point3	_point
Vector3	direction

Detailed Description

An finite segment of an infinite 3D line.

Constructor & Destructor Documentation

G3D::LineSegment::LineSegment ( const Point3 &  __point, const Vector3 &  _direction  )

inlineprotected

 : _point(__point), direction(_direction) {
 }

G3D::LineSegment::LineSegment ( )

inline

: _point(Point3::zero()), direction(Vector3::zero()) {}

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G3D::LineSegment::LineSegment

(

class BinaryInput &

b

)

 {
 deserialize(b);
}

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virtual G3D::LineSegment::~LineSegment ( )

inlinevirtual

{}

Member Function Documentation

Vector3 G3D::LineSegment::closestPoint

(

const Point3 &

point

)

const

Returns the closest point on the line segment to point.

 {

 // The vector from the end of the capsule to the point in question.
 Vector3 v(p - _point);

 // Projection of v onto the line segment scaled by 
 // the length of direction.
 float t = direction.dot(v);

 // Avoid some square roots. Derivation:
 // t/direction.length() <= direction.length()
 // t <= direction.squaredLength()

 if ((t >= 0) && (t <= direction.squaredMagnitude())) {
 
 // The point falls within the segment. Normalize direction,
 // divide t by the length of direction.
 return _point + direction * t / direction.squaredMagnitude();
 
 } else {

 // The point does not fall within the segment; see which end is closer.

 // Distance from 0, squared
 float d0Squared = v.squaredMagnitude();

 // Distance from 1, squared
 float d1Squared = (v - direction).squaredMagnitude();

 if (d0Squared < d1Squared) {

 // Point 0 is closer
 return _point;

 } else {

 // Point 1 is closer
 return _point + direction;
 
 }
 }

}

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void G3D::LineSegment::deserialize

(

class BinaryInput &

b

)

 {
 _point.deserialize(b);
 direction.deserialize(b);
}

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double G3D::LineSegment::distance ( const Point3 &  p ) const

inline

Returns the distance between point and the line

 {
 return (closestPoint(p) - p).magnitude();
 }

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double G3D::LineSegment::distanceSquared ( const Point3 &  p ) const

inline

 {
 return (closestPoint(p) - p).squaredMagnitude();
 }

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static LineSegment G3D::LineSegment::fromTwoPoints ( const Point3 &  point1, const Point3 &  point2  )

inlinestatic

Constructs a line from two (not equal) points.

 {
 return LineSegment(point1, point2 - point1);
 }

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bool G3D::LineSegment::intersectsSolidSphere

(

const class Sphere &

s

)

const

Returns true if some part of this segment is inside the sphere

 {
 return distanceSquared(s.center) <= square(s.radius);
}

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float G3D::LineSegment::length ( ) const

inline

 {
 return direction.magnitude();
 }

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Point3 G3D::LineSegment::midpoint ( ) const

inline

 {
 return _point + direction * 0.5f;
 }

Vector3 G3D::LineSegment::point

(

int

i

)

const

Call with 0 or 1

 {
 switch (i) {
 case 0:
 return _point;

 case 1:
 return _point + direction;

 default:
 debugAssertM(i == 0 || i == 1, "Argument to point must be 0 or 1");
 return _point;
 }
}

Vector3 G3D::LineSegment::randomPoint

(

)

const

 {
 return _point + uniformRandom(0, 1) * direction;
}

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void G3D::LineSegment::serialize

(

class BinaryOutput &

b

)

const

 {
 _point.serialize(b);
 direction.serialize(b);
}

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Member Data Documentation

Point3 G3D::LineSegment::_point

protected

Vector3 G3D::LineSegment::direction

protected

Not normalized

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

• dep/g3dlite/include/G3D/LineSegment.h
• dep/g3dlite/source/LineSegment.cpp