ParaEngine::Plane Class Reference

Defines a plane in 3D space. More...

#include <ParaPlane.h>

Inheritance diagram for ParaEngine::Plane:

Public Types
enum	Side { NO_SIDE, POSITIVE_SIDE, NEGATIVE_SIDE, BOTH_SIDE }
	The "positive side" of the plane is the half space to which the plane normal points. More...

Public Member Functions
	Plane ()
	Default constructor - sets everything to 0.
	Plane (const Plane &rhs)
	Plane (const Vector3 &rkNormal, float fConstant)
	Construct a plane through a normal, and a distance to move the plane along the normal. More...
	Plane (float a, float b, float c, float d)
	Construct a plane using the 4 constants directly.
	Plane (const Vector3 &rkNormal, const Vector3 &rkPoint)
	Plane (const Vector3 &rkPoint0, const Vector3 &rkPoint1, const Vector3 &rkPoint2)
Side	getSide (const Vector3 &rkPoint) const
Side	getSide (const AxisAlignedBox &rkBox) const
	returns the side where the aligneBox is. More...
Side	getSide (const CShapeAABB &rkBox) const
	returns the side where the aligneBox is. More...
Side	getSide (const Vector3 &centre, const Vector3 &halfSize) const
	Returns which side of the plane that the given box lies on. More...
float	getDistance (const Vector3 &rkPoint) const
	This is a pseudo distance. More...
void	redefine (const Vector3 &rkPoint0, const Vector3 &rkPoint1, const Vector3 &rkPoint2)
	Redefine this plane based on 3 points. More...
void	redefine (const Vector3 &rkNormal, const Vector3 &rkPoint)
	Redefine this plane based on a normal and a point. More...
Plane &	Set (float nx, float ny, float nz, float _d)
Plane &	Set (const Vector3 &p, const Vector3 &_n)
Plane &	Set (const Vector3 &p0, const Vector3 &p1, const Vector3 &p2)
Vector3	projectVector (const Vector3 &v) const
	Project a vector onto the plane. More...
float	normalise (void)
	Normalizes the plane. More...
float	PlaneDotCoord (const Vector3 &pV) const
float	PlaneDotNormal (const Vector3 &pV) const
Plane	PlaneTransform (const Matrix4 &M) const
float	a () const
float	b () const
float	c () const
	operator Vector3 () const
	operator Vector4 () const
Plane	operator* (const Matrix4 &m) const
Plane &	operator*= (const Matrix4 &m)
Plane	operator- () const
	operator const float * () const
	operator float * ()
bool	operator== (const Plane &rhs) const
	Comparison operator.
bool	operator!= (const Plane &rhs) const

Public Attributes
Vector3	normal
float	d

Friends
std::ostream &	operator<< (std::ostream &o, const Plane &p)

Detailed Description

Defines a plane in 3D space.

Remarks

A plane is defined in 3D space by the equation Ax + By + Cz + D = 0

This equates to a vector (the normal of the plane, whose x, y and z components equate to the coefficients A, B and C respectively), and a constant (D) which is the distance along the normal you have to go to move the plane back to the origin.

Member Enumeration Documentation

Side

enum ParaEngine::Plane::Side

The "positive side" of the plane is the half space to which the plane normal points.

The "negative side" is the other half space. The flag "no side" indicates the plane itself.

Constructor & Destructor Documentation

Plane()

ParaEngine::Plane::Plane	(	const Vector3 &	rkNormal,
		float	fConstant
	)

Construct a plane through a normal, and a distance to move the plane along the normal.

Member Function Documentation

getDistance()

float ParaEngine::Plane::getDistance

(

const Vector3 &

rkPoint

)

const

This is a pseudo distance.

The sign of the return value is positive if the point is on the positive side of the plane, negative if the point is on the negative side, and zero if the point is on the plane.

The absolute value of the return value is the true distance only when the plane normal is a unit length vector.

getSide() [1/3]

Plane::Side ParaEngine::Plane::getSide

(

const AxisAlignedBox &

rkBox

)

const

returns the side where the aligneBox is.

the flag BOTH_SIDE indicates an intersecting box. one corner ON the plane is sufficient to consider the box and the plane intersecting.

getSide() [2/3]

Plane::Side ParaEngine::Plane::getSide

(

const CShapeAABB &

rkBox

)

const

returns the side where the aligneBox is.

the flag BOTH_SIDE indicates an intersecting box. one corner ON the plane is sufficient to consider the box and the plane intersecting.

getSide() [3/3]

Plane::Side ParaEngine::Plane::getSide	(	const Vector3 &	centre,
		const Vector3 &	halfSize
	)		const

Returns which side of the plane that the given box lies on.

The box is defined as centre/half-size pairs for effectively.

Parameters

centre	The centre of the box.
halfSize	The half-size of the box.

Returns

POSITIVE_SIDE if the box complete lies on the "positive side" of the plane, NEGATIVE_SIDE if the box complete lies on the "negative side" of the plane, and BOTH_SIDE if the box intersects the plane.

normalise()

float ParaEngine::Plane::normalise

(

void

)

Normalizes the plane.

Remarks

This method normalizes the plane's normal and the length scale of d is as well.

Note

This function will not crash for zero-sized vectors, but there will be no changes made to their components.

Returns

The previous length of the plane's normal.

projectVector()

Vector3 ParaEngine::Plane::projectVector

(

const Vector3 &

v

)

const

Project a vector onto the plane.

Remarks

This gives you the element of the input vector that is perpendicular to the normal of the plane. You can get the element which is parallel to the normal of the plane by subtracting the result of this method from the original vector, since parallel + perpendicular = original.

Parameters

v	The input vector

redefine() [1/2]

void ParaEngine::Plane::redefine	(	const Vector3 &	rkPoint0,
		const Vector3 &	rkPoint1,
		const Vector3 &	rkPoint2
	)

Redefine this plane based on 3 points.

redefine() [2/2]

void ParaEngine::Plane::redefine	(	const Vector3 &	rkNormal,
		const Vector3 &	rkPoint
	)

Redefine this plane based on a normal and a point.

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

• Client/trunk/ParaEngineClient/math/ParaPlane.h
• Client/trunk/ParaEngineClient/math/ParaPlane.cpp