# Ogre::Plane Class Reference
[Math]

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

`#include <OgrePlane.h>`

Inheritance diagram for Ogre::Plane:
[legend]

List of all members.

## 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, Real fConstant)
| Construct a plane through a normal, and a distance to move the plane along the normal.
| Plane (Real a, Real b, Real c, Real 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.
Side | getSide (const Vector3 &centre, const Vector3 &halfSize) const
| Returns which side of the plane that the given box lies on.
Real | getDistance (const Vector3 &rkPoint) const
| This is a pseudodistance.
void | redefine (const Vector3 &rkPoint0, const Vector3 &rkPoint1, const Vector3 &rkPoint2)
| Redefine this plane based on 3 points.
void | redefine (const Vector3 &rkNormal, const Vector3 &rkPoint)
| Redefine this plane based on a normal and a point.
Vector3 | projectVector (const Vector3 &v) const
| Project a vector onto the plane.
Real | normalise (void)
| Normalises the plane.
bool | operator== (const Plane &rhs) const
| Comparison operator.
bool | operator!= (const Plane &rhs) const

## Public Attributes

Vector3 | normal
Real | d

## Friends

_OgreExport friend 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.

Definition at line 61 of file OgrePlane.h.

## Member Enumeration Documentation

enum Ogre::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.

Enumerator:

  NO_SIDE |
  POSITIVE_SIDE |
  NEGATIVE_SIDE |
  BOTH_SIDE |

Definition at line 80 of file OgrePlane.h.

## Constructor & Destructor Documentation

Ogre::Plane::Plane | ( |  | ) |

Default constructor - sets everything to 0.

Ogre::Plane::Plane | ( | const Plane & | rhs | ) |

Ogre::Plane::Plane | ( | const Vector3 & | rkNormal,
|  | Real | fConstant |
| ) |  |  |

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

Ogre::Plane::Plane | ( | Real | a,
|  | Real | b,
|  | Real | c,
|  | Real | d |
| ) |  |  |

Construct a plane using the 4 constants directly.

Ogre::Plane::Plane | ( | const Vector3 & | rkNormal,
|  | const Vector3 & | rkPoint |
| ) |  |  |

Ogre::Plane::Plane | ( | const Vector3 & | rkPoint0,
|  | const Vector3 & | rkPoint1,
|  | const Vector3 & | rkPoint2 |
| ) |  |  |

## Member Function Documentation

Real Ogre::Plane::getDistance | ( | const Vector3 & | rkPoint | ) | const

This is a pseudodistance.

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.

Referenced by Ogre::PlaneBoundedVolume::intersects().

Side Ogre::Plane::getSide | ( | const Vector3 & | rkPoint | ) | const

Referenced by Ogre::PlaneBoundedVolume::intersects().

Side Ogre::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.

Side Ogre::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.

Real Ogre::Plane::normalise | ( | void |  | ) |

Normalises the plane.

Remarks:
  This method normalises 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.

bool Ogre::Plane::operator!= | ( | const Plane & | rhs | ) | const

Definition at line 152 of file OgrePlane.h.

References d, and normal.

bool Ogre::Plane::operator== | ( | const Plane & | rhs | ) | const

Comparison operator.

Definition at line 148 of file OgrePlane.h.

References d, and normal.

Vector3 Ogre::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

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

Redefine this plane based on a normal and a point.

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

Redefine this plane based on 3 points.

## Friends And Related Function Documentation

_OgreExport friend std::ostream& operator<< | ( | std::ostream & | o,
|  | const Plane & | p |
| ) |  |  | `[friend]`

## Member Data Documentation

Real Ogre::Plane::d

Definition at line 145 of file OgrePlane.h.

Referenced by operator!=(), Ogre::Matrix4::operator*(), and operator==().

Vector3 Ogre::Plane::normal

Definition at line 144 of file OgrePlane.h.

Referenced by operator!=(), Ogre::Matrix4::operator*(), and operator==().

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

- OgrePlane.h

Copyright © 2008 Torus Knot Software Ltd
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
Last modified Wed Nov 3 2010 19:24:58