# Ogre::Vector2 Class Reference

Standard 2-dimensional vector. More...

`#include <OgreVector2.h>`

List of all members.

## Public Member Functions

| Vector2 ()
| Vector2 (Real fX, Real fY)
| Vector2 (Real afCoordinate[2])
| Vector2 (int afCoordinate[2])
| Vector2 (const Real *const r)
| Vector2 (const Vector2 &rkVector)
Real | operator[] (size_t i) const
Real & | operator[] (size_t i)
Vector2 & | operator= (const Vector2 &rkVector)
| Assigns the value of the other vector.
bool | operator== (const Vector2 &rkVector) const
bool | operator!= (const Vector2 &rkVector) const
Vector2 | operator+ (const Vector2 &rkVector) const
Vector2 | operator- (const Vector2 &rkVector) const
Vector2 | operator * (Real fScalar) const
Vector2 | operator * (const Vector2 &rhs) const
Vector2 | operator/ (Real fScalar) const
Vector2 | operator- () const
Vector2 & | operator+= (const Vector2 &rkVector)
Vector2 & | operator-= (const Vector2 &rkVector)
Vector2 & | operator *= (Real fScalar)
Vector2 & | operator/= (Real fScalar)
Real | length () const
| Returns the length (magnitude) of the vector.
Real | squaredLength () const
| Returns the square of the length(magnitude) of the vector.
Real | dotProduct (const Vector2 &vec) const
| Calculates the dot (scalar) product of this vector with another.
Real | normalise ()
| Normalises the vector.
Vector2 | midPoint (const Vector2 &vec) const
| Returns a vector at a point half way between this and the passed in vector.
bool | operator< (const Vector2 &rhs) const
| Returns true if the vector's scalar components are all greater that the ones of the vector it is compared against.
bool | operator> (const Vector2 &rhs) const
| Returns true if the vector's scalar components are all smaller that the ones of the vector it is compared against.
void | makeFloor (const Vector2 &cmp)
| Sets this vector's components to the minimum of its own and the ones of the passed in vector.
void | makeCeil (const Vector2 &cmp)
| Sets this vector's components to the maximum of its own and the ones of the passed in vector.
Vector2 | perpendicular (void) const
| Generates a vector perpendicular to this vector (eg an 'up' vector).
Vector2 | crossProduct (const Vector2 &rkVector) const
| Calculates the cross-product of 2 vectors, i.e.
Vector2 | randomDeviant (Real angle) const
| Generates a new random vector which deviates from this vector by a given angle in a random direction.
bool | isZeroLength (void) const
| Returns true if this vector is zero length.
Vector2 | normalisedCopy (void) const
| As normalise, except that this vector is unaffected and the normalised vector is returned as a copy.
Vector2 | reflect (const Vector2 &normal) const
| Calculates a reflection vector to the plane with the given normal .

## Static Public Attributes

const Vector2 | ZERO
const Vector2 | UNIT_X
const Vector2 | UNIT_Y
const Vector2 | NEGATIVE_UNIT_X
const Vector2 | NEGATIVE_UNIT_Y
const Vector2 | UNIT_SCALE

## Friends

Vector2 | operator * (Real fScalar, const Vector2 &rkVector)
_OgreExport friend std::ostream & | operator<< (std::ostream &o, const Vector2 &v)
| Function for writing to a stream.

## Detailed Description

Standard 2-dimensional vector.

Remarks:
  A direction in 2D space represented as distances along the 2 orthoganal axes (x, y). Note that positions, directions and scaling factors can be represented by a vector, depending on how you interpret the values.

Definition at line 42 of file OgreVector2.h.

## Constructor & Destructor Documentation

Ogre::Vector2::Vector2 | ( |  | ) |

| Definition at line 53 of file OgreVector2.h.

Ogre::Vector2::Vector2 | ( | Real | fX,
|  | Real | fY
| ) |

| Definition at line 57 of file OgreVector2.h. References Ogre::Real.

Ogre::Vector2::Vector2 | ( | Real | afCoordinate[2] | ) |

| Definition at line 62 of file OgreVector2.h. References Ogre::Real.

Ogre::Vector2::Vector2 | ( | int | afCoordinate[2] | ) |

| Definition at line 68 of file OgreVector2.h. References Ogre::Real.

Ogre::Vector2::Vector2 | ( | const Real *const | r | ) |

| Definition at line 74 of file OgreVector2.h. References Ogre::Real.

Ogre::Vector2::Vector2 | ( | const Vector2 & | rkVector | ) |

| Definition at line 79 of file OgreVector2.h.

## Member Function Documentation

Vector2 Ogre::Vector2::crossProduct | ( | const Vector2 & | rkVector | ) | const

Calculates the cross-product of 2 vectors, i.e.

the vector that lies perpendicular to them both.

Remarks:
  The cross-product is normally used to calculate the normal vector of a plane, by calculating the cross-product of 2 non-equivalent vectors which lie on the plane (e.g. 2 edges of a triangle).

Parameters:

  vec | Vector which, together with this one, will be used to calculate the cross-product.

Returns:
  A vector which is the result of the cross-product. This vector will NOT be normalised, to maximise efficiency
  - call Vector3::normalise on the result if you wish this to be done. As for which side the resultant vector will be on, the returned vector will be on the side from which the arc from 'this' to rkVector is anticlockwise, e.g. UNIT_Y.crossProduct(UNIT_Z) = UNIT_X, whilst UNIT_Z.crossProduct(UNIT_Y) = -UNIT_X.

  For a clearer explanation, look a the left and the bottom edges of your monitor's screen. Assume that the first vector is the left edge and the second vector is the bottom edge, both of them starting from the lower-left corner of the screen. The resulting vector is going to be perpendicular to both of them and will go inside the screen, towards the cathode tube (assuming you're using a CRT monitor, of course).

Definition at line 397 of file OgreVector2.h.

References x, and y.

Real Ogre::Vector2::dotProduct | ( | const Vector2 & | vec | ) | const

Calculates the dot (scalar) product of this vector with another.

Remarks:
  The dot product can be used to calculate the angle between 2 vectors. If both are unit vectors, the dot product is the cosine of the angle; otherwise the dot product must be divided by the product of the lengths of both vectors to get the cosine of the angle. This result can further be used to calculate the distance of a point from a plane.

Parameters:

  vec | Vector with which to calculate the dot product (together with this one).

Returns:
  A float representing the dot product value.

Definition at line 272 of file OgreVector2.h.

References Ogre::Real, x, and y.

bool Ogre::Vector2::isZeroLength | ( | void |  | ) | const

| Returns true if this vector is zero length. Definition at line 432 of file OgreVector2.h. References Ogre::Real.

Real Ogre::Vector2::length | ( |  | ) | const

Returns the length (magnitude) of the vector.

Warning:
  This operation requires a square root and is expensive in terms of CPU operations. If you don't need to know the exact length (e.g. for just comparing lengths) use squaredLength() instead.

Definition at line 238 of file OgreVector2.h.

References Ogre::Real.

void Ogre::Vector2::makeCeil | ( | const Vector2 & | cmp | ) |

Sets this vector's components to the maximum of its own and the ones of the passed in vector.

Remarks:
  'Maximum' in this case means the combination of the highest value of x, y and z from both vectors. Highest is taken just numerically, not magnitude, so 1 > -3.

Definition at line 353 of file OgreVector2.h.

References x, and y.

void Ogre::Vector2::makeFloor | ( | const Vector2 & | cmp | ) |

Sets this vector's components to the minimum of its own and the ones of the passed in vector.

Remarks:
  'Minimum' in this case means the combination of the lowest value of x, y and z from both vectors. Lowest is taken just numerically, not magnitude, so -1 < 0.

Definition at line 340 of file OgreVector2.h.

References x, and y.

Vector2 Ogre::Vector2::midPoint | ( | const Vector2 & | vec | ) | const

| Returns a vector at a point half way between this and the passed in vector. Definition at line 306 of file OgreVector2.h. References x, and y.

Real Ogre::Vector2::normalise | ( | void |  | ) |

Normalises the vector.

Remarks:
  This method normalises the vector such that it's length / magnitude is 1. The result is called a unit vector.

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 vector.

Definition at line 286 of file OgreVector2.h.

References Ogre::Real.

Referenced by normalisedCopy().

Vector2 Ogre::Vector2::normalisedCopy | ( | void |  | ) | const

| As normalise, except that this vector is unaffected and the normalised vector is returned as a copy. Definition at line 441 of file OgreVector2.h. References normalise().

Vector2 Ogre::Vector2::operator * | ( | const Vector2 & | rhs | ) | const

| Definition at line 151 of file OgreVector2.h. References x, and y.

Vector2 Ogre::Vector2::operator * | ( | Real | fScalar | ) | const

| Definition at line 141 of file OgreVector2.h. References Ogre::Real, x, and y.

Vector2& Ogre::Vector2::operator *= | ( | Real | fScalar | ) |

| Definition at line 211 of file OgreVector2.h. References Ogre::Real.

bool Ogre::Vector2::operator!= | ( | const Vector2 & | rkVector | ) | const

| Definition at line 115 of file OgreVector2.h. References x, and y.

Vector2 Ogre::Vector2::operator+ | ( | const Vector2 & | rkVector | ) | const

| Definition at line 121 of file OgreVector2.h. References x, and y.

Vector2& Ogre::Vector2::operator+= | ( | const Vector2 & | rkVector | ) |

| Definition at line 195 of file OgreVector2.h. References x, and y.

Vector2 Ogre::Vector2::operator- | ( |  | ) | const

| Definition at line 174 of file OgreVector2.h. References x, and y.

Vector2 Ogre::Vector2::operator- | ( | const Vector2 & | rkVector | ) | const

| Definition at line 131 of file OgreVector2.h. References x, and y.

Vector2& Ogre::Vector2::operator-= | ( | const Vector2 & | rkVector | ) |

| Definition at line 203 of file OgreVector2.h. References x, and y.

Vector2 Ogre::Vector2::operator/ | ( | Real | fScalar | ) | const

| Definition at line 161 of file OgreVector2.h. References Ogre::Real, x, and y.

Vector2& Ogre::Vector2::operator/= | ( | Real | fScalar | ) |

| Definition at line 219 of file OgreVector2.h. References Ogre::Real.

bool Ogre::Vector2::operator< | ( | const Vector2 & | rhs | ) | const

| Returns true if the vector's scalar components are all greater that the ones of the vector it is compared against. Definition at line 316 of file OgreVector2.h. References x, and y.

Vector2& Ogre::Vector2::operator= | ( | const Vector2 & | rkVector | ) |

Assigns the value of the other vector.

Parameters:

  rkVector | The other vector

Definition at line 102 of file OgreVector2.h.

References x, and y.

bool Ogre::Vector2::operator== | ( | const Vector2 & | rkVector | ) | const

| Definition at line 110 of file OgreVector2.h. References x, and y.

bool Ogre::Vector2::operator> | ( | const Vector2 & | rhs | ) | const

| Returns true if the vector's scalar components are all smaller that the ones of the vector it is compared against. Definition at line 326 of file OgreVector2.h. References x, and y.

Real& Ogre::Vector2::operator[] | ( | size_t | i | ) |

| Definition at line 91 of file OgreVector2.h. References Ogre::Real.

Real Ogre::Vector2::operator[] | ( | size_t | i | ) | const

| Definition at line 84 of file OgreVector2.h. References Ogre::Real.

Vector2 Ogre::Vector2::perpendicular | ( | void |  | ) | const

Generates a vector perpendicular to this vector (eg an 'up' vector).

Remarks:
  This method will return a vector which is perpendicular to this vector. There are an infinite number of possibilities but this method will guarantee to generate one of them. If you need more control you should use the Quaternion class.

Definition at line 366 of file OgreVector2.h.

Vector2 Ogre::Vector2::randomDeviant | ( | Real | angle | ) | const

Generates a new random vector which deviates from this vector by a given angle in a random direction.

Remarks:
  This method assumes that the random number generator has already been seeded appropriately.

Parameters:

  angle | The angle at which to deviate in radians
  up | Any vector perpendicular to this one (which could generated by cross-product of this vector and any other non-colinear vector). If you choose not to provide this the function will derive one on it's own, however if you provide one yourself the function will be faster (this allows you to reuse up vectors if you call this method more than once)

Returns:
  A random vector which deviates from this vector by angle. This vector will not be normalised, normalise it if you wish afterwards.

Definition at line 420 of file OgreVector2.h.

References Ogre::Real.

Vector2 Ogre::Vector2::reflect | ( | const Vector2 & | normal | ) | const

Calculates a reflection vector to the plane with the given normal .

Remarks:
  NB assumes 'this' is pointing AWAY FROM the plane, invert if it is not.

Definition at line 451 of file OgreVector2.h.

Real Ogre::Vector2::squaredLength | ( |  | ) | const

Returns the square of the length(magnitude) of the vector.

Remarks:
  This method is for efficiency - calculating the actual length of a vector requires a square root, which is expensive in terms of the operations required. This method returns the square of the length of the vector, i.e. the same as the length but before the square root is taken. Use this if you want to find the longest / shortest vector without incurring the square root.

Definition at line 253 of file OgreVector2.h.

References Ogre::Real.

## Friends And Related Function Documentation

Vector2 operator * | ( | Real | fScalar,
|  | const Vector2 & | rkVector
| ) | `[friend]`

| Definition at line 184 of file OgreVector2.h.

_OgreExport friend std::ostream& operator<< | ( | std::ostream & | o,
|  | const Vector2 & | v
| ) | `[friend]`

| Function for writing to a stream. Definition at line 467 of file OgreVector2.h.

## Member Data Documentation

const Vector2 Ogre::Vector2::NEGATIVE_UNIT_X `[static]`

| Definition at line 460 of file OgreVector2.h.

const Vector2 Ogre::Vector2::NEGATIVE_UNIT_Y `[static]`

| Definition at line 461 of file OgreVector2.h.

const Vector2 Ogre::Vector2::UNIT_SCALE `[static]`

| Definition at line 462 of file OgreVector2.h.

const Vector2 Ogre::Vector2::UNIT_X `[static]`

| Definition at line 458 of file OgreVector2.h.

const Vector2 Ogre::Vector2::UNIT_Y `[static]`

| Definition at line 459 of file OgreVector2.h.

Real Ogre::Vector2::val[2]

| Definition at line 49 of file OgreVector2.h.

Real Ogre::Vector2::x

| Definition at line 47 of file OgreVector2.h. Referenced by crossProduct(), dotProduct(), makeCeil(), makeFloor(), midPoint(), operator *(), operator!=(), operator+(), operator+=(), operator-(), operator-=(), operator/(), operator<(), operator=(), operator==(), and operator>().

Real Ogre::Vector2::y

| Definition at line 47 of file OgreVector2.h. Referenced by crossProduct(), dotProduct(), makeCeil(), makeFloor(), midPoint(), operator *(), operator!=(), operator+(), operator+=(), operator-(), operator-=(), operator/(), operator<(), operator=(), operator==(), and operator>().

const Vector2 Ogre::Vector2::ZERO `[static]`

| Definition at line 457 of file OgreVector2.h.

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

- OgreVector2.h

Copyright © 2000-2005 by The OGRE Team
Last modified Sun Nov 20 12:41:13 2005