Standard 2-dimensional vector. More...

#include <ParaVector2.h>

Public Member Functions
	Vector2 (const float fX, const float fY)

	Vector2 (const float scaler)

	Vector2 (const float afCoordinate[2])

	Vector2 (const int afCoordinate[2])

	Vector2 (float *const r)

float	operator[] (const size_t i) const

float &	operator[] (const size_t i)

float *	ptr ()
	Pointer accessor for direct copying.

const float *	ptr () const
	Pointer accessor for direct copying.

Vector2 &	operator= (const Vector2 &rkVector)
	Assigns the value of the other vector. More...

Vector2 &	operator= (const float fScalar)

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* (const float fScalar) const

Vector2	operator* (const Vector2 &rhs) const

Vector2	operator* (const Matrix4 &mat) const

Vector2	operator/ (const float fScalar) const

Vector2	operator/ (const Vector2 &rhs) const

const Vector2 &	operator+ () const

Vector2	operator- () const

Vector2 &	operator+= (const Vector2 &rkVector)

Vector2 &	operator+= (const float fScaler)

Vector2 &	operator-= (const Vector2 &rkVector)

Vector2 &	operator-= (const float fScaler)

Vector2 &	*operator=** (const float fScalar)

Vector2 &	*operator=** (const Vector2 &rkVector)

Vector2 &	operator/= (const float fScalar)

Vector2 &	operator/= (const Vector2 &rkVector)

float	length () const
	Returns the length (magnitude) of the vector. More...

float	squaredLength () const
	Returns the square of the length(magnitude) of the vector. More...

float	dotProduct (const Vector2 &vec) const
	Calculates the dot (scalar) product of this vector with another. More...

float	normalise ()
	Normalises the vector. More...

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. More...

void	makeCeil (const Vector2 &cmp)
	Sets this vector's components to the maximum of its own and the ones of the passed in vector. More...

Vector2	perpendicular (void) const
	Generates a vector perpendicular to this vector (eg an 'up' vector). More...

float	crossProduct (const Vector2 &rkVector) const
	Calculates the 2 dimensional cross-product of 2 vectors, which results in a single floating point value which is 2 times the area of the triangle.

Vector2	randomDeviant (float angle) const
	Generates a new random vector which deviates from this vector by a given angle in a random direction. More...

bool	isZeroLength (void) const
	Returns true if this vector is zero length. More...

Vector2	normalisedCopy (void) const
	As normalise, except that this vector is unaffected and the normalised vector is returned as a copy. More...

Vector2	reflect (const Vector2 &normal) const
	Calculates a reflection vector to the plane with the given normal . More...

Public Attributes
float	x

float	y

Static Public Attributes
static const Vector2	ZERO

static const Vector2	UNIT_X

static const Vector2	UNIT_Y

static const Vector2	NEGATIVE_UNIT_X

static const Vector2	NEGATIVE_UNIT_Y

static const Vector2	UNIT_SCALE

Friends
Vector2	operator* (const float fScalar, const Vector2 &rkVector)

Vector2	operator/ (const float fScalar, const Vector2 &rkVector)

Vector2	operator+ (const Vector2 &lhs, const float rhs)

Vector2	operator+ (const float lhs, const Vector2 &rhs)

Vector2	operator- (const Vector2 &lhs, const float rhs)

Vector2	operator- (const float lhs, const Vector2 &rhs)

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 orthogonal axes (x, y). Note that positions, directions and scaling factors can be represented by a vector, depending on how you interpret the values.

Member Function Documentation

§ dotProduct()

float ParaEngine::Vector2::dotProduct ( const Vector2 & vec ) const

inline

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.

§ isZeroLength()

bool ParaEngine::Vector2::isZeroLength ( void ) const

inline

Returns true if this vector is zero length.

§ length()

float ParaEngine::Vector2::length ( ) const

inline

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.

§ makeCeil()

void ParaEngine::Vector2::makeCeil ( const Vector2 & cmp )

inline

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.

§ makeFloor()

void ParaEngine::Vector2::makeFloor ( const Vector2 & cmp )

inline

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.

§ normalise()

float ParaEngine::Vector2::normalise ( void )

inline

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.

§ normalisedCopy()

Vector2 ParaEngine::Vector2::normalisedCopy ( void ) const

inline

As normalise, except that this vector is unaffected and the normalised vector is returned as a copy.

§ operator=()

Vector2& ParaEngine::Vector2::operator= ( const Vector2 & rkVector )

inline

Assigns the value of the other vector.

Parameters

rkVector The other vector

§ perpendicular()

Vector2 ParaEngine::Vector2::perpendicular ( void ) const

inline

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.

§ randomDeviant()

Vector2 ParaEngine::Vector2::randomDeviant ( float angle ) const

inline

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.

§ reflect()

Vector2 ParaEngine::Vector2::reflect ( const Vector2 & normal ) const

inline

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.

§ squaredLength()

float ParaEngine::Vector2::squaredLength ( ) const

inline

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.

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

Client/trunk/ParaEngineClient/math/ParaVector2.h
Client/trunk/ParaEngineClient/math/ParaVector2.cpp
Client/trunk/ParaEngineClient/math/ParaVector3.inl

Public Member Functions

Public Attributes

Static Public Attributes

Friends

Detailed Description

Member Function Documentation

§ dotProduct()

§ isZeroLength()

§ length()

§ makeCeil()

§ makeFloor()

§ normalise()

§ normalisedCopy()

§ operator=()

§ perpendicular()

§ randomDeviant()

§ reflect()

§ squaredLength()