Vec4 Class Reference

#include <vec4.h>

List of all members.

---

Detailed Description

The vector class.

It is stored as an array so ,that it can be, e.g. loaded directly into an OpenGL function. The fourth float is ignored when convenient, such as cross products and such. Dunno about lengths though. By default, not, perhaps.

Author:

Stephen Bridges

Todo:

Decide about fourth cell/thingy.

Public Member Functions
	Vec4 ()
	Default constructor zeroes array.
	Vec4 (float *in)
	Constructor for array of floats.
	Vec4 (float x, float y, float z, float w)
	Constructor for four seperate floats.
	~Vec4 ()
	Empty destructor.
	Vec4 (const Vec4 &other)
	Copy constructor.
Vec4 &	operator= (const Vec4 &other)
	Equals operator.
float &	operator() (unsigned int i)
	Indexing operator.
float	operator() (unsigned int i) const
	Indexing operator.
Vec4	operator+ (const Vec4 &other) const
	Add vectors, all cells.
Vec4 &	operator+= (const Vec4 &other)
	+= operator, all cells
Vec4	operator- (const Vec4 &other) const
	Subtracts, all cells.
Vec4 &	operator-= (const Vec4 &other)
	Subtracts, all cells.
Vec4	operator- (void) const
	Unary negating operator.
Vec4	operator/ (const float &other) const
	Note: prints to cerr on divbyzero.
Vec4 &	operator/= (const float &other)
	Note: prints to cerr on divbyzero.
Vec4	operator * (const float &other) const
	Multiplication.
Vec4 &	operator *= (const float &other)
	Multiplication.
Vec4	operator * (const Matrix4x4 &other) const
	This is just a wrapper for the *= operator.
Vec4 &	operator *= (const Matrix4x4 &other)
	Multiply by matrix.
bool	operator== (const Vec4 &other) const
	Equality tester.
bool	operator!= (const Vec4 &other) const
	Inequality tester.
void	Zero (void)
	Zeroes array.
void	Print (void)
	Prints vector (as row) to cout.
float	Length (void)
	Calculates the length of the vector.
float	SqrLength (void)
	Calculates the square of the length of the vector.
void	Normalise (void)
	Make length of vector zero.
void	Clean (void)
	Clean out values that are near zero.
int	mainDir (void)
	Gives the axis in which the vector is most strongly pointing.
void	rotate (float xin, float yin, float zin)
	Rotates a vector.
Public Attributes
float	v [4]
	The data array.

---

Member Function Documentation

float Vec4::Length (  void   )

Calculates the length of the vector. Note: This ignores the fourth var. Returns: Length as float.

Here is the call graph for this function:

int Vec4::mainDir (  void   )

Gives the axis in which the vector is most strongly pointing. This seems a bit esoteric, but useful in collision detection for projecting triangles onto 2D surfaces as choosing the axis carefully can increase accuracy. Returns: An integer indicating which cell/axis is largest

Vec4 & Vec4::operator *= (  const Matrix4x4 &  other  )

Multiply by matrix. Rather vitally important, some might say. This assumes the bottom row of the matrix will be uninteresting.

float Vec4::operator() (  unsigned int  i  )  const [inline]

Indexing operator. This takes indices into the vector and returns a copy of the correct cell. Parameters: i  Down. Returns: Copy of cell.

float & Vec4::operator() (  unsigned int  i  )  [inline]

Indexing operator. This takes indices into the vector and returns a reference to the correct cell. Parameters: i  Down. Returns: Changable reference.

Vec4 Vec4::operator- (  void   )  const

Unary negating operator. Does not negate 4th cell, as that just seems silly.

Vec4 & Vec4::operator= (  const Vec4 &  other  )

Equals operator. Returns a reference for somethin = something = something lines.

void Vec4::rotate (  float  xin, float  yin, float  zin )

Rotates a vector. Hopefully can be replaced with an affine transform. Now will 100% radian goodness. No degrees here!

float Vec4::SqrLength (  void   )  [inline]

Calculates the square of the length of the vector. Note: This ignores the fourth var. It is also more efficient with no pesky sqrt()s. Inlined as we'll probably call it a lot. Returns: Squared Length as float.

---

Member Data Documentation

float Vec4::v[4]

The data array. Currently publically available.

---

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

• vec4.h
• vec4.cpp

---