a relative or absolute (= relative to (0,0)) location on a grid More...

#include <graphics.h>

Public Member Functions
	vector ()
	construct a vector, the value defaults to (0,0)

	vector (short int x, short int y)
	construct a vector from its x and y coordinates

short int	x_get () const
	get the x component

short int	y_get () const
	get the y component

vector	operator+ (const vector p) const
	add two vectors by adding the x and y coordinates

vector	operator+= (const vector p)
	add a vector to an existing vector

vector	operator+ (void) const
	return the vector unmodified

vector	operator- (const vector p) const
	subtract two vectors by subtracting the coordinates

vector	operator-= (const vector p)
	subtract a vector from an existing vector

vector	operator- (void) const
	returns the negative of the vector (point-mirrored in the origin)

vector	operator/ (int n) const
	divides a vector by an integer by dividing the coordinates

vector &	operator/= (int n)
	divides an existing vector by an integer

vector	operator* (int n) const
	multiplies a vector by an integer by multiplying the coordinates

vector &	operator*= (int n)
	multiplies an existing vector by an integer

vector	operator* (const vector rhs) const
	multiplying two vectors multiplies their X and Y components

bool	operator== (const vector p) const
	reports whether two vectors are equal

bool	operator!= (const vector p) const
	reports whether two vectors are unequal

vector	direction (void) const
	returns the direction of a vector

vector	abs (void) const
	returns the absolute of a vector

vector	x_projection (void) const
	returns the projection of the vector on the x axis

vector	y_projection (void) const
	returns the projection of the vector on the y axis

vector	mirrored (void) const
	returns with x and y swapped

bool	is_within (const vector p) const
	reports whether te vector is within the box [0,p>

Static Public Member Functions
static vector	origin ()
	the vector (0,0)

static vector	zero ()
	the vector (0,0)

static vector	one ()
	the vector (1,1)

Related Functions
(Note that these are not member functions.)
std::ostream &	operator<< (std::ostream &s, const vector p)
	prints a vector

Detailed Description

a relative or absolute (= relative to (0,0)) location on a grid

A vector is a pair of 16-bit integer values that are the x and y coordinates of an absolute or relative location on an integer grid. A vector can be constructed from its x and y values. When no values are supplied a vector defaults to (0,0).

Vectors are intended to represent a location, displacement, or size on a garphics screen. 16 bits should be more than enough for this purpose.

When a vector is used to identify a pixel on a screen (0,0) is the top-left pixel.

Two vectors can be added or subtracted to yield a new vector. A vector can be multiplied or divided by an integer to yield a new vector. Vectors can be compared for equality and inequality. The x_projection() and y_projection() functions return the projection of the vector on the two axises. The function is_within() tests whether a vector is within the box bounded by the origin and the argument.

For debugging, a << operator is provided to print a vector.

A vector fits in a single (32 bits) word. It has no references to other objects.

Definition at line 52 of file graphics.h.

Member Function Documentation

vector bmptk::graphics::vector::abs ( void ) const

inline

returns the absolute of a vector

The absolute of a vector is the original vector, mirrored into the first quadrant by the x and y axises. In other words, the x and y of the absolute are the absolutes of the original x and y.

Definition at line 156 of file graphics.h.

vector bmptk::graphics::vector::direction ( void ) const

inline

returns the direction of a vector

The direction of a vector is a vector that, for both its x and y component, has the value 1 or -1, and the same sign as the original vector.

Definition at line 147 of file graphics.h.

bool bmptk::graphics::vector::is_within ( const vector p ) const

inline

reports whether te vector is within the box [0,p>

The call a.is_within(b) returns true iff a is within the rectangle [(0,0),b], where the boundary lines that go through (0,0) are included, but the boundaries that go through b are excluded.

Definition at line 187 of file graphics.h.

vector bmptk::graphics::vector::mirrored ( void ) const

inline

returns with x and y swapped

In other words, the return vector as mirrored in the y=x line.

Definition at line 178 of file graphics.h.

vector bmptk::graphics::vector::x_projection ( void ) const

inline

returns the projection of the vector on the x axis

In other words, the vector with y set to 0.

Definition at line 166 of file graphics.h.

vector bmptk::graphics::vector::y_projection ( void ) const

inline

returns the projection of the vector on the y axis

In other words, the vector with x set to 0.

Definition at line 172 of file graphics.h.

Friends And Related Function Documentation

std::ostream & operator<<	(	std::ostream &	s,
		const vector	p
	)

This operator prints a vector in the (%d,%d) format.

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

graphics/graphics.h

Public Member Functions

Static Public Member Functions

Related Functions

Detailed Description

Member Function Documentation

Friends And Related Function Documentation