donner::Box< T > Struct Template Reference

A 2D axis-aligned bounding box. More...

#include "donner/base/Box.h"

Public Member Functions
	Box ()
	Default constructor: Creates an empty box centered on (0, 0).
	Box (const Vector2< T > &topLeft, const Vector2< T > &bottomRight)
	Construct a new box with the given top-left and bottom-right corners.
	~Box ()=default
	Destructor.
	Box (const Box< T > &other)=default
	Copy constructor.
Box< T > &	operator= (const Box< T > &other)=default
	Copy assignment operator.
	Box (Box< T > &&other) noexcept=default
	Move constructor.
Box< T > &	operator= (Box< T > &&other) noexcept=default
	Move assignment operator.
void	addPoint (const Vector2< T > &point)
	Expand to include the provided point.
void	addBox (const Box< T > &box)
	Adds a bounding box inside this bounding box.
Box	toOrigin () const
	Return a box with the same size but moved to the origin, i.e.
T	width () const
	Returns the box width.
T	height () const
	Returns the box height.
Vector2< T >	size () const
	Returns the box size.
bool	isEmpty () const
	Returns true if the box has zero width or height.
bool	contains (const Vector2< T > &point) const
	Returns true if the box contains the given point.
Box< T >	inflatedBy (T amount) const
	Inflates the box size by the given amount in all directions.
Box< T >	operator- (const Vector2< T > &vec) const
	Return the box moved by subtracting the given vector.
Box< T > &	operator-= (const Vector2< T > &vec)
	Move the box by subtracting the given vector.
Box< T >	operator+ (const Vector2< T > &vec) const
	Return the box moved by adding the given vector.
Box< T > &	operator+= (const Vector2< T > &vec)
	Move the box by adding the given vector.
bool	operator== (const Box< T > &other) const
	Equality operator.
bool	operator!= (const Box< T > &rhs) const
	Inequality operator.

Static Public Member Functions
static Box< T >	FromXYWH (T x, T y, T width, T height)
	Creates a Box from x, y, width, and height.
static Box< T >	CreateEmpty (const Vector2< T > &point)
	Create an empty box that is centered on the given point.
static Box< T >	WithSize (const Vector2< T > &size)
	Create a box with the given size, with the top-left corner at the origin.
static Box< T >	Union (const Box< T > &a, const Box< T > &b)
	Create a new box that is expanded to include both boxes.

Public Attributes
Vector2< T >	topLeft
	The top-left corner of the box.
Vector2< T >	bottomRight
	The bottom-right corner of the box.

Friends
std::ostream &	operator<< (std::ostream &os, const Box< T > &box)
	Ostream output operator.

Detailed Description

template<typename T>
struct donner::Box< T >

A 2D axis-aligned bounding box.

For example, to construct a box, add points to it, and query its size:

Boxd box(Vector2d(-1.0, -1.0), Vector2d(1.0, 1.0));
box.addPoint(Vector2d(2.0, 0.0));
 
assert(box == Boxd(Vector2d(-1.0, -1.0), Vector2d(2.0, 1.0)));
assert(box.size() == Vector2d(3.0, 2.0));

Template Parameters

T	Element type, e.g. double, float, int, etc.

Constructor & Destructor Documentation

Box() [1/3]

template<typename T >

donner::Box< T >::Box ( const Vector2< T > & topLeft, const Vector2< T > & bottomRight )

inline

Construct a new box with the given top-left and bottom-right corners.

Parameters

topLeft	Top-left corner.
bottomRight	Bottom-right corner.

Box() [2/3]

template<typename T >

donner::Box< T >::Box ( const Box< T > & other )

default

Copy constructor.

Parameters

other

Other box.

Box() [3/3]

template<typename T >

donner::Box< T >::Box ( Box< T > && other )

defaultnoexcept

Move constructor.

Parameters

other

Other box.

Member Function Documentation

addBox()

template<typename T >

void donner::Box< T >::addBox ( const Box< T > & box )

inline

Adds a bounding box inside this bounding box.

Parameters

box	Box to add.

addPoint()

template<typename T >

void donner::Box< T >::addPoint ( const Vector2< T > & point )

inline

Expand to include the provided point.

Parameters

point

Point to include.

contains()

template<typename T >

bool donner::Box< T >::contains ( const Vector2< T > & point ) const

inline

Returns true if the box contains the given point.

Parameters

point

Point to check.

CreateEmpty()

template<typename T >

static Box< T > donner::Box< T >::CreateEmpty ( const Vector2< T > & point )

inlinestatic

Create an empty box that is centered on the given point.

Parameters

point

Center point.

FromXYWH()

template<typename T >

static Box< T > donner::Box< T >::FromXYWH ( T x, T y, T width, T height )

inlinestatic

Creates a Box from x, y, width, and height.

Parameters

x	X coordinate of the top-left corner.
y	Y coordinate of the top-left corner.
width	Width of the box.
height	Height of the box.

inflatedBy()

template<typename T >

Box< T > donner::Box< T >::inflatedBy ( T amount ) const

inline

Inflates the box size by the given amount in all directions.

Parameters

amount

Amount to inflate the box by.

operator=() [1/2]

template<typename T >

Box< T > & donner::Box< T >::operator= ( Box< T > && other )

defaultnoexcept

Move assignment operator.

Parameters

other

Other box.

operator=() [2/2]

template<typename T >

Box< T > & donner::Box< T >::operator= ( const Box< T > & other )

default

Copy assignment operator.

Parameters

other

Other box.

toOrigin()

template<typename T >

Box donner::Box< T >::toOrigin ( ) const

inline

Return a box with the same size but moved to the origin, i.e.

with the top-left corner at (0, 0).

Union()

template<typename T >

static Box< T > donner::Box< T >::Union ( const Box< T > & a, const Box< T > & b )

inlinestatic

Create a new box that is expanded to include both boxes.

Parameters

a	First box.
b	Second box.

WithSize()

template<typename T >

static Box< T > donner::Box< T >::WithSize ( const Vector2< T > & size )

inlinestatic

Create a box with the given size, with the top-left corner at the origin.

Parameters

size	Size of the box.

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

• donner/base/Box.h