Utility class for manipulating 2D axis aligned rectangles. More...

#include <gf/Rect.h>

Public Member Functions
constexpr	Rect () noexcept
	Default constructor. More...

constexpr	Rect (T rectLeft, T rectTop, T rectWidth, T rectHeight) noexcept
	Construct the rectangle from its coordinates. More...

	Rect (const Vector< T, 2 > &rectPosition, const Vector< T, 2 > &rectSize) noexcept
	Construct the rectangle from position and size. More...

constexpr Vector< T, 2 >	getPosition () const noexcept
	Get the position of the rectangle. More...

constexpr Vector< T, 2 >	getSize () const noexcept
	Get the size of the rectangle. More...

constexpr bool	isEmpty () const noexcept
	Check if the rectangle is empty. More...

constexpr Vector< T, 2 >	getCenter () const noexcept
	Get the center of the rectangle. More...

constexpr Vector< T, 2 >	getTopLeft () const noexcept
	Get the top left corner. More...

constexpr Vector< T, 2 >	getTopRight () const noexcept
	Get the top right corner. More...

constexpr Vector< T, 2 >	getBottomLeft () const noexcept
	Get the bottom left corner. More...

constexpr Vector< T, 2 >	getBottomRight () const noexcept
	Get the bottom right corner. More...

constexpr bool	contains (const Vector< T, 2 > &point) const noexcept
	Check if a point is inside the rectangle's area. More...

constexpr bool	contains (const Rect< T > &other) const noexcept
	Check if a rectangle is inside the rectangle's area. More...

constexpr bool	intersects (const Rect< T > &other) const noexcept
	Check the intersection between two rectangles. More...

bool	intersects (const Rect< T > &other, Rect< T > &result) const noexcept
	Check the intersection between two rectangles. More...

constexpr Rect< T >	extend (T value) const noexcept
	Extend the rectangle. More...

constexpr Rect< T >	shrink (T value) const noexcept
	Shrink the rectangle. More...

Public Attributes
union {
struct {
T left
	Left coordinate of the rectangle. More...

T top
	Top coordinate of the rectangle. More...

T width
	Width of the rectangle. More...

T height
	Height of the rectangle. More...

}

struct {
Vector< T, 2 > position
	Position of the rectangle. More...

Vector< T, 2 > size
	Size of the rectangle. More...

}

};

Related Functions
(Note that these are not member functions.)
template<typename T >
bool	operator== (const Rect< T > &lhs, const Rect< T > &rhs)
	Equality operator. More...

template<typename T >
bool	operator!= (const Rect< T > &lhs, const Rect< T > &rhs)
	Inequality operator. More...

Detailed Description

template<typename T>
struct gf::Rect< T >

Utility class for manipulating 2D axis aligned rectangles.

A rectangle is defined by its top-left corner and its size. It is a very simple class defined for convenience, so its member variables (left, top, width and height) are public and can be accessed directly. You can also access the position and the size of the rectangle directly as gf::Vector.

gf::Rect uses the usual rules for its boundaries:

The left and top edges are included in the rectangle's area
The right (left + width) and bottom (top + height) edges are excluded from the rectangle's area

This means that gf::RectI(0, 0, 1, 1) and gf::RectI(1, 1, 1, 1) don't intersect.

gf::Rect is a template and may be used with any numeric type, but for simplicity, some common typedef are defined:

gf::RectI with int as T
gf::RectU with unsigned as T
gf::RectZ with std::size_t as T
gf::RectF with float as T

So that you don't have to care about the template syntax.

Usage example:

// Define a rectangle, located at (0, 0) with a size of 20x5
gf::RectI r1(0, 0, 20, 5);
// Define another rectangle, located at (4, 2) with a size of 18x10
gf::Vector2i position(4, 2);
gf::Vector2i size(18, 10);
gf::RectI r2(position, size);
// Test intersections with the point (3, 1)
bool b1 = r1.contains({ 3, 1 }); // true
bool b2 = r2.contains({ 3, 1 }); // false
// Test the intersection between r1 and r2
gf::RectI result;
bool b3 = r1.intersects(r2, result); // true
// result == (4, 2, 16, 3)

Constructor & Destructor Documentation

template<typename T>

constexpr gf::Rect< T >::Rect ( )

inlinenoexcept

Default constructor.

Creates an empty rectangle (it is equivalent to calling Rect(0, 0, 0, 0)).

template<typename T>

constexpr gf::Rect< T >::Rect	(	T	rectLeft,
		T	rectTop,
		T	rectWidth,
		T	rectHeight
	)

inlinenoexcept

Construct the rectangle from its coordinates.

Be careful, the last two parameters are the width and height, not the right and bottom coordinates!

Parameters

rectLeft	Left coordinate of the rectangle
rectTop	Top coordinate of the rectangle
rectWidth	Width of the rectangle
rectHeight	Height of the rectangle

template<typename T>

gf::Rect< T >::Rect	(	const Vector< T, 2 > &	rectPosition,
		const Vector< T, 2 > &	rectSize
	)

inlinenoexcept

Construct the rectangle from position and size.

Be careful, the last parameter is the size, not the bottom-right corner!

Parameters

rectPosition	Position of the top left corner of the rectangle
rectSize	Size of the rectangle

Member Function Documentation

template<typename T>

constexpr bool gf::Rect< T >::contains ( const Vector< T, 2 > & point ) const

inlinenoexcept

Check if a point is inside the rectangle's area.

Parameters

point Point to test

Returns: True if the point is inside, false otherwise

See also: intersects()

template<typename T>

constexpr bool gf::Rect< T >::contains ( const Rect< T > & other ) const

inlinenoexcept

Check if a rectangle is inside the rectangle's area.

Parameters

other Rectangle to test

Returns: True if the rectangle is inside, false otherwise

See also: intersects()

template<typename T>

constexpr Rect<T> gf::Rect< T >::extend ( T value ) const

inlinenoexcept

Extend the rectangle.

Parameters

value The amount to extend

Returns: A new extended rectangle

See also: shrink()

template<typename T>

constexpr Vector<T, 2> gf::Rect< T >::getBottomLeft ( ) const

inlinenoexcept

Get the bottom left corner.

Returns: The bottom left corner

template<typename T>

constexpr Vector<T, 2> gf::Rect< T >::getBottomRight ( ) const

inlinenoexcept

Get the bottom right corner.

Returns: The bottom right corner

template<typename T>

constexpr Vector<T, 2> gf::Rect< T >::getCenter ( ) const

inlinenoexcept

Get the center of the rectangle.

Returns: The center of the rectangle

template<typename T>

constexpr Vector<T, 2> gf::Rect< T >::getPosition ( ) const

inlinenoexcept

Get the position of the rectangle.

It is a synonym for the position member

Returns: The position of the rectangle

See also: getSize()

template<typename T>

constexpr Vector<T, 2> gf::Rect< T >::getSize ( ) const

inlinenoexcept

Get the size of the rectangle.

It is a synonym for the size member

Returns: The size of the rectangle

See also: getPosition()

template<typename T>

constexpr Vector<T, 2> gf::Rect< T >::getTopLeft ( ) const

inlinenoexcept

Get the top left corner.

Returns: The top left corner

template<typename T>

constexpr Vector<T, 2> gf::Rect< T >::getTopRight ( ) const

inlinenoexcept

Get the top right corner.

Returns: The top right corner

template<typename T>

constexpr bool gf::Rect< T >::intersects ( const Rect< T > & other ) const

inlinenoexcept

Check the intersection between two rectangles.

Parameters

other Rectangle to test

Returns: True if rectangles overlap, false otherwise

See also: contains()

template<typename T>

bool gf::Rect< T >::intersects	(	const Rect< T > &	other,
		Rect< T > &	result
	)		const

inlinenoexcept

Check the intersection between two rectangles.

This overload returns the overlapped rectangle in the result parameter.

Parameters

other	Rectangle to test
result	Rectangle to be filled with the intersection

Returns: True if rectangles overlap, false otherwise

See also: contains

template<typename T>

constexpr bool gf::Rect< T >::isEmpty ( ) const

inlinenoexcept

Check if the rectangle is empty.

An empty rectangle is a rectangle that has one of its size coordinates that is zero.

Returns: True if the rectangle is empty

template<typename T>

constexpr Rect<T> gf::Rect< T >::shrink ( T value ) const

inlinenoexcept

Shrink the rectangle.

Parameters

value The amount to shrink

Returns: A new shrinked rectangle

See also: extend()

Friends And Related Function Documentation

template<typename T >

bool operator!=	(	const Rect< T > &	lhs,
		const Rect< T > &	rhs
	)

Parameters

lhs	First rectangle
rhs	Second rectangle

Returns: True if the two rectangles are different

template<typename T >

bool operator==	(	const Rect< T > &	lhs,
		const Rect< T > &	rhs
	)

Parameters

lhs	First rectangle
rhs	Second rectangle

Returns: True if the two rectangles are the same

Member Data Documentation

union { ... }

An anonymous union to handle the various representations

template<typename T>

T gf::Rect< T >::height

Height of the rectangle.

template<typename T>

T gf::Rect< T >::left

Left coordinate of the rectangle.

template<typename T>

Vector<T, 2> gf::Rect< T >::position

Position of the rectangle.

template<typename T>

Vector<T, 2> gf::Rect< T >::size

Size of the rectangle.

template<typename T>

T gf::Rect< T >::top

Top coordinate of the rectangle.

template<typename T>

T gf::Rect< T >::width

Width of the rectangle.

Public Member Functions

Public Attributes

Related Functions

Detailed Description

template<typename T> struct gf::Rect< T >

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation

template<typename T>
struct gf::Rect< T >