LRegion Class Reference

#include <LRegion.h>

Collection of non-overlapping rectangles. More...

Detailed Description

Collection of non-overlapping rectangles.

The LRegion class provides an efficient mechanism for creating sets of rectangles that do not overlap in their geometries. It offers methods for performing operations such as additions, subtractions, intersections, and more on rectangles. This class is extensively used by the library for tasks like calculating surface damage, defining opaque, translucent, and input regions, among others. Internally, LRegion employs the algorithm and functions from the Pixman library.

Public Member Functions
	LRegion ()
	Constructor for creating an empty LRegion. More...
	LRegion (const LRect &rect)
	Initialize the region with a rect. More...
	~LRegion ()
	Destructor for freeing resources associated with LRegion. More...
	LRegion (const LRegion &other)
	Copy constructor for creating an LRegion by copying another LRegion. More...
LRegion &	operator= (const LRegion &other)
	Assignment operator for assigning the content of one LRegion to another. More...
void	clear ()
	Clears the LRegion, deleting all rectangles. More...
void	addRect (const LRect &rect)
	Adds a rectangle to the LRegion (union operation). More...
void	addRect (const LPoint &pos, const LSize &size)
	Adds a rectangle to the LRegion (union operation). More...
void	addRect (Int32 x, Int32 y, const LSize &size)
	Adds a rectangle to the LRegion (union operation). More...
void	addRect (const LPoint &pos, Int32 w, Int32 h)
	Adds a rectangle to the LRegion (union operation). More...
void	addRect (Int32 x, Int32 y, Int32 w, Int32 h)
	Adds a rectangle to the LRegion (union operation). More...
void	addRegion (const LRegion &region)
	Adds the content of another LRegion to this LRegion (union operation). More...
void	subtractRect (const LRect &rect)
	Subtracts a rectangle from the LRegion. More...
void	subtractRect (const LPoint &pos, const LSize &size)
	Subtracts a rectangle from the LRegion. More...
void	subtractRect (const LPoint &pos, Int32 w, Int32 h)
	Subtracts a rectangle from the LRegion. More...
void	subtractRect (Int32 x, Int32 y, const LSize &size)
	Subtracts a rectangle from the LRegion. More...
void	subtractRect (Int32 x, Int32 y, Int32 w, Int32 h)
	Subtracts a rectangle from the LRegion. More...
void	subtractRegion (const LRegion &region)
	Subtracts another LRegion from this LRegion. More...
void	intersectRegion (const LRegion &region)
	Intersects this LRegion with another LRegion. More...
void	multiply (Float32 factor)
	Multiplies the components of each rectangle in the LRegion by the given factor. More...
void	multiply (Float32 xFactor, Float32 yFactor)
	Multiplies the components of each rectangle in the LRegion by the given factor. More...
bool	containsPoint (const LPoint &point) const
	Check if the LRegion contains a specific point. More...
void	offset (const LPoint &offset)
	Translate each rectangle in the LRegion by the specified offset. More...
void	offset (Int32 x, Int32 y)
	Translate each rectangle in the LRegion by the specified offset. More...
void	inverse (const LRect &rect)
	Invert the region contained within the specified rectangle. More...
bool	empty () const
	Check if the LRegion is empty (contains no rectangles). More...
void	clip (const LRect &rect)
	Clips the LRegion to the area defined by the specified rectangle. More...
void	clip (const LPoint &pos, const LSize &size)
	Clips the LRegion to the area defined by the specified rectangle. More...
void	clip (Int32 x, Int32 y, Int32 w, Int32 h)
	Clips the LRegion to the area defined by the specified rectangle. More...
const LBox &	extents () const
	Get the extents of the LRegion. More...
LBox *	boxes (Int32 *n) const
	Retrieves the list of rectangles that form the LRegion. More...
void	transform (const LSize &size, LFramebuffer::Transform transform)
	Applies a specified transforma to all rectangles within the given size. More...

Constructor & Destructor Documentation

LRegion() [1/3]

LRegion

(

)

Constructor for creating an empty LRegion.

LRegion() [2/3]

LRegion

(

const LRect &

rect

)

Initialize the region with a rect.

~LRegion()

~LRegion

(

)

Destructor for freeing resources associated with LRegion.

LRegion() [3/3]

LRegion

(

const LRegion &

other

)

Copy constructor for creating an LRegion by copying another LRegion.

Parameters

other

The LRegion to copy from.

Member Function Documentation

operator=()

Louvre::LRegion & operator=

(

const LRegion &

other

)

Assignment operator for assigning the content of one LRegion to another.

Parameters

other

The LRegion to assign from.

Returns

A reference to the modified LRegion.

clear()

void clear

(

)

Clears the LRegion, deleting all rectangles.

addRect() [1/5]

void addRect

(

const LRect &

rect

)

Adds a rectangle to the LRegion (union operation).

Parameters

rect	The rectangle to add.

addRect() [2/5]

void addRect	(	const LPoint &	pos,
		const LSize &	size
	)

Adds a rectangle to the LRegion (union operation).

Parameters

pos	The rectangle's top-left corner.
size	The rectangle's size.

addRect() [3/5]

void addRect	(	Int32	x,
		Int32	y,
		const LSize &	size
	)

Adds a rectangle to the LRegion (union operation).

Parameters

x	The x-coordinate of the rectangle's top-left corner.
y	The y-coordinate of the rectangle's top-left corner.
size	The rectangle's size.

addRect() [4/5]

void addRect	(	const LPoint &	pos,
		Int32	w,
		Int32	h
	)

Adds a rectangle to the LRegion (union operation).

Parameters

pos	The rectangle's top-left corner.
w	The width of the rectangle.
h	The height of the rectangle.

addRect() [5/5]

void addRect	(	Int32	x,
		Int32	y,
		Int32	w,
		Int32	h
	)

Adds a rectangle to the LRegion (union operation).

Parameters

x	The x-coordinate of the rectangle's top-left corner.
y	The y-coordinate of the rectangle's top-left corner.
w	The width of the rectangle.
h	The height of the rectangle.

addRegion()

void addRegion

(

const LRegion &

region

)

Adds the content of another LRegion to this LRegion (union operation).

Parameters

region

The LRegion to add.

subtractRect() [1/5]

void subtractRect

(

const LRect &

rect

)

Subtracts a rectangle from the LRegion.

Parameters

rect	The rectangle to subtract.

subtractRect() [2/5]

void subtractRect	(	const LPoint &	pos,
		const LSize &	size
	)

Subtracts a rectangle from the LRegion.

Parameters

pos	The rectangle's top-left corner.
size	The rectangle's size.

subtractRect() [3/5]

void subtractRect	(	const LPoint &	pos,
		Int32	w,
		Int32	h
	)

Subtracts a rectangle from the LRegion.

Parameters

pos	The rectangle's top-left corner.
w	The width of the rectangle.
h	The height of the rectangle.

subtractRect() [4/5]

void subtractRect	(	Int32	x,
		Int32	y,
		const LSize &	size
	)

Subtracts a rectangle from the LRegion.

Parameters

x	The x-coordinate of the rectangle's top-left corner.
y	The y-coordinate of the rectangle's top-left corner.
size	The rectangle's size.

subtractRect() [5/5]

void subtractRect	(	Int32	x,
		Int32	y,
		Int32	w,
		Int32	h
	)

Subtracts a rectangle from the LRegion.

Parameters

x	The x-coordinate of the rectangle's top-left corner.
y	The y-coordinate of the rectangle's top-left corner.
w	The width of the rectangle.
h	The height of the rectangle.

subtractRegion()

void subtractRegion

(

const LRegion &

region

)

Subtracts another LRegion from this LRegion.

Parameters

region

The LRegion to subtract.

intersectRegion()

void intersectRegion

(

const LRegion &

region

)

Intersects this LRegion with another LRegion.

Parameters

region

The LRegion to intersect with.

multiply() [1/2]

void multiply

(

Float32

factor

)

Multiplies the components of each rectangle in the LRegion by the given factor.

Parameters

factor

The factor to multiply by.

multiply() [2/2]

void multiply	(	Float32	xFactor,
		Float32	yFactor
	)

Multiplies the components of each rectangle in the LRegion by the given factor.

Parameters

xFactor	The x-axis factor to multiply by.
yFactor	The y-axis factor to multiply by.

containsPoint()

bool containsPoint

(

const LPoint &

point

)

const

Check if the LRegion contains a specific point.

Parameters

point

The point to check.

Returns

true if the region contains the point, false otherwise.

offset() [1/2]

void offset

(

const LPoint &

offset

)

Translate each rectangle in the LRegion by the specified offset.

Parameters

offset

The offset to apply.

offset() [2/2]

void offset	(	Int32	x,
		Int32	y
	)

Translate each rectangle in the LRegion by the specified offset.

Parameters

x	The x offset to apply.
y	The y offset to apply.

inverse()

void inverse

(

const LRect &

rect

)

Invert the region contained within the specified rectangle.

Parameters

rect	The rectangle to define the area of inversion.

empty()

bool empty

(

)

const

Check if the LRegion is empty (contains no rectangles).

Returns

true if the region is empty, false otherwise.

clip() [1/3]

void clip

(

const LRect &

rect

)

Clips the LRegion to the area defined by the specified rectangle.

Parameters

rect	The rectangle used for clipping.

clip() [2/3]

void clip	(	const LPoint &	pos,
		const LSize &	size
	)

Clips the LRegion to the area defined by the specified rectangle.

clip() [3/3]

void clip	(	Int32	x,
		Int32	y,
		Int32	w,
		Int32	h
	)

Clips the LRegion to the area defined by the specified rectangle.

extents()

const LBox & extents

(

)

const

Get the extents of the LRegion.

This method returns a pointer to an LBox that represents the bounding box of the LRegion. The LBox contains the minimum and maximum coordinates that enclose the LRegion.

Returns

A pointer to the extents of the LRegion as an LBox.

boxes()

LBox * boxes

(

Int32 *

n

)

const

Retrieves the list of rectangles that form the LRegion.

Parameters

n	A pointer to an integer that will be set to the number of rectangles.

Returns

A pointer to an array of LBox objects representing the rectangles.

Note

This variant allows you to access the rectangles using the native Pixman method, which is considerably faster.

transform()

void transform	(	const LSize &	size,
		LFramebuffer::Transform	transform
	)

Applies a specified transforma to all rectangles within the given size.

This function clips the rectangles within the specified size and applies the specified transform.

Parameters

size	The size used for clipping and transformation.
transform	The transform to be applied to the rectangles.