LRegion Class Reference

Collection of non-overlapping rectangles. More...

#include <LRegion.h>

Public Member Functions
	LRegion () noexcept
	Constructor for creating an empty LRegion.
	LRegion (const LRect &rect) noexcept
	Initialize the region with a rect.
	~LRegion () noexcept
	Destructor for freeing resources associated with LRegion.
	LRegion (const LRegion &other) noexcept
	Copy constructor.
	LRegion (LRegion &&other) noexcept
	Move constructor.
LRegion &	operator= (const LRegion &other) noexcept
	Copy assignment operator.
LRegion &	operator= (LRegion &&other) noexcept
	Move assignment operator.
void	clear () noexcept
	Clears the LRegion, deleting all rectangles.
void	addRect (const LRect &rect) noexcept
	Adds a rectangle to the LRegion (union operation).
void	addRect (const LPoint &pos, const LSize &size) noexcept
	Adds a rectangle to the LRegion (union operation).
void	addRect (Int32 x, Int32 y, const LSize &size) noexcept
	Adds a rectangle to the LRegion (union operation).
void	addRect (const LPoint &pos, Int32 w, Int32 h) noexcept
	Adds a rectangle to the LRegion (union operation).
void	addRect (Int32 x, Int32 y, Int32 w, Int32 h) noexcept
	Adds a rectangle to the LRegion (union operation).
void	addRegion (const LRegion &region) noexcept
	Adds the content of another LRegion to this LRegion (union operation).
void	subtractRect (const LRect &rect) noexcept
	Subtracts a rectangle from the LRegion.
void	subtractRect (const LPoint &pos, const LSize &size) noexcept
	Subtracts a rectangle from the LRegion.
void	subtractRect (const LPoint &pos, Int32 w, Int32 h) noexcept
	Subtracts a rectangle from the LRegion.
void	subtractRect (Int32 x, Int32 y, const LSize &size) noexcept
	Subtracts a rectangle from the LRegion.
void	subtractRect (Int32 x, Int32 y, Int32 w, Int32 h) noexcept
	Subtracts a rectangle from the LRegion.
void	subtractRegion (const LRegion &region) noexcept
	Subtracts another LRegion from this LRegion.
void	intersectRegion (const LRegion &region) noexcept
	Intersects this LRegion with another LRegion.
void	multiply (Float32 factor) noexcept
	Multiplies the components of each rectangle in the LRegion by the given factor.
void	multiply (Float32 xFactor, Float32 yFactor) noexcept
	Multiplies the components of each rectangle in the LRegion by the given factor.
bool	containsPoint (const LPoint &point) const noexcept
	Check if the LRegion contains a specific point.
void	offset (const LPoint &offset) noexcept
	Translate each rectangle in the LRegion by the specified offset.
void	offset (Int32 x, Int32 y) noexcept
	Translate each rectangle in the LRegion by the specified offset.
void	inverse (const LRect &rect) noexcept
	Invert the region contained within the specified rectangle.
bool	empty () const noexcept
	Check if the LRegion is empty (contains no rectangles).
void	clip (const LRect &rect) noexcept
	Clips the LRegion to the area defined by the specified rectangle.
void	clip (const LPoint &pos, const LSize &size) noexcept
	Clips the LRegion to the area defined by the specified rectangle.
void	clip (Int32 x, Int32 y, Int32 w, Int32 h) noexcept
	Clips the LRegion to the area defined by the specified rectangle.
const LBox &	extents () const noexcept
	Gets the extents of the LRegion.
const LBox *	boxes (Int32 *n) const noexcept
	Retrieves the list of rectangles that form the LRegion.
void	transform (const LSize &size, LTransform transform) noexcept
	Applies the specified transform to all rectangles within the given size.
LPointF	closestPointFrom (const LPointF &point, Float32 padding=0.f) const noexcept
	Returns the point within the region closest to the given point.
void	simplifyToExtents (Int32 threshold) noexcept
	Replace the rectangles with a single enclosing one if the number is >= threshold.

Static Public Member Functions
static const LRegion &	EmptyRegion () noexcept
	Const reference to an empty region.

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.

Constructor & Destructor Documentation

LRegion() [1/4]

LRegion ( )

inlinenoexcept

Constructor for creating an empty LRegion.

LRegion() [2/4]

LRegion ( const LRect &  rect )

inlinenoexcept

Initialize the region with a rect.

~LRegion()

~LRegion ( )

inlinenoexcept

Destructor for freeing resources associated with LRegion.

LRegion() [3/4]

LRegion ( const LRegion &  other )

inlinenoexcept

Copy constructor.

Parameters

other

The LRegion to copy from.

LRegion() [4/4]

LRegion ( LRegion &&  other )

inlinenoexcept

Move constructor.

Constructs an LRegion by moving the contents from another LRegion, leaving the source LRegion empty.
The source LRegion remains valid and can be used afterwards.

Parameters

other

The LRegion to move from.

Member Function Documentation

operator=() [1/2]

LRegion & operator= ( const LRegion &  other )

inlinenoexcept

Copy assignment operator.

Parameters

other

The LRegion to assign from.

Returns

A reference to the modified LRegion.

operator=() [2/2]

LRegion & operator= ( LRegion &&  other )

inlinenoexcept

Move assignment operator.

Assigns the contents of another LRegion to this LRegion by moving, leaving the source LRegion empty.
The source LRegion remains valid and can be used afterwards.

Parameters

other

The LRegion to move from.

Returns

A reference to this LRegion after the move.

clear()

void clear ( )

inlinenoexcept

Clears the LRegion, deleting all rectangles.

addRect() [1/5]

void addRect ( const LRect &  rect )

inlinenoexcept

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  )

inlinenoexcept

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  )

inlinenoexcept

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  )

inlinenoexcept

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  )

inlinenoexcept

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 )

inlinenoexcept

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 )

inlinenoexcept

Subtracts a rectangle from the LRegion.

Parameters

rect	The rectangle to subtract.

subtractRect() [2/5]

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

inlinenoexcept

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  )

inlinenoexcept

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  )

inlinenoexcept

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  )

inlinenoexcept

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 )

inlinenoexcept

Subtracts another LRegion from this LRegion.

Parameters

region

The LRegion to subtract.

intersectRegion()

void intersectRegion ( const LRegion &  region )

inlinenoexcept

Intersects this LRegion with another LRegion.

Parameters

region

The LRegion to intersect with.

multiply() [1/2]

void multiply ( Float32  factor )

noexcept

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  )

noexcept

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

inlinenoexcept

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 )

inlinenoexcept

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  )

inlinenoexcept

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 )

inlinenoexcept

Invert the region contained within the specified rectangle.

Parameters

rect	The rectangle to define the area of inversion.

empty()

bool empty ( ) const

inlinenoexcept

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 )

inlinenoexcept

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  )

inlinenoexcept

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

clip() [3/3]

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

inlinenoexcept

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

extents()

const LBox & extents ( ) const

inlinenoexcept

Gets 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()

const LBox * boxes ( Int32 *  n ) const

inlinenoexcept

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, LTransform  transform  )

noexcept

Applies the specified transform 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.

closestPointFrom()

LPointF closestPointFrom ( const LPointF &  point, Float32  padding = 0.f  ) const

noexcept

Returns the point within the region closest to the given point.

If the point is inside the region or the region is empty, the same point is returned.

Parameters

point	The point to find the closest point within the region.
padding	Optional padding applied to each of the region boxes.

simplifyToExtents()

void simplifyToExtents ( Int32  threshold )

inlinenoexcept

Replace the rectangles with a single enclosing one if the number is >= threshold.

Parameters

threshold

The threshold value. If the number of rectangles is greater than or equal to this value, the rectangles will be simplified to a single enclosing rectangle.

EmptyRegion()

static const LRegion & EmptyRegion ( )

inlinestaticnoexcept

Const reference to an empty region.