IlvRegion Class Reference

Geometric class. More...

#include <ilviews/base/region.h>

List of all members.

Public Member Functions
	IlvRegion (const IlvRegion &)
	Constructor.
	IlvRegion (const IlvRect &rect)
	Constructor.
	IlvRegion ()
	Constructor.
void	add (const IlvRegion &region)
	Adds a region to this region.
void	add (const IlvRect &rect)
	Adds a rectangle to this region.
void	apply (const IlvTransformer *t)
	Transforms this region.
const IlvRect &	boundingBox () const
	Gets the region bounding box.
void	compact ()
	Compacts the rectangles of this region.
void	computeDifference (const IlvRect &rect1, const IlvRect &rect2)
	Computes a new region as the difference of the two specified rectangles.
IlBoolean	contains (const IlvRect &rect) const
	Tests is a rectangle is covered by this region.
IlBoolean	contains (const IlvPoint &point) const
	Tests if a point is located in this region.
IlvRegion *	copy () const
	Copies a region.
void	empty ()
	Removes all the rectangle from this region.
IlUShort	getCardinal () const
	Gets the number of stored rectangles.
const IlvRect &	getRect (IlUShort idx) const
	Gets one rectangle of this region.
void	grow (IlvPos dw, IlvPos dh)
	Enlarges a region.
void	intersection (const IlvRegion &region)
	Computes the intersection with another region.
void	intersection (const IlvRect &rect)
	Computes the intersection with a rectangle.
IlBoolean	intersects (const IlvRegion &region) const
	Tests whether another region intersects this region.
IlBoolean	intersects (const IlvRect &rect) const
	Tests if a rectangle intersects this region.
void	inverse (const IlvTransformer *t)
	Inverse transforms a region.
IlBoolean	isEmpty () const
	Tests if the region is empty.
IlBoolean	isFull () const
	Tests if the region is full.
const IlvRegion &	operator= (const IlvRegion &)
	Assigns a region.
void	subtract (const IlvRect &rect)
	Subtracts a rectangle from this region.
void	translate (IlvPos x, IlvPos y)
	Translates a region.

---

Detailed Description

Geometric class.

Library: display

The IlvRegion class maintains a list of rectangles (instances of the class IlvRect to speed up internal tasks related to regions of interest, such as redrawing operations. A region is created by specifying a rectangle or a region. It can also be created empty.

See also:

IlvRect.

---

Constructor & Destructor Documentation

IlvRegion::IlvRegion

(

)

Constructor.

This constructor initializes a new empty region.

IlvRegion::IlvRegion

(

const IlvRect &

rect

)

Constructor.

This constructor initializes a new region that contains a single rectangle.

Parameters:

rect

The initial rectangle stored in this region.

IlvRegion::IlvRegion

(

const IlvRegion &

)

Constructor.

This constructor initializes a new region by creating a copy of region.

---

Member Function Documentation

void IlvRegion::add

(

const IlvRegion &

region

)

Adds a region to this region.

Parameters:

region

The region to add.

void IlvRegion::add

(

const IlvRect &

rect

)

Adds a rectangle to this region.

Parameters:

rect

The rectangle to add.

void IlvRegion::apply

(

const IlvTransformer *

t

)

Transforms this region.

The resulting object has all its rectangles transformed.

Parameters:

t

The transformer to be applied.

const IlvRect& IlvRegion::boundingBox

(

)

const

Gets the region bounding box.

Returns:

The bounding rectangle of all the rectangles that this region object contains.

void IlvRegion::compact

(

)

Compacts the rectangles of this region.

Calling this method ensures that no rectangle of the region is intersecting with another rectangle of the region.

void IlvRegion::computeDifference	(	const IlvRect &	rect1,
		const IlvRect &	rect2
	)

Computes a new region as the difference of the two specified rectangles.

This method calls the empty method before filling the region with the difference of rect1 less rect2.

Parameters:

	rect1	The initial rectangle.
	rect2	The rectangle to subtract.

IlBoolean IlvRegion::contains

(

const IlvRect &

rect

)

const

Tests is a rectangle is covered by this region.

Parameters:

rect

The rectangle that is tested.

Returns:

IlTrue if rect is entirely inside one of the rectangles stored in this region. If rect is not contained in any of this region's rectangles, it returns IlFalse.

IlBoolean IlvRegion::contains

(

const IlvPoint &

point

)

const

Tests if a point is located in this region.

Parameters:

point

The point that is tested.

Returns:

IlTrue if point is inside one of the rectangles stored in this region. If point is outside all of the region's rectangles, it returns IlFalse.

IlvRegion* IlvRegion::copy

(

)

const

Copies a region.

This member function creates and returns a new object that is the exact copy of this.

Returns:

A pointer to a copy of the current object.

void IlvRegion::empty

(

)

Removes all the rectangle from this region.

The resulting object is an empty region.

IlUShort IlvRegion::getCardinal

(

)

const

Gets the number of stored rectangles.

Returns:

The number of rectangles that this region handles.

const IlvRect& IlvRegion::getRect

(

IlUShort

idx

)

const

Gets one rectangle of this region.

Parameters:

idx

The index of the rectangle you want to retrieve.

Returns:

The idx ^th rectangle stored in this region. The first rectangle of a region has an index of 0.

void IlvRegion::grow	(	IlvPos	dw,
		IlvPos	dh
	)

Enlarges a region.

All rectangles are enlarged, resulting in an enlarged region.

Parameters:

	dw	The horizontal growing value.
	dh	The vertical growing value.

void IlvRegion::intersection

(

const IlvRegion &

region

)

Computes the intersection with another region.

Sets the current region so it becomes the result of the intersection of the whole region with another region.

Parameters:

region

The region from which the intersection is computed.

void IlvRegion::intersection

(

const IlvRect &

rect

)

Computes the intersection with a rectangle.

Sets the current region so it becomes the result of the intersection of the whole region with a rectangle.

Parameters:

rect

The rectangle from which the intersection is computed.

IlBoolean IlvRegion::intersects

(

const IlvRegion &

region

)

const

Tests whether another region intersects this region.

Parameters:

region

The region that is tested.

Returns:

IlTrue if region intersects with any of the rectangles stored in this region. If region does not intersect with any of these rectangles, it returns IlFalse.

IlBoolean IlvRegion::intersects

(

const IlvRect &

rect

)

const

Tests if a rectangle intersects this region.

Parameters:

rect

The rectangle that is tested.

Returns:

IlTrue if rect intersects with any of the rectangles stored in this region. If rect does not intersect with any of these rectangles, it returns IlFalse.

void IlvRegion::inverse

(

const IlvTransformer *

t

)

Inverse transforms a region.

The resulting object has all its rectangles inversely transformed.

Parameters:

t

The transformer which inverse to be applied.

IlBoolean IlvRegion::isEmpty

(

)

const

Tests if the region is empty.

An empty region is a region that contains no point or rectangle at all.

Returns:

IlTrue if this object does not store any rectangle or if all the rectangles it contains have null dimensions. Otherwise, it returns IlFalse.

IlBoolean IlvRegion::isFull

(

)

const

Tests if the region is full.

A full region is a region that contains every possible point or rectangle.

Returns:

IlTrue if this object corresponds to a full region. Otherwise, it returns IlFalse.

const IlvRegion& IlvRegion::operator=

(

const IlvRegion &

)

Assigns a region.

Parameters:

region

The region that must be assigned.

Returns:

The current object after the assignment is done.

void IlvRegion::subtract

(

const IlvRect &

rect

)

Subtracts a rectangle from this region.

Parameters:

rect

The rectangle to subtract.

void IlvRegion::translate	(	IlvPos	x,
		IlvPos	y
	)

Translates a region.

All rectangles are translated, resulting in a translated region.

Parameters:

	x	The horizontal translation value.
	y	The vertical translation value.