BPolygon Class Reference

A closed, many-sided figure which defines an area in a two-dimensional Cartesian coordinate system. More...

Public Member Functions
	BPolygon ()
	Initializes an empty polygon without any points.
	BPolygon (const BPoint *points, int32 count)
	Initializes a new BPolygon object from an array of points.
	BPolygon (const BPolygon &other)
	Initializes a new BPolygon object from another BPolygon and copies the list of BPoint objects from other.
	BPolygon (const BPolygon *other)
	Initializes a new BPolygon object from a pointer to another BPolygon and copies the list of BPoint objects from other.
virtual	~BPolygon ()
	Destroys the object and frees the memory used by the associated BPoint objects.
void	AddPoints (const BPoint *points, int32 count)
	Adds an array of BPoint objects.
int32	CountPoints () const
	Returns the number of points associated with the polygon.
BRect	Frame () const
	Returns the frame rectangle that encloses the BPolygon object.
void	MapTo (BRect source, BRect destination)
	Modifies each BPoint in the BPolygon so that the shape fits inside the destination rectangle.
BPolygon &	operator= (const BPolygon &other)
	Initializes a new BPolygon object and copies the list of BPoint objects from other.
void	PrintToStream () const
	Prints each of the points of the BPolygon to standard output.

Detailed Description

A closed, many-sided figure which defines an area in a two-dimensional Cartesian coordinate system.

A BPolygon is defined as a set of BPoint objects, each BPoint represents a vertex of the polygon. Unlike a BRect, a BPolygon can can have any number of sides and the sides don't have to be aligned on coordinate axes.

BPolygon objects are most commonly used for drawing. BView::StrokePolygon() and BView::FillPolygon() allow you to draw a polygon in a BView by taking a BPolygon object as an argument.

See also

BView::StrokePolygon()

BView::FillPolygon()

Since

BeOS R3

Constructor & Destructor Documentation

BPolygon() [1/4]

BPolygon::BPolygon	(	const BPoint *	points,
		int32	count
	)

Initializes a new BPolygon object from an array of points.

Parameters

points	The array of BPoint objects to add.
count	The number of BPoint objects in the array.

Since

BeOS R3

BPolygon() [2/4]

BPolygon::BPolygon

(

const BPolygon &

other

)

Initializes a new BPolygon object from another BPolygon and copies the list of BPoint objects from other.

Parameters

other

The BPolygon object to copy from.

Since

Haiku R1

BPolygon() [3/4]

BPolygon::BPolygon

(

const BPolygon *

other

)

Initializes a new BPolygon object from a pointer to another BPolygon and copies the list of BPoint objects from other.

Parameters

other

A pointer to a BPolygon object to copy from.

Since

BeOS R3

BPolygon() [4/4]

BPolygon::BPolygon

(

)

Initializes an empty polygon without any points.

See also

BPolygon::AddPoints() to add points to the BPolygon.

Since

BeOS R3

~BPolygon()

BPolygon::~BPolygon ( )

virtual

Destroys the object and frees the memory used by the associated BPoint objects.

Since

BeOS R3

Member Function Documentation

AddPoints()

void BPolygon::AddPoints	(	const BPoint *	points,
		int32	count
	)

Adds an array of BPoint objects.

Parameters

points	The array of BPoint objects to add.
count	The number of BPoint objects in the array.

Since

BeOS R3

CountPoints()

int32 BPolygon::CountPoints

(

)

const

Returns the number of points associated with the polygon.

Since

BeOS R3

Frame()

BRect BPolygon::Frame

(

)

const

Returns the frame rectangle that encloses the BPolygon object.

Since

BeOS R3

MapTo()

void BPolygon::MapTo	(	BRect	source,
		BRect	destination
	)

Modifies each BPoint in the BPolygon so that the shape fits inside the destination rectangle.

The source rectangle is used so that the points are mapped proportionally. To modify a polygon so that it is inscribed in the destination rectangle exactly, pass the frame rectangle as the source.

Since

BeOS R3

operator=()

BPolygon & BPolygon::operator=

(

const BPolygon &

other

)

Initializes a new BPolygon object and copies the list of BPoint objects from other.

Parameters

other

The BPolygon object to copy from.

Since

BeOS R3

PrintToStream()

void BPolygon::PrintToStream

(

)

const

Prints each of the points of the BPolygon to standard output.

See also

BPoint::PrintToStream()

Since

BeOS R3