# Q3PointArray Class Reference[Qt3Support module]

` #include <Q3PointArray>`

This class is part of the Qt 3 support library. It is provided to keep old source code working. We strongly advise against using it in new code. See Porting to Qt 4 for more information.

Inherits QPolygon.

## Public Functions

 Q3PointArray () Q3PointArray ( const QRect & r, bool closed = false ) Q3PointArray ( const QPolygon & other ) Q3PointArray copy () const Q3PointArray cubicBezier () const bool isNull () void makeArc ( int x, int y, int w, int h, int a1, int a2 ) void makeArc ( int x, int y, int w, int h, int a1, int a2, const QMatrix & xf ) void makeEllipse ( int x, int y, int w, int h )
• 18 public functions inherited from QPolygon
• 64 public functions inherited from QVector

• 2 static public members inherited from QVector

## Detailed Description

The Q3PointArray class provides an array of points.

Q3PointArray is a QPolygon subclass that provides functions to make it more source compatible with the QPointArray class in Qt 3.

In Qt 4, we recommend that you use QPainterPath for representing arcs, ellipses, and Bezier curves, rather than QPolygon.

## Member Function Documentation

### Q3PointArray::Q3PointArray ()

Constructs an empty Q3PointArray.

### Q3PointArray::Q3PointArray ( const QRect & r, bool closed = false )

Constructs a point array from the rectangle r.

If closed is false, then the point array just contains the following four points of the rectangle ordered clockwise. The bottom-right point is located at (r.x() + r.width(), r.y() + r.height()).

### Q3PointArray::Q3PointArray ( const QPolygon & other )

Constructs a copy of other.

### Q3PointArray Q3PointArray::copy () const

Returns a copy of this Q3PointArray.

### Q3PointArray Q3PointArray::cubicBezier () const

Returns the Bezier points for the four control points in this array.

### void Q3PointArray::makeArc ( int x, int y, int w, int h, int a1, int a2 )

Sets the points of the array to those describing an arc of an ellipse with size, width w by height h, and position (x, y), starting from angle a1 and spanning by angle a2. The resulting array has sufficient resolution for pixel accuracy (see the overloaded function which takes an additional QMatrix parameter).

Angles are specified in 16ths of a degree, i.e. a full circle equals 5760 (16*360). Positive values mean counter-clockwise, whereas negative values mean the clockwise direction. Zero degrees is at the 3 o'clock position.