# Q3PointArray Class

Header: | #include <Q3PointArray> |

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) |

### Additional Inherited Members

- 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.

### bool Q3PointArray::isNull()

Returns isEmpty(). Use isEmpty() instead.

### 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.

### void Q3PointArray::makeArc(int* x*, int* y*, int* w*, int* h*, int* a1*, int* a2*, const QMatrix &* xf*)

This is an overloaded function.

Sets the points of the array to those describing an arc of an ellipse with width *w* and height *h* and position (*x*, *y*), starting from angle *a1*, and spanning angle by *a2*, and transformed by the matrix *xf*. The resulting array has sufficient resolution for pixel accuracy.

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.

### void Q3PointArray::makeEllipse(int* x*, int* y*, int* w*, int* h*)

Sets the points of the array to those describing an ellipse with size, width *w* by height *h*, and position (*x*, *y*).

The returned array has sufficient resolution for use as pixels.

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