---
name: "QwtSimpleCompassRose"
section: "3"
platform: "linux"
package: "libqwt-doc"
version: "6.1.4-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/QwtSimpleCompassRose"
---

# QwtSimpleCompassRose(3)

A simple rose for QwtCompass.

## NAME

QwtSimpleCompassRose - A simple rose for **QwtCompass**.

## SYNOPSIS

`#include <qwt_compass_rose.h>`

Inherits **QwtCompassRose**.

### Public Member Functions

**QwtSimpleCompassRose** (int **numThorns**=8, int **numThornLevels**=-1)\
 virtual **~QwtSimpleCompassRose** ()\
 Destructor.  void **setWidth** (double)\
 double **width** () const\
 void **setNumThorns** (int)\
 int **numThorns** () const\
 void **setNumThornLevels** (int)\
 int **numThornLevels** () const\
 void **setShrinkFactor** (double factor)\
 double **shrinkFactor** () const\
 virtual void **draw** (QPainter \*, const QPointF &center, double radius, double north, QPalette::ColorGroup=QPalette::Active) const\

### Static Public Member Functions

static void **drawRose** (QPainter \*, const QPalette &, const QPointF &center, double radius, double north, double **width**, int **numThorns**, int **numThornLevels**, double **shrinkFactor**)\

## Detailed Description

A simple rose for **QwtCompass**.

## Constructor & Destructor Documentation

### QwtSimpleCompassRose::QwtSimpleCompassRose (int numThorns = `8`, int numThornLevels = `-1`)

Constructor

**Parameters:**

*numThorns* Number of thorns \
 *numThornLevels* Number of thorn levels

## Member Function Documentation

### void QwtSimpleCompassRose::draw (QPainter \* painter, const QPointF & center, double radius, double north, QPalette::ColorGroup cg = `QPalette::Active`) const` [virtual]`

Draw the rose

**Parameters:**

*painter* Painter \
 *center* Center point \
 *radius* Radius of the rose \
 *north* Position \
 *cg* Color group

Implements **QwtCompassRose**.

### void QwtSimpleCompassRose::drawRose (QPainter \* painter, const QPalette & palette, const QPointF & center, double radius, double north, double width, int numThorns, int numThornLevels, double shrinkFactor)` [static]`

Draw the rose

**Parameters:**

*painter* Painter \
 *palette* Palette \
 *center* Center of the rose \
 *radius* Radius of the rose \
 *north* Position pointing to north \
 *width* Width of the rose \
 *numThorns* Number of thorns \
 *numThornLevels* Number of thorn levels \
 *shrinkFactor* Factor to shrink the thorns with each level

### int QwtSimpleCompassRose::numThornLevels () const

**Returns:**

Number of thorn levels

**See also:**

**setNumThorns()**, **setNumThornLevels()**

### int QwtSimpleCompassRose::numThorns () const

**Returns:**

Number of thorns

**See also:**

**setNumThorns()**, **setNumThornLevels()**

### void QwtSimpleCompassRose::setNumThornLevels (int numThornLevels)

Set the of thorns levels

**Parameters:**

*numThornLevels* Number of thorns levels

**See also:**

**setNumThorns()**, **numThornLevels()**

### void QwtSimpleCompassRose::setNumThorns (int numThorns)

Set the number of thorns on one level The number is aligned to a multiple of 4, with a minimum of 4

**Parameters:**

*numThorns* Number of thorns

**See also:**

**numThorns()**, **setNumThornLevels()**

### void QwtSimpleCompassRose::setShrinkFactor (double factor)

Set the Factor how to shrink the thorns with each level The default value is 0.9.

**Parameters:**

*factor* Shrink factor

**See also:**

**shrinkFactor()**

### void QwtSimpleCompassRose::setWidth (double width)

Set the width of the rose heads. Lower value make thinner heads. The range is limited from 0.03 to 0.4.

**Parameters:**

*width* Width

### double QwtSimpleCompassRose::shrinkFactor () const

**Returns:**

Factor how to shrink the thorns with each level

**See also:**

**setShrinkFactor()**

### double QwtSimpleCompassRose::width () const

**Returns:**

Width of the rose

**See also:**

**setWidth()**

## Author

Generated automatically by Doxygen for Qwt User's Guide from the source code.