QgsRegularPolygon Class Reference

Regular Polygon geometry type. More...

#include <qgsregularpolygon.h>

Public Types
enum	ConstructionOption { InscribedCircle, CircumscribedCircle }
	A regular polygon can be constructed inscribed in a circle or circumscribed about a circle. More...

Public Member Functions
	QgsRegularPolygon ()=default
	Constructor for QgsRegularPolygon. More...
	QgsRegularPolygon (const QgsPoint &center, double radius, double azimuth, unsigned int numberSides, ConstructionOption circle)
	Constructs a regular polygon by center and parameters for the first vertex. More...
	QgsRegularPolygon (const QgsPoint &center, const QgsPoint &pt1, unsigned int numberSides, ConstructionOption circle)
	Constructs a regular polygon by center and another point. More...
	QgsRegularPolygon (const QgsPoint &pt1, const QgsPoint &pt2, unsigned int numberSides)
	Constructs a regular polygon by two points of the first side. More...
double	apothem () const
	Returns the apothem of the regular polygon. More...
double	area () const
	Returns the area. More...
QgsPoint	center () const
	Returns the center point of the regular polygon. More...
double	centralAngle () const
	Returns the measure of the central angle (the angle subtended at the center of the polygon by one of its sides) in degrees. More...
QgsCircle	circumscribedCircle () const
	Returns the circumscribed circle. More...
QgsPoint	firstVertex () const
	Returns the first vertex (corner) of the regular polygon. More...
QgsCircle	inscribedCircle () const
	Returns the inscribed circle. More...
double	interiorAngle () const
	Returns the measure of the interior angles in degrees. More...
bool	isEmpty () const
	A regular polygon is empty if radius equal to 0 or number of sides < 3. More...
double	length () const
	Returns the length of a side. More...
unsigned int	numberSides () const
	Returns the number of sides of the regular polygon. More...
bool	operator!= (const QgsRegularPolygon &rp) const
bool	operator== (const QgsRegularPolygon &rp) const
double	perimeter () const
	Returns the perimeter. More...
QgsPointSequence	points () const
	Returns a list including the vertices of the regular polygon. More...
double	radius () const
	Returns the radius. More...
void	setCenter (const QgsPoint &center)
	Sets the center point. More...
void	setFirstVertex (const QgsPoint &firstVertex)
	Sets the first vertex. More...
void	setNumberSides (unsigned int numberSides)
	Sets the number of sides. More...
void	setRadius (double radius)
	Sets the radius. More...
QgsLineString *	toLineString () const
	Returns as a linestring. More...
QgsPolygon *	toPolygon () const
	Returns as a polygon. More...
QString	toString (int pointPrecision=17, int radiusPrecision=17, int anglePrecision=2) const
	Returns a string representation of the regular polygon. More...
QgsTriangle	toTriangle () const
	Returns as a triangle. More...
QVector< QgsTriangle >	triangulate () const
	Returns a triangulation (vertices from sides to the center) of the regular polygon. More...

Detailed Description

Regular Polygon geometry type.

A regular polygon is a polygon that is equiangular (all angles are equal in measure) and equilateral (all sides have the same length). The regular polygon is defined by a center point with a number of sides/vertices, a radius and the first vertex.

Since

QGIS 3.0

Definition at line 41 of file qgsregularpolygon.h.

Member Enumeration Documentation

enum QgsRegularPolygon::ConstructionOption

A regular polygon can be constructed inscribed in a circle or circumscribed about a circle.

Enumerator
InscribedCircle
CircumscribedCircle

Definition at line 49 of file qgsregularpolygon.h.

Constructor & Destructor Documentation

QgsRegularPolygon::QgsRegularPolygon ( )

default

Constructor for QgsRegularPolygon.

QgsRegularPolygon::QgsRegularPolygon	(	const QgsPoint &	center,
		double	radius,
		double	azimuth,
		unsigned int	numberSides,
		ConstructionOption	circle
	)

Constructs a regular polygon by center and parameters for the first vertex.

An empty regular polygon is returned if numberSides < 3 or ConstructionOption isn't valid.

Parameters

center	The center of the regular polygon.
radius	Distance from the center and the first vertex or sides (see ConstructionOption).
azimuth	Angle in degrees started from the North to the first vertex.
numberSides	Number of sides of the regular polygon.
circle	Option to create the polygon.

See also

ConstructionOption

Definition at line 23 of file qgsregularpolygon.cpp.

QgsRegularPolygon::QgsRegularPolygon	(	const QgsPoint &	center,
		const QgsPoint &	pt1,
		unsigned int	numberSides,
		ConstructionOption	circle
	)

Constructs a regular polygon by center and another point.

Parameters

center	The center of the regular polygon.
pt1	The first vertex if the polygon is inscribed in circle or the midpoint of a side if the polygon is circumscribed about circle.
numberSides	Number of sides of the regular polygon.
circle	Option to create the polygon inscribed in circle (the radius is the distance between the center and vertices) or circumscribed about circle (the radius is the distance from the center to the midpoints of the sides).

Definition at line 52 of file qgsregularpolygon.cpp.

QgsRegularPolygon::QgsRegularPolygon	(	const QgsPoint &	pt1,
		const QgsPoint &	pt2,
		unsigned int	numberSides
	)

Constructs a regular polygon by two points of the first side.

Parameters

pt1	The first vertex of the first side, also first vertex of the regular polygon.
pt2	The second vertex of the first side.
numberSides	Number of sides of the regular polygon.

Definition at line 81 of file qgsregularpolygon.cpp.

Member Function Documentation

double QgsRegularPolygon::apothem ( ) const

inline

Returns the apothem of the regular polygon.

The apothem is the radius of the inscribed circle.

See also

radius()

Definition at line 118 of file qgsregularpolygon.h.

double QgsRegularPolygon::area

(

)

const

Returns the area.

Returns 0 if the regular polygon is empty.

Definition at line 275 of file qgsregularpolygon.cpp.

QgsPoint QgsRegularPolygon::center ( ) const

inline

Returns the center point of the regular polygon.

See also

setCenter()

Definition at line 97 of file qgsregularpolygon.h.

double QgsRegularPolygon::centralAngle

(

)

const

Returns the measure of the central angle (the angle subtended at the center of the polygon by one of its sides) in degrees.

Definition at line 325 of file qgsregularpolygon.cpp.

QgsCircle QgsRegularPolygon::circumscribedCircle

(

)

const

Returns the circumscribed circle.

Definition at line 252 of file qgsregularpolygon.cpp.

QgsPoint QgsRegularPolygon::firstVertex ( ) const

inline

Returns the first vertex (corner) of the regular polygon.

See also

setFirstVertex()

Definition at line 111 of file qgsregularpolygon.h.

QgsCircle QgsRegularPolygon::inscribedCircle

(

)

const

Returns the inscribed circle.

Definition at line 246 of file qgsregularpolygon.cpp.

double QgsRegularPolygon::interiorAngle

(

)

const

Returns the measure of the interior angles in degrees.

Definition at line 320 of file qgsregularpolygon.cpp.

bool QgsRegularPolygon::isEmpty

(

)

const

A regular polygon is empty if radius equal to 0 or number of sides < 3.

Definition at line 114 of file qgsregularpolygon.cpp.

double QgsRegularPolygon::length

(

)

const

Returns the length of a side.

Returns 0 if the regular polygon is empty.

Definition at line 295 of file qgsregularpolygon.cpp.

unsigned int QgsRegularPolygon::numberSides ( ) const

inline

Returns the number of sides of the regular polygon.

See also

setNumberSides()

Definition at line 124 of file qgsregularpolygon.h.

bool QgsRegularPolygon::operator!=

(

const QgsRegularPolygon &

rp

)

const

Definition at line 109 of file qgsregularpolygon.cpp.

bool QgsRegularPolygon::operator==

(

const QgsRegularPolygon &

rp

)

const

Definition at line 101 of file qgsregularpolygon.cpp.

double QgsRegularPolygon::perimeter

(

)

const

Returns the perimeter.

Returns 0 if the regular polygon is empty.

Definition at line 285 of file qgsregularpolygon.cpp.

QgsPointSequence QgsRegularPolygon::points

(

)

const

Returns a list including the vertices of the regular polygon.

Definition at line 153 of file qgsregularpolygon.cpp.

double QgsRegularPolygon::radius ( ) const

inline

Returns the radius.

This is also the radius of the circumscribing circle.

See also

apothem()

setRadius()

Definition at line 105 of file qgsregularpolygon.h.

void QgsRegularPolygon::setCenter

(

const QgsPoint &

center

)

Sets the center point.

Radius is unchanged. The first vertex is reprojected from the new center.

See also

center()

Definition at line 121 of file qgsregularpolygon.cpp.

void QgsRegularPolygon::setFirstVertex

(

const QgsPoint &

firstVertex

)

Sets the first vertex.

Radius is unchanged. The center is reprojected from the new first vertex.

See also

firstVertex()

Definition at line 137 of file qgsregularpolygon.cpp.

void QgsRegularPolygon::setNumberSides

(

unsigned int

numberSides

)

Sets the number of sides.

If numberSides < 3, the number of sides is unchanged.

See also

numberSides()

Definition at line 145 of file qgsregularpolygon.cpp.

void QgsRegularPolygon::setRadius

(

double

radius

)

Sets the radius.

Center is unchanged. The first vertex is reprojected from the center with the new radius.

See also

radius()

Definition at line 129 of file qgsregularpolygon.cpp.

QgsLineString * QgsRegularPolygon::toLineString

(

)

const

Returns as a linestring.

Definition at line 194 of file qgsregularpolygon.cpp.

QgsPolygon * QgsRegularPolygon::toPolygon

(

)

const

Returns as a polygon.

Definition at line 181 of file qgsregularpolygon.cpp.

QString QgsRegularPolygon::toString	(	int	pointPrecision = 17,
		int	radiusPrecision = 17,
		int	anglePrecision = 2
	)		const

Returns a string representation of the regular polygon.

Members will be truncated to the specified precision.

Definition at line 258 of file qgsregularpolygon.cpp.

QgsTriangle QgsRegularPolygon::toTriangle

(

)

const

Returns as a triangle.

An empty triangle is returned if the regular polygon is empty or if the number of sides is different from 3.

Definition at line 211 of file qgsregularpolygon.cpp.

QVector< QgsTriangle > QgsRegularPolygon::triangulate

(

)

const

Returns a triangulation (vertices from sides to the center) of the regular polygon.

An empty list is returned if the regular polygon is empty.

Definition at line 224 of file qgsregularpolygon.cpp.

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The documentation for this class was generated from the following files:

• /build/qgis-3.4.15+24xenial/src/core/geometry/qgsregularpolygon.h
• /build/qgis-3.4.15+24xenial/src/core/geometry/qgsregularpolygon.cpp