Does vector analysis using the geos library and handles import, export, exception handling*. More...

#include <qgsgeos.h>

Inheritance diagram for QgsGeos:

Public Member Functions
	QgsGeos (const QgsAbstractGeometryV2 *geometry, double precision=0)
	GEOS geometry engine constructor. More...

	~QgsGeos ()

double	area (QString *errorMsg=nullptr) const override

QgsAbstractGeometryV2 *	buffer (double distance, int segments, QString *errorMsg=nullptr) const override

QgsAbstractGeometryV2 *	buffer (double distance, int segments, int endCapStyle, int joinStyle, double mitreLimit, QString *errorMsg=nullptr) const override

bool	centroid (QgsPointV2 &pt, QString *errorMsg=nullptr) const override

QgsGeometry	closestPoint (const QgsGeometry &other, QString *errorMsg=nullptr) const
	Returns the closest point on the geometry to the other geometry. More...

QgsAbstractGeometryV2 *	combine (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

QgsAbstractGeometryV2 *	combine (const QList< QgsAbstractGeometryV2 > &, QString errorMsg=nullptr) const override

bool	contains (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

QgsAbstractGeometryV2 *	convexHull (QString *errorMsg=nullptr) const override

bool	crosses (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

QgsAbstractGeometryV2 *	difference (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

bool	disjoint (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

double	distance (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

QgsAbstractGeometryV2 *	envelope (QString *errorMsg=nullptr) const override

void	geometryChanged () override
	Removes caches. More...

QgsAbstractGeometryV2 *	interpolate (double distance, QString *errorMsg=nullptr) const override

QgsAbstractGeometryV2 *	intersection (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

bool	intersects (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

bool	isEmpty (QString *errorMsg=nullptr) const override

bool	isEqual (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

bool	isValid (QString *errorMsg=nullptr) const override

double	length (QString *errorMsg=nullptr) const override

double	lineLocatePoint (const QgsPointV2 &point, QString *errorMsg=nullptr) const
	Returns a distance representing the location along this linestring of the closest point on this linestring geometry to the specified point. More...

QgsGeometry	mergeLines (QString *errorMsg=nullptr) const
	Merges any connected lines in a LineString/MultiLineString geometry and converts them to single line strings. More...

QgsAbstractGeometryV2 *	offsetCurve (double distance, int segments, int joinStyle, double mitreLimit, QString *errorMsg=nullptr) const override

bool	overlaps (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

bool	pointOnSurface (QgsPointV2 &pt, QString *errorMsg=nullptr) const override

void	prepareGeometry () override

QString	relate (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override
	Returns the Dimensional Extended 9 Intersection Model (DE-9IM) representation of the relationship between the geometries. More...

bool	relatePattern (const QgsAbstractGeometryV2 &geom, const QString &pattern, QString *errorMsg=nullptr) const override
	Tests whether two geometries are related by a specified Dimensional Extended 9 Intersection Model (DE-9IM) pattern. More...

QgsAbstractGeometryV2 *	reshapeGeometry (const QgsLineStringV2 &reshapeWithLine, int errorCode, QString errorMsg=nullptr) const

QgsGeometry	shortestLine (const QgsGeometry &other, QString *errorMsg=nullptr) const
	Returns the shortest line joining this geometry to the other geometry. More...

QgsAbstractGeometryV2 *	simplify (double tolerance, QString *errorMsg=nullptr) const override

int	splitGeometry (const QgsLineStringV2 &splitLine, QList< QgsAbstractGeometryV2 > &newGeometries, bool topological, QgsPointSequenceV2 &topologyTestPoints, QString errorMsg=nullptr) const override
	Splits this geometry according to a given line. More...

QgsAbstractGeometryV2 *	symDifference (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

bool	touches (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

bool	within (const QgsAbstractGeometryV2 &geom, QString *errorMsg=nullptr) const override

Public Member Functions inherited from QgsGeometryEngine
	QgsGeometryEngine (const QgsAbstractGeometryV2 *geometry)

virtual	~QgsGeometryEngine ()

virtual QgsAbstractGeometryV2 *	combine (const QList< QgsAbstractGeometryV2 * > &, QString *errorMsg=nullptr) const =0

Static Public Member Functions
static GEOSGeometry *	asGeos (const QgsAbstractGeometryV2 *geom, double precision=0)

static QgsPointV2	coordSeqPoint (const GEOSCoordSequence *cs, int i, bool hasZ, bool hasM)

static QgsAbstractGeometryV2 *	fromGeos (const GEOSGeometry *geos)
	Create a geometry from a GEOSGeometry. More...

static QgsPolygonV2 *	fromGeosPolygon (const GEOSGeometry *geos)

static GEOSContextHandle_t	getGEOSHandler ()

Additional Inherited Members
Protected Member Functions inherited from QgsGeometryEngine
	QgsGeometryEngine ()

Protected Attributes inherited from QgsGeometryEngine
const QgsAbstractGeometryV2 *	mGeometry

Detailed Description

Does vector analysis using the geos library and handles import, export, exception handling*.

Note: this API is not considered stable and may change for 2.12; not available in Python bindings

Definition at line 32 of file qgsgeos.h.

Constructor & Destructor Documentation

◆ QgsGeos()

QgsGeos::QgsGeos	(	const QgsAbstractGeometryV2 *	geometry,
		double	precision = `0`
	)

GEOS geometry engine constructor.

Parameters

geometry	The geometry
precision	The precision of the grid to which to snap the geometry vertices. If 0, no snapping is performed.

Definition at line 135 of file qgsgeos.cpp.

◆ ~QgsGeos()

QgsGeos::~QgsGeos ( )

Definition at line 144 of file qgsgeos.cpp.

Member Function Documentation

◆ area()

double QgsGeos::area ( QString * errorMsg = nullptr ) const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 348 of file qgsgeos.cpp.

◆ asGeos()

GEOSGeometry * QgsGeos::asGeos	(	const QgsAbstractGeometryV2 *	geom,
		double	precision = `0`
	)

static

Definition at line 1054 of file qgsgeos.cpp.

◆ buffer() [1/2]

QgsAbstractGeometryV2 * QgsGeos::buffer	(	double	distance,
		int	segments,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1278 of file qgsgeos.cpp.

◆ buffer() [2/2]

QgsAbstractGeometryV2 * QgsGeos::buffer	(	double	distance,
		int	segments,
		int	endCapStyle,
		int	joinStyle,
		double	mitreLimit,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1294 of file qgsgeos.cpp.

◆ centroid()

bool QgsGeos::centroid	(	QgsPointV2 &	pt,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1346 of file qgsgeos.cpp.

◆ closestPoint()

QgsGeometry QgsGeos::closestPoint	(	const QgsGeometry &	other,
		QString *	errorMsg = `nullptr`
	)		const

Returns the closest point on the geometry to the other geometry.

Note: added in QGIS 2.14

See also: shortestLine()

Definition at line 1817 of file qgsgeos.cpp.

◆ combine() [1/2]

QgsAbstractGeometryV2 * QgsGeos::combine	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 191 of file qgsgeos.cpp.

◆ combine() [2/2]

QgsAbstractGeometryV2 * QgsGeos::combine	(	const QList< QgsAbstractGeometryV2 *> &	geomList,
		QString *	errorMsg = `nullptr`
	)		const

override

Definition at line 196 of file qgsgeos.cpp.

◆ contains()

bool QgsGeos::contains	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 275 of file qgsgeos.cpp.

◆ convexHull()

QgsAbstractGeometryV2 * QgsGeos::convexHull ( QString * errorMsg = nullptr ) const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1417 of file qgsgeos.cpp.

◆ coordSeqPoint()

QgsPointV2 QgsGeos::coordSeqPoint	(	const GEOSCoordSequence *	cs,
		int	i,
		bool	hasZ,
		bool	hasM
	)

static

Definition at line 1017 of file qgsgeos.cpp.

◆ crosses()

bool QgsGeos::crosses	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 260 of file qgsgeos.cpp.

◆ difference()

QgsAbstractGeometryV2 * QgsGeos::difference	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 186 of file qgsgeos.cpp.

◆ disjoint()

bool QgsGeos::disjoint	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 280 of file qgsgeos.cpp.

◆ distance()

double QgsGeos::distance	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 225 of file qgsgeos.cpp.

◆ envelope()

QgsAbstractGeometryV2 * QgsGeos::envelope ( QString * errorMsg = nullptr ) const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1373 of file qgsgeos.cpp.

◆ fromGeos()

QgsAbstractGeometryV2 * QgsGeos::fromGeos ( const GEOSGeometry * geos )

static

Create a geometry from a GEOSGeometry.

Parameters

geos	GEOSGeometry. Ownership is NOT transferred.

Definition at line 865 of file qgsgeos.cpp.

◆ fromGeosPolygon()

QgsPolygonV2 * QgsGeos::fromGeosPolygon ( const GEOSGeometry * geos )

static

Definition at line 953 of file qgsgeos.cpp.

◆ geometryChanged()

void QgsGeos::geometryChanged ( )

overridevirtual

Removes caches.

Implements QgsGeometryEngine.

Definition at line 152 of file qgsgeos.cpp.

◆ getGEOSHandler()

GEOSContextHandle_t QgsGeos::getGEOSHandler ( )

static

Definition at line 2416 of file qgsgeos.cpp.

◆ interpolate()

QgsAbstractGeometryV2 * QgsGeos::interpolate	(	double	distance,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1331 of file qgsgeos.cpp.

◆ intersection()

QgsAbstractGeometryV2 * QgsGeos::intersection	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 181 of file qgsgeos.cpp.

◆ intersects()

bool QgsGeos::intersects	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 250 of file qgsgeos.cpp.

◆ isEmpty()

bool QgsGeos::isEmpty ( QString * errorMsg = nullptr ) const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1468 of file qgsgeos.cpp.

◆ isEqual()

bool QgsGeos::isEqual	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1448 of file qgsgeos.cpp.

◆ isValid()

bool QgsGeos::isValid ( QString * errorMsg = nullptr ) const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1434 of file qgsgeos.cpp.

◆ length()

double QgsGeos::length ( QString * errorMsg = nullptr ) const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 365 of file qgsgeos.cpp.

◆ lineLocatePoint()

double QgsGeos::lineLocatePoint	(	const QgsPointV2 &	point,
		QString *	errorMsg = `nullptr`
	)		const

Returns a distance representing the location along this linestring of the closest point on this linestring geometry to the specified point.

Ie, the returned value indicates how far along this linestring you need to traverse to get to the closest location where this linestring comes to the specified point.

Parameters

point	point to seek proximity to
errorMsg	error messages emitted, if any

Note: only valid for linestring geometries

Returns: distance along line, or -1 on error

Definition at line 1895 of file qgsgeos.cpp.

◆ mergeLines()

QgsGeometry QgsGeos::mergeLines ( QString * errorMsg = nullptr ) const

Merges any connected lines in a LineString/MultiLineString geometry and converts them to single line strings.

Parameters

errorMsg if specified, will be set to any reported GEOS errors

Returns: a LineString or MultiLineString geometry, with any connected lines joined. An empty geometry will be returned if the input geometry was not a LineString/MultiLineString geometry.

Note: added in QGIS 2.18

Definition at line 1798 of file qgsgeos.cpp.

◆ offsetCurve()

QgsAbstractGeometryV2 * QgsGeos::offsetCurve	(	double	distance,
		int	segments,
		int	joinStyle,
		double	mitreLimit,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1674 of file qgsgeos.cpp.

◆ overlaps()

bool QgsGeos::overlaps	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 270 of file qgsgeos.cpp.

◆ pointOnSurface()

bool QgsGeos::pointOnSurface	(	QgsPointV2 &	pt,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1388 of file qgsgeos.cpp.

◆ prepareGeometry()

void QgsGeos::prepareGeometry ( )

overridevirtual

Implements QgsGeometryEngine.

Definition at line 161 of file qgsgeos.cpp.

◆ relate()

QString QgsGeos::relate	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Returns the Dimensional Extended 9 Intersection Model (DE-9IM) representation of the relationship between the geometries.

Parameters

geom	geometry to relate to
errorMsg	destination storage for any error message

Returns: DE-9IM string for relationship, or an empty string if an error occurred

Note: added in QGIS 2.12

Implements QgsGeometryEngine.

Definition at line 285 of file qgsgeos.cpp.

◆ relatePattern()

bool QgsGeos::relatePattern	(	const QgsAbstractGeometryV2 &	geom,
		const QString &	pattern,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Tests whether two geometries are related by a specified Dimensional Extended 9 Intersection Model (DE-9IM) pattern.

Parameters

geom	geometry to relate to
pattern	DE-9IM pattern for match
errorMsg	destination storage for any error message

Returns: true if geometry relationship matches with pattern

Note: added in QGIS 2.14

Implements QgsGeometryEngine.

Definition at line 319 of file qgsgeos.cpp.

◆ reshapeGeometry()

QgsAbstractGeometryV2 * QgsGeos::reshapeGeometry	(	const QgsLineStringV2 &	reshapeWithLine,
		int *	errorCode,
		QString *	errorMsg = `nullptr`
	)		const

Definition at line 1690 of file qgsgeos.cpp.

◆ shortestLine()

QgsGeometry QgsGeos::shortestLine	(	const QgsGeometry &	other,
		QString *	errorMsg = `nullptr`
	)		const

Returns the shortest line joining this geometry to the other geometry.

Note: added in QGIS 2.14

See also: closestPoint()

Definition at line 1852 of file qgsgeos.cpp.

◆ simplify()

QgsAbstractGeometryV2 * QgsGeos::simplify	(	double	tolerance,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 1316 of file qgsgeos.cpp.

◆ splitGeometry()

int QgsGeos::splitGeometry	(	const QgsLineStringV2 &	splitLine,
		QList< QgsAbstractGeometryV2 *> &	newGeometries,
		bool	topological,
		QgsPointSequenceV2 &	topologyTestPoints,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Splits this geometry according to a given line.

Parameters

	splitLine	the line that splits the geometry
[out]	newGeometries	list of new geometries that have been created with the split
	topological	true if topological editing is enabled
[out]	topologyTestPoints	points that need to be tested for topological completeness in the dataset
[out]	errorMsg	error messages emitted, if any

Returns: 0 in case of success, 1 if geometry has not been split, error else

Reimplemented from QgsGeometryEngine.

Definition at line 381 of file qgsgeos.cpp.

◆ symDifference()

QgsAbstractGeometryV2 * QgsGeos::symDifference	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 220 of file qgsgeos.cpp.

◆ touches()

bool QgsGeos::touches	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 255 of file qgsgeos.cpp.

◆ within()

bool QgsGeos::within	(	const QgsAbstractGeometryV2 &	geom,
		QString *	errorMsg = `nullptr`
	)		const

overridevirtual

Implements QgsGeometryEngine.

Definition at line 265 of file qgsgeos.cpp.

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

/tmp/buildd/qgis-2.18.21+99unstable/src/core/geometry/qgsgeos.h
/tmp/buildd/qgis-2.18.21+99unstable/src/core/geometry/qgsgeos.cpp

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsGeos()

◆ ~QgsGeos()

Member Function Documentation

◆ area()

◆ asGeos()

◆ buffer() [1/2]

◆ buffer() [2/2]

◆ centroid()

◆ closestPoint()

◆ combine() [1/2]

◆ combine() [2/2]

◆ contains()

◆ convexHull()

◆ coordSeqPoint()

◆ crosses()

◆ difference()

◆ disjoint()

◆ distance()

◆ envelope()

◆ fromGeos()

◆ fromGeosPolygon()

◆ geometryChanged()

◆ getGEOSHandler()

◆ interpolate()

◆ intersection()

◆ intersects()

◆ isEmpty()

◆ isEqual()

◆ isValid()

◆ length()

◆ lineLocatePoint()

◆ mergeLines()

◆ offsetCurve()

◆ overlaps()

◆ pointOnSurface()

◆ prepareGeometry()

◆ relate()

◆ relatePattern()

◆ reshapeGeometry()

◆ shortestLine()

◆ simplify()

◆ splitGeometry()

◆ symDifference()

◆ touches()

◆ within()