QGIS API Documentation  3.37.0-Master (a5b4d9743e8)
Classes | Public Types | Public Member Functions | Protected Member Functions | Protected Attributes | Friends | List of all members
QgsAbstractGeometry Class Referenceabstract

Abstract base class for all geometries. More...

#include <qgsabstractgeometry.h>

Inheritance diagram for QgsAbstractGeometry:
Inheritance graph
[legend]

Classes

class  const_part_iterator
 The part_iterator class provides STL-style iterator for const references to geometry parts. More...
 
class  part_iterator
 The part_iterator class provides STL-style iterator for geometry parts. More...
 
class  vertex_iterator
 The vertex_iterator class provides STL-style iterator for vertices. More...
 

Public Types

enum  AxisOrder { XY = 0 , YX }
 Axis order for GML generation. More...
 
enum  SegmentationToleranceType { MaximumAngle = 0 , MaximumDifference }
 Segmentation tolerance as maximum angle or maximum difference between approximation and circle. More...
 
enum  WkbFlag { FlagExportTrianglesAsPolygons = 1 << 0 , FlagExportNanAsDoubleMin = 1 << 1 }
 WKB export flags. More...
 
typedef QFlags< WkbFlagWkbFlags
 

Public Member Functions

 QgsAbstractGeometry ()=default
 Constructor for QgsAbstractGeometry. More...
 
 QgsAbstractGeometry (const QgsAbstractGeometry &geom)
 
virtual ~QgsAbstractGeometry ()=default
 
virtual bool addMValue (double mValue=0)=0
 Adds a measure to the geometry, initialized to a preset value. More...
 
virtual bool addZValue (double zValue=0)=0
 Adds a z-dimension to the geometry, initialized to a preset value. More...
 
virtual void adjacentVertices (QgsVertexId vertex, QgsVertexId &previousVertex, QgsVertexId &nextVertex) const =0
 Returns the vertices adjacent to a specified vertex within a geometry. More...
 
virtual double area () const
 Returns the planar, 2-dimensional area of the geometry. More...
 
virtual QDomElement asGml2 (QDomDocument &doc, int precision=17, const QString &ns="gml", AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const =0
 Returns a GML2 representation of the geometry. More...
 
virtual QDomElement asGml3 (QDomDocument &doc, int precision=17, const QString &ns="gml", AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const =0
 Returns a GML3 representation of the geometry. More...
 
QString asJson (int precision=17)
 Returns a GeoJSON representation of the geometry as a QString. More...
 
virtual json asJsonObject (int precision=17) const
 Returns a json object representation of the geometry. More...
 
virtual QString asKml (int precision=17) const =0
 Returns a KML representation of the geometry. More...
 
virtual QPainterPath asQPainterPath () const =0
 Returns the geometry represented as a QPainterPath. More...
 
virtual QByteArray asWkb (WkbFlags flags=QgsAbstractGeometry::WkbFlags()) const =0
 Returns a WKB representation of the geometry. More...
 
virtual QString asWkt (int precision=17) const =0
 Returns a WKT representation of the geometry. More...
 
virtual QgsAbstractGeometryboundary () const =0
 Returns the closure of the combinatorial boundary of the geometry (ie the topological boundary of the geometry). More...
 
virtual QgsRectangle boundingBox () const
 Returns the minimal bounding box for the geometry. More...
 
virtual QgsBox3D boundingBox3D () const =0
 Returns the 3D bounding box for the geometry. More...
 
virtual bool boundingBoxIntersects (const QgsBox3D &box3d) const
 Returns true if the bounding box of this geometry intersects with a box3d. More...
 
virtual bool boundingBoxIntersects (const QgsRectangle &rectangle) const
 Returns true if the bounding box of this geometry intersects with a rectangle. More...
 
virtual QgsPoint centroid () const
 Returns the centroid of the geometry. More...
 
virtual void clear ()=0
 Clears the geometry, ie reset it to a null geometry. More...
 
virtual QgsAbstractGeometryclone () const =0
 Clones the geometry by performing a deep copy. More...
 
virtual double closestSegment (const QgsPoint &pt, QgsPoint &segmentPt, QgsVertexId &vertexAfter, int *leftOf=nullptr, double epsilon=4 *std::numeric_limits< double >::epsilon()) const =0
 Searches for the closest segment of the geometry to a given point. More...
 
virtual int compareTo (const QgsAbstractGeometry *other) const
 Comparator for sorting of geometry. More...
 
const_part_iterator const_parts_begin () const
 Returns STL-style iterator pointing to the const first part of the geometry. More...
 
const_part_iterator const_parts_end () const
 Returns STL-style iterator pointing to the imaginary const part after the last part of the geometry. More...
 
virtual bool convertTo (Qgis::WkbType type)
 Converts the geometry to a specified type. More...
 
virtual QgsCoordinateSequence coordinateSequence () const =0
 Retrieves the sequence of geometries, rings and nodes. More...
 
virtual QgsAbstractGeometrycreateEmptyWithSameType () const =0
 Creates a new geometry with the same class and same WKB type as the original and transfers ownership. More...
 
virtual bool deleteVertex (QgsVertexId position)=0
 Deletes a vertex within the geometry. More...
 
virtual int dimension () const =0
 Returns the inherent dimension of the geometry. More...
 
virtual void draw (QPainter &p) const =0
 Draws the geometry using the specified QPainter. More...
 
virtual bool dropMValue ()=0
 Drops any measure values which exist in the geometry. More...
 
virtual bool dropZValue ()=0
 Drops any z-dimensions which exist in the geometry. More...
 
virtual void filterVertices (const std::function< bool(const QgsPoint &) > &filter)
 Filters the vertices from the geometry in place, removing any which do not return true for the filter function check. More...
 
virtual bool fromWkb (QgsConstWkbPtr &wkb)=0
 Sets the geometry from a WKB string. More...
 
virtual bool fromWkt (const QString &wkt)=0
 Sets the geometry from a WKT string. More...
 
virtual bool fuzzyDistanceEqual (const QgsAbstractGeometry &other, double epsilon=1e-8) const =0
 Performs fuzzy distance comparison between this geometry and other using an epsilon. More...
 
virtual bool fuzzyEqual (const QgsAbstractGeometry &other, double epsilon=1e-8) const =0
 Performs fuzzy comparison between this geometry and other using an epsilon. More...
 
virtual QString geometryType () const =0
 Returns a unique string representing the geometry type. More...
 
virtual bool hasCurvedSegments () const
 Returns true if the geometry contains curved segments. More...
 
virtual bool insertVertex (QgsVertexId position, const QgsPoint &vertex)=0
 Inserts a vertex into the geometry. More...
 
bool is3D () const
 Returns true if the geometry is 3D and contains a z-value. More...
 
virtual bool isEmpty () const
 Returns true if the geometry is empty. More...
 
bool isMeasure () const
 Returns true if the geometry contains m values. More...
 
virtual bool isValid (QString &error, Qgis::GeometryValidityFlags flags=Qgis::GeometryValidityFlags()) const =0
 Checks validity of the geometry, and returns true if the geometry is valid. More...
 
virtual double length () const
 Returns the planar, 2-dimensional length of the geometry. More...
 
virtual bool moveVertex (QgsVertexId position, const QgsPoint &newPos)=0
 Moves a vertex within the geometry. More...
 
virtual int nCoordinates () const
 Returns the number of nodes contained in the geometry. More...
 
virtual bool nextVertex (QgsVertexId &id, QgsPoint &vertex) const =0
 Returns next vertex id and coordinates. More...
 
virtual void normalize ()=0
 Reorganizes the geometry into a normalized form (or "canonical" form). More...
 
virtual bool operator!= (const QgsAbstractGeometry &other) const =0
 
QgsAbstractGeometryoperator= (const QgsAbstractGeometry &geom)
 
virtual bool operator== (const QgsAbstractGeometry &other) const =0
 
virtual int partCount () const =0
 Returns count of parts contained in the geometry. More...
 
QgsGeometryPartIterator parts ()
 Returns Java-style iterator for traversal of parts of the geometry. More...
 
QgsGeometryConstPartIterator parts () const
 Returns Java-style iterator for traversal of parts of the geometry. More...
 
part_iterator parts_begin ()
 Returns STL-style iterator pointing to the first part of the geometry. More...
 
part_iterator parts_end ()
 Returns STL-style iterator pointing to the imaginary part after the last part of the geometry. More...
 
virtual double perimeter () const
 Returns the planar, 2-dimensional perimeter of the geometry. More...
 
virtual bool removeDuplicateNodes (double epsilon=4 *std::numeric_limits< double >::epsilon(), bool useZValues=false)=0
 Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry. More...
 
virtual int ringCount (int part=0) const =0
 Returns the number of rings of which this geometry is built. More...
 
virtual QgsAbstractGeometrysegmentize (double tolerance=M_PI/180., SegmentationToleranceType toleranceType=MaximumAngle) const
 Returns a version of the geometry without curves. More...
 
virtual double segmentLength (QgsVertexId startVertex) const =0
 Returns the length of the segment of the geometry which begins at startVertex. More...
 
virtual const QgsAbstractGeometrysimplifiedTypeRef () const
 Returns a reference to the simplest lossless representation of this geometry, e.g. More...
 
virtual QgsAbstractGeometrysnappedToGrid (double hSpacing, double vSpacing, double dSpacing=0, double mSpacing=0) const =0
 Makes a new geometry with all the points or vertices snapped to the closest point of the grid. More...
 
virtual void swapXy ()=0
 Swaps the x and y coordinates from the geometry. More...
 
virtual QgsAbstractGeometrytoCurveType () const =0
 Returns the geometry converted to the more generic curve type. More...
 
virtual void transform (const QgsCoordinateTransform &ct, Qgis::TransformDirection d=Qgis::TransformDirection::Forward, bool transformZ=false)=0
 Transforms the geometry using a coordinate transform. More...
 
virtual void transform (const QTransform &t, double zTranslate=0.0, double zScale=1.0, double mTranslate=0.0, double mScale=1.0)=0
 Transforms the x and y components of the geometry using a QTransform object t. More...
 
virtual bool transform (QgsAbstractGeometryTransformer *transformer, QgsFeedback *feedback=nullptr)=0
 Transforms the vertices from the geometry in place, using the specified geometry transformer object. More...
 
virtual void transformVertices (const std::function< QgsPoint(const QgsPoint &) > &transform)
 Transforms the vertices from the geometry in place, applying the transform function to every vertex. More...
 
virtual double vertexAngle (QgsVertexId vertex) const =0
 Returns approximate angle at a vertex. More...
 
virtual QgsPoint vertexAt (QgsVertexId id) const =0
 Returns the point corresponding to a specified vertex id. More...
 
virtual int vertexCount (int part=0, int ring=0) const =0
 Returns the number of vertices of which this geometry is built. More...
 
virtual int vertexNumberFromVertexId (QgsVertexId id) const =0
 Returns the vertex number corresponding to a vertex id. More...
 
QgsVertexIterator vertices () const
 Returns a read-only, Java-style iterator for traversal of vertices of all the geometry, including all geometry parts and rings. More...
 
vertex_iterator vertices_begin () const
 Returns STL-style iterator pointing to the first vertex of the geometry. More...
 
vertex_iterator vertices_end () const
 Returns STL-style iterator pointing to the imaginary vertex after the last vertex of the geometry. More...
 
virtual int wkbSize (QgsAbstractGeometry::WkbFlags flags=QgsAbstractGeometry::WkbFlags()) const =0
 Returns the length of the QByteArray returned by asWkb() More...
 
Qgis::WkbType wkbType () const
 Returns the WKB type of the geometry. More...
 
QString wktTypeStr () const
 Returns the WKT type string of the geometry. More...
 

Protected Member Functions

virtual QgsRectangle calculateBoundingBox () const
 Default calculator for the minimal bounding box for the geometry. More...
 
virtual QgsBox3D calculateBoundingBox3D () const
 Calculates the minimal 3D bounding box for the geometry. More...
 
virtual int childCount () const
 Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e. More...
 
virtual QgsAbstractGeometrychildGeometry (int index) const
 Returns pointer to child geometry (for geometries with child geometries - i.e. More...
 
virtual QgsPoint childPoint (int index) const
 Returns point at index (for geometries without child geometries - i.e. More...
 
virtual void clearCache () const
 Clears any cached parameters associated with the geometry, e.g., bounding boxes. More...
 
virtual int compareToSameClass (const QgsAbstractGeometry *other) const =0
 Compares to an other geometry of the same class, and returns a integer for sorting of the two geometries. More...
 
virtual bool hasChildGeometries () const
 Returns whether the geometry has any child geometries (false for point / curve, true otherwise) More...
 
void setZMTypeFromSubGeometry (const QgsAbstractGeometry *subggeom, Qgis::WkbType baseGeomType)
 Updates the geometry type based on whether sub geometries contain z or m values. More...
 
int sortIndex () const
 Returns the sort index for the geometry, used in the compareTo() method to compare geometries of different types. More...
 

Protected Attributes

Qgis::WkbType mWkbType = Qgis::WkbType::Unknown
 

Friends

class TestQgsGeometry
 

Detailed Description

Abstract base class for all geometries.

Note
QgsAbstractGeometry objects are inherently Cartesian/planar geometries. They have no concept of geodesy, and none of the methods or properties exposed from the QgsAbstractGeometry API (or QgsGeometry API) utilize geodesic calculations. Accordingly, properties like length() and area() and spatial operations like centroid() are always calculated using strictly Cartesian mathematics. In contrast, the QgsDistanceArea class exposes methods for working with geodesic calculations and spatial operations on geometries, and should be used whenever calculations which account for the curvature of the Earth (or any other celestial body) are required.

Definition at line 79 of file qgsabstractgeometry.h.

Member Typedef Documentation

◆ WkbFlags

Definition at line 311 of file qgsabstractgeometry.h.

Member Enumeration Documentation

◆ AxisOrder

Axis order for GML generation.

Enumerator
XY 

X comes before Y (or lon before lat)

YX 

Y comes before X (or lat before lon)

Definition at line 138 of file qgsabstractgeometry.h.

◆ SegmentationToleranceType

Segmentation tolerance as maximum angle or maximum difference between approximation and circle.

Enumerator
MaximumAngle 

Maximum angle between generating radii (lines from arc center to output vertices)

MaximumDifference 

Maximum distance between an arbitrary point on the original curve and closest point on its approximation.

Definition at line 120 of file qgsabstractgeometry.h.

◆ WkbFlag

WKB export flags.

Since
QGIS 3.14
Enumerator
FlagExportTrianglesAsPolygons 

Triangles should be exported as polygon geometries.

FlagExportNanAsDoubleMin 

Use -DOUBLE_MAX to represent NaN (since QGIS 3.30)

Definition at line 306 of file qgsabstractgeometry.h.

Constructor & Destructor Documentation

◆ QgsAbstractGeometry() [1/2]

QgsAbstractGeometry::QgsAbstractGeometry ( )
default

Constructor for QgsAbstractGeometry.

◆ ~QgsAbstractGeometry()

virtual QgsAbstractGeometry::~QgsAbstractGeometry ( )
virtualdefault

◆ QgsAbstractGeometry() [2/2]

QgsAbstractGeometry::QgsAbstractGeometry ( const QgsAbstractGeometry geom)

Definition at line 27 of file qgsabstractgeometry.cpp.

Member Function Documentation

◆ addMValue()

virtual bool QgsAbstractGeometry::addMValue ( double  mValue = 0)
pure virtual

Adds a measure to the geometry, initialized to a preset value.

Parameters
mValueinitial m-value for all nodes
Returns
true on success
See also
dropMValue()
addZValue()

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ addZValue()

virtual bool QgsAbstractGeometry::addZValue ( double  zValue = 0)
pure virtual

Adds a z-dimension to the geometry, initialized to a preset value.

Parameters
zValueinitial z-value for all nodes
Returns
true on success
See also
dropZValue()
addMValue()

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ adjacentVertices()

virtual void QgsAbstractGeometry::adjacentVertices ( QgsVertexId  vertex,
QgsVertexId previousVertex,
QgsVertexId nextVertex 
) const
pure virtual

Returns the vertices adjacent to a specified vertex within a geometry.

Implemented in QgsPoint, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ area()

double QgsAbstractGeometry::area ( ) const
virtual

Returns the planar, 2-dimensional area of the geometry.

Warning
QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the area returned by this method is calculated using strictly Cartesian mathematics. In contrast, the QgsDistanceArea class exposes methods for calculating the areas of geometries using geodesic calculations which account for the curvature of the Earth (or any other celestial body).
See also
length()
perimeter()

Reimplemented in QgsGeometryCollection, and QgsCurvePolygon.

Definition at line 206 of file qgsabstractgeometry.cpp.

◆ asGml2()

virtual QDomElement QgsAbstractGeometry::asGml2 ( QDomDocument &  doc,
int  precision = 17,
const QString &  ns = "gml",
AxisOrder  axisOrder = QgsAbstractGeometry::AxisOrder::XY 
) const
pure virtual

Returns a GML2 representation of the geometry.

Parameters
docDOM document
precisionnumber of decimal places for coordinates
nsXML namespace
axisOrderAxis order for generated GML
See also
asWkb()
asWkt()
asGml3()
asJson()

Implemented in QgsPoint, QgsMultiSurface, QgsMultiPolygon, QgsMultiPoint, QgsMultiLineString, QgsMultiCurve, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ asGml3()

virtual QDomElement QgsAbstractGeometry::asGml3 ( QDomDocument &  doc,
int  precision = 17,
const QString &  ns = "gml",
AxisOrder  axisOrder = QgsAbstractGeometry::AxisOrder::XY 
) const
pure virtual

Returns a GML3 representation of the geometry.

Parameters
docDOM document
precisionnumber of decimal places for coordinates
nsXML namespace
axisOrderAxis order for generated GML
See also
asWkb()
asWkt()
asGml2()
asJson()

Implemented in QgsTriangle, QgsPoint, QgsMultiSurface, QgsMultiPolygon, QgsMultiPoint, QgsMultiLineString, QgsMultiCurve, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ asJson()

QString QgsAbstractGeometry::asJson ( int  precision = 17)

Returns a GeoJSON representation of the geometry as a QString.

Parameters
precisionnumber of decimal places for coordinates
See also
asWkb()
asWkt()
asGml2()
asGml3()
asJsonObject()

Definition at line 221 of file qgsabstractgeometry.cpp.

◆ asJsonObject()

json QgsAbstractGeometry::asJsonObject ( int  precision = 17) const
virtual

Returns a json object representation of the geometry.

See also
asWkb()
asWkt()
asGml2()
asGml3()
asJson()
Note
not available in Python bindings
Since
QGIS 3.10

Reimplemented in QgsPoint, QgsMultiSurface, QgsMultiPolygon, QgsMultiPoint, QgsMultiLineString, QgsMultiCurve, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

Definition at line 226 of file qgsabstractgeometry.cpp.

◆ asKml()

virtual QString QgsAbstractGeometry::asKml ( int  precision = 17) const
pure virtual

Returns a KML representation of the geometry.

Since
QGIS 3.12

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ asQPainterPath()

virtual QPainterPath QgsAbstractGeometry::asQPainterPath ( ) const
pure virtual

Returns the geometry represented as a QPainterPath.

Warning
not all geometry subclasses can be represented by a QPainterPath, e.g. points and multipoint geometries will return an empty path.
Since
QGIS 3.16

Implemented in QgsPoint, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ asWkb()

virtual QByteArray QgsAbstractGeometry::asWkb ( WkbFlags  flags = QgsAbstractGeometry::WkbFlags()) const
pure virtual

Returns a WKB representation of the geometry.

The optional flags argument specifies flags controlling WKB export behavior (since QGIS 3.14).

See also
asWkt
asGml2
asGml3
asJson()

Implemented in QgsPoint, QgsPolygon, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ asWkt()

virtual QString QgsAbstractGeometry::asWkt ( int  precision = 17) const
pure virtual

Returns a WKT representation of the geometry.

Parameters
precisionnumber of decimal places for coordinates
See also
asWkb()
asGml2()
asGml3()
asJson()

Implemented in QgsPolygon, QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ boundary()

virtual QgsAbstractGeometry* QgsAbstractGeometry::boundary ( ) const
pure virtual

Returns the closure of the combinatorial boundary of the geometry (ie the topological boundary of the geometry).

For instance, a polygon geometry will have a boundary consisting of the linestrings for each ring in the polygon.

Returns
boundary for geometry. May be nullptr for some geometry types.

Implemented in QgsTriangle, QgsPolygon, QgsPoint, QgsMultiSurface, QgsMultiPolygon, QgsMultiPoint, QgsMultiCurve, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ boundingBox()

QgsRectangle QgsAbstractGeometry::boundingBox ( ) const
virtual

Returns the minimal bounding box for the geometry.

Definition at line 117 of file qgsabstractgeometry.cpp.

◆ boundingBox3D()

virtual QgsBox3D QgsAbstractGeometry::boundingBox3D ( ) const
pure virtual

Returns the 3D bounding box for the geometry.

Since
QGIS 3.34

Implemented in QgsSurface, QgsPoint, QgsGeometryCollection, and QgsCurve.

◆ boundingBoxIntersects() [1/2]

bool QgsAbstractGeometry::boundingBoxIntersects ( const QgsBox3D box3d) const
virtual

Returns true if the bounding box of this geometry intersects with a box3d.

Since this test only considers the bounding box of the geometry, is is very fast to calculate and handles invalid geometries.

Since
QGIS 3.34

Reimplemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, and QgsCompoundCurve.

Definition at line 425 of file qgsabstractgeometry.cpp.

◆ boundingBoxIntersects() [2/2]

bool QgsAbstractGeometry::boundingBoxIntersects ( const QgsRectangle rectangle) const
virtual

Returns true if the bounding box of this geometry intersects with a rectangle.

Since this test only considers the bounding box of the geometry, is is very fast to calculate and handles invalid geometries.

Since
QGIS 3.20

Reimplemented in QgsPoint, and QgsLineString.

Definition at line 420 of file qgsabstractgeometry.cpp.

◆ calculateBoundingBox()

QgsRectangle QgsAbstractGeometry::calculateBoundingBox ( ) const
protectedvirtual

Default calculator for the minimal bounding box for the geometry.

Derived classes should override this method if a more efficient bounding box calculation is available.

Definition at line 122 of file qgsabstractgeometry.cpp.

◆ calculateBoundingBox3D()

QgsBox3D QgsAbstractGeometry::calculateBoundingBox3D ( ) const
protectedvirtual

Calculates the minimal 3D bounding box for the geometry.

See also
calculateBoundingBox()
Since
QGIS 3.34

Reimplemented in QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

Definition at line 127 of file qgsabstractgeometry.cpp.

◆ centroid()

QgsPoint QgsAbstractGeometry::centroid ( ) const
virtual

Returns the centroid of the geometry.

Reimplemented in QgsLineString.

Definition at line 231 of file qgsabstractgeometry.cpp.

◆ childCount()

virtual int QgsAbstractGeometry::childCount ( ) const
inlineprotectedvirtual

Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e.

curve / point)

Note
used for vertex_iterator implementation

Reimplemented in QgsPoint, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

Definition at line 1128 of file qgsabstractgeometry.h.

◆ childGeometry()

virtual QgsAbstractGeometry* QgsAbstractGeometry::childGeometry ( int  index) const
inlineprotectedvirtual

Returns pointer to child geometry (for geometries with child geometries - i.e.

geom. collection / polygon)

Note
used for vertex_iterator implementation

Reimplemented in QgsGeometryCollection, and QgsCurvePolygon.

Definition at line 1134 of file qgsabstractgeometry.h.

◆ childPoint()

QgsPoint QgsAbstractGeometry::childPoint ( int  index) const
protectedvirtual

Returns point at index (for geometries without child geometries - i.e.

curve / point)

Note
used for vertex_iterator implementation

Reimplemented in QgsPoint, and QgsCurve.

Definition at line 402 of file qgsabstractgeometry.cpp.

◆ clear()

virtual void QgsAbstractGeometry::clear ( )
pure virtual

◆ clearCache()

void QgsAbstractGeometry::clearCache ( ) const
protectedvirtual

Clears any cached parameters associated with the geometry, e.g., bounding boxes.

Reimplemented in QgsSurface, QgsGeometryCollection, and QgsCurve.

Definition at line 176 of file qgsabstractgeometry.cpp.

◆ clone()

virtual QgsAbstractGeometry* QgsAbstractGeometry::clone ( ) const
pure virtual

◆ closestSegment()

virtual double QgsAbstractGeometry::closestSegment ( const QgsPoint pt,
QgsPoint segmentPt,
QgsVertexId vertexAfter,
int *  leftOf = nullptr,
double  epsilon = 4 *std::numeric_limits< double >::epsilon() 
) const
pure virtual

Searches for the closest segment of the geometry to a given point.

Parameters
ptspecifies the point to find closest segment to
segmentPtstorage for the closest point within the geometry
vertexAfterstorage for the ID of the vertex at the end of the closest segment
leftOfindicates whether the point lies on the left side of the geometry (-1 if point is to the left of the geometry, +1 if the point is to the right of the geometry, or 0 for cases where left/right could not be determined, e.g. point exactly on a line) false if point is to right of segment)
epsilonepsilon for segment snapping
Returns
squared distance to closest segment or negative value on error

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ compareTo()

int QgsAbstractGeometry::compareTo ( const QgsAbstractGeometry other) const
virtual

Comparator for sorting of geometry.

Since
QGIS 3.20

Definition at line 42 of file qgsabstractgeometry.cpp.

◆ compareToSameClass()

virtual int QgsAbstractGeometry::compareToSameClass ( const QgsAbstractGeometry other) const
protectedpure virtual

Compares to an other geometry of the same class, and returns a integer for sorting of the two geometries.

Note
The actual logic for the sorting is an internal detail only and is subject to change between QGIS versions. The result should only be used for direct comparison of geometries and not stored for later use.
Since
QGIS 3.20

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ const_parts_begin()

const_part_iterator QgsAbstractGeometry::const_parts_begin ( ) const
inline

Returns STL-style iterator pointing to the const first part of the geometry.

See also
const_parts_end()
Since
QGIS 3.6

Definition at line 937 of file qgsabstractgeometry.h.

◆ const_parts_end()

QgsAbstractGeometry::const_part_iterator QgsAbstractGeometry::const_parts_end ( ) const

Returns STL-style iterator pointing to the imaginary const part after the last part of the geometry.

See also
const_parts_begin()
Since
QGIS 3.6

Definition at line 348 of file qgsabstractgeometry.cpp.

◆ convertTo()

bool QgsAbstractGeometry::convertTo ( Qgis::WkbType  type)
virtual

Converts the geometry to a specified type.

Returns
true if conversion was successful

Reimplemented in QgsPoint, and QgsLineString.

Definition at line 286 of file qgsabstractgeometry.cpp.

◆ coordinateSequence()

virtual QgsCoordinateSequence QgsAbstractGeometry::coordinateSequence ( ) const
pure virtual

Retrieves the sequence of geometries, rings and nodes.

Returns
coordinate sequence

Implemented in QgsPoint, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ createEmptyWithSameType()

virtual QgsAbstractGeometry* QgsAbstractGeometry::createEmptyWithSameType ( ) const
pure virtual

Creates a new geometry with the same class and same WKB type as the original and transfers ownership.

To create it, the geometry is default constructed and then the WKB is changed.

See also
clone()

Implemented in QgsTriangle, QgsPolygon, QgsPoint, QgsMultiSurface, QgsMultiPolygon, QgsMultiPoint, QgsMultiLineString, QgsMultiCurve, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ deleteVertex()

virtual bool QgsAbstractGeometry::deleteVertex ( QgsVertexId  position)
pure virtual

Deletes a vertex within the geometry.

Parameters
positionvertex id for vertex to delete
Returns
true if delete was successful
See also
insertVertex
moveVertex

Implemented in QgsTriangle, QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ dimension()

virtual int QgsAbstractGeometry::dimension ( ) const
pure virtual

Returns the inherent dimension of the geometry.

For example, this is 0 for a point geometry, 1 for a linestring and 2 for a polygon.

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ draw()

virtual void QgsAbstractGeometry::draw ( QPainter &  p) const
pure virtual

Draws the geometry using the specified QPainter.

Parameters
pdestination QPainter

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ dropMValue()

virtual bool QgsAbstractGeometry::dropMValue ( )
pure virtual

Drops any measure values which exist in the geometry.

Returns
true if m-values were present and have been removed
See also
addMValue()
dropZValue()

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ dropZValue()

virtual bool QgsAbstractGeometry::dropZValue ( )
pure virtual

Drops any z-dimensions which exist in the geometry.

Returns
true if Z values were present and have been removed
See also
addZValue()
dropMValue()

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ filterVertices()

void QgsAbstractGeometry::filterVertices ( const std::function< bool(const QgsPoint &) > &  filter)
virtual

Filters the vertices from the geometry in place, removing any which do not return true for the filter function check.

Has no meaning when called on a single point geometry.

Depending on the filter used, this may result in an invalid geometry.

Note
Not available in Python bindings
Since
QGIS 3.2

Reimplemented in QgsPoint, QgsMultiPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

Definition at line 322 of file qgsabstractgeometry.cpp.

◆ fromWkb()

virtual bool QgsAbstractGeometry::fromWkb ( QgsConstWkbPtr wkb)
pure virtual

Sets the geometry from a WKB string.

After successful read the wkb argument will be at the position where the reading has stopped.

See also
fromWkt

Implemented in QgsTriangle, QgsPolygon, QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ fromWkt()

virtual bool QgsAbstractGeometry::fromWkt ( const QString &  wkt)
pure virtual

◆ fuzzyDistanceEqual()

virtual bool QgsAbstractGeometry::fuzzyDistanceEqual ( const QgsAbstractGeometry other,
double  epsilon = 1e-8 
) const
pure virtual

Performs fuzzy distance comparison between this geometry and other using an epsilon.

Traditionally, the comparison is done by examining the specific values (such as x and y) that define the location of vertices in the geometry. It focuses on the numerical differences or relationships between these values. On the other hand, comparing distances between points considers the actual spatial separation or length between the points, regardless of their coordinate values. This comparison involves measuring the distance between two points using formulas like the distance formula. Here, it's the "distance comparison" (fuzzyDistanceEqual).

See also
fuzzyEqual
QgsGeometryUtilsBase::fuzzyEqual
Since
QGIS 3.36

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ fuzzyEqual()

virtual bool QgsAbstractGeometry::fuzzyEqual ( const QgsAbstractGeometry other,
double  epsilon = 1e-8 
) const
pure virtual

Performs fuzzy comparison between this geometry and other using an epsilon.

The comparison is done by examining the specific values (such as x and y) that define the location of vertices in the geometry.

See also
fuzzyDistanceEqual
QgsGeometryUtilsBase::fuzzyDistanceEqual
Since
QGIS 3.36

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ geometryType()

virtual QString QgsAbstractGeometry::geometryType ( ) const
pure virtual

◆ hasChildGeometries()

bool QgsAbstractGeometry::hasChildGeometries ( ) const
protectedvirtual

Returns whether the geometry has any child geometries (false for point / curve, true otherwise)

Note
used for vertex_iterator implementation

Definition at line 397 of file qgsabstractgeometry.cpp.

◆ hasCurvedSegments()

bool QgsAbstractGeometry::hasCurvedSegments ( ) const
virtual

Returns true if the geometry contains curved segments.

Reimplemented in QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

Definition at line 415 of file qgsabstractgeometry.cpp.

◆ insertVertex()

virtual bool QgsAbstractGeometry::insertVertex ( QgsVertexId  position,
const QgsPoint vertex 
)
pure virtual

Inserts a vertex into the geometry.

Parameters
positionvertex id for position of inserted vertex
vertexvertex to insert
Returns
true if insert was successful
See also
moveVertex
deleteVertex

Implemented in QgsTriangle, QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ is3D()

bool QgsAbstractGeometry::is3D ( ) const
inline

Returns true if the geometry is 3D and contains a z-value.

See also
isMeasure

Definition at line 253 of file qgsabstractgeometry.h.

◆ isEmpty()

bool QgsAbstractGeometry::isEmpty ( ) const
virtual

Returns true if the geometry is empty.

Reimplemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

Definition at line 408 of file qgsabstractgeometry.cpp.

◆ isMeasure()

bool QgsAbstractGeometry::isMeasure ( ) const
inline

Returns true if the geometry contains m values.

See also
is3D

Definition at line 262 of file qgsabstractgeometry.h.

◆ isValid()

virtual bool QgsAbstractGeometry::isValid ( QString &  error,
Qgis::GeometryValidityFlags  flags = Qgis::GeometryValidityFlags() 
) const
pure virtual

Checks validity of the geometry, and returns true if the geometry is valid.

Parameters
errorwill be set to the validity error message
flagsindicates optional flags which control the type of validity checking performed (corresponding to Qgis::GeometryValidityFlags).
Returns
true if geometry is valid
Since
QGIS 3.8

Implemented in QgsSurface, QgsPoint, QgsMultiPoint, QgsLineString, QgsGeometryCollection, QgsCurve, QgsCompoundCurve, and QgsCircularString.

◆ length()

double QgsAbstractGeometry::length ( ) const
virtual

Returns the planar, 2-dimensional length of the geometry.

Warning
QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the length returned by this method is calculated using strictly Cartesian mathematics. In contrast, the QgsDistanceArea class exposes methods for calculating the lengths of geometries using geodesic calculations which account for the curvature of the Earth (or any other celestial body).
See also
area()
perimeter()

Reimplemented in QgsLineString, QgsGeometryCollection, QgsCompoundCurve, and QgsCircularString.

Definition at line 196 of file qgsabstractgeometry.cpp.

◆ moveVertex()

virtual bool QgsAbstractGeometry::moveVertex ( QgsVertexId  position,
const QgsPoint newPos 
)
pure virtual

Moves a vertex within the geometry.

Parameters
positionvertex id for vertex to move
newPosnew position of vertex
Returns
true if move was successful
See also
insertVertex
deleteVertex

Implemented in QgsTriangle, QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ nCoordinates()

int QgsAbstractGeometry::nCoordinates ( ) const
virtual

Returns the number of nodes contained in the geometry.

Reimplemented in QgsPoint, QgsMultiPoint, QgsLineString, QgsGeometryCollection, and QgsCurvePolygon.

Definition at line 180 of file qgsabstractgeometry.cpp.

◆ nextVertex()

virtual bool QgsAbstractGeometry::nextVertex ( QgsVertexId id,
QgsPoint vertex 
) const
pure virtual

Returns next vertex id and coordinates.

Parameters
idinitial value should be the starting vertex id. The next vertex id will be stored in this variable if found.
vertexcontainer for found node
Returns
false if at end

Implemented in QgsPoint, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ normalize()

virtual void QgsAbstractGeometry::normalize ( )
pure virtual

Reorganizes the geometry into a normalized form (or "canonical" form).

Polygon rings will be rearranged so that their starting vertex is the lower left and ring orientation follows the right hand rule, collections are ordered by geometry type, and other normalization techniques are applied. The resultant geometry will be geometrically equivalent to the original geometry.

Since
QGIS 3.20

Implemented in QgsPoint, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ operator!=()

virtual bool QgsAbstractGeometry::operator!= ( const QgsAbstractGeometry other) const
pure virtual

◆ operator=()

QgsAbstractGeometry & QgsAbstractGeometry::operator= ( const QgsAbstractGeometry geom)

Definition at line 32 of file qgsabstractgeometry.cpp.

◆ operator==()

virtual bool QgsAbstractGeometry::operator== ( const QgsAbstractGeometry other) const
pure virtual

◆ partCount()

virtual int QgsAbstractGeometry::partCount ( ) const
pure virtual

Returns count of parts contained in the geometry.

See also
vertexCount
ringCount

Implemented in QgsPoint, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ parts() [1/2]

QgsGeometryPartIterator QgsAbstractGeometry::parts ( )

Returns Java-style iterator for traversal of parts of the geometry.

This iterator can safely be used to modify parts of the geometry.

Example

# print the WKT representation of each part in a multi-point geometry
geometry = QgsMultiPoint.fromWkt( 'MultiPoint( 0 0, 1 1, 2 2)' )
for part in geometry.parts():
print(part.asWkt())
# single part geometries only have one part - this loop will iterate once only
geometry = QgsLineString.fromWkt( 'LineString( 0 0, 10 10 )' )
for part in geometry.parts():
print(part.asWkt())
# parts can be modified during the iteration
geometry = QgsMultiPoint.fromWkt( 'MultiPoint( 0 0, 1 1, 2 2)' )
for part in geometry.parts():
part.transform(ct)
# part iteration can also be combined with vertex iteration
geometry = QgsMultiPolygon.fromWkt( 'MultiPolygon((( 0 0, 0 10, 10 10, 10 0, 0 0 ),( 5 5, 5 6, 6 6, 6 5, 5 5)),((20 2, 22 2, 22 4, 20 4, 20 2)))' )
for part in geometry.parts():
for v in part.vertices():
print(v.x(), v.y())
bool fromWkt(const QString &wkt) override
Sets the geometry from a WKT string.
bool fromWkt(const QString &wkt) override
Sets the geometry from a WKT string.
bool fromWkt(const QString &wkt) override
Sets the geometry from a WKT string.
See also
vertices()
Since
QGIS 3.6

Definition at line 338 of file qgsabstractgeometry.cpp.

◆ parts() [2/2]

QgsGeometryConstPartIterator QgsAbstractGeometry::parts ( ) const

Returns Java-style iterator for traversal of parts of the geometry.

This iterator returns read-only references to parts and cannot be used to modify the parts.

Note
Not available in Python bindings
Since
QGIS 3.6

Definition at line 343 of file qgsabstractgeometry.cpp.

◆ parts_begin()

part_iterator QgsAbstractGeometry::parts_begin ( )
inline

Returns STL-style iterator pointing to the first part of the geometry.

See also
parts_end()
parts()
Since
QGIS 3.6

Definition at line 868 of file qgsabstractgeometry.h.

◆ parts_end()

QgsAbstractGeometry::part_iterator QgsAbstractGeometry::parts_end ( )

Returns STL-style iterator pointing to the imaginary part after the last part of the geometry.

See also
parts_begin()
parts()
Since
QGIS 3.6

Definition at line 332 of file qgsabstractgeometry.cpp.

◆ perimeter()

double QgsAbstractGeometry::perimeter ( ) const
virtual

Returns the planar, 2-dimensional perimeter of the geometry.

Warning
QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the perimeter returned by this method is calculated using strictly Cartesian mathematics. In contrast, the QgsDistanceArea class exposes methods for calculating the perimeters of geometries using geodesic calculations which account for the curvature of the Earth (or any other celestial body).
See also
area()
length()

Reimplemented in QgsGeometryCollection, and QgsCurvePolygon.

Definition at line 201 of file qgsabstractgeometry.cpp.

◆ removeDuplicateNodes()

virtual bool QgsAbstractGeometry::removeDuplicateNodes ( double  epsilon = 4 *std::numeric_limits< double >::epsilon(),
bool  useZValues = false 
)
pure virtual

Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry.

The epsilon parameter specifies the tolerance for coordinates when determining that vertices are identical.

By default, z values are not considered when detecting duplicate nodes. E.g. two nodes with the same x and y coordinate but different z values will still be considered duplicate and one will be removed. If useZValues is true, then the z values are also tested and nodes with the same x and y but different z will be maintained.

Note that duplicate nodes are not tested between different parts of a multipart geometry. E.g. a multipoint geometry with overlapping points will not be changed by this method.

The function will return true if nodes were removed, or false if no duplicate nodes were found.

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ ringCount()

virtual int QgsAbstractGeometry::ringCount ( int  part = 0) const
pure virtual

Returns the number of rings of which this geometry is built.

Implemented in QgsPoint, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ segmentize()

QgsAbstractGeometry * QgsAbstractGeometry::segmentize ( double  tolerance = M_PI / 180.,
SegmentationToleranceType  toleranceType = MaximumAngle 
) const
virtual

Returns a version of the geometry without curves.

Caller takes ownership of the returned geometry.

Parameters
tolerancesegmentation tolerance
toleranceTypemaximum segmentation angle or maximum difference between approximation and curve

Reimplemented in QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

Definition at line 430 of file qgsabstractgeometry.cpp.

◆ segmentLength()

virtual double QgsAbstractGeometry::segmentLength ( QgsVertexId  startVertex) const
pure virtual

Returns the length of the segment of the geometry which begins at startVertex.

Warning
QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the lengths returned by this method are calculated using strictly Cartesian mathematics.

Implemented in QgsPoint, QgsMultiPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ setZMTypeFromSubGeometry()

void QgsAbstractGeometry::setZMTypeFromSubGeometry ( const QgsAbstractGeometry subggeom,
Qgis::WkbType  baseGeomType 
)
protected

Updates the geometry type based on whether sub geometries contain z or m values.

Definition at line 75 of file qgsabstractgeometry.cpp.

◆ simplifiedTypeRef()

const QgsAbstractGeometry * QgsAbstractGeometry::simplifiedTypeRef ( ) const
virtual

Returns a reference to the simplest lossless representation of this geometry, e.g.

if the geometry is a multipart geometry type with a single member geometry, a reference to that part will be returned.

This method employs the following logic:

  • For multipart geometries containing a single part only a direct reference to that part will be returned.
  • For compound curve geometries containing a single curve only a direct reference to that curve will be returned.

This method returns a reference only, and does not involve any geometry cloning.

Note
Ownership of the returned geometry is NOT transferred, and remains with the original geometry object. Callers must take care to ensure that the original geometry object exists for the lifespan of the returned object.
Since
QGIS 3.20

Reimplemented in QgsGeometryCollection, and QgsCompoundCurve.

Definition at line 317 of file qgsabstractgeometry.cpp.

◆ snappedToGrid()

virtual QgsAbstractGeometry* QgsAbstractGeometry::snappedToGrid ( double  hSpacing,
double  vSpacing,
double  dSpacing = 0,
double  mSpacing = 0 
) const
pure virtual

Makes a new geometry with all the points or vertices snapped to the closest point of the grid.

Ownership is transferred to the caller.

If the gridified geometry could not be calculated nullptr will be returned. It may generate an invalid geometry (in some corner cases). It can also be thought as rounding the edges and it may be useful for removing errors.

Example:

geometry.snappedToGrid(1, 1)

In this case we use a 2D grid of 1x1 to gridify. In this case, it can be thought like rounding the x and y of all the points/vertices to full units (remove all decimals).

Parameters
hSpacingHorizontal spacing of the grid (x axis). 0 to disable.
vSpacingVertical spacing of the grid (y axis). 0 to disable.
dSpacingDepth spacing of the grid (z axis). 0 (default) to disable.
mSpacingCustom dimension spacing of the grid (m axis). 0 (default) to disable.

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ sortIndex()

int QgsAbstractGeometry::sortIndex ( ) const
protected

Returns the sort index for the geometry, used in the compareTo() method to compare geometries of different types.

Since
QGIS 3.20

Definition at line 359 of file qgsabstractgeometry.cpp.

◆ swapXy()

virtual void QgsAbstractGeometry::swapXy ( )
pure virtual

Swaps the x and y coordinates from the geometry.

This can be used to repair geometries which have accidentally had their latitude and longitude coordinates reversed.

Since
QGIS 3.2

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ toCurveType()

virtual QgsAbstractGeometry* QgsAbstractGeometry::toCurveType ( ) const
pure virtual

Returns the geometry converted to the more generic curve type.

E.g. QgsLineString -> QgsCompoundCurve, QgsPolygon -> QgsCurvePolygon, QgsMultiLineString -> QgsMultiCurve, QgsMultiPolygon -> QgsMultiSurface

Returns
the converted geometry. Caller takes ownership

Implemented in QgsTriangle, QgsPolygon, QgsPoint, QgsMultiSurface, QgsMultiPolygon, QgsMultiPoint, QgsMultiLineString, QgsMultiCurve, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ transform() [1/3]

virtual void QgsAbstractGeometry::transform ( const QgsCoordinateTransform ct,
Qgis::TransformDirection  d = Qgis::TransformDirection::Forward,
bool  transformZ = false 
)
pure virtual

Transforms the geometry using a coordinate transform.

Parameters
ctcoordinate transform
dtransformation direction
transformZset to true to also transform z coordinates. This requires that the z coordinates in the geometry represent height relative to the vertical datum of the source CRS (generally ellipsoidal heights) and are expressed in its vertical units (generally meters). If false, then z coordinates will not be changed by the transform.

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ transform() [2/3]

virtual void QgsAbstractGeometry::transform ( const QTransform &  t,
double  zTranslate = 0.0,
double  zScale = 1.0,
double  mTranslate = 0.0,
double  mScale = 1.0 
)
pure virtual

Transforms the x and y components of the geometry using a QTransform object t.

Optionally, the geometry's z values can be scaled via zScale and translated via zTranslate. Similarly, m-values can be scaled via mScale and translated via mTranslate.

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ transform() [3/3]

virtual bool QgsAbstractGeometry::transform ( QgsAbstractGeometryTransformer transformer,
QgsFeedback feedback = nullptr 
)
pure virtual

Transforms the vertices from the geometry in place, using the specified geometry transformer object.

Depending on the transformer used, this may result in an invalid geometry.

The optional feedback argument can be used to cancel the transformation before it completes. If this is done, the geometry will be left in a semi-transformed state.

Returns
true if the geometry was successfully transformed.
Since
QGIS 3.18

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ transformVertices()

void QgsAbstractGeometry::transformVertices ( const std::function< QgsPoint(const QgsPoint &) > &  transform)
virtual

Transforms the vertices from the geometry in place, applying the transform function to every vertex.

Depending on the transform used, this may result in an invalid geometry.

Transform functions are not permitted to alter the dimensionality of vertices. If a transform which adds (or removes) z/m values is desired, first call the corresponding addZValue() or addMValue() function to change the geometry's dimensionality and then transform.

Note
Not available in Python bindings
Since
QGIS 3.4

Reimplemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

Definition at line 327 of file qgsabstractgeometry.cpp.

◆ vertexAngle()

virtual double QgsAbstractGeometry::vertexAngle ( QgsVertexId  vertex) const
pure virtual

Returns approximate angle at a vertex.

This is usually the average angle between adjacent segments, and can be pictured as the orientation of a line following the curvature of the geometry at the specified vertex.

Parameters
vertexthe vertex id
Returns
rotation in radians, clockwise from north

Implemented in QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ vertexAt()

virtual QgsPoint QgsAbstractGeometry::vertexAt ( QgsVertexId  id) const
pure virtual

Returns the point corresponding to a specified vertex id.

Implemented in QgsPoint, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ vertexCount()

virtual int QgsAbstractGeometry::vertexCount ( int  part = 0,
int  ring = 0 
) const
pure virtual

Returns the number of vertices of which this geometry is built.

Implemented in QgsPoint, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ vertexNumberFromVertexId()

virtual int QgsAbstractGeometry::vertexNumberFromVertexId ( QgsVertexId  id) const
pure virtual

Returns the vertex number corresponding to a vertex id.

The vertex numbers start at 0, so a return value of 0 corresponds to the first vertex.

Returns -1 if a corresponding vertex could not be found.

Implemented in QgsPoint, QgsMultiPoint, QgsGeometryCollection, QgsCurvePolygon, and QgsCurve.

◆ vertices()

QgsVertexIterator QgsAbstractGeometry::vertices ( ) const

Returns a read-only, Java-style iterator for traversal of vertices of all the geometry, including all geometry parts and rings.

Warning
The iterator returns a copy of individual vertices, and accordingly geometries cannot be modified using the iterator. See transformVertices() for a safe method to modify vertices "in-place".

Example

# print the x and y coordinate for each vertex in a LineString
geometry = QgsLineString.fromWkt( 'LineString( 0 0, 1 1, 2 2)' )
for v in geometry.vertices():
print(v.x(), v.y())
# vertex iteration includes all parts and rings
geometry = QgsMultiPolygon.fromWkt( 'MultiPolygon((( 0 0, 0 10, 10 10, 10 0, 0 0 ),( 5 5, 5 6, 6 6, 6 5, 5 5)),((20 2, 22 2, 22 4, 20 4, 20 2)))' )
for v in geometry.vertices():
print(v.x(), v.y())
See also
parts()

Definition at line 354 of file qgsabstractgeometry.cpp.

◆ vertices_begin()

vertex_iterator QgsAbstractGeometry::vertices_begin ( ) const
inline

Returns STL-style iterator pointing to the first vertex of the geometry.

See also
vertices_end()
vertices()

Definition at line 1011 of file qgsabstractgeometry.h.

◆ vertices_end()

vertex_iterator QgsAbstractGeometry::vertices_end ( ) const
inline

Returns STL-style iterator pointing to the imaginary vertex after the last vertex of the geometry.

See also
vertices_begin()
vertices()

Definition at line 1023 of file qgsabstractgeometry.h.

◆ wkbSize()

virtual int QgsAbstractGeometry::wkbSize ( QgsAbstractGeometry::WkbFlags  flags = QgsAbstractGeometry::WkbFlags()) const
pure virtual

Returns the length of the QByteArray returned by asWkb()

The optional flags argument specifies flags controlling WKB export behavior

Since
QGIS 3.16

Implemented in QgsPolygon, QgsPoint, QgsLineString, QgsGeometryCollection, QgsCurvePolygon, QgsCompoundCurve, and QgsCircularString.

◆ wkbType()

Qgis::WkbType QgsAbstractGeometry::wkbType ( ) const
inline

Returns the WKB type of the geometry.

See also
geometryType
wktTypeStr

Definition at line 240 of file qgsabstractgeometry.h.

◆ wktTypeStr()

QString QgsAbstractGeometry::wktTypeStr ( ) const

Returns the WKT type string of the geometry.

See also
geometryType
wkbType

Definition at line 211 of file qgsabstractgeometry.cpp.

Friends And Related Function Documentation

◆ TestQgsGeometry

friend class TestQgsGeometry
friend

Definition at line 1169 of file qgsabstractgeometry.h.

Member Data Documentation

◆ mWkbType

Qgis::WkbType QgsAbstractGeometry::mWkbType = Qgis::WkbType::Unknown
protected

Definition at line 1143 of file qgsabstractgeometry.h.


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