QGIS API Documentation  3.5.0-Master (591bb75)
Public Types | Public Member Functions | Protected Member Functions | List of all members
QgsCurve Class Referenceabstract

Abstract base class for curved geometry type. More...

#include <qgscurve.h>

Inheritance diagram for QgsCurve:
Inheritance graph
[legend]

Public Types

enum  Orientation { Clockwise, CounterClockwise }
 Curve orientation. More...
 
- Public Types inherited from QgsAbstractGeometry
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...
 

Public Member Functions

 QgsCurve ()=default
 Constructor for QgsCurve. More...
 
virtual void addToPainterPath (QPainterPath &path) const =0
 Adds a curve to a painter path. More...
 
void adjacentVertices (QgsVertexId vertex, QgsVertexId &previousVertex, QgsVertexId &nextVertex) const override
 Returns the vertices adjacent to a specified vertex within a geometry. More...
 
virtual QPolygonF asQPolygonF () const
 Returns a QPolygonF representing the points. More...
 
QgsAbstractGeometryboundary () const override
 Returns the closure of the combinatorial boundary of the geometry (ie the topological boundary of the geometry). More...
 
QgsRectangle boundingBox () const override
 Returns the minimal bounding box for the geometry. More...
 
const QgsCurvecast (const QgsAbstractGeometry *geom) const
 Cast the geom to a QgsCurve. More...
 
QgsCurveclone () const override=0
 Clones the geometry by performing a deep copy. More...
 
QgsCoordinateSequence coordinateSequence () const override
 Retrieves the sequence of geometries, rings and nodes. More...
 
virtual QgsCurvecurveSubstring (double startDistance, double endDistance) const =0
 Returns a new curve representing a substring of this curve. More...
 
virtual QgsLineStringcurveToLine (double tolerance=M_PI_2/90, SegmentationToleranceType toleranceType=MaximumAngle) const =0
 Returns a new line string geometry corresponding to a segmentized approximation of the curve. More...
 
virtual void drawAsPolygon (QPainter &p) const =0
 Draws the curve as a polygon on the specified QPainter. More...
 
virtual QgsPoint endPoint () const =0
 Returns the end point of the curve. More...
 
virtual bool equals (const QgsCurve &other) const =0
 Checks whether this curve exactly equals another curve. More...
 
virtual QgsPointinterpolatePoint (double distance) const =0
 Returns an interpolated point on the curve at the specified distance. More...
 
virtual bool isClosed () const
 Returns true if the curve is closed. More...
 
virtual bool isRing () const
 Returns true if the curve is a ring. More...
 
bool nextVertex (QgsVertexId &id, QgsPoint &vertex) const override
 Returns next vertex id and coordinates. More...
 
virtual int numPoints () const =0
 Returns the number of points in the curve. More...
 
bool operator!= (const QgsAbstractGeometry &other) const override
 
bool operator== (const QgsAbstractGeometry &other) const override
 
Orientation orientation () const
 Returns the curve's orientation, e.g. More...
 
int partCount () const override
 Returns count of parts contained in the geometry. More...
 
virtual bool pointAt (int node, QgsPoint &point, QgsVertexId::VertexType &type) const =0
 Returns the point and vertex id of a point within the curve. More...
 
virtual void points (QgsPointSequence &pt) const =0
 Returns a list of points within the curve. More...
 
virtual QgsCurvereversed () const =0
 Returns a reversed copy of the curve, where the direction of the curve has been flipped. More...
 
int ringCount (int part=0) const override
 Returns the number of rings of which this geometry is built. More...
 
QgsCurvesegmentize (double tolerance=M_PI_2/90, SegmentationToleranceType toleranceType=MaximumAngle) const override
 Returns a geometry without curves. More...
 
double sinuosity () const
 Returns the curve sinuosity, which is the ratio of the curve length() to curve straightDistance2d(). More...
 
virtual QgsPoint startPoint () const =0
 Returns the starting point of the curve. More...
 
double straightDistance2d () const
 Returns the straight distance of the curve, i.e. More...
 
virtual void sumUpArea (double &sum) const =0
 Sums up the area of the curve by iterating over the vertices (shoelace formula). More...
 
QgsCurvetoCurveType () const override
 Returns the geometry converted to the more generic curve type. More...
 
QgsPoint vertexAt (QgsVertexId id) const override
 Returns the point corresponding to a specified vertex id. More...
 
int vertexCount (int part=0, int ring=0) const override
 Returns the number of vertices of which this geometry is built. More...
 
int vertexNumberFromVertexId (QgsVertexId id) const override
 Returns the vertex number corresponding to a vertex id. More...
 
virtual double xAt (int index) const =0
 Returns the x-coordinate of the specified node in the line string. More...
 
virtual double yAt (int index) const =0
 Returns the y-coordinate of the specified node in the line string. More...
 
- Public Member Functions inherited from QgsAbstractGeometry
 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 double area () const
 Returns the 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...
 
virtual QString asJson (int precision=17) const =0
 Returns a GeoJSON representation of the geometry. More...
 
virtual QByteArray asWkb () 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 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 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...
 
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 (QgsWkbTypes::Type type)
 Converts the geometry to a specified type. 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 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 double length () const
 Returns the 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...
 
QgsAbstractGeometryoperator= (const QgsAbstractGeometry &geom)
 
QgsGeometryConstPartIterator parts () const
 Returns Java-style iterator for traversal of parts of the geometry. More...
 
QgsGeometryPartIterator parts ()
 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 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 double segmentLength (QgsVertexId startVertex) const =0
 Returns the length of the segment of the geometry which begins at startVertex. 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 void transform (const QgsCoordinateTransform &ct, QgsCoordinateTransform::TransformDirection d=QgsCoordinateTransform::ForwardTransform, bool transformZ=false) SIP_THROW(QgsCsException)=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 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...
 
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...
 
QgsWkbTypes::Type 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

int childCount () const override
 Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e. More...
 
QgsPoint childPoint (int index) const override
 Returns point at index (for geometries without child geometries - i.e. More...
 
void clearCache () const override
 Clears any cached parameters associated with the geometry, e.g., bounding boxes. More...
 
bool snapToGridPrivate (double hSpacing, double vSpacing, double dSpacing, double mSpacing, const QVector< double > &srcX, const QVector< double > &srcY, const QVector< double > &srcZ, const QVector< double > &srcM, QVector< double > &outX, QVector< double > &outY, QVector< double > &outZ, QVector< double > &outM) const
 Helper function for QgsCurve subclasses to snap to grids. More...
 
- Protected Member Functions inherited from QgsAbstractGeometry
virtual QgsRectangle calculateBoundingBox () const
 Default calculator for the minimal bounding box for the geometry. More...
 
virtual QgsAbstractGeometrychildGeometry (int index) const
 Returns pointer to child geometry (for geometries with child geometries - i.e. 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, QgsWkbTypes::Type baseGeomType)
 Updates the geometry type based on whether sub geometries contain z or m values. More...
 

Additional Inherited Members

- Protected Attributes inherited from QgsAbstractGeometry
QgsWkbTypes::Type mWkbType = QgsWkbTypes::Unknown
 

Detailed Description

Abstract base class for curved geometry type.

Since
QGIS 2.10

Definition at line 35 of file qgscurve.h.

Member Enumeration Documentation

◆ Orientation

Curve orientation.

Enumerator
Clockwise 

Clockwise orientation.

CounterClockwise 

Counter-clockwise orientation.

Definition at line 233 of file qgscurve.h.

Constructor & Destructor Documentation

◆ QgsCurve()

QgsCurve::QgsCurve ( )
default

Constructor for QgsCurve.

Member Function Documentation

◆ addToPainterPath()

virtual void QgsCurve::addToPainterPath ( QPainterPath &  path) const
pure virtual

Adds a curve to a painter path.

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ adjacentVertices()

void QgsCurve::adjacentVertices ( QgsVertexId  vertex,
QgsVertexId previousVertex,
QgsVertexId nextVertex 
) const
overridevirtual

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

Since
QGIS 3.0

Implements QgsAbstractGeometry.

Definition at line 95 of file qgscurve.cpp.

◆ asQPolygonF()

QPolygonF QgsCurve::asQPolygonF ( ) const
virtual

Returns a QPolygonF representing the points.

Reimplemented in QgsLineString.

Definition at line 191 of file qgscurve.cpp.

◆ boundary()

QgsAbstractGeometry * QgsCurve::boundary ( ) const
overridevirtual

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 null for some geometry types.
Since
QGIS 3.0

Implements QgsAbstractGeometry.

Definition at line 132 of file qgscurve.cpp.

◆ boundingBox()

QgsRectangle QgsCurve::boundingBox ( ) const
overridevirtual

Returns the minimal bounding box for the geometry.

Implements QgsAbstractGeometry.

Definition at line 182 of file qgscurve.cpp.

◆ cast()

const QgsCurve* QgsCurve::cast ( const QgsAbstractGeometry geom) const
inline

Cast the geom to a QgsCurve.

Should be used by qgsgeometry_cast<QgsCurve *>( geometry ).

Note
Not available in Python. Objects will be automatically be converted to the appropriate target type.
Since
QGIS 3.0

Definition at line 257 of file qgscurve.h.

◆ childCount()

int QgsCurve::childCount ( ) const
overrideprotectedvirtual

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
Since
QGIS 3.0

Reimplemented from QgsAbstractGeometry.

Definition at line 230 of file qgscurve.cpp.

◆ childPoint()

QgsPoint QgsCurve::childPoint ( int  index) const
overrideprotectedvirtual

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

curve / point)

Note
used for vertex_iterator implementation
Since
QGIS 3.0

Reimplemented from QgsAbstractGeometry.

Definition at line 235 of file qgscurve.cpp.

◆ clearCache()

void QgsCurve::clearCache ( ) const
overrideprotectedvirtual

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

Reimplemented from QgsAbstractGeometry.

Definition at line 224 of file qgscurve.cpp.

◆ clone()

QgsCurve* QgsCurve::clone ( ) const
overridepure virtual

Clones the geometry by performing a deep copy.

Implements QgsAbstractGeometry.

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ coordinateSequence()

QgsCoordinateSequence QgsCurve::coordinateSequence ( ) const
overridevirtual

Retrieves the sequence of geometries, rings and nodes.

Returns
coordinate sequence

Implements QgsAbstractGeometry.

Definition at line 60 of file qgscurve.cpp.

◆ curveSubstring()

virtual QgsCurve* QgsCurve::curveSubstring ( double  startDistance,
double  endDistance 
) const
pure virtual

Returns a new curve representing a substring of this curve.

The startDistance and endDistance arguments specify the length along the curve which the substring should start and end at. If the endDistance is greater than the total length of the curve then any "extra" length will be ignored.

If z or m values are present, the output z and m will be interpolated using the existing vertices' z or m values.

Since
QGIS 3.4

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ curveToLine()

virtual QgsLineString* QgsCurve::curveToLine ( double  tolerance = M_PI_2/90,
SegmentationToleranceType  toleranceType = MaximumAngle 
) const
pure virtual

Returns a new line string geometry corresponding to a segmentized approximation of the curve.

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

Uses a MaximumAngle tolerance of 1 degrees by default (360 segments in a full circle)

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ drawAsPolygon()

virtual void QgsCurve::drawAsPolygon ( QPainter &  p) const
pure virtual

Draws the curve as a polygon on the specified QPainter.

Parameters
pdestination QPainter

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ endPoint()

virtual QgsPoint QgsCurve::endPoint ( ) const
pure virtual

Returns the end point of the curve.

See also
startPoint

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ equals()

virtual bool QgsCurve::equals ( const QgsCurve other) const
pure virtual

Checks whether this curve exactly equals another curve.

Since
QGIS 3.0

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ interpolatePoint()

virtual QgsPoint* QgsCurve::interpolatePoint ( double  distance) const
pure virtual

Returns an interpolated point on the curve at the specified distance.

If z or m values are present, the output z and m will be interpolated using the existing vertices' z or m values.

If distance is negative, or is greater than the length of the curve, a nullptr will be returned.

Since
QGIS 3.4

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ isClosed()

bool QgsCurve::isClosed ( ) const
virtual

Returns true if the curve is closed.

Definition at line 39 of file qgscurve.cpp.

◆ isRing()

bool QgsCurve::isRing ( ) const
virtual

Returns true if the curve is a ring.

Definition at line 55 of file qgscurve.cpp.

◆ nextVertex()

bool QgsCurve::nextVertex ( QgsVertexId id,
QgsPoint vertex 
) const
overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 70 of file qgscurve.cpp.

◆ numPoints()

virtual int QgsCurve::numPoints ( ) const
pure virtual

Returns the number of points in the curve.

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ operator!=()

bool QgsCurve::operator!= ( const QgsAbstractGeometry other) const
overridevirtual

Implements QgsAbstractGeometry.

Definition at line 34 of file qgscurve.cpp.

◆ operator==()

bool QgsCurve::operator== ( const QgsAbstractGeometry other) const
overridevirtual

Implements QgsAbstractGeometry.

Definition at line 25 of file qgscurve.cpp.

◆ orientation()

QgsCurve::Orientation QgsCurve::orientation ( ) const

Returns the curve's orientation, e.g.

clockwise or counter-clockwise.

Warning
The result is not predictable for non-closed curves.
Since
QGIS 3.6

Definition at line 217 of file qgscurve.cpp.

◆ partCount()

int QgsCurve::partCount ( ) const
overridevirtual

Returns count of parts contained in the geometry.

See also
vertexCount
ringCount

Implements QgsAbstractGeometry.

Definition at line 164 of file qgscurve.cpp.

◆ pointAt()

virtual bool QgsCurve::pointAt ( int  node,
QgsPoint point,
QgsVertexId::VertexType type 
) const
pure virtual

Returns the point and vertex id of a point within the curve.

Parameters
nodenode number, where the first node is 0
pointwill be set to point at corresponding node in the curve
typewill be set to the vertex type of the node
Returns
true if node exists within the curve

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ points()

virtual void QgsCurve::points ( QgsPointSequence pt) const
pure virtual

Returns a list of points within the curve.

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ reversed()

virtual QgsCurve* QgsCurve::reversed ( ) const
pure virtual

Returns a reversed copy of the curve, where the direction of the curve has been flipped.

Since
QGIS 2.14

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ ringCount()

int QgsCurve::ringCount ( int  part = 0) const
overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 158 of file qgscurve.cpp.

◆ segmentize()

QgsCurve * QgsCurve::segmentize ( double  tolerance = M_PI_2 / 90,
SegmentationToleranceType  toleranceType = MaximumAngle 
) const
overridevirtual

Returns a geometry without curves.

Caller takes ownership

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

Reimplemented from QgsAbstractGeometry.

Definition at line 146 of file qgscurve.cpp.

◆ sinuosity()

double QgsCurve::sinuosity ( ) const

Returns the curve sinuosity, which is the ratio of the curve length() to curve straightDistance2d().

Larger numbers indicate a more "sinuous" curve (i.e. more "bendy"). The minimum value returned of 1.0 indicates a perfectly straight curve.

If a curve isClosed(), it has infinite sinuosity and will return NaN.

Since
QGIS 3.2

Definition at line 208 of file qgscurve.cpp.

◆ snapToGridPrivate()

bool QgsCurve::snapToGridPrivate ( double  hSpacing,
double  vSpacing,
double  dSpacing,
double  mSpacing,
const QVector< double > &  srcX,
const QVector< double > &  srcY,
const QVector< double > &  srcZ,
const QVector< double > &  srcM,
QVector< double > &  outX,
QVector< double > &  outY,
QVector< double > &  outZ,
QVector< double > &  outM 
) const
protected

Helper function for QgsCurve subclasses to snap to grids.

Note
Not available in Python bindings.

Definition at line 245 of file qgscurve.cpp.

◆ startPoint()

virtual QgsPoint QgsCurve::startPoint ( ) const
pure virtual

Returns the starting point of the curve.

See also
endPoint

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ straightDistance2d()

double QgsCurve::straightDistance2d ( ) const

Returns the straight distance of the curve, i.e.

the direct/euclidean distance between the first and last vertex of the curve. (Also known as "as the crow flies" distance).

Since
QGIS 3.2

Definition at line 203 of file qgscurve.cpp.

◆ sumUpArea()

virtual void QgsCurve::sumUpArea ( double &  sum) const
pure virtual

Sums up the area of the curve by iterating over the vertices (shoelace formula).

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ toCurveType()

QgsCurve * QgsCurve::toCurveType ( ) const
overridevirtual

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

Implements QgsAbstractGeometry.

Reimplemented in QgsLineString.

Definition at line 177 of file qgscurve.cpp.

◆ vertexAt()

QgsPoint QgsCurve::vertexAt ( QgsVertexId  id) const
overridevirtual

Returns the point corresponding to a specified vertex id.

Implements QgsAbstractGeometry.

Definition at line 169 of file qgscurve.cpp.

◆ vertexCount()

int QgsCurve::vertexCount ( int  part = 0,
int  ring = 0 
) const
overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 151 of file qgscurve.cpp.

◆ vertexNumberFromVertexId()

int QgsCurve::vertexNumberFromVertexId ( QgsVertexId  id) const
overridevirtual

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.

Since
QGIS 3.0

Implements QgsAbstractGeometry.

Definition at line 123 of file qgscurve.cpp.

◆ xAt()

virtual double QgsCurve::xAt ( int  index) const
pure virtual

Returns the x-coordinate of the specified node in the line string.

Parameters
indexindex of node, where the first node in the line is 0
Returns
x-coordinate of node, or 0.0 if index is out of bounds

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.

◆ yAt()

virtual double QgsCurve::yAt ( int  index) const
pure virtual

Returns the y-coordinate of the specified node in the line string.

Parameters
indexindex of node, where the first node in the line is 0
Returns
y-coordinate of node, or 0.0 if index is out of bounds

Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.


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