QGIS API Documentation  3.21.0-Master (3191652dc5)
Public Member Functions | Static Public Member Functions | Protected Member Functions | List of all members
QgsCircularString Class Reference

Circular string geometry type. More...

#include <qgscircularstring.h>

Inheritance diagram for QgsCircularString:
Inheritance graph
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Public Member Functions

 QgsCircularString () SIP_HOLDGIL
 Constructs an empty circular string. More...
 
 QgsCircularString (const QgsPoint &p1, const QgsPoint &p2, const QgsPoint &p3) SIP_HOLDGIL
 Constructs a circular string with a single arc passing through p1, p2 and p3. More...
 
 QgsCircularString (const QVector< double > &x, const QVector< double > &y, const QVector< double > &z=QVector< double >(), const QVector< double > &m=QVector< double >()) SIP_HOLDGIL
 Construct a circular string from arrays of coordinates. More...
 
bool addMValue (double mValue=0) override
 Adds a measure to the geometry, initialized to a preset value. More...
 
void addToPainterPath (QPainterPath &path) const override
 Adds a curve to a painter path. More...
 
bool addZValue (double zValue=0) override
 Adds a z-dimension to the geometry, initialized to a preset value. More...
 
void append (const QgsCircularString *string)
 Appends the contents of another circular string to the end of this circular string. More...
 
QDomElement asGml2 (QDomDocument &doc, int precision=17, const QString &ns="gml", QgsAbstractGeometry::AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const override
 Returns a GML2 representation of the geometry. More...
 
QDomElement asGml3 (QDomDocument &doc, int precision=17, const QString &ns="gml", QgsAbstractGeometry::AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const override
 Returns a GML3 representation of the geometry. More...
 
json asJsonObject (int precision=17) const override
 Returns a json object representation of the geometry. More...
 
QByteArray asWkb (QgsAbstractGeometry::WkbFlags flags=QgsAbstractGeometry::WkbFlags()) const override
 
QString asWkt (int precision=17) const override
 Returns a WKT representation of the geometry. More...
 
void clear () override
 Clears the geometry, ie reset it to a null geometry. More...
 
QgsCircularStringclone () const override
 Clones the geometry by performing a deep copy. More...
 
double closestSegment (const QgsPoint &pt, QgsPoint &segmentPt, QgsVertexId &vertexAfter, int *leftOf=nullptr, double epsilon=4 *std::numeric_limits< double >::epsilon()) const override
 Searches for the closest segment of the geometry to a given point. More...
 
QgsCircularStringcreateEmptyWithSameType () const override
 Creates a new geometry with the same class and same WKB type as the original and transfers ownership. More...
 
QgsCircularStringcurveSubstring (double startDistance, double endDistance) const override
 Returns a new curve representing a substring of this curve. More...
 
QgsLineStringcurveToLine (double tolerance=M_PI_2/90, SegmentationToleranceType toleranceType=MaximumAngle) const override
 Returns a new line string geometry corresponding to a segmentized approximation of the curve. More...
 
bool deleteVertex (QgsVertexId position) override
 Deletes a vertex within the geometry. More...
 
int dimension () const override SIP_HOLDGIL
 Returns the inherent dimension of the geometry. More...
 
void draw (QPainter &p) const override
 Draws the geometry using the specified QPainter. More...
 
void drawAsPolygon (QPainter &p) const override
 Draws the curve as a polygon on the specified QPainter. More...
 
bool dropMValue () override
 Drops any measure values which exist in the geometry. More...
 
bool dropZValue () override
 Drops any z-dimensions which exist in the geometry. More...
 
QgsPoint endPoint () const override SIP_HOLDGIL
 Returns the end point of the curve. More...
 
bool equals (const QgsCurve &other) const override
 Checks whether this curve exactly equals another curve. More...
 
void filterVertices (const std::function< bool(const QgsPoint &) > &filter) override
 Filters the vertices from the geometry in place, removing any which do not return true for the filter function check. More...
 
bool fromWkb (QgsConstWkbPtr &wkb) override
 Sets the geometry from a WKB string. More...
 
bool fromWkt (const QString &wkt) override
 Sets the geometry from a WKT string. More...
 
QString geometryType () const override SIP_HOLDGIL
 Returns a unique string representing the geometry type. More...
 
bool hasCurvedSegments () const override
 Returns true if the geometry contains curved segments. More...
 
int indexOf (const QgsPoint &point) const final
 Returns the index of the first vertex matching the given point, or -1 if a matching vertex is not found. More...
 
bool insertVertex (QgsVertexId position, const QgsPoint &vertex) override
 Inserts a vertex into the geometry. More...
 
QgsPointinterpolatePoint (double distance) const override
 Returns an interpolated point on the curve at the specified distance. More...
 
bool isEmpty () const override SIP_HOLDGIL
 Returns true if the geometry is empty. More...
 
bool isValid (QString &error, int flags=0) const override
 Checks validity of the geometry, and returns true if the geometry is valid. More...
 
double length () const override
 Returns the planar, 2-dimensional length of the geometry. More...
 
bool moveVertex (QgsVertexId position, const QgsPoint &newPos) override
 Moves a vertex within the geometry. More...
 
int numPoints () const override SIP_HOLDGIL
 Returns the number of points in the curve. More...
 
bool pointAt (int node, QgsPoint &point, QgsVertexId::VertexType &type) const override
 Returns the point and vertex id of a point within the curve. More...
 
QgsPoint pointN (int i) const SIP_HOLDGIL
 Returns the point at index i within the circular string. More...
 
void points (QgsPointSequence &pts) const override
 Returns a list of points within the curve. More...
 
bool removeDuplicateNodes (double epsilon=4 *std::numeric_limits< double >::epsilon(), bool useZValues=false) override
 Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry. More...
 
QgsCircularStringreversed () const override
 Returns a reversed copy of the curve, where the direction of the curve has been flipped. More...
 
void scroll (int firstVertexIndex) final
 Scrolls the curve vertices so that they start with the vertex at the given index. More...
 
double segmentLength (QgsVertexId startVertex) const override
 Returns the length of the segment of the geometry which begins at startVertex. More...
 
void setPoints (const QgsPointSequence &points)
 Sets the circular string's points. More...
 
QgsCircularStringsnappedToGrid (double hSpacing, double vSpacing, double dSpacing=0, double mSpacing=0) const override
 Makes a new geometry with all the points or vertices snapped to the closest point of the grid. More...
 
std::tuple< std::unique_ptr< QgsCurve >, std::unique_ptr< QgsCurve > > splitCurveAtVertex (int index) const final
 Splits the curve at the specified vertex index, returning two curves which represent the portion of the curve up to an including the vertex at index, and the portion of the curve from the vertex at index (inclusive) to the end of the curve. More...
 
QgsPoint startPoint () const override SIP_HOLDGIL
 Returns the starting point of the curve. More...
 
void sumUpArea (double &sum) const override
 Sums up the area of the curve by iterating over the vertices (shoelace formula). More...
 
void swapXy () override
 Swaps the x and y coordinates from the geometry. More...
 
void transform (const QgsCoordinateTransform &ct, QgsCoordinateTransform::TransformDirection d=QgsCoordinateTransform::ForwardTransform, bool transformZ=false) override SIP_THROW(QgsCsException)
 Transforms the geometry using a coordinate transform. More...
 
void transform (const QTransform &t, double zTranslate=0.0, double zScale=1.0, double mTranslate=0.0, double mScale=1.0) override
 Transforms the x and y components of the geometry using a QTransform object t. More...
 
bool transform (QgsAbstractGeometryTransformer *transformer, QgsFeedback *feedback=nullptr) override
 Transforms the vertices from the geometry in place, using the specified geometry transformer object. More...
 
void transformVertices (const std::function< QgsPoint(const QgsPoint &) > &transform) override
 Transforms the vertices from the geometry in place, applying the transform function to every vertex. More...
 
double vertexAngle (QgsVertexId vertex) const override
 Returns approximate angle at a vertex. More...
 
int wkbSize (QgsAbstractGeometry::WkbFlags flags=QgsAbstractGeometry::WkbFlags()) const override
 Returns the length of the QByteArray returned by asWkb() More...
 
double xAt (int index) const override SIP_HOLDGIL
 Returns the x-coordinate of the specified node in the line string. More...
 
double yAt (int index) const override SIP_HOLDGIL
 Returns the y-coordinate of the specified node in the line string. More...
 
- Public Member Functions inherited from QgsCurve
 QgsCurve ()=default
 Constructor for QgsCurve. More...
 
void adjacentVertices (QgsVertexId vertex, QgsVertexId &previousVertex, QgsVertexId &nextVertex) const override
 Returns the vertices adjacent to a specified vertex within a geometry. More...
 
QString asKml (int precision=17) const override
 Returns a KML representation of the geometry. More...
 
QPainterPath asQPainterPath () const override
 Returns the geometry represented as a QPainterPath. 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...
 
QgsCoordinateSequence coordinateSequence () const override
 Retrieves the sequence of geometries, rings and nodes. More...
 
virtual bool isClosed () const SIP_HOLDGIL
 Returns true if the curve is closed. More...
 
virtual bool isClosed2D () const SIP_HOLDGIL
 Returns true if the curve is closed. More...
 
virtual bool isRing () const SIP_HOLDGIL
 Returns true if the curve is a ring. More...
 
bool isValid (QString &error, int flags=0) const override
 Checks validity of the geometry, and returns true if the geometry is valid. More...
 
bool nextVertex (QgsVertexId &id, QgsPoint &vertex) const override
 Returns next vertex id and coordinates. More...
 
void normalize () final SIP_HOLDGIL
 Reorganizes the geometry into a normalized form (or "canonical" form). 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...
 
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...
 
double straightDistance2d () const
 Returns the straight distance of the curve, i.e. 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...
 
- Public Member Functions inherited from QgsAbstractGeometry
 QgsAbstractGeometry ()=default
 Constructor for QgsAbstractGeometry. More...
 
 QgsAbstractGeometry (const QgsAbstractGeometry &geom)
 
virtual ~QgsAbstractGeometry ()=default
 
virtual double area () const
 Returns the planar, 2-dimensional area of the geometry. More...
 
QString asJson (int precision=17)
 Returns a GeoJSON representation of the geometry as a QString. More...
 
virtual QByteArray asWkb (WkbFlags flags=QgsAbstractGeometry::WkbFlags()) const =0
 Returns a WKB representation of the geometry. More...
 
virtual bool boundingBoxIntersects (const QgsRectangle &rectangle) const SIP_HOLDGIL
 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 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 (QgsWkbTypes::Type type)
 Converts the geometry to a specified type. More...
 
bool is3D () const SIP_HOLDGIL
 Returns true if the geometry is 3D and contains a z-value. More...
 
bool isMeasure () const SIP_HOLDGIL
 Returns true if the geometry contains m values. More...
 
virtual int nCoordinates () const
 Returns the number of nodes contained in the geometry. More...
 
QgsAbstractGeometryoperator= (const QgsAbstractGeometry &geom)
 
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 const QgsAbstractGeometrysimplifiedTypeRef () const SIP_HOLDGIL
 Returns a reference to the simplest lossless representation of this geometry, e.g. 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 SIP_HOLDGIL
 Returns the WKB type of the geometry. More...
 
QString wktTypeStr () const
 Returns the WKT type string of the geometry. More...
 

Static Public Member Functions

static const QgsCircularStringcast (const QgsAbstractGeometry *geom)
 Cast the geom to a QgsCircularString. More...
 
static QgsCircularString fromTwoPointsAndCenter (const QgsPoint &p1, const QgsPoint &p2, const QgsPoint &center, bool useShortestArc=true)
 Creates a circular string with a single arc representing the curve from p1 to p2 with the specified center. More...
 
- Static Public Member Functions inherited from QgsCurve
static const QgsCurvecast (const QgsAbstractGeometry *geom)
 Cast the geom to a QgsCurve. More...
 

Protected Member Functions

QgsRectangle calculateBoundingBox () const override
 Default calculator for the minimal bounding box for the geometry. More...
 
int compareToSameClass (const QgsAbstractGeometry *other) const final
 Compares to an other geometry of the same class, and returns a integer for sorting of the two geometries. More...
 
- Protected Member Functions inherited from QgsCurve
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 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...
 
int sortIndex () const
 Returns the sort index for the geometry, used in the compareTo() method to compare geometries of different types. More...
 

Additional Inherited Members

- Public Types inherited from QgsCurve
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...
 
enum  WkbFlag { FlagExportTrianglesAsPolygons = 1 << 0 }
 WKB export flags. More...
 
- Protected Attributes inherited from QgsCurve
QgsRectangle mBoundingBox
 Cached bounding box. More...
 
- Protected Attributes inherited from QgsAbstractGeometry
QgsWkbTypes::Type mWkbType = QgsWkbTypes::Unknown
 

Detailed Description

Circular string geometry type.

Since
QGIS 2.10

Definition at line 34 of file qgscircularstring.h.

Constructor & Destructor Documentation

◆ QgsCircularString() [1/3]

QgsCircularString::QgsCircularString ( )

Constructs an empty circular string.

Definition at line 36 of file qgscircularstring.cpp.

◆ QgsCircularString() [2/3]

QgsCircularString::QgsCircularString ( const QgsPoint p1,
const QgsPoint p2,
const QgsPoint p3 
)

Constructs a circular string with a single arc passing through p1, p2 and p3.

Since
QGIS 3.2

Definition at line 41 of file qgscircularstring.cpp.

◆ QgsCircularString() [3/3]

QgsCircularString::QgsCircularString ( const QVector< double > &  x,
const QVector< double > &  y,
const QVector< double > &  z = QVector<double>(),
const QVector< double > &  m = QVector<double>() 
)

Construct a circular string from arrays of coordinates.

If the z or m arrays are non-empty then the resultant circular string will have z and m types accordingly.

This constructor is more efficient then calling setPoints().

If the sizes of x and y are non-equal then the resultant circular string will be created using the minimum size of these arrays.

Warning
It is the caller's responsibility to ensure that the supplied arrays are of odd sizes.
Since
QGIS 3.20

Definition at line 74 of file qgscircularstring.cpp.

Member Function Documentation

◆ addMValue()

bool QgsCircularString::addMValue ( double  mValue = 0)
overridevirtual

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()
Since
QGIS 2.12

Implements QgsAbstractGeometry.

Definition at line 1812 of file qgscircularstring.cpp.

◆ addToPainterPath()

void QgsCircularString::addToPainterPath ( QPainterPath &  path) const
overridevirtual

Adds a curve to a painter path.

Implements QgsCurve.

Definition at line 1159 of file qgscircularstring.cpp.

◆ addZValue()

bool QgsCircularString::addZValue ( double  zValue = 0)
overridevirtual

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()
Since
QGIS 2.12

Implements QgsAbstractGeometry.

Definition at line 1794 of file qgscircularstring.cpp.

◆ append()

void QgsCircularString::append ( const QgsCircularString string)

Appends the contents of another circular string to the end of this circular string.

Parameters
stringcircular string to append. Ownership is not transferred.
Warning
It is the caller's responsibility to ensure that the first point in the appended string matches the last point in the existing curve, or the result will be undefined.
Since
QGIS 3.20

Definition at line 1039 of file qgscircularstring.cpp.

◆ asGml2()

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

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()

Implements QgsAbstractGeometry.

Definition at line 539 of file qgscircularstring.cpp.

◆ asGml3()

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

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()

Implements QgsAbstractGeometry.

Definition at line 547 of file qgscircularstring.cpp.

◆ asJsonObject()

json QgsCircularString::asJsonObject ( int  precision = 17) const
overridevirtual

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 from QgsAbstractGeometry.

Definition at line 566 of file qgscircularstring.cpp.

◆ asWkb()

QByteArray QgsCircularString::asWkb ( QgsAbstractGeometry::WkbFlags  flags = QgsAbstractGeometry::WkbFlags()) const
override

Definition at line 511 of file qgscircularstring.cpp.

◆ asWkt()

QString QgsCircularString::asWkt ( int  precision = 17) const
overridevirtual

Returns a WKT representation of the geometry.

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

Implements QgsAbstractGeometry.

Definition at line 524 of file qgscircularstring.cpp.

◆ calculateBoundingBox()

QgsRectangle QgsCircularString::calculateBoundingBox ( ) const
overrideprotectedvirtual

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.

Reimplemented from QgsAbstractGeometry.

Definition at line 272 of file qgscircularstring.cpp.

◆ cast()

static const QgsCircularString* QgsCircularString::cast ( const QgsAbstractGeometry geom)
inlinestatic

Cast the geom to a QgsCircularString.

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

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

Definition at line 180 of file qgscircularstring.h.

◆ clear()

void QgsCircularString::clear ( )
overridevirtual

Clears the geometry, ie reset it to a null geometry.

Implements QgsAbstractGeometry.

Definition at line 262 of file qgscircularstring.cpp.

◆ clone()

QgsCircularString * QgsCircularString::clone ( ) const
overridevirtual

Clones the geometry by performing a deep copy.

Implements QgsCurve.

Definition at line 257 of file qgscircularstring.cpp.

◆ closestSegment()

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

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

Implements QgsAbstractGeometry.

Definition at line 1308 of file qgscircularstring.cpp.

◆ compareToSameClass()

int QgsCircularString::compareToSameClass ( const QgsAbstractGeometry other) const
finalprotectedvirtual

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

Implements QgsAbstractGeometry.

Definition at line 161 of file qgscircularstring.cpp.

◆ createEmptyWithSameType()

QgsCircularString * QgsCircularString::createEmptyWithSameType ( ) const
overridevirtual

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()
Since
3.0

Implements QgsAbstractGeometry.

Definition at line 154 of file qgscircularstring.cpp.

◆ curveSubstring()

QgsCircularString * QgsCircularString::curveSubstring ( double  startDistance,
double  endDistance 
) const
overridevirtual

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

Implements QgsCurve.

Definition at line 1664 of file qgscircularstring.cpp.

◆ curveToLine()

QgsLineString * QgsCircularString::curveToLine ( double  tolerance = M_PI_2/90,
SegmentationToleranceType  toleranceType = MaximumAngle 
) const
overridevirtual

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)

Implements QgsCurve.

Definition at line 618 of file qgscircularstring.cpp.

◆ deleteVertex()

bool QgsCircularString::deleteVertex ( QgsVertexId  position)
overridevirtual

Deletes a vertex within the geometry.

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

Implements QgsAbstractGeometry.

Definition at line 1264 of file qgscircularstring.cpp.

◆ dimension()

int QgsCircularString::dimension ( ) const
overridevirtual

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.

Implements QgsAbstractGeometry.

Definition at line 252 of file qgscircularstring.cpp.

◆ draw()

void QgsCircularString::draw ( QPainter &  p) const
overridevirtual

Draws the geometry using the specified QPainter.

Parameters
pdestination QPainter

Implements QgsAbstractGeometry.

Definition at line 1104 of file qgscircularstring.cpp.

◆ drawAsPolygon()

void QgsCircularString::drawAsPolygon ( QPainter &  p) const
overridevirtual

Draws the curve as a polygon on the specified QPainter.

Parameters
pdestination QPainter

Implements QgsCurve.

Definition at line 1207 of file qgscircularstring.cpp.

◆ dropMValue()

bool QgsCircularString::dropMValue ( )
overridevirtual

Drops any measure values which exist in the geometry.

Returns
true if m-values were present and have been removed
See also
addMValue()
dropZValue()
Since
QGIS 2.14

Implements QgsAbstractGeometry.

Definition at line 1842 of file qgscircularstring.cpp.

◆ dropZValue()

bool QgsCircularString::dropZValue ( )
overridevirtual

Drops any z-dimensions which exist in the geometry.

Returns
true if Z values were present and have been removed
See also
addZValue()
dropMValue()
Since
QGIS 2.14

Implements QgsAbstractGeometry.

Definition at line 1830 of file qgscircularstring.cpp.

◆ endPoint()

QgsPoint QgsCircularString::endPoint ( ) const
overridevirtual

Returns the end point of the curve.

See also
startPoint

Implements QgsCurve.

Definition at line 609 of file qgscircularstring.cpp.

◆ equals()

bool QgsCircularString::equals ( const QgsCurve other) const
overridevirtual

Checks whether this curve exactly equals another curve.

Since
QGIS 3.0

Implements QgsCurve.

Definition at line 126 of file qgscircularstring.cpp.

◆ filterVertices()

void QgsCircularString::filterVertices ( const std::function< bool(const QgsPoint &) > &  filter)
overridevirtual

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 from QgsAbstractGeometry.

Definition at line 839 of file qgscircularstring.cpp.

◆ fromTwoPointsAndCenter()

QgsCircularString QgsCircularString::fromTwoPointsAndCenter ( const QgsPoint p1,
const QgsPoint p2,
const QgsPoint center,
bool  useShortestArc = true 
)
static

Creates a circular string with a single arc representing the curve from p1 to p2 with the specified center.

If useShortestArc is true, then the arc returned will be that corresponding to the shorter arc from p1 to p2. If it is false, the longer arc from p1 to p2 will be used (i.e. winding the other way around the circle).

Since
QGIS 3.2

Definition at line 120 of file qgscircularstring.cpp.

◆ fromWkb()

bool QgsCircularString::fromWkb ( QgsConstWkbPtr wkb)
overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 440 of file qgscircularstring.cpp.

◆ fromWkt()

bool QgsCircularString::fromWkt ( const QString &  wkt)
overridevirtual

Sets the geometry from a WKT string.

See also
fromWkb

Implements QgsAbstractGeometry.

Definition at line 479 of file qgscircularstring.cpp.

◆ geometryType()

QString QgsCircularString::geometryType ( ) const
overridevirtual

Returns a unique string representing the geometry type.

See also
wkbType
wktTypeStr

Implements QgsAbstractGeometry.

Definition at line 247 of file qgscircularstring.cpp.

◆ hasCurvedSegments()

bool QgsCircularString::hasCurvedSegments ( ) const
overridevirtual

Returns true if the geometry contains curved segments.

Reimplemented from QgsAbstractGeometry.

Definition at line 1419 of file qgscircularstring.cpp.

◆ indexOf()

int QgsCircularString::indexOf ( const QgsPoint point) const
finalvirtual

Returns the index of the first vertex matching the given point, or -1 if a matching vertex is not found.

Note
If the curve has m or z values then the search point must have exactly matching m and z values in order to be matched against the curve's vertices.
This method only matches against segment vertices, not curve vertices.
Since
QGIS 3.20

Implements QgsCurve.

Definition at line 702 of file qgscircularstring.cpp.

◆ insertVertex()

bool QgsCircularString::insertVertex ( QgsVertexId  position,
const QgsPoint vertex 
)
overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 1212 of file qgscircularstring.cpp.

◆ interpolatePoint()

QgsPoint * QgsCircularString::interpolatePoint ( double  distance) const
overridevirtual

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, nullptr will be returned.

Since
QGIS 3.4

Implements QgsCurve.

Definition at line 1595 of file qgscircularstring.cpp.

◆ isEmpty()

bool QgsCircularString::isEmpty ( ) const
overridevirtual

Returns true if the geometry is empty.

Reimplemented from QgsAbstractGeometry.

Definition at line 573 of file qgscircularstring.cpp.

◆ isValid()

bool QgsCircularString::isValid ( QString &  error,
int  flags = 0 
) const
overridevirtual

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 QgsGeometry::ValidityFlags).
Returns
true if geometry is valid
Since
QGIS 3.8

Implements QgsAbstractGeometry.

Definition at line 578 of file qgscircularstring.cpp.

◆ length()

double QgsCircularString::length ( ) const
overridevirtual

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 from QgsAbstractGeometry.

Definition at line 589 of file qgscircularstring.cpp.

◆ moveVertex()

bool QgsCircularString::moveVertex ( QgsVertexId  position,
const QgsPoint newPos 
)
overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 1243 of file qgscircularstring.cpp.

◆ numPoints()

int QgsCircularString::numPoints ( ) const
overridevirtual

Returns the number of points in the curve.

Implements QgsCurve.

Definition at line 697 of file qgscircularstring.cpp.

◆ pointAt()

bool QgsCircularString::pointAt ( int  node,
QgsPoint point,
QgsVertexId::VertexType type 
) const
overridevirtual

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

Implements QgsCurve.

Definition at line 1347 of file qgscircularstring.cpp.

◆ pointN()

QgsPoint QgsCircularString::pointN ( int  i) const

Returns the point at index i within the circular string.

Definition at line 742 of file qgscircularstring.cpp.

◆ points()

void QgsCircularString::points ( QgsPointSequence pt) const
overridevirtual

Returns a list of points within the curve.

Implements QgsCurve.

Definition at line 972 of file qgscircularstring.cpp.

◆ removeDuplicateNodes()

bool QgsCircularString::removeDuplicateNodes ( double  epsilon = 4 *std::numeric_limits< double >::epsilon(),
bool  useZValues = false 
)
overridevirtual

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.

Since
QGIS 3.0

Implements QgsAbstractGeometry.

Definition at line 646 of file qgscircularstring.cpp.

◆ reversed()

QgsCircularString * QgsCircularString::reversed ( ) const
overridevirtual

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

Since
QGIS 2.14

Implements QgsCurve.

Definition at line 1579 of file qgscircularstring.cpp.

◆ scroll()

void QgsCircularString::scroll ( int  firstVertexIndex)
finalvirtual

Scrolls the curve vertices so that they start with the vertex at the given index.

Warning
This should only be called on closed curves, or the shape of the curve will be altered and the result is undefined.
The firstVertexIndex must correspond to a segment vertex and not a curve point or the result is undefined.
Since
QGIS 3.20

Implements QgsCurve.

Definition at line 300 of file qgscircularstring.cpp.

◆ segmentLength()

double QgsCircularString::segmentLength ( QgsVertexId  startVertex) const
overridevirtual

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.
Since
QGIS 3.0

Implements QgsAbstractGeometry.

Definition at line 1562 of file qgscircularstring.cpp.

◆ setPoints()

void QgsCircularString::setPoints ( const QgsPointSequence points)

Sets the circular string's points.

Definition at line 982 of file qgscircularstring.cpp.

◆ snappedToGrid()

QgsCircularString * QgsCircularString::snappedToGrid ( double  hSpacing,
double  vSpacing,
double  dSpacing = 0,
double  mSpacing = 0 
) const
overridevirtual

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.
Since
3.0

Implements QgsAbstractGeometry.

Definition at line 633 of file qgscircularstring.cpp.

◆ splitCurveAtVertex()

std::tuple< std::unique_ptr< QgsCurve >, std::unique_ptr< QgsCurve > > QgsCircularString::splitCurveAtVertex ( int  index) const
finalvirtual

Splits the curve at the specified vertex index, returning two curves which represent the portion of the curve up to an including the vertex at index, and the portion of the curve from the vertex at index (inclusive) to the end of the curve.

Note
The vertex index must correspond to a segment vertex, not a curve vertex.
Not available in Python bindings.
Since
QGIS 3.20

Implements QgsCurve.

Definition at line 913 of file qgscircularstring.cpp.

◆ startPoint()

QgsPoint QgsCircularString::startPoint ( ) const
overridevirtual

Returns the starting point of the curve.

See also
endPoint

Implements QgsCurve.

Definition at line 600 of file qgscircularstring.cpp.

◆ sumUpArea()

void QgsCircularString::sumUpArea ( double &  sum) const
overridevirtual

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

Implements QgsCurve.

Definition at line 1358 of file qgscircularstring.cpp.

◆ swapXy()

void QgsCircularString::swapXy ( )
overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 1854 of file qgscircularstring.cpp.

◆ transform() [1/3]

void QgsCircularString::transform ( const QgsCoordinateTransform ct,
QgsCoordinateTransform::TransformDirection  d = QgsCoordinateTransform::ForwardTransform,
bool  transformZ = false 
)
overridevirtual

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.

Implements QgsAbstractGeometry.

Definition at line 1111 of file qgscircularstring.cpp.

◆ transform() [2/3]

void QgsCircularString::transform ( const QTransform &  t,
double  zTranslate = 0.0,
double  zScale = 1.0,
double  mTranslate = 0.0,
double  mScale = 1.0 
)
overridevirtual

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.

Implements QgsAbstractGeometry.

Definition at line 1135 of file qgscircularstring.cpp.

◆ transform() [3/3]

bool QgsCircularString::transform ( QgsAbstractGeometryTransformer transformer,
QgsFeedback feedback = nullptr 
)
overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 795 of file qgscircularstring.cpp.

◆ transformVertices()

void QgsCircularString::transformVertices ( const std::function< QgsPoint(const QgsPoint &) > &  transform)
overridevirtual

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 from QgsAbstractGeometry.

Definition at line 885 of file qgscircularstring.cpp.

◆ vertexAngle()

double QgsCircularString::vertexAngle ( QgsVertexId  vertex) const
overridevirtual

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

Implements QgsAbstractGeometry.

Definition at line 1505 of file qgscircularstring.cpp.

◆ wkbSize()

int QgsCircularString::wkbSize ( QgsAbstractGeometry::WkbFlags  flags = QgsAbstractGeometry::WkbFlags()) const
overridevirtual

Returns the length of the QByteArray returned by asWkb()

The optional flags argument specifies flags controlling WKB export behavior

Since
QGIS 3.16

Implements QgsAbstractGeometry.

Definition at line 504 of file qgscircularstring.cpp.

◆ xAt()

double QgsCircularString::xAt ( int  index) const
overridevirtual

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

Implements QgsCurve.

Definition at line 779 of file qgscircularstring.cpp.

◆ yAt()

double QgsCircularString::yAt ( int  index) const
overridevirtual

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

Implements QgsCurve.

Definition at line 787 of file qgscircularstring.cpp.


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