QGIS API Documentation
3.2.0-Bonn (bc43194)
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Abstract base class for curved geometry type. More...
#include <qgscurve.h>
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... | |
QgsAbstractGeometry * | boundary () 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 QgsCurve * | cast (const QgsAbstractGeometry *geom) const |
Cast the geom to a QgsCurve. More... | |
QgsCurve * | clone () 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 QgsLineString * | curveToLine (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 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 |
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 QgsCurve * | reversed () 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... | |
QgsCurve * | segmentize (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... | |
QgsCurve * | toCurveType () 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... | |
virtual bool | convertTo (QgsWkbTypes::Type type) |
Converts the geometry to a specified type. More... | |
virtual QgsAbstractGeometry * | createEmptyWithSameType () 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... | |
QgsAbstractGeometry & | operator= (const QgsAbstractGeometry &geom) |
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 QgsAbstractGeometry * | snappedToGrid (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 double | vertexAngle (QgsVertexId vertex) const =0 |
Returns approximate angle at a vertex. More... | |
QgsVertexIterator | vertices () const |
Returns Java-style iterator for traversal of vertices of the geometry. 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 QgsAbstractGeometry * | childGeometry (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 | |
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... | |
Protected Attributes inherited from QgsAbstractGeometry | |
QgsWkbTypes::Type | mWkbType = QgsWkbTypes::Unknown |
Abstract base class for curved geometry type.
Definition at line 35 of file qgscurve.h.
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default |
Constructor for QgsCurve.
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pure virtual |
Adds a curve to a painter path.
Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.
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overridevirtual |
Returns the vertices adjacent to a specified vertex within a geometry.
Implements QgsAbstractGeometry.
Definition at line 95 of file qgscurve.cpp.
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Returns a QPolygonF representing the points.
Reimplemented in QgsLineString.
Definition at line 191 of file qgscurve.cpp.
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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.
Implements QgsAbstractGeometry.
Definition at line 132 of file qgscurve.cpp.
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overridevirtual |
Returns the minimal bounding box for the geometry.
Implements QgsAbstractGeometry.
Definition at line 182 of file qgscurve.cpp.
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inline |
Cast the geom to a QgsCurve.
Should be used by qgsgeometry_cast<QgsCurve *>( geometry ).
Definition at line 198 of file qgscurve.h.
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overrideprotectedvirtual |
Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e.
curve / point)
Reimplemented from QgsAbstractGeometry.
Definition at line 223 of file qgscurve.cpp.
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overrideprotectedvirtual |
Returns point at index (for geometries without child geometries - i.e.
curve / point)
Reimplemented from QgsAbstractGeometry.
Definition at line 228 of file qgscurve.cpp.
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overrideprotectedvirtual |
Clears any cached parameters associated with the geometry, e.g., bounding boxes.
Reimplemented from QgsAbstractGeometry.
Definition at line 217 of file qgscurve.cpp.
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overridepure virtual |
Clones the geometry by performing a deep copy.
Implements QgsAbstractGeometry.
Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.
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overridevirtual |
Retrieves the sequence of geometries, rings and nodes.
Implements QgsAbstractGeometry.
Definition at line 60 of file qgscurve.cpp.
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pure virtual |
Returns a new line string geometry corresponding to a segmentized approximation of the curve.
tolerance | segmentation tolerance |
toleranceType | maximum 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.
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pure virtual |
Draws the curve as a polygon on the specified QPainter.
p | destination QPainter |
Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.
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pure virtual |
Returns the end point of the curve.
Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.
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pure virtual |
Checks whether this curve exactly equals another curve.
Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.
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virtual |
Returns true if the curve is closed.
Definition at line 39 of file qgscurve.cpp.
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virtual |
Returns true if the curve is a ring.
Definition at line 55 of file qgscurve.cpp.
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overridevirtual |
Returns next vertex id and coordinates.
id | initial value should be the starting vertex id. The next vertex id will be stored in this variable if found. |
vertex | container for found node |
Implements QgsAbstractGeometry.
Definition at line 70 of file qgscurve.cpp.
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pure virtual |
Returns the number of points in the curve.
Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.
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overridevirtual |
Implements QgsAbstractGeometry.
Definition at line 34 of file qgscurve.cpp.
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overridevirtual |
Implements QgsAbstractGeometry.
Definition at line 25 of file qgscurve.cpp.
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overridevirtual |
Returns count of parts contained in the geometry.
Implements QgsAbstractGeometry.
Definition at line 164 of file qgscurve.cpp.
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pure virtual |
Returns the point and vertex id of a point within the curve.
node | node number, where the first node is 0 |
point | will be set to point at corresponding node in the curve |
type | will be set to the vertex type of the node |
Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.
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pure virtual |
Returns a list of points within the curve.
Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.
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pure virtual |
Returns a reversed copy of the curve, where the direction of the curve has been flipped.
Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.
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overridevirtual |
Returns the number of rings of which this geometry is built.
Implements QgsAbstractGeometry.
Definition at line 158 of file qgscurve.cpp.
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overridevirtual |
Returns a geometry without curves.
Caller takes ownership
tolerance | segmentation tolerance |
toleranceType | maximum segmentation angle or maximum difference between approximation and curve |
Reimplemented from QgsAbstractGeometry.
Definition at line 146 of file qgscurve.cpp.
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.
Definition at line 208 of file qgscurve.cpp.
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protected |
Helper function for QgsCurve subclasses to snap to grids.
Definition at line 238 of file qgscurve.cpp.
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pure virtual |
Returns the starting point of the curve.
Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.
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).
Definition at line 203 of file qgscurve.cpp.
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pure virtual |
Sums up the area of the curve by iterating over the vertices (shoelace formula).
Implemented in QgsLineString, QgsCircularString, and QgsCompoundCurve.
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overridevirtual |
Returns the geometry converted to the more generic curve type.
E.g. QgsLineString -> QgsCompoundCurve, QgsPolygon -> QgsCurvePolygon, QgsMultiLineString -> QgsMultiCurve, QgsMultiPolygon -> QgsMultiSurface
Implements QgsAbstractGeometry.
Reimplemented in QgsLineString.
Definition at line 177 of file qgscurve.cpp.
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overridevirtual |
Returns the point corresponding to a specified vertex id.
Implements QgsAbstractGeometry.
Definition at line 169 of file qgscurve.cpp.
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overridevirtual |
Returns the number of vertices of which this geometry is built.
Implements QgsAbstractGeometry.
Definition at line 151 of file qgscurve.cpp.
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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.
Implements QgsAbstractGeometry.
Definition at line 123 of file qgscurve.cpp.
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pure virtual |
Returns the x-coordinate of the specified node in the line string.
index | index of node, where the first node in the line is 0 |
Implemented in QgsCircularString, QgsCompoundCurve, and QgsLineString.
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pure virtual |
Returns the y-coordinate of the specified node in the line string.
index | index of node, where the first node in the line is 0 |
Implemented in QgsCircularString, QgsCompoundCurve, and QgsLineString.