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QGIS API Documentation
3.0.2-Girona (307d082)
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A geometry is the spatial representation of a feature. More...
#include <qgsgeometry.h>
Classes | |
| class | Error |
Public Types | |
| enum | BufferSide { SideLeft = 0, SideRight } |
| Side of line to buffer. More... | |
| enum | EndCapStyle { CapRound = 1, CapFlat, CapSquare } |
| End cap styles for buffers. More... | |
| enum | JoinStyle { JoinStyleRound = 1, JoinStyleMiter, JoinStyleBevel } |
| Join styles for buffers. More... | |
| enum | OperationResult { Success = 0, NothingHappened = 1000, InvalidBaseGeometry, InvalidInputGeometryType, SelectionIsEmpty, SelectionIsGreaterThanOne, GeometryEngineError, LayerNotEditable, AddPartSelectedGeometryNotFound, AddPartNotMultiGeometry, AddRingNotClosed, AddRingNotValid, AddRingCrossesExistingRings, AddRingNotInExistingFeature, SplitCannotSplitPoint } |
| Success or failure of a geometry operation. More... | |
| enum | ValidationMethod { ValidatorQgisInternal, ValidatorGeos } |
| Available methods for validating geometries. More... | |
Public Member Functions | |
| QgsGeometry () | |
| Constructor. More... | |
| QgsGeometry (const QgsGeometry &) | |
| Copy constructor will prompt a deep copy of the object. More... | |
| QgsGeometry (QgsAbstractGeometry *geom) | |
| Creates a geometry from an abstract geometry object. More... | |
| QgsGeometry (std::unique_ptr< QgsAbstractGeometry > geom) | |
| Creates a geometry from an abstract geometry object. More... | |
| ~QgsGeometry () | |
| OperationResult | addPart (const QVector< QgsPointXY > &points, QgsWkbTypes::GeometryType geomType=QgsWkbTypes::UnknownGeometry) |
| Adds a new part to a the geometry. More... | |
| OperationResult | addPart (const QgsPointSequence &points, QgsWkbTypes::GeometryType geomType=QgsWkbTypes::UnknownGeometry) |
| Adds a new part to a the geometry. More... | |
| OperationResult | addPart (QgsAbstractGeometry *part, QgsWkbTypes::GeometryType geomType=QgsWkbTypes::UnknownGeometry) |
| Adds a new part to this geometry. More... | |
| OperationResult | addPart (GEOSGeometry *newPart) |
| Adds a new island polygon to a multipolygon feature. More... | |
| OperationResult | addPart (const QgsGeometry &newPart) |
| Adds a new island polygon to a multipolygon feature. More... | |
| OperationResult | addRing (const QVector< QgsPointXY > &ring) |
| Adds a new ring to this geometry. More... | |
| OperationResult | addRing (QgsCurve *ring) |
| Adds a new ring to this geometry. More... | |
| void | adjacentVertices (int atVertex, int &beforeVertex, int &afterVertex) const |
| Returns the indexes of the vertices before and after the given vertex index. More... | |
| double | angleAtVertex (int vertex) const |
| Returns the bisector angle for this geometry at the specified vertex. More... | |
| double | area () const |
| Returns the area of the geometry using GEOS. More... | |
| QVector< QgsGeometry > | asGeometryCollection () const |
| Return contents of the geometry as a list of geometries. More... | |
| QString | asJson (int precision=17) const |
| Exports the geometry to a GeoJSON string. More... | |
| QgsMultiPointXY | asMultiPoint () const |
| Returns contents of the geometry as a multi point if wkbType is WKBMultiPoint, otherwise an empty list. More... | |
| QgsMultiPolygonXY | asMultiPolygon () const |
| Returns contents of the geometry as a multi polygon if wkbType is WKBMultiPolygon, otherwise an empty list. More... | |
| QgsMultiPolylineXY | asMultiPolyline () const |
| Returns contents of the geometry as a multi linestring if wkbType is WKBMultiLineString, otherwise an empty list. More... | |
| QgsPointXY | asPoint () const |
| Returns contents of the geometry as a point if wkbType is WKBPoint, otherwise returns [0,0]. More... | |
| QgsPolygonXY | asPolygon () const |
| Returns contents of the geometry as a polygon if wkbType is WKBPolygon, otherwise an empty list. More... | |
| QgsPolylineXY | asPolyline () const |
| Returns contents of the geometry as a polyline if wkbType is WKBLineString, otherwise an empty list. More... | |
| QPointF | asQPointF () const |
| Returns contents of the geometry as a QPointF if wkbType is WKBPoint, otherwise returns a null QPointF. More... | |
| QPolygonF | asQPolygonF () const |
| Returns contents of the geometry as a QPolygonF. More... | |
| QByteArray | asWkb () const |
| Export the geometry to WKB. More... | |
| QString | asWkt (int precision=17) const |
| Exports the geometry to WKT. More... | |
| int | avoidIntersections (const QList< QgsVectorLayer *> &avoidIntersectionsLayers, const QHash< QgsVectorLayer *, QSet< QgsFeatureId > > &ignoreFeatures=(QHash< QgsVectorLayer *, QSet< QgsFeatureId > >())) |
| Modifies geometry to avoid intersections with the layers specified in project properties. More... | |
| QgsRectangle | boundingBox () const |
| Returns the bounding box of the geometry. More... | |
| bool | boundingBoxIntersects (const QgsRectangle &rectangle) const |
| Returns true if the bounding box of this geometry intersects with a rectangle. More... | |
| bool | boundingBoxIntersects (const QgsGeometry &geometry) const |
| Returns true if the bounding box of this geometry intersects with the bounding box of another geometry. More... | |
| QgsGeometry | buffer (double distance, int segments) const |
| Returns a buffer region around this geometry having the given width and with a specified number of segments used to approximate curves. More... | |
| QgsGeometry | buffer (double distance, int segments, EndCapStyle endCapStyle, JoinStyle joinStyle, double miterLimit) const |
| Returns a buffer region around the geometry, with additional style options. More... | |
| QgsGeometry | centroid () const |
| Returns the center of mass of a geometry. More... | |
| QgsGeometry | clipped (const QgsRectangle &rectangle) |
| Clips the geometry using the specified rectangle. More... | |
| double | closestSegmentWithContext (const QgsPointXY &point, QgsPointXY &minDistPoint, int &afterVertex, int *leftOf=nullptr, double epsilon=DEFAULT_SEGMENT_EPSILON) const |
| Searches for the closest segment of geometry to the given point. More... | |
| QgsPointXY | closestVertex (const QgsPointXY &point, int &atVertex, int &beforeVertex, int &afterVertex, double &sqrDist) const |
| Returns the vertex closest to the given point, the corresponding vertex index, squared distance snap point / target point and the indices of the vertices before and after the closest vertex. More... | |
| double | closestVertexWithContext (const QgsPointXY &point, int &atVertex) const |
| Searches for the closest vertex in this geometry to the given point. More... | |
| QgsGeometry | combine (const QgsGeometry &geometry) const |
| Returns a geometry representing all the points in this geometry and other (a union geometry operation). More... | |
| const QgsAbstractGeometry * | constGet () const |
| Returns a non-modifiable (const) reference to the underlying abstract geometry primitive. More... | |
| bool | contains (const QgsPointXY *p) const |
| Tests for containment of a point (uses GEOS) More... | |
| bool | contains (const QgsGeometry &geometry) const |
| Tests for if geometry is contained in another (uses GEOS) More... | |
| bool | convertToMultiType () |
| Converts single type geometry into multitype geometry e.g. More... | |
| bool | convertToSingleType () |
| Converts multi type geometry into single type geometry e.g. More... | |
| void | convertToStraightSegment () |
| Converts the geometry to straight line segments, if it is a curved geometry type. More... | |
| QgsGeometry | convertToType (QgsWkbTypes::GeometryType destType, bool destMultipart=false) const |
| Try to convert the geometry to the requested type. More... | |
| QgsGeometry | convexHull () const |
| Returns the smallest convex polygon that contains all the points in the geometry. More... | |
| bool | crosses (const QgsGeometry &geometry) const |
| Test for if geometry crosses another (uses GEOS) More... | |
| QgsGeometry | delaunayTriangulation (double tolerance=0.0, bool edgesOnly=false) const |
| Returns the Delaunay triangulation for the vertices of the geometry. More... | |
| bool | deletePart (int partNum) |
| Deletes part identified by the part number. More... | |
| bool | deleteRing (int ringNum, int partNum=0) |
| Deletes a ring in polygon or multipolygon. More... | |
| bool | deleteVertex (int atVertex) |
| Deletes the vertex at the given position number and item (first number is index 0) More... | |
| QgsGeometry | densifyByCount (int extraNodesPerSegment) const |
| Returns a copy of the geometry which has been densified by adding the specified number of extra nodes within each segment of the geometry. More... | |
| QgsGeometry | densifyByDistance (double distance) const |
| Densifies the geometry by adding regularly placed extra nodes inside each segment so that the maximum distance between any two nodes does not exceed the specified distance. More... | |
| QgsGeometry | difference (const QgsGeometry &geometry) const |
| Returns a geometry representing the points making up this geometry that do not make up other. More... | |
| bool | disjoint (const QgsGeometry &geometry) const |
| Tests for if geometry is disjoint of another (uses GEOS) More... | |
| double | distance (const QgsGeometry &geom) const |
| Returns the minimum distance between this geometry and another geometry, using GEOS. More... | |
| double | distanceToVertex (int vertex) const |
| Returns the distance along this geometry from its first vertex to the specified vertex. More... | |
| void | draw (QPainter &p) const |
| Draws the geometry onto a QPainter. More... | |
| bool | equals (const QgsGeometry &geometry) const |
| Test if this geometry is exactly equal to another geometry. More... | |
| GEOSGeometry * | exportToGeos (double precision=0) const |
| Returns a geos geometry - caller takes ownership of the object (should be deleted with GEOSGeom_destroy_r) More... | |
| QgsGeometry | extendLine (double startDistance, double endDistance) const |
| Extends a (multi)line geometry by extrapolating out the start or end of the line by a specified distance. More... | |
| QgsGeometry | extrude (double x, double y) |
| Returns an extruded version of this geometry. More... | |
| void | fromGeos (GEOSGeometry *geos) |
| Set the geometry, feeding in a geometry in GEOS format. More... | |
| void | fromWkb (unsigned char *wkb, int length) |
| Set the geometry, feeding in the buffer containing OGC Well-Known Binary and the buffer's length. More... | |
| void | fromWkb (const QByteArray &wkb) |
| Set the geometry, feeding in the buffer containing OGC Well-Known Binary. More... | |
| QgsAbstractGeometry * | get () |
| Returns a modifiable (non-const) reference to the underlying abstract geometry primitive. More... | |
| double | hausdorffDistance (const QgsGeometry &geom) const |
| Returns the Hausdorff distance between this geometry and geom. More... | |
| double | hausdorffDistanceDensify (const QgsGeometry &geom, double densifyFraction) const |
| Returns the Hausdorff distance between this geometry and geom. More... | |
| bool | insertVertex (double x, double y, int beforeVertex) |
| Insert a new vertex before the given vertex index, ring and item (first number is index 0) If the requested vertex number (beforeVertex.back()) is greater than the last actual vertex on the requested ring and item, it is assumed that the vertex is to be appended instead of inserted. More... | |
| bool | insertVertex (const QgsPoint &point, int beforeVertex) |
| Insert a new vertex before the given vertex index, ring and item (first number is index 0) If the requested vertex number (beforeVertex.back()) is greater than the last actual vertex on the requested ring and item, it is assumed that the vertex is to be appended instead of inserted. More... | |
| QgsGeometry | interpolate (double distance) const |
| Returns interpolated point on line at distance. More... | |
| double | interpolateAngle (double distance) const |
| Returns the angle parallel to the linestring or polygon boundary at the specified distance along the geometry. More... | |
| QgsGeometry | intersection (const QgsGeometry &geometry) const |
| Returns a geometry representing the points shared by this geometry and other. More... | |
| bool | intersects (const QgsRectangle &rectangle) const |
| Returns true if this geometry exactly intersects with a rectangle. More... | |
| bool | intersects (const QgsGeometry &geometry) const |
| Returns true if this geometry exactly intersects with another geometry. More... | |
| bool | isEmpty () const |
| Returns true if the geometry is empty (eg a linestring with no vertices, or a collection with no geometries). More... | |
| bool | isGeosEqual (const QgsGeometry &) const |
| Compares the geometry with another geometry using GEOS. More... | |
| bool | isGeosValid () const |
| Checks validity of the geometry using GEOS. More... | |
| bool | isMultipart () const |
| Returns true if WKB of the geometry is of WKBMulti* type. More... | |
| bool | isNull () const |
| Returns true if the geometry is null (ie, contains no underlying geometry accessible via geometry() ). More... | |
| bool | isSimple () const |
| Determines whether the geometry is simple (according to OGC definition), i.e. More... | |
| QString | lastError () const |
| Returns an error string referring to the last error encountered either when this geometry was created or when an operation was performed on the geometry. More... | |
| double | length () const |
| Returns the length of geometry using GEOS. More... | |
| double | lineLocatePoint (const QgsGeometry &point) const |
| Returns a distance representing the location along this linestring of the closest point on this linestring geometry to the specified point. More... | |
| QgsGeometry | makeDifference (const QgsGeometry &other) const |
| Returns the geometry formed by modifying this geometry such that it does not intersect the other geometry. More... | |
| int | makeDifferenceInPlace (const QgsGeometry &other) |
| Changes this geometry such that it does not intersect the other geometry. More... | |
| QgsGeometry | makeValid () const |
| Attempts to make an invalid geometry valid without losing vertices. More... | |
| void | mapToPixel (const QgsMapToPixel &mtp) |
| Transforms the geometry from map units to pixels in place. More... | |
| QgsGeometry | mergeLines () const |
| Merges any connected lines in a LineString/MultiLineString geometry and converts them to single line strings. More... | |
| QgsGeometry | minimalEnclosingCircle (QgsPointXY ¢er, double &radius, unsigned int segments=36) const |
| Returns the minimal enclosing circle for the geometry. More... | |
| QgsGeometry | minimalEnclosingCircle (unsigned int segments=36) const |
| Returns the minimal enclosing circle for the geometry. More... | |
| bool | moveVertex (double x, double y, int atVertex) |
| Moves the vertex at the given position number and item (first number is index 0) to the given coordinates. More... | |
| bool | moveVertex (const QgsPoint &p, int atVertex) |
| Moves the vertex at the given position number and item (first number is index 0) to the given coordinates. More... | |
| QgsGeometry | nearestPoint (const QgsGeometry &other) const |
| Returns the nearest point on this geometry to another geometry. More... | |
| QgsGeometry | offsetCurve (double distance, int segments, JoinStyle joinStyle, double miterLimit) const |
| Returns an offset line at a given distance and side from an input line. More... | |
| operator bool () const | |
| Returns true if the geometry is non empty (ie, isNull() returns false), or false if it is an empty, uninitialized geometry (ie, isNull() returns true). More... | |
| operator QVariant () const | |
| Allows direct construction of QVariants from geometry. More... | |
| QgsGeometry & | operator= (QgsGeometry const &rhs) |
| Creates a deep copy of the object. More... | |
| QgsGeometry | orientedMinimumBoundingBox (double &area, double &angle, double &width, double &height) const |
| Returns the oriented minimum bounding box for the geometry, which is the smallest (by area) rotated rectangle which fully encompasses the geometry. More... | |
| QgsGeometry | orientedMinimumBoundingBox () const |
| Returns the oriented minimum bounding box for the geometry, which is the smallest (by area) rotated rectangle which fully encompasses the geometry. More... | |
| QgsGeometry | orthogonalize (double tolerance=1.0E-8, int maxIterations=1000, double angleThreshold=15.0) const |
| Attempts to orthogonalize a line or polygon geometry by shifting vertices to make the geometries angles either right angles or flat lines. More... | |
| bool | overlaps (const QgsGeometry &geometry) const |
| Test for if geometry overlaps another (uses GEOS) More... | |
| QgsGeometry | pointOnSurface () const |
| Returns a point guaranteed to lie on the surface of a geometry. More... | |
| QgsGeometry | poleOfInaccessibility (double precision, double *distanceToBoundary=nullptr) const |
| Calculates the approximate pole of inaccessibility for a surface, which is the most distant internal point from the boundary of the surface. More... | |
| Q_ENUM (BufferSide) | |
| Q_ENUM (EndCapStyle) | |
| Q_ENUM (JoinStyle) | |
| bool | removeDuplicateNodes (double epsilon=4 *DBL_EPSILON, bool useZValues=false) |
| Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry. More... | |
| QgsGeometry | removeInteriorRings (double minimumAllowedArea=-1) const |
| Removes the interior rings from a (multi)polygon geometry. More... | |
| bool | requiresConversionToStraightSegments () const |
| Returns true if the geometry is a curved geometry type which requires conversion to display as straight line segments. More... | |
| OperationResult | reshapeGeometry (const QgsLineString &reshapeLineString) |
| Replaces a part of this geometry with another line. More... | |
| OperationResult | rotate (double rotation, const QgsPointXY ¢er) |
| Rotate this geometry around the Z axis. More... | |
| void | set (QgsAbstractGeometry *geometry) |
| Sets the underlying geometry store. More... | |
| QgsGeometry | shortestLine (const QgsGeometry &other) const |
| Returns the shortest line joining this geometry to another geometry. More... | |
| QgsGeometry | simplify (double tolerance) const |
| Returns a simplified version of this geometry using a specified tolerance value. More... | |
| QgsGeometry | singleSidedBuffer (double distance, int segments, BufferSide side, JoinStyle joinStyle=JoinStyleRound, double miterLimit=2.0) const |
| Returns a single sided buffer for a (multi)line geometry. More... | |
| QgsGeometry | smooth (const unsigned int iterations=1, const double offset=0.25, double minimumDistance=-1.0, double maxAngle=180.0) const |
| Smooths a geometry by rounding off corners using the Chaikin algorithm. More... | |
| QgsGeometry | snappedToGrid (double hSpacing, double vSpacing, double dSpacing=0, double mSpacing=0) const |
| Returns a new geometry with all points or vertices snapped to the closest point of the grid. More... | |
| OperationResult | splitGeometry (const QVector< QgsPointXY > &splitLine, QVector< QgsGeometry > &newGeometries, bool topological, QVector< QgsPointXY > &topologyTestPoints) |
| Splits this geometry according to a given line. More... | |
| double | sqrDistToVertexAt (QgsPointXY &point SIP_IN, int atVertex) const |
| Returns the squared Cartesian distance between the given point to the given vertex index (vertex at the given position number, ring and item (first number is index 0)) More... | |
| QgsGeometry | subdivide (int maxNodes=256) const |
| Subdivides the geometry. More... | |
| QgsGeometry | symDifference (const QgsGeometry &geometry) const |
| Returns a geometry representing the points making up this geometry that do not make up other. More... | |
| bool | touches (const QgsGeometry &geometry) const |
| Test for if geometry touch another (uses GEOS) More... | |
| OperationResult | transform (const QgsCoordinateTransform &ct, QgsCoordinateTransform::TransformDirection direction=QgsCoordinateTransform::ForwardTransform, bool transformZ=false) |
| Transforms this geometry as described by the coordinate transform ct. More... | |
| OperationResult | transform (const QTransform &t, double zTranslate=0.0, double zScale=1.0, double mTranslate=0.0, double mScale=1.0) |
| Transforms the x and y components of the geometry using a QTransform object t. More... | |
| OperationResult | translate (double dx, double dy, double dz=0.0, double dm=0.0) |
| Translates this geometry by dx, dy, dz and dm. More... | |
| QgsWkbTypes::GeometryType | type () const |
| Returns type of the geometry as a QgsWkbTypes::GeometryType. More... | |
| void | validateGeometry (QVector< QgsGeometry::Error > &errors, ValidationMethod method=ValidatorQgisInternal) const |
| Validates geometry and produces a list of geometry errors. More... | |
| QgsPoint | vertexAt (int atVertex) const |
| Returns coordinates of a vertex. More... | |
| bool | vertexIdFromVertexNr (int number, QgsVertexId &id) const |
| Calculates the vertex ID from a vertex number. More... | |
| int | vertexNrFromVertexId (QgsVertexId id) const |
| Returns the vertex number corresponding to a vertex id. More... | |
| QgsVertexIterator | vertices () const |
| Returns Java-style iterator for traversal of vertices of the geometry. More... | |
| QgsAbstractGeometry::vertex_iterator | vertices_begin () const |
| Returns STL-style iterator pointing to the first vertex of the geometry. More... | |
| QgsAbstractGeometry::vertex_iterator | vertices_end () const |
| Returns STL-style iterator pointing to the imaginary vertex after the last vertex of the geometry. More... | |
| QgsGeometry | voronoiDiagram (const QgsGeometry &extent=QgsGeometry(), double tolerance=0.0, bool edgesOnly=false) const |
| Creates a Voronoi diagram for the nodes contained within the geometry. More... | |
| bool | within (const QgsGeometry &geometry) const |
| Test for if geometry is within another (uses GEOS) More... | |
| QgsWkbTypes::Type | wkbType () const |
| Returns type of the geometry as a WKB type (point / linestring / polygon etc.) More... | |
Static Public Member Functions | |
| static QgsGeometry | collectGeometry (const QVector< QgsGeometry > &geometries) |
| Creates a new multipart geometry from a list of QgsGeometry objects. More... | |
| static bool | compare (const QgsPolylineXY &p1, const QgsPolylineXY &p2, double epsilon=4 *std::numeric_limits< double >::epsilon()) |
| Compares two polylines for equality within a specified tolerance. More... | |
| static bool | compare (const QgsPolygonXY &p1, const QgsPolygonXY &p2, double epsilon=4 *std::numeric_limits< double >::epsilon()) |
| Compares two polygons for equality within a specified tolerance. More... | |
| static bool | compare (const QgsMultiPolygonXY &p1, const QgsMultiPolygonXY &p2, double epsilon=4 *std::numeric_limits< double >::epsilon()) |
| Compares two multipolygons for equality within a specified tolerance. More... | |
| static void | convertPointList (const QVector< QgsPointXY > &input, QgsPointSequence &output) |
| Upgrades a point list from QgsPointXY to QgsPoint. More... | |
| static void | convertPointList (const QgsPointSequence &input, QVector< QgsPointXY > &output) |
| Downgrades a point list from QgsPoint to QgsPointXY. More... | |
| static QgsGeometryEngine * | createGeometryEngine (const QgsAbstractGeometry *geometry) |
| Creates and returns a new geometry engine. More... | |
| static QgsPolygonXY | createPolygonFromQPolygonF (const QPolygonF &polygon) |
| Creates a QgsPolygonXYfrom a QPolygonF. More... | |
| static QgsPolylineXY | createPolylineFromQPolygonF (const QPolygonF &polygon) |
| Creates a QgsPolylineXY from a QPolygonF. More... | |
| static QgsGeometry | fromMultiPointXY (const QgsMultiPointXY &multipoint) |
| Creates a new geometry from a QgsMultiPointXY object. More... | |
| static QgsGeometry | fromMultiPolygonXY (const QgsMultiPolygonXY &multipoly) |
| Creates a new geometry from a QgsMultiPolygon. More... | |
| static QgsGeometry | fromMultiPolylineXY (const QgsMultiPolylineXY &multiline) |
| Creates a new geometry from a QgsMultiPolylineXY object. More... | |
| static QgsGeometry | fromPointXY (const QgsPointXY &point) |
| Creates a new geometry from a QgsPointXY object. More... | |
| static QgsGeometry | fromPolygonXY (const QgsPolygonXY &polygon) |
| Creates a new geometry from a QgsPolygon. More... | |
| static QgsGeometry | fromPolyline (const QgsPolyline &polyline) |
| Creates a new LineString geometry from a list of QgsPoint points. More... | |
| static QgsGeometry | fromPolylineXY (const QgsPolylineXY &polyline) |
| Creates a new LineString geometry from a list of QgsPointXY points. More... | |
| static QgsGeometry | fromQPointF (QPointF point) |
| Construct geometry from a QPointF. More... | |
| static QgsGeometry | fromQPolygonF (const QPolygonF &polygon) |
| Construct geometry from a QPolygonF. More... | |
| static QgsGeometry | fromRect (const QgsRectangle &rect) |
| Creates a new geometry from a QgsRectangle. More... | |
| static QgsGeometry | fromWkt (const QString &wkt) |
| Creates a new geometry from a WKT string. More... | |
| static GEOSContextHandle_t | getGEOSHandler () |
| Return GEOS context handle. More... | |
| static QgsGeometry | polygonize (const QVector< QgsGeometry > &geometries) |
| Creates a GeometryCollection geometry containing possible polygons formed from the constituent linework of a set of geometries. More... | |
| static QgsGeometry | unaryUnion (const QVector< QgsGeometry > &geometries) |
| Compute the unary union on a list of geometries. More... | |
A geometry is the spatial representation of a feature.
Since QGIS 2.10, QgsGeometry acts as a generic container for geometry objects. QgsGeometry is implicitly shared, so making copies of geometries is inexpensive. The geometry container class can also be stored inside a QVariant object.
The actual geometry representation is stored as a QgsAbstractGeometry within the container, and can be accessed via the geometry() method or set using the setGeometry() method.
Definition at line 111 of file qgsgeometry.h.
Side of line to buffer.
| Enumerator | |
|---|---|
| SideLeft | Buffer to left of line. |
| SideRight | Buffer to right of line. |
Definition at line 897 of file qgsgeometry.h.
End cap styles for buffers.
| Enumerator | |
|---|---|
| CapRound | Round cap. |
| CapFlat | Flat cap (in line with start/end of line) |
| CapSquare | Square cap (extends past start/end of line by buffer distance) |
Definition at line 905 of file qgsgeometry.h.
Join styles for buffers.
| Enumerator | |
|---|---|
| JoinStyleRound | Use rounded joins. |
| JoinStyleMiter | Use mitered joins. |
| JoinStyleBevel | Use beveled joins. |
Definition at line 914 of file qgsgeometry.h.
Success or failure of a geometry operation.
This gives details about cause of failure.
Definition at line 120 of file qgsgeometry.h.
Available methods for validating geometries.
| Enumerator | |
|---|---|
| ValidatorQgisInternal | Use internal QgsGeometryValidator method. |
| ValidatorGeos | Use GEOS validation methods. |
Definition at line 1395 of file qgsgeometry.h.
| QgsGeometry::QgsGeometry | ( | ) |
Constructor.
Definition at line 56 of file qgsgeometry.cpp.
| QgsGeometry::QgsGeometry | ( | const QgsGeometry & | other | ) |
Copy constructor will prompt a deep copy of the object.
Definition at line 81 of file qgsgeometry.cpp.
|
explicit |
Creates a geometry from an abstract geometry object.
Ownership of geom is transferred.
Definition at line 67 of file qgsgeometry.cpp.
|
explicit |
Creates a geometry from an abstract geometry object.
Ownership of geom is transferred.
Definition at line 74 of file qgsgeometry.cpp.
| QgsGeometry::~QgsGeometry | ( | ) |
Definition at line 61 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::addPart | ( | const QVector< QgsPointXY > & | points, |
| QgsWkbTypes::GeometryType | geomType = QgsWkbTypes::UnknownGeometry |
||
| ) |
Adds a new part to a the geometry.
| points | points describing part to add |
| geomType | default geometry type to create if no existing geometry |
Definition at line 633 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::addPart | ( | const QgsPointSequence & | points, |
| QgsWkbTypes::GeometryType | geomType = QgsWkbTypes::UnknownGeometry |
||
| ) |
Adds a new part to a the geometry.
| points | points describing part to add |
| geomType | default geometry type to create if no existing geometry |
Definition at line 640 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::addPart | ( | QgsAbstractGeometry * | part, |
| QgsWkbTypes::GeometryType | geomType = QgsWkbTypes::UnknownGeometry |
||
| ) |
Adds a new part to this geometry.
| part | part to add (ownership is transferred) |
| geomType | default geometry type to create if no existing geometry |
Definition at line 656 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::addPart | ( | GEOSGeometry * | newPart | ) |
Adds a new island polygon to a multipolygon feature.
| newPart | part to add. Ownership is NOT transferred. |
Definition at line 735 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::addPart | ( | const QgsGeometry & | newPart | ) |
Adds a new island polygon to a multipolygon feature.
Definition at line 686 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::addRing | ( | const QVector< QgsPointXY > & | ring | ) |
Adds a new ring to this geometry.
This makes only sense for polygon and multipolygons.
| ring | The ring to be added |
Definition at line 614 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::addRing | ( | QgsCurve * | ring | ) |
Adds a new ring to this geometry.
This makes only sense for polygon and multipolygons.
| ring | The ring to be added |
Definition at line 620 of file qgsgeometry.cpp.
| void QgsGeometry::adjacentVertices | ( | int | atVertex, |
| int & | beforeVertex, | ||
| int & | afterVertex | ||
| ) | const |
Returns the indexes of the vertices before and after the given vertex index.
This function takes into account the following factors:
Definition at line 392 of file qgsgeometry.cpp.
| double QgsGeometry::angleAtVertex | ( | int | vertex | ) | const |
Returns the bisector angle for this geometry at the specified vertex.
| vertex | vertex index to calculate bisector angle at |
Definition at line 376 of file qgsgeometry.cpp.
| double QgsGeometry::area | ( | ) | const |
Returns the area of the geometry using GEOS.
Definition at line 1521 of file qgsgeometry.cpp.
| QVector< QgsGeometry > QgsGeometry::asGeometryCollection | ( | ) | const |
Return contents of the geometry as a list of geometries.
Definition at line 2129 of file qgsgeometry.cpp.
| QString QgsGeometry::asJson | ( | int | precision = 17 | ) | const |
Exports the geometry to a GeoJSON string.
Definition at line 1238 of file qgsgeometry.cpp.
| QgsMultiPointXY QgsGeometry::asMultiPoint | ( | ) | const |
Returns contents of the geometry as a multi point if wkbType is WKBMultiPoint, otherwise an empty list.
Definition at line 1410 of file qgsgeometry.cpp.
| QgsMultiPolygonXY QgsGeometry::asMultiPolygon | ( | ) | const |
Returns contents of the geometry as a multi polygon if wkbType is WKBMultiPolygon, otherwise an empty list.
Definition at line 1478 of file qgsgeometry.cpp.
| QgsMultiPolylineXY QgsGeometry::asMultiPolyline | ( | ) | const |
Returns contents of the geometry as a multi linestring if wkbType is WKBMultiLineString, otherwise an empty list.
Definition at line 1434 of file qgsgeometry.cpp.
| QgsPointXY QgsGeometry::asPoint | ( | ) | const |
Returns contents of the geometry as a point if wkbType is WKBPoint, otherwise returns [0,0].
Definition at line 1318 of file qgsgeometry.cpp.
| QgsPolygonXY QgsGeometry::asPolygon | ( | ) | const |
Returns contents of the geometry as a polygon if wkbType is WKBPolygon, otherwise an empty list.
Definition at line 1375 of file qgsgeometry.cpp.
| QgsPolylineXY QgsGeometry::asPolyline | ( | ) | const |
Returns contents of the geometry as a polyline if wkbType is WKBLineString, otherwise an empty list.
Definition at line 1333 of file qgsgeometry.cpp.
| QPointF QgsGeometry::asQPointF | ( | ) | const |
Returns contents of the geometry as a QPointF if wkbType is WKBPoint, otherwise returns a null QPointF.
Definition at line 2155 of file qgsgeometry.cpp.
| QPolygonF QgsGeometry::asQPolygonF | ( | ) | const |
Returns contents of the geometry as a QPolygonF.
If geometry is a linestring, then the result will be an open QPolygonF. If the geometry is a polygon, then the result will be a closed QPolygonF of the geometry's exterior ring.
Definition at line 2161 of file qgsgeometry.cpp.
| QByteArray QgsGeometry::asWkb | ( | ) | const |
| QString QgsGeometry::asWkt | ( | int | precision = 17 | ) | const |
Exports the geometry to WKT.
Definition at line 1229 of file qgsgeometry.cpp.
| int QgsGeometry::avoidIntersections | ( | const QList< QgsVectorLayer *> & | avoidIntersectionsLayers, |
| const QHash< QgsVectorLayer *, QSet< QgsFeatureId > > & | ignoreFeatures = ( QHash<QgsVectorLayer *, QSet<QgsFeatureId> >() ) |
||
| ) |
Modifies geometry to avoid intersections with the layers specified in project properties.
| avoidIntersectionsLayers | list of layers to check for intersections |
| ignoreFeatures | possibility to give a list of features where intersections should be ignored (not available in Python bindings) |
Definition at line 2220 of file qgsgeometry.cpp.
| QgsRectangle QgsGeometry::boundingBox | ( | ) | const |
Returns the bounding box of the geometry.
Definition at line 909 of file qgsgeometry.cpp.
| bool QgsGeometry::boundingBoxIntersects | ( | const QgsRectangle & | rectangle | ) | const |
Returns true if the bounding box of this geometry intersects with a rectangle.
Since this test only considers the bounding box of the geometry, is is very fast to calculate and handles invalid geometries.
Definition at line 1109 of file qgsgeometry.cpp.
| bool QgsGeometry::boundingBoxIntersects | ( | const QgsGeometry & | geometry | ) | const |
Returns true if the bounding box of this geometry intersects with the bounding box of another geometry.
Since this test only considers the bounding box of the geometries, is is very fast to calculate and handles invalid geometries.
Definition at line 1119 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::buffer | ( | double | distance, |
| int | segments | ||
| ) | const |
Returns a buffer region around this geometry having the given width and with a specified number of segments used to approximate curves.
Definition at line 1612 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::buffer | ( | double | distance, |
| int | segments, | ||
| EndCapStyle | endCapStyle, | ||
| JoinStyle | joinStyle, | ||
| double | miterLimit | ||
| ) | const |
Returns a buffer region around the geometry, with additional style options.
| distance | buffer distance |
| segments | for round joins, number of segments to approximate quarter-circle |
| endCapStyle | end cap style |
| joinStyle | join style for corners in geometry |
| miterLimit | limit on the miter ratio used for very sharp corners (JoinStyleMiter only) |
Definition at line 1631 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::centroid | ( | ) | const |
Returns the center of mass of a geometry.
If the input is a NULL geometry, the output will also be a NULL geometry.
If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.
Definition at line 1810 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::clipped | ( | const QgsRectangle & | rectangle | ) |
Clips the geometry using the specified rectangle.
Performs a fast, non-robust intersection between the geometry and a rectangle. The returned geometry may be invalid.
Definition at line 2373 of file qgsgeometry.cpp.
| double QgsGeometry::closestSegmentWithContext | ( | const QgsPointXY & | point, |
| QgsPointXY & | minDistPoint, | ||
| int & | afterVertex, | ||
| int * | leftOf = nullptr, |
||
| double | epsilon = DEFAULT_SEGMENT_EPSILON |
||
| ) | const |
Searches for the closest segment of geometry to the given point.
| point | Specifies the point for search |
| minDistPoint | Receives the nearest point on the segment |
| afterVertex | Receives index of the vertex after the closest segment. The vertex before the closest segment is always afterVertex - 1 |
| leftOf | Out: Returns if the point lies on the left of left side of the geometry ( < 0 means left, > 0 means right, 0 indicates that the test was unsuccessful, e.g. for a point exactly on the line) |
| epsilon | epsilon for segment snapping |
Definition at line 590 of file qgsgeometry.cpp.
| QgsPointXY QgsGeometry::closestVertex | ( | const QgsPointXY & | point, |
| int & | atVertex, | ||
| int & | beforeVertex, | ||
| int & | afterVertex, | ||
| double & | sqrDist | ||
| ) | const |
Returns the vertex closest to the given point, the corresponding vertex index, squared distance snap point / target point and the indices of the vertices before and after the closest vertex.
| point | point to search for |
| atVertex | will be set to the vertex index of the closest found vertex |
| beforeVertex | will be set to the vertex index of the previous vertex from the closest one. Will be set to -1 if not present. |
| afterVertex | will be set to the vertex index of the next vertex after the closest one. Will be set to -1 if not present. |
| sqrDist | will be set to the square distance between the closest vertex and the specified point |
Definition at line 332 of file qgsgeometry.cpp.
| double QgsGeometry::closestVertexWithContext | ( | const QgsPointXY & | point, |
| int & | atVertex | ||
| ) | const |
Searches for the closest vertex in this geometry to the given point.
| point | Specifiest the point for search |
| atVertex | Receives index of the closest vertex |
Definition at line 574 of file qgsgeometry.cpp.
|
static |
Creates a new multipart geometry from a list of QgsGeometry objects.
Definition at line 242 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::combine | ( | const QgsGeometry & | geometry | ) | const |
Returns a geometry representing all the points in this geometry and other (a union geometry operation).
If the input is a NULL geometry, the output will also be a NULL geometry.
If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.
Definition at line 2038 of file qgsgeometry.cpp.
|
static |
Compares two polylines for equality within a specified tolerance.
| p1 | first polyline |
| p2 | second polyline |
| epsilon | maximum difference for coordinates between the polylines |
Definition at line 2619 of file qgsgeometry.cpp.
|
static |
Compares two polygons for equality within a specified tolerance.
| p1 | first polygon |
| p2 | second polygon |
| epsilon | maximum difference for coordinates between the polygons |
Definition at line 2632 of file qgsgeometry.cpp.
|
static |
Compares two multipolygons for equality within a specified tolerance.
| p1 | first multipolygon |
| p2 | second multipolygon |
| epsilon | maximum difference for coordinates between the multipolygons |
Definition at line 2646 of file qgsgeometry.cpp.
| const QgsAbstractGeometry * QgsGeometry::constGet | ( | ) | const |
Returns a non-modifiable (const) reference to the underlying abstract geometry primitive.
This is much faster then calling the non-const get() method.
Definition at line 123 of file qgsgeometry.cpp.
| bool QgsGeometry::contains | ( | const QgsPointXY * | p | ) | const |
Tests for containment of a point (uses GEOS)
Definition at line 1129 of file qgsgeometry.cpp.
| bool QgsGeometry::contains | ( | const QgsGeometry & | geometry | ) | const |
Tests for if geometry is contained in another (uses GEOS)
Definition at line 1142 of file qgsgeometry.cpp.
|
static |
Upgrades a point list from QgsPointXY to QgsPoint.
| input | list of QgsPointXY objects to be upgraded |
| output | destination for list of points converted to QgsPoint |
Definition at line 2527 of file qgsgeometry.cpp.
|
static |
Downgrades a point list from QgsPoint to QgsPointXY.
| input | list of QgsPoint objects to be downgraded |
| output | destination for list of points converted to QgsPointXY |
Definition at line 2536 of file qgsgeometry.cpp.
| bool QgsGeometry::convertToMultiType | ( | ) |
Converts single type geometry into multitype geometry e.g.
a polygon into a multipolygon geometry with one polygon If it is already a multipart geometry, it will return true and not change the geometry.
Definition at line 1265 of file qgsgeometry.cpp.
| bool QgsGeometry::convertToSingleType | ( | ) |
Converts multi type geometry into single type geometry e.g.
a multipolygon into a polygon geometry. Only the first part of the multi geometry will be retained. If it is already a single part geometry, it will return true and not change the geometry.
Definition at line 1297 of file qgsgeometry.cpp.
| void QgsGeometry::convertToStraightSegment | ( | ) |
Converts the geometry to straight line segments, if it is a curved geometry type.
Definition at line 2319 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::convertToType | ( | QgsWkbTypes::GeometryType | destType, |
| bool | destMultipart = false |
||
| ) | const |
Try to convert the geometry to the requested type.
| destType | the geometry type to be converted to |
| destMultipart | determines if the output geometry will be multipart or not |
Definition at line 1247 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::convexHull | ( | ) | const |
Returns the smallest convex polygon that contains all the points in the geometry.
If the input is a NULL geometry, the output will also be a NULL geometry.
If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.
Definition at line 1847 of file qgsgeometry.cpp.
|
static |
Creates and returns a new geometry engine.
Definition at line 3145 of file qgsgeometry.cpp.
|
static |
Creates a QgsPolygonXYfrom a QPolygonF.
| polygon | source polygon |
Definition at line 2601 of file qgsgeometry.cpp.
|
static |
Creates a QgsPolylineXY from a QPolygonF.
| polygon | source polygon |
Definition at line 2608 of file qgsgeometry.cpp.
| bool QgsGeometry::crosses | ( | const QgsGeometry & | geometry | ) | const |
Test for if geometry crosses another (uses GEOS)
Definition at line 1217 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::delaunayTriangulation | ( | double | tolerance = 0.0, |
| bool | edgesOnly = false |
||
| ) | const |
Returns the Delaunay triangulation for the vertices of the geometry.
The tolerance parameter specifies an optional snapping tolerance which can be used to improve the robustness of the triangulation. If edgesOnly is true than line string boundary geometries will be returned instead of polygons. An empty geometry will be returned if the diagram could not be calculated.
Definition at line 1879 of file qgsgeometry.cpp.
| bool QgsGeometry::deletePart | ( | int | partNum | ) |
Deletes part identified by the part number.
Definition at line 2202 of file qgsgeometry.cpp.
| bool QgsGeometry::deleteRing | ( | int | ringNum, |
| int | partNum = 0 |
||
| ) |
Deletes a ring in polygon or multipolygon.
Ring 0 is outer ring and can't be deleted.
Definition at line 2190 of file qgsgeometry.cpp.
| bool QgsGeometry::deleteVertex | ( | int | atVertex | ) |
Deletes the vertex at the given position number and item (first number is index 0)
Definition at line 449 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::densifyByCount | ( | int | extraNodesPerSegment | ) | const |
Returns a copy of the geometry which has been densified by adding the specified number of extra nodes within each segment of the geometry.
If the geometry has z or m values present then these will be linearly interpolated at the added nodes. Curved geometry types are automatically segmentized by this routine.
Definition at line 1796 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::densifyByDistance | ( | double | distance | ) | const |
Densifies the geometry by adding regularly placed extra nodes inside each segment so that the maximum distance between any two nodes does not exceed the specified distance.
E.g. specifying a distance 3 would cause the segment [0 0] -> [10 0] to be converted to [0 0] -> [2.5 0] -> [5 0] -> [7.5 0] -> [10 0], since 3 extra nodes are required on the segment and spacing these at 2.5 increments allows them to be evenly spaced over the segment. If the geometry has z or m values present then these will be linearly interpolated at the added nodes. Curved geometry types are automatically segmentized by this routine.
Definition at line 1803 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::difference | ( | const QgsGeometry & | geometry | ) | const |
Returns a geometry representing the points making up this geometry that do not make up other.
If the input is a NULL geometry, the output will also be a NULL geometry.
If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.
Definition at line 2077 of file qgsgeometry.cpp.
| bool QgsGeometry::disjoint | ( | const QgsGeometry & | geometry | ) | const |
Tests for if geometry is disjoint of another (uses GEOS)
Definition at line 1154 of file qgsgeometry.cpp.
| double QgsGeometry::distance | ( | const QgsGeometry & | geom | ) | const |
Returns the minimum distance between this geometry and another geometry, using GEOS.
Will return a negative value if a geometry is missing.
| geom | geometry to find minimum distance to |
Definition at line 1555 of file qgsgeometry.cpp.
| double QgsGeometry::distanceToVertex | ( | int | vertex | ) | const |
Returns the distance along this geometry from its first vertex to the specified vertex.
| vertex | vertex index to calculate distance to |
Definition at line 360 of file qgsgeometry.cpp.
| void QgsGeometry::draw | ( | QPainter & | p | ) | const |
Draws the geometry onto a QPainter.
| p | destination QPainter |
Definition at line 2392 of file qgsgeometry.cpp.
| bool QgsGeometry::equals | ( | const QgsGeometry & | geometry | ) | const |
Test if this geometry is exactly equal to another geometry.
This is a strict equality check, where the underlying geometries must have exactly the same type, component vertices and vertex order.
Calling this method is dramatically faster than the topological equality test performed by isGeosEqual().
Definition at line 1166 of file qgsgeometry.cpp.
| GEOSGeometry * QgsGeometry::exportToGeos | ( | double | precision = 0 | ) | const |
Returns a geos geometry - caller takes ownership of the object (should be deleted with GEOSGeom_destroy_r)
| precision | The precision of the grid to which to snap the geometry vertices. If 0, no snapping is performed. |
Definition at line 274 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::extendLine | ( | double | startDistance, |
| double | endDistance | ||
| ) | const |
Extends a (multi)line geometry by extrapolating out the start or end of the line by a specified distance.
Lines are extended using the bearing of the first or last segment in the line.
Definition at line 1737 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::extrude | ( | double | x, |
| double | y | ||
| ) |
Returns an extruded version of this geometry.
Definition at line 2117 of file qgsgeometry.cpp.
| void QgsGeometry::fromGeos | ( | GEOSGeometry * | geos | ) |
Set the geometry, feeding in a geometry in GEOS format.
This class will take ownership of the buffer.
Definition at line 326 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsMultiPointXY object.
Definition at line 194 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsMultiPolygon.
Definition at line 214 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsMultiPolylineXY object.
Definition at line 204 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsPointXY object.
Definition at line 159 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsPolygon.
Definition at line 184 of file qgsgeometry.cpp.
|
static |
Creates a new LineString geometry from a list of QgsPoint points.
This method will respect any Z or M dimensions present in the input points. E.g. if input points are PointZ type, the resultant linestring will be a LineStringZ type.
Definition at line 179 of file qgsgeometry.cpp.
|
static |
Creates a new LineString geometry from a list of QgsPointXY points.
Using fromPolyline() is preferred, as fromPolyline() is more efficient and will respect any Z or M dimensions present in the input points.
Definition at line 169 of file qgsgeometry.cpp.
|
static |
Construct geometry from a QPointF.
| point | source QPointF |
Definition at line 2584 of file qgsgeometry.cpp.
|
static |
Construct geometry from a QPolygonF.
If the polygon is closed than the resultant geometry will be a polygon, if it is open than the geometry will be a polyline.
| polygon | source QPolygonF |
Definition at line 2589 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a QgsRectangle.
Definition at line 224 of file qgsgeometry.cpp.
| void QgsGeometry::fromWkb | ( | unsigned char * | wkb, |
| int | length | ||
| ) |
Set the geometry, feeding in the buffer containing OGC Well-Known Binary and the buffer's length.
This class will take ownership of the buffer.
Definition at line 261 of file qgsgeometry.cpp.
| void QgsGeometry::fromWkb | ( | const QByteArray & | wkb | ) |
Set the geometry, feeding in the buffer containing OGC Well-Known Binary.
Definition at line 268 of file qgsgeometry.cpp.
|
static |
Creates a new geometry from a WKT string.
Definition at line 149 of file qgsgeometry.cpp.
| QgsAbstractGeometry * QgsGeometry::get | ( | ) |
Returns a modifiable (non-const) reference to the underlying abstract geometry primitive.
This method can be slow to call, as it may trigger a detachment of the geometry and a deep copy. Where possible, use constGet() instead.
Definition at line 128 of file qgsgeometry.cpp.
|
static |
Return GEOS context handle.
Definition at line 2579 of file qgsgeometry.cpp.
| double QgsGeometry::hausdorffDistance | ( | const QgsGeometry & | geom | ) | const |
Returns the Hausdorff distance between this geometry and geom.
This is basically a measure of how similar or dissimilar 2 geometries are.
This algorithm is an approximation to the standard Hausdorff distance. This approximation is exact or close enough for a large subset of useful cases. Examples of these are:
If the default approximate provided by this method is insufficient, use hausdorffDistanceDensify() instead.
In case of error -1 will be returned.
Definition at line 1567 of file qgsgeometry.cpp.
| double QgsGeometry::hausdorffDistanceDensify | ( | const QgsGeometry & | geom, |
| double | densifyFraction | ||
| ) | const |
Returns the Hausdorff distance between this geometry and geom.
This is basically a measure of how similar or dissimilar 2 geometries are.
This function accepts a densifyFraction argument. The function performs a segment densification before computing the discrete Hausdorff distance. The densifyFraction parameter sets the fraction by which to densify each segment. Each segment will be split into a number of equal-length subsegments, whose fraction of the total length is closest to the given fraction.
This method can be used when the default approximation provided by hausdorffDistance() is not sufficient. Decreasing the densifyFraction parameter will make the distance returned approach the true Hausdorff distance for the geometries.
In case of error -1 will be returned.
Definition at line 1579 of file qgsgeometry.cpp.
| bool QgsGeometry::insertVertex | ( | double | x, |
| double | y, | ||
| int | beforeVertex | ||
| ) |
Insert a new vertex before the given vertex index, ring and item (first number is index 0) If the requested vertex number (beforeVertex.back()) is greater than the last actual vertex on the requested ring and item, it is assumed that the vertex is to be appended instead of inserted.
Returns false if atVertex does not correspond to a valid vertex on this geometry (including if this geometry is a Point). It is up to the caller to distinguish between these error conditions. (Or maybe we add another method to this object to help make the distinction?)
Definition at line 482 of file qgsgeometry.cpp.
| bool QgsGeometry::insertVertex | ( | const QgsPoint & | point, |
| int | beforeVertex | ||
| ) |
Insert a new vertex before the given vertex index, ring and item (first number is index 0) If the requested vertex number (beforeVertex.back()) is greater than the last actual vertex on the requested ring and item, it is assumed that the vertex is to be appended instead of inserted.
Returns false if atVertex does not correspond to a valid vertex on this geometry (including if this geometry is a Point). It is up to the caller to distinguish between these error conditions. (Or maybe we add another method to this object to help make the distinction?)
Definition at line 508 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::interpolate | ( | double | distance | ) | const |
Returns interpolated point on line at distance.
If the input is a NULL geometry, the output will also be a NULL geometry.
If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.
Definition at line 1920 of file qgsgeometry.cpp.
| double QgsGeometry::interpolateAngle | ( | double | distance | ) | const |
Returns the angle parallel to the linestring or polygon boundary at the specified distance along the geometry.
Angles are in radians, clockwise from north. If the distance coincides precisely at a node then the average angle from the segment either side of the node is returned.
| distance | distance along geometry |
Definition at line 1962 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::intersection | ( | const QgsGeometry & | geometry | ) | const |
Returns a geometry representing the points shared by this geometry and other.
If the input is a NULL geometry, the output will also be a NULL geometry.
If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.
Definition at line 2016 of file qgsgeometry.cpp.
| bool QgsGeometry::intersects | ( | const QgsRectangle & | rectangle | ) | const |
Returns true if this geometry exactly intersects with a rectangle.
This test is exact and can be slow for complex geometries.
The GEOS library is used to perform the intersection test. Geometries which are not valid may return incorrect results.
Definition at line 1091 of file qgsgeometry.cpp.
| bool QgsGeometry::intersects | ( | const QgsGeometry & | geometry | ) | const |
Returns true if this geometry exactly intersects with another geometry.
This test is exact and can be slow for complex geometries.
The GEOS library is used to perform the intersection test. Geometries which are not valid may return incorrect results.
Definition at line 1097 of file qgsgeometry.cpp.
| bool QgsGeometry::isEmpty | ( | ) | const |
Returns true if the geometry is empty (eg a linestring with no vertices, or a collection with no geometries).
A null geometry will always return true for isEmpty().
Definition at line 307 of file qgsgeometry.cpp.
| bool QgsGeometry::isGeosEqual | ( | const QgsGeometry & | g | ) | const |
Compares the geometry with another geometry using GEOS.
This method performs a slow, topological check, where geometries are considered equal if all of the their component edges overlap. E.g. lines with the same vertex locations but opposite direction will be considered equal by this method.
Consider using the much faster, stricter equality test performed by equals() instead.
Definition at line 2277 of file qgsgeometry.cpp.
| bool QgsGeometry::isGeosValid | ( | ) | const |
Checks validity of the geometry using GEOS.
Definition at line 2255 of file qgsgeometry.cpp.
| bool QgsGeometry::isMultipart | ( | ) | const |
Returns true if WKB of the geometry is of WKBMulti* type.
Definition at line 317 of file qgsgeometry.cpp.
| bool QgsGeometry::isNull | ( | ) | const |
Returns true if the geometry is null (ie, contains no underlying geometry accessible via geometry() ).
Definition at line 144 of file qgsgeometry.cpp.
| bool QgsGeometry::isSimple | ( | ) | const |
Determines whether the geometry is simple (according to OGC definition), i.e.
it has no anomalous geometric points, such as self-intersection or self-tangency. Uses GEOS library for the test.
Definition at line 2267 of file qgsgeometry.cpp.
| QString QgsGeometry::lastError | ( | ) | const |
Returns an error string referring to the last error encountered either when this geometry was created or when an operation was performed on the geometry.
Definition at line 2522 of file qgsgeometry.cpp.
| double QgsGeometry::length | ( | ) | const |
Returns the length of geometry using GEOS.
Definition at line 1544 of file qgsgeometry.cpp.
| double QgsGeometry::lineLocatePoint | ( | const QgsGeometry & | point | ) | const |
Returns a distance representing the location along this linestring of the closest point on this linestring geometry to the specified point.
Ie, the returned value indicates how far along this linestring you need to traverse to get to the closest location where this linestring comes to the specified point.
| point | point to seek proximity to |
Definition at line 1943 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::makeDifference | ( | const QgsGeometry & | other | ) | const |
Returns the geometry formed by modifying this geometry such that it does not intersect the other geometry.
| other | geometry that should not be intersect |
Definition at line 888 of file qgsgeometry.cpp.
| int QgsGeometry::makeDifferenceInPlace | ( | const QgsGeometry & | other | ) |
Changes this geometry such that it does not intersect the other geometry.
| other | geometry that should not be intersect |
Definition at line 868 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::makeValid | ( | ) | const |
Attempts to make an invalid geometry valid without losing vertices.
Already-valid geometries are returned without further intervention. In case of full or partial dimensional collapses, the output geometry may be a collection of lower-to-equal dimension geometries or a geometry of lower dimension. Single polygons may become multi-geometries in case of self-intersections. It preserves Z values, but M values will be dropped.
If an error was encountered during the process, more information can be retrieved by calling error() on the returned geometry.
Definition at line 2236 of file qgsgeometry.cpp.
| void QgsGeometry::mapToPixel | ( | const QgsMapToPixel & | mtp | ) |
Transforms the geometry from map units to pixels in place.
| mtp | map to pixel transform |
Definition at line 2364 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::mergeLines | ( | ) | const |
Merges any connected lines in a LineString/MultiLineString geometry and converts them to single line strings.
Definition at line 2057 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::minimalEnclosingCircle | ( | QgsPointXY & | center, |
| double & | radius, | ||
| unsigned int | segments = 36 |
||
| ) | const |
Returns the minimal enclosing circle for the geometry.
| center | Center of the minimal enclosing circle returneds |
| radius | Radius of the minimal enclosing circle returned |
| segments | Number of segments used to segment geometry. |
Definition at line 1031 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::minimalEnclosingCircle | ( | unsigned int | segments = 36 | ) | const |
Returns the minimal enclosing circle for the geometry.
| segments | Number of segments used to segment geometry. |
Definition at line 1058 of file qgsgeometry.cpp.
| bool QgsGeometry::moveVertex | ( | double | x, |
| double | y, | ||
| int | atVertex | ||
| ) |
Moves the vertex at the given position number and item (first number is index 0) to the given coordinates.
Returns false if atVertex does not correspond to a valid vertex on this geometry
Definition at line 413 of file qgsgeometry.cpp.
| bool QgsGeometry::moveVertex | ( | const QgsPoint & | p, |
| int | atVertex | ||
| ) |
Moves the vertex at the given position number and item (first number is index 0) to the given coordinates.
Returns false if atVertex does not correspond to a valid vertex on this geometry
Definition at line 431 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::nearestPoint | ( | const QgsGeometry & | other | ) | const |
Returns the nearest point on this geometry to another geometry.
Definition at line 556 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::offsetCurve | ( | double | distance, |
| int | segments, | ||
| JoinStyle | joinStyle, | ||
| double | miterLimit | ||
| ) | const |
Returns an offset line at a given distance and side from an input line.
| distance | buffer distance |
| segments | for round joins, number of segments to approximate quarter-circle |
| joinStyle | join style for corners in geometry |
| miterLimit | limit on the miter ratio used for very sharp corners (JoinStyleMiter only) |
Definition at line 1650 of file qgsgeometry.cpp.
| QgsGeometry::operator bool | ( | ) | const |
Returns true if the geometry is non empty (ie, isNull() returns false), or false if it is an empty, uninitialized geometry (ie, isNull() returns true).
Definition at line 2545 of file qgsgeometry.cpp.
|
inline |
Allows direct construction of QVariants from geometry.
Definition at line 1720 of file qgsgeometry.h.
| QgsGeometry & QgsGeometry::operator= | ( | QgsGeometry const & | rhs | ) |
Creates a deep copy of the object.
Definition at line 88 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::orientedMinimumBoundingBox | ( | double & | area, |
| double & | angle, | ||
| double & | width, | ||
| double & | height | ||
| ) | const |
Returns the oriented minimum bounding box for the geometry, which is the smallest (by area) rotated rectangle which fully encompasses the geometry.
The area, angle (clockwise in degrees from North), width and height of the rotated bounding box will also be returned.
Definition at line 918 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::orientedMinimumBoundingBox | ( | ) | const |
Returns the oriented minimum bounding box for the geometry, which is the smallest (by area) rotated rectangle which fully encompasses the geometry.
Definition at line 977 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::orthogonalize | ( | double | tolerance = 1.0E-8, |
| int | maxIterations = 1000, |
||
| double | angleThreshold = 15.0 |
||
| ) | const |
Attempts to orthogonalize a line or polygon geometry by shifting vertices to make the geometries angles either right angles or flat lines.
This is an iterative algorithm which will loop until either the vertices are within a specified tolerance of right angles or a set number of maximum iterations is reached. The angle threshold parameter specifies how close to a right angle or straight line an angle must be before it is attempted to be straightened.
Definition at line 1066 of file qgsgeometry.cpp.
| bool QgsGeometry::overlaps | ( | const QgsGeometry & | geometry | ) | const |
Test for if geometry overlaps another (uses GEOS)
Definition at line 1193 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::pointOnSurface | ( | ) | const |
Returns a point guaranteed to lie on the surface of a geometry.
While the centroid() of a geometry may be located outside of the geometry itself (e.g., for concave shapes), the point on surface will always be inside the geometry.
If the input is a NULL geometry, the output will also be a NULL geometry.
If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.
Definition at line 1825 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::poleOfInaccessibility | ( | double | precision, |
| double * | distanceToBoundary = nullptr |
||
| ) | const |
Calculates the approximate pole of inaccessibility for a surface, which is the most distant internal point from the boundary of the surface.
This function uses the 'polylabel' algorithm (Vladimir Agafonkin, 2016), which is an iterative approach guaranteed to find the true pole of inaccessibility within a specified tolerance. More precise tolerances require more iterations and will take longer to calculate. Optionally, the distance to the polygon boundary from the pole can be stored.
Definition at line 1840 of file qgsgeometry.cpp.
|
static |
Creates a GeometryCollection geometry containing possible polygons formed from the constituent linework of a set of geometries.
The input geometries must be fully noded (i.e. nodes exist at every common intersection of the geometries). The easiest way to ensure this is to first call unaryUnion() on the set of input geometries and then pass the result to polygonize(). An empty geometry will be returned in the case of errors.
Definition at line 2300 of file qgsgeometry.cpp.
| QgsGeometry::Q_ENUM | ( | BufferSide | ) |
| QgsGeometry::Q_ENUM | ( | EndCapStyle | ) |
| QgsGeometry::Q_ENUM | ( | JoinStyle | ) |
| bool QgsGeometry::removeDuplicateNodes | ( | double | epsilon = 4 * DBL_EPSILON, |
| bool | useZValues = false |
||
| ) |
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.
Definition at line 1082 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::removeInteriorRings | ( | double | minimumAllowedArea = -1 | ) | const |
Removes the interior rings from a (multi)polygon geometry.
If the minimumAllowedArea parameter is specified then only rings smaller than this minimum area will be removed.
Definition at line 700 of file qgsgeometry.cpp.
| bool QgsGeometry::requiresConversionToStraightSegments | ( | ) | const |
Returns true if the geometry is a curved geometry type which requires conversion to display as straight line segments.
Definition at line 2330 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::reshapeGeometry | ( | const QgsLineString & | reshapeLineString | ) |
Replaces a part of this geometry with another line.
Definition at line 829 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::rotate | ( | double | rotation, |
| const QgsPointXY & | center | ||
| ) |
Rotate this geometry around the Z axis.
| rotation | clockwise rotation in degrees |
| center | rotation center |
Definition at line 765 of file qgsgeometry.cpp.
| void QgsGeometry::set | ( | QgsAbstractGeometry * | geometry | ) |
Sets the underlying geometry store.
Ownership of geometry is transferred.
Definition at line 134 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::shortestLine | ( | const QgsGeometry & | other | ) | const |
Returns the shortest line joining this geometry to another geometry.
Definition at line 565 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::simplify | ( | double | tolerance | ) | const |
Returns a simplified version of this geometry using a specified tolerance value.
Definition at line 1777 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::singleSidedBuffer | ( | double | distance, |
| int | segments, | ||
| BufferSide | side, | ||
| JoinStyle | joinStyle = JoinStyleRound, |
||
| double | miterLimit = 2.0 |
||
| ) | const |
Returns a single sided buffer for a (multi)line geometry.
The buffer is only applied to one side of the line.
| distance | buffer distance |
| segments | for round joins, number of segments to approximate quarter-circle |
| side | side of geometry to buffer |
| joinStyle | join style for corners |
| miterLimit | limit on the miter ratio used for very sharp corners |
Definition at line 1693 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::smooth | ( | const unsigned int | iterations = 1, |
| const double | offset = 0.25, |
||
| double | minimumDistance = -1.0, |
||
| double | maxAngle = 180.0 |
||
| ) | const |
Smooths a geometry by rounding off corners using the Chaikin algorithm.
This operation roughly doubles the number of vertices in a geometry.
| iterations | number of smoothing iterations to run. More iterations results in a smoother geometry |
| offset | fraction of line to create new vertices along, between 0 and 1.0, e.g., the default value of 0.25 will create new vertices 25% and 75% along each line segment of the geometry for each iteration. Smaller values result in "tighter" smoothing. |
| minimumDistance | minimum segment length to apply smoothing to |
| maxAngle | maximum angle at node (0-180) at which smoothing will be applied |
Definition at line 2659 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::snappedToGrid | ( | double | hSpacing, |
| double | vSpacing, | ||
| double | dSpacing = 0, |
||
| double | mSpacing = 0 |
||
| ) | const |
Returns a new geometry with all points or vertices snapped to the closest point of the grid.
If the gridified geometry could not be calculated (or was totally collapsed) an empty geometry will be returned. Note that snapping to grid 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.
| hSpacing | Horizontal spacing of the grid (x axis). 0 to disable. |
| vSpacing | Vertical spacing of the grid (y axis). 0 to disable. |
| dSpacing | Depth spacing of the grid (z axis). 0 (default) to disable. |
| mSpacing | Custom dimension spacing of the grid (m axis). 0 (default) to disable. |
Definition at line 1073 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::splitGeometry | ( | const QVector< QgsPointXY > & | splitLine, |
| QVector< QgsGeometry > & | newGeometries, | ||
| bool | topological, | ||
| QVector< QgsPointXY > & | topologyTestPoints | ||
| ) |
Splits this geometry according to a given line.
| splitLine | the line that splits the geometry | |
| [out] | newGeometries | list of new geometries that have been created with the split |
| topological | true if topological editing is enabled | |
| [out] | topologyTestPoints | points that need to be tested for topological completeness in the dataset |
Definition at line 781 of file qgsgeometry.cpp.
| double QgsGeometry::sqrDistToVertexAt | ( | QgsPointXY &point | SIP_IN, |
| int | atVertex | ||
| ) | const |
Returns the squared Cartesian distance between the given point to the given vertex index (vertex at the given position number, ring and item (first number is index 0))
Definition at line 550 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::subdivide | ( | int | maxNodes = 256 | ) | const |
Subdivides the geometry.
The returned geometry will be a collection containing subdivided parts from the original geometry, where no part has more then the specified maximum number of nodes (maxNodes).
This is useful for dividing a complex geometry into less complex parts, which are better able to be spatially indexed and faster to perform further operations such as intersects on. The returned geometry parts may not be valid and may contain self-intersections.
The minimum allowed value for maxNodes is 8.
Curved geometries will be segmentized before subdivision.
If the input is a NULL geometry, the output will also be a NULL geometry.
If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.
Definition at line 1893 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::symDifference | ( | const QgsGeometry & | geometry | ) | const |
Returns a geometry representing the points making up this geometry that do not make up other.
If the input is a NULL geometry, the output will also be a NULL geometry.
If an error was encountered while creating the result, more information can be retrieved by calling error() on the returned geometry.
Definition at line 2097 of file qgsgeometry.cpp.
| bool QgsGeometry::touches | ( | const QgsGeometry & | geometry | ) | const |
Test for if geometry touch another (uses GEOS)
Definition at line 1181 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::transform | ( | const QgsCoordinateTransform & | ct, |
| QgsCoordinateTransform::TransformDirection | direction = QgsCoordinateTransform::ForwardTransform, |
||
| bool | transformZ = false |
||
| ) |
Transforms this geometry as described by the coordinate transform ct.
The transformation defaults to a forward transform, but the direction can be swapped by setting the direction argument.
By default, z-coordinates are not transformed, even if the coordinate transform includes a vertical datum transformation. To transform z-coordinates, set transformZ to true. 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).
Definition at line 2340 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::transform | ( | const QTransform & | t, |
| double | zTranslate = 0.0, |
||
| double | zScale = 1.0, |
||
| double | mTranslate = 0.0, |
||
| double | mScale = 1.0 |
||
| ) |
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.
Definition at line 2352 of file qgsgeometry.cpp.
| QgsGeometry::OperationResult QgsGeometry::translate | ( | double | dx, |
| double | dy, | ||
| double | dz = 0.0, |
||
| double | dm = 0.0 |
||
| ) |
Translates this geometry by dx, dy, dz and dm.
Definition at line 752 of file qgsgeometry.cpp.
| QgsWkbTypes::GeometryType QgsGeometry::type | ( | ) | const |
Returns type of the geometry as a QgsWkbTypes::GeometryType.
Definition at line 298 of file qgsgeometry.cpp.
|
static |
Compute the unary union on a list of geometries.
May be faster than an iterative union on a set of geometries. The returned geometry will be fully noded, i.e. a node will be created at every common intersection of the input geometries. An empty geometry will be returned in the case of errors.
Definition at line 2289 of file qgsgeometry.cpp.
| void QgsGeometry::validateGeometry | ( | QVector< QgsGeometry::Error > & | errors, |
| ValidationMethod | method = ValidatorQgisInternal |
||
| ) | const |
Validates geometry and produces a list of geometry errors.
The method argument dictates which validator to utilize.
Definition at line 2250 of file qgsgeometry.cpp.
| QgsPoint QgsGeometry::vertexAt | ( | int | atVertex | ) | const |
Returns coordinates of a vertex.
| atVertex | index of the vertex |
Definition at line 534 of file qgsgeometry.cpp.
| bool QgsGeometry::vertexIdFromVertexNr | ( | int | number, |
| QgsVertexId & | id | ||
| ) | const |
Calculates the vertex ID from a vertex number.
If a matching vertex was found, it will be stored in id.
Returns true if vertex was found.
Definition at line 2477 of file qgsgeometry.cpp.
| int QgsGeometry::vertexNrFromVertexId | ( | QgsVertexId | id | ) | const |
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.
Definition at line 2513 of file qgsgeometry.cpp.
| QgsVertexIterator QgsGeometry::vertices | ( | ) | const |
Returns Java-style iterator for traversal of vertices of the geometry.
Definition at line 1605 of file qgsgeometry.cpp.
| QgsAbstractGeometry::vertex_iterator QgsGeometry::vertices_begin | ( | ) | const |
Returns STL-style iterator pointing to the first vertex of the geometry.
Definition at line 1591 of file qgsgeometry.cpp.
| QgsAbstractGeometry::vertex_iterator QgsGeometry::vertices_end | ( | ) | const |
Returns STL-style iterator pointing to the imaginary vertex after the last vertex of the geometry.
Definition at line 1598 of file qgsgeometry.cpp.
| QgsGeometry QgsGeometry::voronoiDiagram | ( | const QgsGeometry & | extent = QgsGeometry(), |
| double | tolerance = 0.0, |
||
| bool | edgesOnly = false |
||
| ) | const |
Creates a Voronoi diagram for the nodes contained within the geometry.
Returns the Voronoi polygons for the nodes contained within the geometry. If extent is specified then it will be used as a clipping envelope for the diagram. If no extent is set then the clipping envelope will be automatically calculated. In either case the diagram will be clipped to the larger of the provided envelope OR the envelope surrounding all input nodes. The tolerance parameter specifies an optional snapping tolerance which can be used to improve the robustness of the diagram calculation. If edgesOnly is true than line string boundary geometries will be returned instead of polygons. An empty geometry will be returned if the diagram could not be calculated.
Definition at line 1865 of file qgsgeometry.cpp.
| bool QgsGeometry::within | ( | const QgsGeometry & | geometry | ) | const |
Test for if geometry is within another (uses GEOS)
Definition at line 1205 of file qgsgeometry.cpp.
| QgsWkbTypes::Type QgsGeometry::wkbType | ( | ) | const |
Returns type of the geometry as a WKB type (point / linestring / polygon etc.)
Definition at line 285 of file qgsgeometry.cpp.
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