QGIS API Documentation
3.0.2-Girona (307d082)
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Circular string geometry type. More...
#include <qgscircularstring.h>
Public Member Functions | |
QgsCircularString () | |
bool | addMValue (double mValue=0) override |
Adds a measure to the geometry, initialized to a preset value. More... | |
void | addToPainterPath (QPainterPath &path) const override |
Adds a curve to a painter path. More... | |
bool | addZValue (double zValue=0) override |
Adds a z-dimension to the geometry, initialized to a preset value. More... | |
QDomElement | asGml2 (QDomDocument &doc, int precision=17, const QString &ns="gml") const override |
Returns a GML2 representation of the geometry. More... | |
QDomElement | asGml3 (QDomDocument &doc, int precision=17, const QString &ns="gml") const override |
Returns a GML3 representation of the geometry. More... | |
QString | asJson (int precision=17) const override |
Returns a GeoJSON representation of the geometry. More... | |
QByteArray | asWkb () const override |
Returns a WKB representation of the geometry. More... | |
QString | asWkt (int precision=17) const override |
Returns a WKT representation of the geometry. More... | |
const QgsCircularString * | cast (const QgsAbstractGeometry *geom) const |
Cast the geom to a QgsCircularString. More... | |
void | clear () override |
Clears the geometry, ie reset it to a null geometry. More... | |
QgsCircularString * | clone () const override |
Clones the geometry by performing a deep copy. More... | |
double | closestSegment (const QgsPoint &pt, QgsPoint &segmentPt, QgsVertexId &vertexAfter, int *leftOf=nullptr, double epsilon=4 *DBL_EPSILON) const override |
Searches for the closest segment of the geometry to a given point. More... | |
QgsCircularString * | createEmptyWithSameType () const override |
Creates a new geometry with the same class and same WKB type as the original and transfers ownership. More... | |
QgsLineString * | curveToLine (double tolerance=M_PI_2/90, SegmentationToleranceType toleranceType=MaximumAngle) const override |
Returns a new line string geometry corresponding to a segmentized approximation of the curve. More... | |
bool | deleteVertex (QgsVertexId position) override |
Deletes a vertex within the geometry. More... | |
int | dimension () const override |
Returns the inherent dimension of the geometry. More... | |
void | draw (QPainter &p) const override |
Draws the geometry using the specified QPainter. More... | |
void | drawAsPolygon (QPainter &p) const override |
Draws the curve as a polygon on the specified QPainter. More... | |
bool | dropMValue () override |
Drops any measure values which exist in the geometry. More... | |
bool | dropZValue () override |
Drops any z-dimensions which exist in the geometry. More... | |
QgsPoint | endPoint () const override |
Returns the end point of the curve. More... | |
bool | equals (const QgsCurve &other) const override |
Checks whether this curve exactly equals another curve. More... | |
bool | fromWkb (QgsConstWkbPtr &wkb) override |
Sets the geometry from a WKB string. More... | |
bool | fromWkt (const QString &wkt) override |
Sets the geometry from a WKT string. More... | |
QString | geometryType () const override |
Returns a unique string representing the geometry type. More... | |
bool | hasCurvedSegments () const override |
Returns true if the geometry contains curved segments. More... | |
bool | insertVertex (QgsVertexId position, const QgsPoint &vertex) override |
Inserts a vertex into the geometry. More... | |
bool | isEmpty () const override |
Returns true if the geometry is empty. More... | |
double | length () const override |
Returns the length of the geometry. More... | |
bool | moveVertex (QgsVertexId position, const QgsPoint &newPos) override |
Moves a vertex within the geometry. More... | |
int | numPoints () const override |
Returns the number of points in the curve. More... | |
bool | pointAt (int node, QgsPoint &point, QgsVertexId::VertexType &type) const override |
Returns the point and vertex id of a point within the curve. More... | |
QgsPoint | pointN (int i) const |
Returns the point at index i within the circular string. More... | |
void | points (QgsPointSequence &pts) const override |
Returns a list of points within the curve. More... | |
bool | removeDuplicateNodes (double epsilon=4 *DBL_EPSILON, bool useZValues=false) override |
Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry. More... | |
QgsCircularString * | reversed () const override |
Returns a reversed copy of the curve, where the direction of the curve has been flipped. More... | |
double | segmentLength (QgsVertexId startVertex) const override |
Returns the length of the segment of the geometry which begins at startVertex. More... | |
void | setPoints (const QgsPointSequence &points) |
Sets the circular string's points. More... | |
QgsCircularString * | snappedToGrid (double hSpacing, double vSpacing, double dSpacing=0, double mSpacing=0) const override |
Makes a new geometry with all the points or vertices snapped to the closest point of the grid. More... | |
QgsPoint | startPoint () const override |
Returns the starting point of the curve. More... | |
void | sumUpArea (double &sum) const override |
Sums up the area of the curve by iterating over the vertices (shoelace formula). More... | |
void | transform (const QgsCoordinateTransform &ct, QgsCoordinateTransform::TransformDirection d=QgsCoordinateTransform::ForwardTransform, bool transformZ=false) override |
Transforms the geometry using a coordinate transform. More... | |
void | transform (const QTransform &t, double zTranslate=0.0, double zScale=1.0, double mTranslate=0.0, double mScale=1.0) override |
Transforms the x and y components of the geometry using a QTransform object t. More... | |
double | vertexAngle (QgsVertexId vertex) const override |
Returns approximate angle at a vertex. More... | |
double | xAt (int index) const override |
Returns the x-coordinate of the specified node in the line string. More... | |
double | yAt (int index) const override |
Returns the y-coordinate of the specified node in the line string. More... | |
Public Member Functions inherited from QgsCurve | |
QgsCurve ()=default | |
Constructor for QgsCurve. More... | |
void | adjacentVertices (QgsVertexId vertex, QgsVertexId &previousVertex, QgsVertexId &nextVertex) const override |
Returns the vertices adjacent to a specified vertex within a geometry. More... | |
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... | |
QgsCoordinateSequence | coordinateSequence () const override |
Retrieves the sequence of geometries, rings and nodes. 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... | |
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... | |
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... | |
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... | |
Public Member Functions inherited from QgsAbstractGeometry | |
QgsAbstractGeometry ()=default | |
Constructor for QgsAbstractGeometry. More... | |
QgsAbstractGeometry (const QgsAbstractGeometry &geom) | |
virtual | ~QgsAbstractGeometry ()=default |
virtual double | area () const |
Returns the area of the geometry. More... | |
virtual QgsPoint | centroid () const |
Returns the centroid of the geometry. More... | |
virtual bool | convertTo (QgsWkbTypes::Type type) |
Converts the geometry to a specified type. More... | |
bool | is3D () const |
Returns true if the geometry is 3D and contains a z-value. More... | |
bool | isMeasure () const |
Returns true if the geometry contains m values. 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... | |
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 | |
QgsRectangle | calculateBoundingBox () const override |
Default calculator for the minimal bounding box for the geometry. More... | |
Protected Member Functions inherited from QgsCurve | |
int | childCount () const override |
Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e. More... | |
QgsPoint | childPoint (int index) const override |
Returns point at index (for geometries without child geometries - i.e. More... | |
void | clearCache () const override |
Clears any cached parameters associated with the geometry, e.g., bounding boxes. More... | |
bool | snapToGridPrivate (double hSpacing, double vSpacing, double dSpacing, double mSpacing, const QVector< double > &srcX, const QVector< double > &srcY, const QVector< double > &srcZ, const QVector< double > &srcM, QVector< double > &outX, QVector< double > &outY, QVector< double > &outZ, QVector< double > &outM) const |
Helper function for QgsCurve subclasses to snap to grids. More... | |
Protected Member Functions inherited from QgsAbstractGeometry | |
virtual 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 | 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 |
QgsCircularString::QgsCircularString | ( | ) |
Definition at line 31 of file qgscircularstring.cpp.
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overridevirtual |
Adds a measure to the geometry, initialized to a preset value.
mValue | initial m-value for all nodes |
Implements QgsAbstractGeometry.
Definition at line 1086 of file qgscircularstring.cpp.
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overridevirtual |
Adds a curve to a painter path.
Implements QgsCurve.
Definition at line 632 of file qgscircularstring.cpp.
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overridevirtual |
Adds a z-dimension to the geometry, initialized to a preset value.
zValue | initial z-value for all nodes |
Implements QgsAbstractGeometry.
Definition at line 1068 of file qgscircularstring.cpp.
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overridevirtual |
Returns a GML2 representation of the geometry.
doc | DOM document |
precision | number of decimal places for coordinates |
ns | XML namespace |
Implements QgsAbstractGeometry.
Definition at line 304 of file qgscircularstring.cpp.
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overridevirtual |
Returns a GML3 representation of the geometry.
doc | DOM document |
precision | number of decimal places for coordinates |
ns | XML namespace |
Implements QgsAbstractGeometry.
Definition at line 312 of file qgscircularstring.cpp.
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overridevirtual |
Returns a GeoJSON representation of the geometry.
precision | number of decimal places for coordinates |
Implements QgsAbstractGeometry.
Definition at line 330 of file qgscircularstring.cpp.
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overridevirtual |
Returns a WKB representation of the geometry.
Implements QgsAbstractGeometry.
Definition at line 279 of file qgscircularstring.cpp.
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overridevirtual |
Returns a WKT representation of the geometry.
precision | number of decimal places for coordinates |
Implements QgsAbstractGeometry.
Definition at line 295 of file qgscircularstring.cpp.
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overrideprotectedvirtual |
Default calculator for the minimal bounding box for the geometry.
Derived classes should override this method if a more efficient bounding box calculation is available.
Reimplemented from QgsAbstractGeometry.
Definition at line 96 of file qgscircularstring.cpp.
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Cast the geom to a QgsCircularString.
Should be used by qgsgeometry_cast<QgsCircularString *>( geometry ).
Definition at line 108 of file qgscircularstring.h.
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overridevirtual |
Clears the geometry, ie reset it to a null geometry.
Implements QgsAbstractGeometry.
Definition at line 86 of file qgscircularstring.cpp.
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overridevirtual |
Clones the geometry by performing a deep copy.
Implements QgsCurve.
Definition at line 81 of file qgscircularstring.cpp.
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Searches for the closest segment of the geometry to a given point.
pt | specifies the point to find closest segment to |
segmentPt | storage for the closest point within the geometry |
vertexAfter | storage for the ID of the vertex at the end of the closest segment |
leftOf | indicates whether the point lies on the left side of the geometry (-1 if point is to the left of the geometry, +1 if the point is to the right of the geometry, or 0 for cases where left/right could not be determined, e.g. point exactly on a line) false if point is to right of segment) |
epsilon | epsilon for segment snapping |
Implements QgsAbstractGeometry.
Definition at line 781 of file qgscircularstring.cpp.
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overridevirtual |
Creates a new geometry with the same class and same WKB type as the original and transfers ownership.
To create it, the geometry is default constructed and then the WKB is changed.
Implements QgsAbstractGeometry.
Definition at line 64 of file qgscircularstring.cpp.
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overridevirtual |
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)
Implements QgsCurve.
Definition at line 373 of file qgscircularstring.cpp.
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overridevirtual |
Deletes a vertex within the geometry.
position | vertex id for vertex to delete |
Implements QgsAbstractGeometry.
Definition at line 737 of file qgscircularstring.cpp.
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overridevirtual |
Returns the inherent dimension of the geometry.
For example, this is 0 for a point geometry, 1 for a linestring and 2 for a polygon.
Implements QgsAbstractGeometry.
Definition at line 76 of file qgscircularstring.cpp.
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overridevirtual |
Draws the geometry using the specified QPainter.
p | destination QPainter |
Implements QgsAbstractGeometry.
Definition at line 577 of file qgscircularstring.cpp.
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overridevirtual |
Draws the curve as a polygon on the specified QPainter.
p | destination QPainter |
Implements QgsCurve.
Definition at line 680 of file qgscircularstring.cpp.
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overridevirtual |
Drops any measure values which exist in the geometry.
Implements QgsAbstractGeometry.
Definition at line 1116 of file qgscircularstring.cpp.
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overridevirtual |
Drops any z-dimensions which exist in the geometry.
Implements QgsAbstractGeometry.
Definition at line 1104 of file qgscircularstring.cpp.
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overridevirtual |
Returns the end point of the curve.
Implements QgsCurve.
Definition at line 364 of file qgscircularstring.cpp.
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overridevirtual |
Checks whether this curve exactly equals another curve.
Implements QgsCurve.
Definition at line 36 of file qgscircularstring.cpp.
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overridevirtual |
Sets the geometry from a WKB string.
After successful read the wkb argument will be at the position where the reading has stopped.
Implements QgsAbstractGeometry.
Definition at line 226 of file qgscircularstring.cpp.
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Sets the geometry from a WKT string.
Implements QgsAbstractGeometry.
Definition at line 265 of file qgscircularstring.cpp.
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overridevirtual |
Returns a unique string representing the geometry type.
Implements QgsAbstractGeometry.
Definition at line 71 of file qgscircularstring.cpp.
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overridevirtual |
Returns true if the geometry contains curved segments.
Reimplemented from QgsAbstractGeometry.
Definition at line 892 of file qgscircularstring.cpp.
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overridevirtual |
Inserts a vertex into the geometry.
position | vertex id for position of inserted vertex |
vertex | vertex to insert |
Implements QgsAbstractGeometry.
Definition at line 685 of file qgscircularstring.cpp.
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overridevirtual |
Returns true if the geometry is empty.
Reimplemented from QgsAbstractGeometry.
Definition at line 338 of file qgscircularstring.cpp.
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overridevirtual |
Returns the length of the geometry.
Reimplemented from QgsAbstractGeometry.
Definition at line 344 of file qgscircularstring.cpp.
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overridevirtual |
Moves a vertex within the geometry.
position | vertex id for vertex to move |
newPos | new position of vertex |
Implements QgsAbstractGeometry.
Definition at line 716 of file qgscircularstring.cpp.
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overridevirtual |
Returns the number of points in the curve.
Implements QgsCurve.
Definition at line 452 of file qgscircularstring.cpp.
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overridevirtual |
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 |
Implements QgsCurve.
Definition at line 820 of file qgscircularstring.cpp.
QgsPoint QgsCircularString::pointN | ( | int | i | ) | const |
Returns the point at index i within the circular string.
Definition at line 457 of file qgscircularstring.cpp.
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overridevirtual |
Returns a list of points within the curve.
Implements QgsCurve.
Definition at line 510 of file qgscircularstring.cpp.
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overridevirtual |
Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry.
The epsilon parameter specifies the tolerance for coordinates when determining that vertices are identical.
By default, z values are not considered when detecting duplicate nodes. E.g. two nodes with the same x and y coordinate but different z values will still be considered duplicate and one will be removed. If useZValues is true, then the z values are also tested and nodes with the same x and y but different z will be maintained.
Note that duplicate nodes are not tested between different parts of a multipart geometry. E.g. a multipoint geometry with overlapping points will not be changed by this method.
The function will return true if nodes were removed, or false if no duplicate nodes were found.
Implements QgsAbstractGeometry.
Definition at line 401 of file qgscircularstring.cpp.
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overridevirtual |
Returns a reversed copy of the curve, where the direction of the curve has been flipped.
Implements QgsCurve.
Definition at line 1052 of file qgscircularstring.cpp.
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overridevirtual |
Returns the length of the segment of the geometry which begins at startVertex.
Implements QgsAbstractGeometry.
Definition at line 1035 of file qgscircularstring.cpp.
void QgsCircularString::setPoints | ( | const QgsPointSequence & | points | ) |
Sets the circular string's points.
Definition at line 520 of file qgscircularstring.cpp.
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overridevirtual |
Makes a new geometry with all the points or vertices snapped to the closest point of the grid.
Ownership is transferred to the caller.
If the gridified geometry could not be calculated a nullptr will be returned. It may generate an invalid geometry (in some corner cases). It can also be thought as rounding the edges and it may be useful for removing errors. Example:
In this case we use a 2D grid of 1x1 to gridify. In this case, it can be thought like rounding the x and y of all the points/vertices to full units (remove all decimals).
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. |
Implements QgsAbstractGeometry.
Definition at line 388 of file qgscircularstring.cpp.
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overridevirtual |
Returns the starting point of the curve.
Implements QgsCurve.
Definition at line 355 of file qgscircularstring.cpp.
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overridevirtual |
Sums up the area of the curve by iterating over the vertices (shoelace formula).
Implements QgsCurve.
Definition at line 831 of file qgscircularstring.cpp.
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overridevirtual |
Transforms the geometry using a coordinate transform.
ct | coordinate transform |
d | transformation direction |
transformZ | set to true to also transform z coordinates. This requires that the z coordinates in the geometry represent height relative to the vertical datum of the source CRS (generally ellipsoidal heights) and are expressed in its vertical units (generally meters). If false, then z coordinates will not be changed by the transform. |
Implements QgsAbstractGeometry.
Definition at line 584 of file qgscircularstring.cpp.
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overridevirtual |
Transforms the x and y components of the geometry using a QTransform object t.
Optionally, the geometry's z values can be scaled via zScale and translated via zTranslate. Similarly, m-values can be scaled via mScale and translated via mTranslate.
Implements QgsAbstractGeometry.
Definition at line 608 of file qgscircularstring.cpp.
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overridevirtual |
Returns approximate angle at a vertex.
This is usually the average angle between adjacent segments, and can be pictured as the orientation of a line following the curvature of the geometry at the specified vertex.
vertex | the vertex id |
Implements QgsAbstractGeometry.
Definition at line 978 of file qgscircularstring.cpp.
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overridevirtual |
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 |
Implements QgsCurve.
Definition at line 494 of file qgscircularstring.cpp.
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overridevirtual |
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 |
Implements QgsCurve.
Definition at line 502 of file qgscircularstring.cpp.