QGIS API Documentation
3.10.0-A Coruña (6c816b4204)
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Line string geometry type, with support for z-dimension and m-values. More...
#include <qgslinestring.h>
Public Member Functions | |
QgsLineString () | |
QgsLineString (const QVector< QgsPoint > &points) | |
Construct a linestring from a vector of points. More... | |
QgsLineString (const QVector< double > &x, const QVector< double > &y, const QVector< double > &z=QVector< double >(), const QVector< double > &m=QVector< double >(), bool is25DType=false) | |
Construct a linestring from arrays of coordinates. More... | |
QgsLineString (const QgsPoint &p1, const QgsPoint &p2) | |
Constructs a linestring with a single segment from p1 to p2. More... | |
QgsLineString (const QVector< QgsPointXY > &points) | |
Construct a linestring from list of points. More... | |
QgsLineString (const QgsLineSegment2D &segment) | |
Construct a linestring from a single 2d line segment. More... | |
bool | addMValue (double mValue=0) override |
Adds a measure to the geometry, initialized to a preset value. More... | |
void | addToPainterPath (QPainterPath &path) const override |
Adds a curve to a painter path. More... | |
void | addVertex (const QgsPoint &pt) |
Adds a new vertex to the end of the line string. More... | |
bool | addZValue (double zValue=0) override |
Adds a z-dimension to the geometry, initialized to a preset value. More... | |
void | append (const QgsLineString *line) |
Appends the contents of another line string to the end of this line string. More... | |
QDomElement | asGml2 (QDomDocument &doc, int precision=17, const QString &ns="gml", QgsAbstractGeometry::AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const override |
Returns a GML2 representation of the geometry. More... | |
QDomElement | asGml3 (QDomDocument &doc, int precision=17, const QString &ns="gml", QgsAbstractGeometry::AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const override |
Returns a GML3 representation of the geometry. More... | |
json | asJsonObject (int precision=17) const override |
Returns a json object representation of the geometry. More... | |
QPolygonF | asQPolygonF () const override |
Returns a QPolygonF representing the points. 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 QgsLineString * | cast (const QgsAbstractGeometry *geom) const |
Cast the geom to a QgsLineString. More... | |
QgsPoint | centroid () const override |
Returns the centroid of the geometry. More... | |
void | clear () override |
Clears the geometry, ie reset it to a null geometry. More... | |
QgsLineString * | clone () const override |
Clones the geometry by performing a deep copy. More... | |
void | close () |
Closes the line string by appending the first point to the end of the line, if it is not already closed. More... | |
double | closestSegment (const QgsPoint &pt, QgsPoint &segmentPt, QgsVertexId &vertexAfter, int *leftOf=nullptr, double epsilon=4 *std::numeric_limits< double >::epsilon()) const override |
Searches for the closest segment of the geometry to a given point. More... | |
bool | convertTo (QgsWkbTypes::Type type) override |
Converts the geometry to a specified type. More... | |
QgsLineString * | createEmptyWithSameType () const override |
Creates a new geometry with the same class and same WKB type as the original and transfers ownership. More... | |
QgsLineString * | curveSubstring (double startDistance, double endDistance) const override |
Returns a new curve representing a substring of this curve. 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... | |
void | extend (double startDistance, double endDistance) |
Extends the line geometry by extrapolating out the start or end of the line by a specified distance. More... | |
void | filterVertices (const std::function< bool(const QgsPoint &) > &filter) override |
Filters the vertices from the geometry in place, removing any which do not return true for the filter function check. More... | |
bool | fromWkb (QgsConstWkbPtr &wkb) override |
Sets the geometry from a WKB string. More... | |
bool | fromWkt (const QString &wkt) override |
Sets the geometry from a WKT string. More... | |
QString | geometryType () const override |
Returns a unique string representing the geometry type. More... | |
bool | insertVertex (QgsVertexId position, const QgsPoint &vertex) override |
Inserts a vertex into the geometry. More... | |
QgsPoint * | interpolatePoint (double distance) const override |
Returns an interpolated point on the curve at the specified distance. More... | |
bool | isEmpty () const override |
Returns true if the geometry is empty. More... | |
double | length () const override |
Returns the planar, 2-dimensional length of the geometry. More... | |
double | length3D () const |
Returns the length in 3D world of the line string. More... | |
double | mAt (int index) const |
Returns the m value of the specified node in the line string. More... | |
const double * | mData () const |
Returns a const pointer to the m vertex data, or nullptr if the linestring does not have m values. More... | |
bool | moveVertex (QgsVertexId position, const QgsPoint &newPos) override |
Moves a vertex within the geometry. More... | |
int | nCoordinates () const override |
Returns the number of nodes contained in 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 specified point from inside the line string. More... | |
void | points (QgsPointSequence &pt) const override |
Returns a list of points within the curve. More... | |
bool | removeDuplicateNodes (double epsilon=4 *std::numeric_limits< double >::epsilon(), bool useZValues=false) override |
Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry. More... | |
QgsLineString * | 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 | setMAt (int index, double m) |
Sets the m value of the specified node in the line string. More... | |
void | setPoints (const QgsPointSequence &points) |
Resets the line string to match the specified list of points. More... | |
void | setXAt (int index, double x) |
Sets the x-coordinate of the specified node in the line string. More... | |
void | setYAt (int index, double y) |
Sets the y-coordinate of the specified node in the line string. More... | |
void | setZAt (int index, double z) |
Sets the z-coordinate of the specified node in the line string. More... | |
QgsLineString * | 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 | swapXy () override |
Swaps the x and y coordinates from the geometry. More... | |
QgsCompoundCurve * | toCurveType () const override |
Returns the geometry converted to the more generic curve type QgsCompoundCurve. More... | |
void | transform (const QgsCoordinateTransform &ct, QgsCoordinateTransform::TransformDirection d=QgsCoordinateTransform::ForwardTransform, bool transformZ=false) override SIP_THROW(QgsCsException) |
Transforms the geometry using a coordinate transform. More... | |
void | transform (const QTransform &t, double zTranslate=0.0, double zScale=1.0, double mTranslate=0.0, double mScale=1.0) override |
Transforms the x and y components of the geometry using a QTransform object t. More... | |
void | transformVertices (const std::function< QgsPoint(const QgsPoint &) > &transform) override |
Transforms the vertices from the geometry in place, applying the transform function to every vertex. More... | |
double | vertexAngle (QgsVertexId vertex) const override |
Returns approximate angle at a vertex. More... | |
double | xAt (int index) const override |
Returns the x-coordinate of the specified node in the line string. More... | |
const double * | xData () const |
Returns a const pointer to the x vertex data. More... | |
double | yAt (int index) const override |
Returns the y-coordinate of the specified node in the line string. More... | |
const double * | yData () const |
Returns a const pointer to the y vertex data. More... | |
double | zAt (int index) const |
Returns the z-coordinate of the specified node in the line string. More... | |
const double * | zData () const |
Returns a const pointer to the z vertex data, or nullptr if the linestring does not have z values. More... | |
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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... | |
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 | isValid (QString &error, int flags=0) const override |
Checks validity of the geometry, and returns true if the geometry is valid. More... | |
bool | nextVertex (QgsVertexId &id, QgsPoint &vertex) const override |
Returns next vertex id and coordinates. More... | |
bool | operator!= (const QgsAbstractGeometry &other) const override |
bool | operator== (const QgsAbstractGeometry &other) const override |
Orientation | orientation () const |
Returns the curve's orientation, e.g. More... | |
int | partCount () const override |
Returns count of parts contained in the geometry. More... | |
int | ringCount (int part=0) const override |
Returns the number of rings of which this geometry is built. More... | |
QgsCurve * | segmentize (double tolerance=M_PI_2/90, SegmentationToleranceType toleranceType=MaximumAngle) const override |
Returns a geometry without curves. More... | |
double | sinuosity () const |
Returns the curve sinuosity, which is the ratio of the curve length() to curve straightDistance2d(). More... | |
double | straightDistance2d () const |
Returns the straight distance of the curve, i.e. 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... | |
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QgsAbstractGeometry ()=default | |
Constructor for QgsAbstractGeometry. More... | |
QgsAbstractGeometry (const QgsAbstractGeometry &geom) | |
virtual | ~QgsAbstractGeometry ()=default |
virtual double | area () const |
Returns the planar, 2-dimensional area of the geometry. More... | |
QString | asJson (int precision=17) |
Returns a GeoJSON representation of the geometry as a QString. More... | |
const_part_iterator | const_parts_begin () const |
Returns STL-style iterator pointing to the const first part of the geometry. More... | |
const_part_iterator | const_parts_end () const |
Returns STL-style iterator pointing to the imaginary const part after the last part of the geometry. More... | |
virtual bool | hasCurvedSegments () const |
Returns true if the geometry contains curved segments. 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... | |
QgsAbstractGeometry & | operator= (const QgsAbstractGeometry &geom) |
QgsGeometryConstPartIterator | parts () const |
Returns Java-style iterator for traversal of parts of the geometry. More... | |
QgsGeometryPartIterator | parts () |
Returns Java-style iterator for traversal of parts of the geometry. More... | |
part_iterator | parts_begin () |
Returns STL-style iterator pointing to the first part of the geometry. More... | |
part_iterator | parts_end () |
Returns STL-style iterator pointing to the imaginary part after the last part of the geometry. More... | |
virtual double | perimeter () const |
Returns the planar, 2-dimensional perimeter of the geometry. More... | |
QgsVertexIterator | vertices () const |
Returns a read-only, Java-style iterator for traversal of vertices of all the geometry, including all geometry parts and rings. More... | |
vertex_iterator | vertices_begin () const |
Returns STL-style iterator pointing to the first vertex of the geometry. More... | |
vertex_iterator | vertices_end () const |
Returns STL-style iterator pointing to the imaginary vertex after the last vertex of the geometry. More... | |
QgsWkbTypes::Type | wkbType () const |
Returns the WKB type of the geometry. More... | |
QString | wktTypeStr () const |
Returns the WKT type string of the geometry. More... | |
Static Public Member Functions | |
static QgsLineString * | fromBezierCurve (const QgsPoint &start, const QgsPoint &controlPoint1, const QgsPoint &controlPoint2, const QgsPoint &end, int segments=30) |
Returns a new linestring created by segmentizing the bezier curve between start and end, with the specified control points. More... | |
static QgsLineString * | fromQPolygonF (const QPolygonF &polygon) |
Returns a new linestring from a QPolygonF polygon input. More... | |
Protected Member Functions | |
QgsRectangle | calculateBoundingBox () const override |
Default calculator for the minimal bounding box for the geometry. More... | |
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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... | |
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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... | |
Friends | |
class | QgsPolygon |
class | QgsTriangle |
Additional Inherited Members | |
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enum | Orientation { Clockwise, CounterClockwise } |
Curve orientation. More... | |
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enum | AxisOrder { XY = 0, YX } |
Axis order for GML generation. More... | |
enum | SegmentationToleranceType { MaximumAngle = 0, MaximumDifference } |
Segmentation tolerance as maximum angle or maximum difference between approximation and circle. More... | |
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QgsWkbTypes::Type | mWkbType = QgsWkbTypes::Unknown |
Line string geometry type, with support for z-dimension and m-values.
Definition at line 43 of file qgslinestring.h.
QgsLineString::QgsLineString | ( | ) |
Definition at line 42 of file qgslinestring.cpp.
QgsLineString::QgsLineString | ( | const QVector< QgsPoint > & | points | ) |
Construct a linestring from a vector of points.
Z and M type will be set based on the type of the first point in the vector.
Definition at line 47 of file qgslinestring.cpp.
QgsLineString::QgsLineString | ( | const QVector< double > & | x, |
const QVector< double > & | y, | ||
const QVector< double > & | z = QVector<double>() , |
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const QVector< double > & | m = QVector<double>() , |
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bool | is25DType = false |
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Construct a linestring from arrays of coordinates.
If the z or m arrays are non-empty then the resultant linestring will have z and m types accordingly. This constructor is more efficient then calling setPoints() or repeatedly calling addVertex()
If the z vector is filled, then the geometry type will either be a LineStringZ(M) or LineString25D depending on the is25DType argument. If is25DType is true
(and the m vector is unfilled) then the created Linestring will be a LineString25D type. Otherwise, the LineString will be LineStringZ (or LineStringZM) type.
Definition at line 84 of file qgslinestring.cpp.
Constructs a linestring with a single segment from p1 to p2.
Definition at line 130 of file qgslinestring.cpp.
QgsLineString::QgsLineString | ( | const QVector< QgsPointXY > & | points | ) |
Construct a linestring from list of points.
This constructor is more efficient then calling setPoints() or repeatedly calling addVertex()
Definition at line 155 of file qgslinestring.cpp.
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explicit |
Construct a linestring from a single 2d line segment.
Definition at line 167 of file qgslinestring.cpp.
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overridevirtual |
Adds a measure to the geometry, initialized to a preset value.
mValue | initial m-value for all nodes |
true
on success Implements QgsAbstractGeometry.
Definition at line 1506 of file qgslinestring.cpp.
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overridevirtual |
Adds a curve to a painter path.
Implements QgsCurve.
Definition at line 1000 of file qgslinestring.cpp.
void QgsLineString::addVertex | ( | const QgsPoint & | pt | ) |
Adds a new vertex to the end of the line string.
pt | vertex to add |
Definition at line 1216 of file qgslinestring.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 |
true
on success Implements QgsAbstractGeometry.
Definition at line 1482 of file qgslinestring.cpp.
void QgsLineString::append | ( | const QgsLineString * | line | ) |
Appends the contents of another line string to the end of this line string.
line | line to append. Ownership is not transferred. |
Definition at line 759 of file qgslinestring.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 |
axisOrder | Axis order for generated GML |
Implements QgsAbstractGeometry.
Definition at line 481 of file qgslinestring.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 |
axisOrder | Axis order for generated GML |
Implements QgsAbstractGeometry.
Definition at line 496 of file qgslinestring.cpp.
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overridevirtual |
Returns a json object representation of the geometry.
Reimplemented from QgsAbstractGeometry.
Definition at line 510 of file qgslinestring.cpp.
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overridevirtual |
Returns a QPolygonF representing the points.
Reimplemented from QgsCurve.
Definition at line 366 of file qgslinestring.cpp.
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overridevirtual |
Returns a WKB representation of the geometry.
Implements QgsAbstractGeometry.
Definition at line 444 of file qgslinestring.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 466 of file qgslinestring.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 398 of file qgslinestring.cpp.
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inline |
Cast the geom to a QgsLineString.
Should be used by qgsgeometry_cast<QgsLineString *>( geometry ).
Definition at line 652 of file qgslinestring.h.
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overridevirtual |
Returns the centroid of the geometry.
Reimplemented from QgsAbstractGeometry.
Definition at line 1324 of file qgslinestring.cpp.
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overridevirtual |
Clears the geometry, ie reset it to a null geometry.
Implements QgsAbstractGeometry.
Definition at line 298 of file qgslinestring.cpp.
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overridevirtual |
Clones the geometry by performing a deep copy.
Implements QgsCurve.
Definition at line 293 of file qgslinestring.cpp.
void QgsLineString::close | ( | ) |
Closes the line string by appending the first point to the end of the line, if it is not already closed.
Definition at line 1414 of file qgslinestring.cpp.
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overridevirtual |
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 1236 of file qgslinestring.cpp.
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overridevirtual |
Converts the geometry to a specified type.
true
if conversion was successful Reimplemented from QgsAbstractGeometry.
Definition at line 1565 of file qgslinestring.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 1057 of file qgslinestring.cpp.
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overridevirtual |
Returns a new curve representing a substring of this curve.
The startDistance and endDistance arguments specify the length along the curve which the substring should start and end at. If the endDistance is greater than the total length of the curve then any "extra" length will be ignored.
If z or m values are present, the output z and m will be interpolated using the existing vertices' z or m values.
Implements QgsCurve.
Definition at line 899 of file qgslinestring.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 |
Implements QgsCurve.
Definition at line 587 of file qgslinestring.cpp.
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overridevirtual |
Deletes a vertex within the geometry.
position | vertex id for vertex to delete |
true
if delete was successful Implements QgsAbstractGeometry.
Definition at line 1183 of file qgslinestring.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 1069 of file qgslinestring.cpp.
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overridevirtual |
Draws the geometry using the specified QPainter.
p | destination QPainter |
Implements QgsAbstractGeometry.
Definition at line 995 of file qgslinestring.cpp.
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overridevirtual |
Draws the curve as a polygon on the specified QPainter.
p | destination QPainter |
Implements QgsCurve.
Definition at line 1019 of file qgslinestring.cpp.
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overridevirtual |
Drops any measure values which exist in the geometry.
true
if m-values were present and have been removed Implements QgsAbstractGeometry.
Definition at line 1548 of file qgslinestring.cpp.
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overridevirtual |
Drops any z-dimensions which exist in the geometry.
true
if Z values were present and have been removed Implements QgsAbstractGeometry.
Definition at line 1537 of file qgslinestring.cpp.
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overridevirtual |
Returns the end point of the curve.
Implements QgsCurve.
Definition at line 572 of file qgslinestring.cpp.
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overridevirtual |
Checks whether this curve exactly equals another curve.
Implements QgsCurve.
Definition at line 265 of file qgslinestring.cpp.
void QgsLineString::extend | ( | double | startDistance, |
double | endDistance | ||
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Extends the 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 1031 of file qgslinestring.cpp.
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overridevirtual |
Filters the vertices from the geometry in place, removing any which do not return true
for the filter function check.
Has no meaning when called on a single point geometry.
Depending on the filter used, this may result in an invalid geometry.
Reimplemented from QgsAbstractGeometry.
Definition at line 1585 of file qgslinestring.cpp.
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static |
Returns a new linestring created by segmentizing the bezier curve between start and end, with the specified control points.
The segments parameter controls how many line segments will be present in the returned linestring.
Any z or m values present in the input coordinates will be interpolated along with the x and y values.
Definition at line 184 of file qgslinestring.cpp.
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static |
Returns a new linestring from a QPolygonF polygon input.
Definition at line 245 of file qgslinestring.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 381 of file qgslinestring.cpp.
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overridevirtual |
Sets the geometry from a WKT string.
Implements QgsAbstractGeometry.
Definition at line 427 of file qgslinestring.cpp.
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overridevirtual |
Returns a unique string representing the geometry type.
Implements QgsAbstractGeometry.
Definition at line 1064 of file qgslinestring.cpp.
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overridevirtual |
Inserts a vertex into the geometry.
position | vertex id for position of inserted vertex |
vertex | vertex to insert |
true
if insert was successful Implements QgsAbstractGeometry.
Definition at line 1137 of file qgslinestring.cpp.
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overridevirtual |
Returns an interpolated point on the curve at the specified distance.
If z or m values are present, the output z and m will be interpolated using the existing vertices' z or m values.
If distance is negative, or is greater than the length of the curve, nullptr
will be returned.
Implements QgsCurve.
Definition at line 837 of file qgslinestring.cpp.
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Returns true
if the geometry is empty.
Reimplemented from QgsAbstractGeometry.
Definition at line 308 of file qgslinestring.cpp.
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Returns the planar, 2-dimensional length of the geometry.
Reimplemented from QgsAbstractGeometry.
Definition at line 527 of file qgslinestring.cpp.
double QgsLineString::length3D | ( | ) | const |
Returns the length in 3D world of the line string.
If it is not a 3D line string, return its 2D length.
Definition at line 541 of file qgslinestring.cpp.
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inline |
Returns the m value of the specified node in the line string.
index | index of node, where the first node in the line is 0 |
nan
if index is out of bounds or the line does not have m values Definition at line 320 of file qgslinestring.h.
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inline |
Returns a const pointer to the m vertex data, or nullptr
if the linestring does not have m values.
Definition at line 257 of file qgslinestring.h.
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Moves a vertex within the geometry.
position | vertex id for vertex to move |
newPos | new position of vertex |
true
if move was successful Implements QgsAbstractGeometry.
Definition at line 1163 of file qgslinestring.cpp.
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Returns the number of nodes contained in the geometry.
Reimplemented from QgsAbstractGeometry.
Definition at line 599 of file qgslinestring.cpp.
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Returns the number of points in the curve.
Implements QgsCurve.
Definition at line 594 of file qgslinestring.cpp.
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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 |
true
if node exists within the curve Implements QgsCurve.
Definition at line 1313 of file qgslinestring.cpp.
QgsPoint QgsLineString::pointN | ( | int | i | ) | const |
Returns the specified point from inside the line string.
i | index of point, starting at 0 for the first point |
Definition at line 604 of file qgslinestring.cpp.
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Returns a list of points within the curve.
Implements QgsCurve.
Definition at line 689 of file qgslinestring.cpp.
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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 326 of file qgslinestring.cpp.
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Returns a reversed copy of the curve, where the direction of the curve has been flipped.
Implements QgsCurve.
Definition at line 821 of file qgslinestring.cpp.
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Returns the length of the segment of the geometry which begins at startVertex.
Implements QgsAbstractGeometry.
Definition at line 1466 of file qgslinestring.cpp.
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inline |
Sets the m value of the specified node in the line string.
index | index of node, where the first node in the line is 0. Corresponding node must already exist in line string, and the line string must have m values. |
m | m value of node |
Definition at line 493 of file qgslinestring.h.
void QgsLineString::setPoints | ( | const QgsPointSequence & | points | ) |
Resets the line string to match the specified list of points.
The line string will inherit the dimensionality of the first point in the list.
points | new points for line string. If empty, line string will be cleared. |
Definition at line 700 of file qgslinestring.cpp.
void QgsLineString::setXAt | ( | int | index, |
double | x | ||
) |
Sets the x-coordinate of the specified node in the line string.
index | index of node, where the first node in the line is 0. Corresponding node must already exist in line string. |
x | x-coordinate of node |
Definition at line 669 of file qgslinestring.cpp.
void QgsLineString::setYAt | ( | int | index, |
double | y | ||
) |
Sets the y-coordinate of the specified node in the line string.
index | index of node, where the first node in the line is 0. Corresponding node must already exist in line string. |
y | y-coordinate of node |
Definition at line 676 of file qgslinestring.cpp.
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inline |
Sets the z-coordinate of the specified node in the line string.
index | index of node, where the first node in the line is 0. Corresponding node must already exist in line string, and the line string must have z-dimension. |
z | z-coordinate of node |
Definition at line 448 of file qgslinestring.h.
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Makes a new geometry with all the points or vertices snapped to the closest point of the grid.
Ownership is transferred to the caller.
If the gridified geometry could not be calculated nullptr
will be returned. It may generate an invalid geometry (in some corner cases). It can also be thought as rounding the edges and it may be useful for removing errors. Example:
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 313 of file qgslinestring.cpp.
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Returns the starting point of the curve.
Implements QgsCurve.
Definition at line 563 of file qgslinestring.cpp.
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Sums up the area of the curve by iterating over the vertices (shoelace formula).
Implements QgsCurve.
Definition at line 1368 of file qgslinestring.cpp.
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Swaps the x and y coordinates from the geometry.
This can be used to repair geometries which have accidentally had their latitude and longitude coordinates reversed.
Implements QgsAbstractGeometry.
Definition at line 1559 of file qgslinestring.cpp.
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Returns the geometry converted to the more generic curve type QgsCompoundCurve.
Reimplemented from QgsCurve.
Definition at line 1024 of file qgslinestring.cpp.
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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 1080 of file qgslinestring.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 1102 of file qgslinestring.cpp.
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overridevirtual |
Transforms the vertices from the geometry in place, applying the transform function to every vertex.
Depending on the transform used, this may result in an invalid geometry.
Transform functions are not permitted to alter the dimensionality of vertices. If a transform which adds (or removes) z/m values is desired, first call the corresponding addZValue() or addMValue() function to change the geometry's dimensionality and then transform.
Reimplemented from QgsAbstractGeometry.
Definition at line 1631 of file qgslinestring.cpp.
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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 1423 of file qgslinestring.cpp.
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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 653 of file qgslinestring.cpp.
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inline |
Returns a const pointer to the x vertex data.
Definition at line 217 of file qgslinestring.h.
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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 661 of file qgslinestring.cpp.
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inline |
Returns a const pointer to the y vertex data.
Definition at line 228 of file qgslinestring.h.
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inline |
Returns the z-coordinate of the specified node in the line string.
index | index of node, where the first node in the line is 0 |
nan
if index is out of bounds or the line does not have a z dimension Definition at line 274 of file qgslinestring.h.
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inline |
Returns a const pointer to the z vertex data, or nullptr
if the linestring does not have z values.
Definition at line 241 of file qgslinestring.h.
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friend |
Definition at line 776 of file qgslinestring.h.
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friend |
Definition at line 777 of file qgslinestring.h.