QGIS API Documentation  3.21.0-Master (909859188c)
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QgsDualEdgeTriangulation Class Reference

DualEdgeTriangulation is an implementation of a triangulation class based on the dual edge data structure. More...

#include <qgsdualedgetriangulation.h>

Inheritance diagram for QgsDualEdgeTriangulation:
Inheritance graph
[legend]

Public Member Functions

 QgsDualEdgeTriangulation ()
 
 QgsDualEdgeTriangulation (int nop)
 Constructor with a number of points to reserve. More...
 
 ~QgsDualEdgeTriangulation () override
 
void addLine (const QVector< QgsPoint > &points, QgsInterpolator::SourceType lineType) override
 Adds a line (e.g. More...
 
int addPoint (const QgsPoint &p) override
 Adds a point to the triangulation. More...
 
bool calcNormal (double x, double y, QgsPoint &result) override
 Calculates the normal at a point on the surface. More...
 
bool calcPoint (double x, double y, QgsPoint &result) override
 Calculates x-, y and z-value of the point on the surface and assigns it to 'result'. More...
 
void eliminateHorizontalTriangles () override
 Eliminates the horizontal triangles by swapping or by insertion of new points. More...
 
int oppositePoint (int p1, int p2) override
 Returns the number of the point opposite to the triangle points p1, p2 (which have to be on a halfedge). More...
 
void performConsistencyTest () override
 Performs a consistency check, remove this later. More...
 
QgsPointpoint (int i) const override
 Draws the points, edges and the forced lines. More...
 
bool pointInside (double x, double y) override
 Returns true, if the point with coordinates x and y is inside the convex hull and false otherwise. More...
 
QList< int > pointsAroundEdge (double x, double y) override
 Returns a value list with the numbers of the four points, which would be affected by an edge swap. This function is e.g. needed by NormVecDecorator to know the points, for which the normals have to be recalculated. The returned ValueList has to be deleted by the code which calls the method. More...
 
int pointsCount () const override
 Returns the number of points. More...
 
void ruppertRefinement () override
 Adds points to make the triangles better shaped (algorithm of ruppert) More...
 
bool saveTriangulation (QgsFeatureSink *sink, QgsFeedback *feedback=nullptr) const override
 Saves the triangulation features to a feature sink. More...
 
void setForcedCrossBehavior (QgsTriangulation::ForcedCrossBehavior b) override
 Sets the behavior of the triangulation in case of crossing forced lines. More...
 
void setTriangleInterpolator (TriangleInterpolator *interpolator) override
 Sets an interpolator object. More...
 
QList< int > surroundingTriangles (int pointno) override
 Returns a value list with the information of the triangles surrounding (counterclockwise) a point. More...
 
bool swapEdge (double x, double y) override
 Swaps the edge which is closest to the point with x and y coordinates (if this is possible) More...
 
bool triangleVertices (double x, double y, QgsPoint &p1, int &n1, QgsPoint &p2, int &n2, QgsPoint &p3, int &n3) override
 Finds out in which triangle the point with coordinates x and y is and assigns the numbers of the vertices to 'n1', 'n2' and 'n3' and the vertices to 'p1', 'p2' and 'p3'. More...
 
bool triangleVertices (double x, double y, QgsPoint &p1, QgsPoint &p2, QgsPoint &p3) override
 Finds out, in which triangle the point with coordinates x and y is and assigns the points at the vertices to 'p1', 'p2' and 'p3. More...
 
virtual QgsMesh triangulationToMesh (QgsFeedback *feedback=nullptr) const override
 Returns a QgsMesh corresponding to the triangulation. More...
 
double xMax () const override
 Returns the largest x-coordinate value of the bounding box. More...
 
double xMin () const override
 Returns the smallest x-coordinate value of the bounding box. More...
 
double yMax () const override
 Returns the largest y-coordinate value of the bounding box. More...
 
double yMin () const override
 Returns the smallest x-coordinate value of the bounding box. More...
 
- Public Member Functions inherited from QgsTriangulation
virtual ~QgsTriangulation ()=default
 

Friends

class TestQgsInterpolator
 

Additional Inherited Members

- Public Types inherited from QgsTriangulation
enum  ForcedCrossBehavior { SnappingTypeVertex , DeleteFirst , InsertVertex }
 Enumeration describing the behavior, if two forced lines cross. More...
 
- Static Public Member Functions inherited from QgsTriangulation
static QgsFields triangulationFields ()
 Returns the fields output by features when calling saveTriangulation(). More...
 

Detailed Description

DualEdgeTriangulation is an implementation of a triangulation class based on the dual edge data structure.

Note
Not available in Python bindings.
Since
QGIS 3.16

Definition at line 49 of file qgsdualedgetriangulation.h.

Constructor & Destructor Documentation

◆ QgsDualEdgeTriangulation() [1/2]

QgsDualEdgeTriangulation::QgsDualEdgeTriangulation ( )
inline

Definition at line 183 of file qgsdualedgetriangulation.h.

◆ QgsDualEdgeTriangulation() [2/2]

QgsDualEdgeTriangulation::QgsDualEdgeTriangulation ( int  nop)
inline

Constructor with a number of points to reserve.

Definition at line 189 of file qgsdualedgetriangulation.h.

◆ ~QgsDualEdgeTriangulation()

QgsDualEdgeTriangulation::~QgsDualEdgeTriangulation ( )
override

Definition at line 50 of file qgsdualedgetriangulation.cpp.

Member Function Documentation

◆ addLine()

void QgsDualEdgeTriangulation::addLine ( const QVector< QgsPoint > &  points,
QgsInterpolator::SourceType  lineType 
)
overridevirtual

Adds a line (e.g.

a break-, structure- or an isoline) to the triangulation, by specifying a list of source points.

Implements QgsTriangulation.

Definition at line 91 of file qgsdualedgetriangulation.cpp.

◆ addPoint()

int QgsDualEdgeTriangulation::addPoint ( const QgsPoint point)
overridevirtual

Adds a point to the triangulation.

The point should have a z-value matching the value to interpolate.

Implements QgsTriangulation.

Definition at line 123 of file qgsdualedgetriangulation.cpp.

◆ calcNormal()

bool QgsDualEdgeTriangulation::calcNormal ( double  x,
double  y,
QgsPoint result 
)
overridevirtual

Calculates the normal at a point on the surface.

Implements QgsTriangulation.

Definition at line 756 of file qgsdualedgetriangulation.cpp.

◆ calcPoint()

bool QgsDualEdgeTriangulation::calcPoint ( double  x,
double  y,
QgsPoint result 
)
overridevirtual

Calculates x-, y and z-value of the point on the surface and assigns it to 'result'.

Returns true in case of success and false in case of failure

Implements QgsTriangulation.

Definition at line 769 of file qgsdualedgetriangulation.cpp.

◆ eliminateHorizontalTriangles()

void QgsDualEdgeTriangulation::eliminateHorizontalTriangles ( )
overridevirtual

Eliminates the horizontal triangles by swapping or by insertion of new points.

Implements QgsTriangulation.

Definition at line 1770 of file qgsdualedgetriangulation.cpp.

◆ oppositePoint()

int QgsDualEdgeTriangulation::oppositePoint ( int  p1,
int  p2 
)
overridevirtual

Returns the number of the point opposite to the triangle points p1, p2 (which have to be on a halfedge).

Returns -1 if point is a virtual point. Returns -10 if point crosses over edges.

Implements QgsTriangulation.

Definition at line 1046 of file qgsdualedgetriangulation.cpp.

◆ performConsistencyTest()

void QgsDualEdgeTriangulation::performConsistencyTest ( )
overridevirtual

Performs a consistency check, remove this later.

Implements QgsTriangulation.

Definition at line 71 of file qgsdualedgetriangulation.cpp.

◆ point()

QgsPoint * QgsDualEdgeTriangulation::point ( int  i) const
inlineoverridevirtual

Draws the points, edges and the forced lines.

Returns a pointer to the point with number i

Implements QgsTriangulation.

Definition at line 200 of file qgsdualedgetriangulation.h.

◆ pointInside()

bool QgsDualEdgeTriangulation::pointInside ( double  x,
double  y 
)
overridevirtual

Returns true, if the point with coordinates x and y is inside the convex hull and false otherwise.

Implements QgsTriangulation.

Definition at line 2723 of file qgsdualedgetriangulation.cpp.

◆ pointsAroundEdge()

QList< int > QgsDualEdgeTriangulation::pointsAroundEdge ( double  x,
double  y 
)
overridevirtual

Returns a value list with the numbers of the four points, which would be affected by an edge swap. This function is e.g. needed by NormVecDecorator to know the points, for which the normals have to be recalculated. The returned ValueList has to be deleted by the code which calls the method.

Implements QgsTriangulation.

Definition at line 3142 of file qgsdualedgetriangulation.cpp.

◆ pointsCount()

int QgsDualEdgeTriangulation::pointsCount ( ) const
inlineoverridevirtual

Returns the number of points.

Implements QgsTriangulation.

Definition at line 195 of file qgsdualedgetriangulation.h.

◆ ruppertRefinement()

void QgsDualEdgeTriangulation::ruppertRefinement ( )
overridevirtual

Adds points to make the triangles better shaped (algorithm of ruppert)

Implements QgsTriangulation.

Definition at line 1859 of file qgsdualedgetriangulation.cpp.

◆ saveTriangulation()

bool QgsDualEdgeTriangulation::saveTriangulation ( QgsFeatureSink sink,
QgsFeedback feedback = nullptr 
) const
overridevirtual

Saves the triangulation features to a feature sink.

The sink must be setup to accept LineString features, with fields matching those returned by triangulationFields().

Returns
true in case of success
See also
triangulationFields()
Since
QGIS 3.0

Implements QgsTriangulation.

Definition at line 3200 of file qgsdualedgetriangulation.cpp.

◆ setForcedCrossBehavior()

void QgsDualEdgeTriangulation::setForcedCrossBehavior ( QgsTriangulation::ForcedCrossBehavior  b)
overridevirtual

Sets the behavior of the triangulation in case of crossing forced lines.

Implements QgsTriangulation.

Definition at line 1760 of file qgsdualedgetriangulation.cpp.

◆ setTriangleInterpolator()

void QgsDualEdgeTriangulation::setTriangleInterpolator ( TriangleInterpolator interpolator)
overridevirtual

Sets an interpolator object.

Implements QgsTriangulation.

Definition at line 1765 of file qgsdualedgetriangulation.cpp.

◆ surroundingTriangles()

QList< int > QgsDualEdgeTriangulation::surroundingTriangles ( int  pointno)
overridevirtual

Returns a value list with the information of the triangles surrounding (counterclockwise) a point.

Four integer values describe a triangle, the first three are the number of the half edges of the triangle and the fourth is -10, if the third (and most counterclockwise) edge is a breakline, and -20 otherwise. Any virtual point needs to have the number -1

Implements QgsTriangulation.

Definition at line 1080 of file qgsdualedgetriangulation.cpp.

◆ swapEdge()

bool QgsDualEdgeTriangulation::swapEdge ( double  x,
double  y 
)
overridevirtual

Swaps the edge which is closest to the point with x and y coordinates (if this is possible)

Implements QgsTriangulation.

Definition at line 3081 of file qgsdualedgetriangulation.cpp.

◆ triangleVertices() [1/2]

bool QgsDualEdgeTriangulation::triangleVertices ( double  x,
double  y,
QgsPoint p1,
int &  n1,
QgsPoint p2,
int &  n2,
QgsPoint p3,
int &  n3 
)
overridevirtual

Finds out in which triangle the point with coordinates x and y is and assigns the numbers of the vertices to 'n1', 'n2' and 'n3' and the vertices to 'p1', 'p2' and 'p3'.

Implements QgsTriangulation.

Definition at line 1116 of file qgsdualedgetriangulation.cpp.

◆ triangleVertices() [2/2]

bool QgsDualEdgeTriangulation::triangleVertices ( double  x,
double  y,
QgsPoint p1,
QgsPoint p2,
QgsPoint p3 
)
overridevirtual

Finds out, in which triangle the point with coordinates x and y is and assigns the points at the vertices to 'p1', 'p2' and 'p3.

Implements QgsTriangulation.

Definition at line 1224 of file qgsdualedgetriangulation.cpp.

◆ triangulationToMesh()

QgsMesh QgsDualEdgeTriangulation::triangulationToMesh ( QgsFeedback feedback = nullptr) const
overridevirtual

Returns a QgsMesh corresponding to the triangulation.

Since
QGIS 3.16

Implements QgsTriangulation.

Definition at line 3263 of file qgsdualedgetriangulation.cpp.

◆ xMax()

double QgsDualEdgeTriangulation::xMax ( ) const
inlineoverridevirtual

Returns the largest x-coordinate value of the bounding box.

Implements QgsTriangulation.

Definition at line 72 of file qgsdualedgetriangulation.h.

◆ xMin()

double QgsDualEdgeTriangulation::xMin ( ) const
inlineoverridevirtual

Returns the smallest x-coordinate value of the bounding box.

Implements QgsTriangulation.

Definition at line 74 of file qgsdualedgetriangulation.h.

◆ yMax()

double QgsDualEdgeTriangulation::yMax ( ) const
inlineoverridevirtual

Returns the largest y-coordinate value of the bounding box.

Implements QgsTriangulation.

Definition at line 76 of file qgsdualedgetriangulation.h.

◆ yMin()

double QgsDualEdgeTriangulation::yMin ( ) const
inlineoverridevirtual

Returns the smallest x-coordinate value of the bounding box.

Implements QgsTriangulation.

Definition at line 78 of file qgsdualedgetriangulation.h.

Friends And Related Function Documentation

◆ TestQgsInterpolator

friend class TestQgsInterpolator
friend

Definition at line 178 of file qgsdualedgetriangulation.h.


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