QGIS API Documentation
3.0.2-Girona (307d082)
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DualEdgeTriangulation is an implementation of a triangulation class based on the dual edge data structure. More...
#include <DualEdgeTriangulation.h>
Public Member Functions | |
DualEdgeTriangulation () | |
DualEdgeTriangulation (int nop, Triangulation *decorator) | |
~DualEdgeTriangulation () 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, Vector3D *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 | getNumberOfPoints () const override |
Returns the number of points. More... | |
int | getOppositePoint (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... | |
QgsPoint * | getPoint (int i) const override |
Draws the points, edges and the forced lines. More... | |
QList< int > * | getPointsAroundEdge (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... | |
QList< int > | getSurroundingTriangles (int pointno) override |
Returns a pointer to a value list with the information of the triangles surrounding (counterclockwise) a point. More... | |
bool | getTriangle (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 | getTriangle (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... | |
double | getXMax () const override |
Returns the largest x-coordinate value of the bounding box. More... | |
double | getXMin () const override |
Returns the smallest x-coordinate value of the bounding box. More... | |
double | getYMax () const override |
Returns the largest y-coordinate value of the bounding box. More... | |
double | getYMin () const override |
Returns the smallest x-coordinate value of the bounding box. More... | |
void | performConsistencyTest () override |
Performs a consistency check, remove this later. 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... | |
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 | setBreakEdgeColor (int r, int g, int b) override |
Sets the color of the breaklines. More... | |
void | setDecorator (Triangulation *d) |
void | setEdgeColor (int r, int g, int b) override |
Sets the color of the normal edges. More... | |
void | setForcedCrossBehavior (Triangulation::ForcedCrossBehavior b) override |
Sets the behavior of the triangulation in case of crossing forced lines. More... | |
void | setForcedEdgeColor (int r, int g, int b) override |
Sets the color of the forced edges. More... | |
void | setTriangleInterpolator (TriangleInterpolator *interpolator) override |
Sets an interpolator object. More... | |
bool | swapEdge (double x, double y) override |
Reads the dual edge structure of a taff file. More... | |
Public Member Functions inherited from Triangulation | |
virtual | ~Triangulation ()=default |
Protected Member Functions | |
int | baseEdgeOfPoint (int point) |
Returns the number of an edge which points to the point with number 'point' or -1 if there is an error. More... | |
int | baseEdgeOfTriangle (const QgsPoint &point) |
Returns the number of a HalfEdge from a triangle in which 'point' is in. If the number -10 is returned, this means, that 'point' is outside the convex hull. If -5 is returned, then numerical problems with the leftOfTest occurred (and the value of the possible edge is stored in the variable 'mUnstableEdge'. -20 means, that the inserted point is exactly on an edge (the number is stored in the variable 'mEdgeWithPoint'). -25 means, that the point is already in the triangulation (the number of the point is stored in the member 'mTwiceInsPoint'. If -100 is returned, this means that something else went wrong. More... | |
bool | checkSwap (unsigned int edge, unsigned int recursiveDeep) |
Checks, if 'edge' has to be swapped because of the empty circle criterion. If so, doSwap(...) is called. More... | |
void | doOnlySwap (unsigned int edge) |
Swaps 'edge' and does no recursiv testing. More... | |
void | doSwap (unsigned int edge, unsigned int recursiveDeep) |
Swaps 'edge' and test recursively for other swaps (delaunay criterion) More... | |
bool | edgeOnConvexHull (int edge) |
Returns true, if a half edge is on the convex hull and false otherwise. More... | |
void | evaluateInfluenceRegion (QgsPoint *point, int edge, QSet< int > &set) |
Function needed for the ruppert algorithm. Tests, if point is in the circle through both endpoints of edge and the endpoint of edge->dual->next->point. If so, the function calls itself recursively for edge->next and edge->next->next. Stops, if it finds a forced edge or a convex hull edge. More... | |
bool | halfEdgeBBoxTest (int edge, double xlowleft, double ylowleft, double xupright, double yupright) const |
Tests, if the bounding box of the halfedge with index i intersects the specified bounding box. The main purpose for this method is the drawing of the triangulation. More... | |
unsigned int | insertEdge (int dual, int next, int point, bool mbreak, bool forced) |
Inserts an edge and makes sure, everything is OK with the storage of the edge. The number of the HalfEdge is returned. More... | |
int | insertForcedSegment (int p1, int p2, QgsInterpolator::SourceType segmentType) |
Inserts a forced segment between the points with the numbers p1 and p2 into the triangulation and returns the number of a HalfEdge belonging to this forced edge or -100 in case of failure. More... | |
int | splitHalfEdge (int edge, float position) |
Inserts a new point on the halfedge with number 'edge'. The position can have a value from 0 to 1 (e.g. 0.5 would be in the middle). The return value is the number of the new inserted point. tin is the triangulation, which should be used to calculate the elevation of the inserted point. More... | |
double | swapMinAngle (int edge) const |
Calculates the minimum angle, which would be present, if the specified halfedge would be swapped. More... | |
bool | swapPossible (unsigned int edge) |
Returns true, if it is possible to swap an edge, otherwise false(concave quad or edge on (or outside) the convex hull) More... | |
void | triangulatePolygon (QList< int > *poly, QList< int > *free, int mainedge) |
Divides a polygon in a triangle and two polygons and calls itself recursively for these two polygons. 'poly' is a pointer to a list with the numbers of the edges of the polygon, 'free' is a pointer to a list of free halfedges, and 'mainedge' is the number of the edge, towards which the new triangle is inserted. Mainedge has to be the same as poly->begin(), otherwise the recursion does not work. More... | |
Protected Attributes | |
QColor | mBreakEdgeColor |
Color to paint the breaklines. More... | |
Triangulation * | mDecorator = nullptr |
Pointer to the decorator using this triangulation. It it is used directly, mDecorator equals this. More... | |
QColor | mEdgeColor |
Color to paint the normal edges. More... | |
unsigned int | mEdgeInside = 0 |
Number of an edge which does not point to the virtual point. It continuously updated for a fast search. More... | |
unsigned int | mEdgeOutside = 0 |
Number of an edge on the outside of the convex hull. It is updated in method 'baseEdgeOfTriangle' to enable insertion of points outside the convex hull. More... | |
unsigned int | mEdgeWithPoint = 0 |
If an inserted point is exactly on an existing edge, 'baseEdgeOfTriangle' returns -20 and sets the variable 'mEdgeWithPoint'. More... | |
Triangulation::ForcedCrossBehavior | mForcedCrossBehavior = Triangulation::DeleteFirst |
Member to store the behavior in case of crossing forced segments. More... | |
QColor | mForcedEdgeColor |
Color to paint the forced edges. More... | |
QVector< HalfEdge * > | mHalfEdge |
Stores pointers to the HalfEdges. More... | |
QVector< QgsPoint * > | mPointVector |
Stores pointers to all points in the triangulations (including the points contained in the lines) More... | |
TriangleInterpolator * | mTriangleInterpolator = nullptr |
Association to an interpolator object. More... | |
int | mTwiceInsPoint = 0 |
If a point has been inserted twice, its number is stored in this member. More... | |
unsigned int | mUnstableEdge = 0 |
If an instability occurs in 'baseEdgeOfTriangle', mUnstableEdge is set to the value of the current edge. More... | |
double | xMax = 0 |
X-coordinate of the upper right corner of the bounding box. More... | |
double | xMin = 0 |
X-coordinate of the lower left corner of the bounding box. More... | |
double | yMax = 0 |
Y-coordinate of the upper right corner of the bounding box. More... | |
double | yMin = 0 |
Y-coordinate of the lower left corner of the bounding box. More... | |
Static Protected Attributes | |
static const unsigned int | DEFAULT_STORAGE_FOR_HALF_EDGES = 300006 |
Default value for the number of storable HalfEdges at the beginning. More... | |
static const unsigned int | DEFAULT_STORAGE_FOR_POINTS = 100000 |
Default value for the number of storable points at the beginning. More... | |
static const int | MAX_BASE_ITERATIONS = 300000 |
Threshold for the leftOfTest to handle numerical instabilities. More... | |
Friends | |
class | TestQgsInterpolator |
Additional Inherited Members | |
Public Types inherited from Triangulation | |
enum | ForcedCrossBehavior { SnappingTypeVertex, DeleteFirst, InsertVertex } |
Enumeration describing the behavior, if two forced lines cross. More... | |
Static Public Member Functions inherited from Triangulation | |
static QgsFields | triangulationFields () |
Returns the fields output by features when calling saveTriangulation(). More... | |
DualEdgeTriangulation is an implementation of a triangulation class based on the dual edge data structure.
Definition at line 43 of file DualEdgeTriangulation.h.
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Definition at line 179 of file DualEdgeTriangulation.h.
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Definition at line 189 of file DualEdgeTriangulation.h.
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Definition at line 28 of file DualEdgeTriangulation.cpp.
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Adds a line (e.g.
a break-, structure- or an isoline) to the triangulation, by specifying a list of source points.
Implements Triangulation.
Definition at line 69 of file DualEdgeTriangulation.cpp.
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Adds a point to the triangulation.
The point should have a z-value matching the value to interpolate.
Implements Triangulation.
Definition at line 101 of file DualEdgeTriangulation.cpp.
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Returns the number of an edge which points to the point with number 'point' or -1 if there is an error.
Definition at line 372 of file DualEdgeTriangulation.cpp.
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Returns the number of a HalfEdge from a triangle in which 'point' is in. If the number -10 is returned, this means, that 'point' is outside the convex hull. If -5 is returned, then numerical problems with the leftOfTest occurred (and the value of the possible edge is stored in the variable 'mUnstableEdge'. -20 means, that the inserted point is exactly on an edge (the number is stored in the variable 'mEdgeWithPoint'). -25 means, that the point is already in the triangulation (the number of the point is stored in the member 'mTwiceInsPoint'. If -100 is returned, this means that something else went wrong.
Definition at line 444 of file DualEdgeTriangulation.cpp.
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Calculates the normal at a point on the surface.
Implements Triangulation.
Definition at line 621 of file DualEdgeTriangulation.cpp.
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Calculates x-, y and z-value of the point on the surface and assigns it to 'result'.
Returns true in case of success and flase in case of failure
Implements Triangulation.
Definition at line 634 of file DualEdgeTriangulation.cpp.
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Checks, if 'edge' has to be swapped because of the empty circle criterion. If so, doSwap(...) is called.
Definition at line 647 of file DualEdgeTriangulation.cpp.
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Swaps 'edge' and does no recursiv testing.
Definition at line 664 of file DualEdgeTriangulation.cpp.
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Swaps 'edge' and test recursively for other swaps (delaunay criterion)
Definition at line 682 of file DualEdgeTriangulation.cpp.
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Returns true, if a half edge is on the convex hull and false otherwise.
Definition at line 3136 of file DualEdgeTriangulation.cpp.
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Eliminates the horizontal triangles by swapping or by insertion of new points.
Implements Triangulation.
Definition at line 1535 of file DualEdgeTriangulation.cpp.
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Function needed for the ruppert algorithm. Tests, if point is in the circle through both endpoints of edge and the endpoint of edge->dual->next->point. If so, the function calls itself recursively for edge->next and edge->next->next. Stops, if it finds a forced edge or a convex hull edge.
Definition at line 3141 of file DualEdgeTriangulation.cpp.
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Returns the number of points.
Implements Triangulation.
Definition at line 199 of file DualEdgeTriangulation.h.
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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 Triangulation.
Definition at line 856 of file DualEdgeTriangulation.cpp.
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Draws the points, edges and the forced lines.
Returns a pointer to the point with number i
Implements Triangulation.
Definition at line 204 of file DualEdgeTriangulation.h.
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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 Triangulation.
Definition at line 2915 of file DualEdgeTriangulation.cpp.
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Returns a pointer to 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 Triangulation.
Definition at line 890 of file DualEdgeTriangulation.cpp.
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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 Triangulation.
Definition at line 926 of file DualEdgeTriangulation.cpp.
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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 Triangulation.
Definition at line 1034 of file DualEdgeTriangulation.cpp.
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Returns the largest x-coordinate value of the bounding box.
Implements Triangulation.
Definition at line 66 of file DualEdgeTriangulation.h.
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Returns the smallest x-coordinate value of the bounding box.
Implements Triangulation.
Definition at line 68 of file DualEdgeTriangulation.h.
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Returns the largest y-coordinate value of the bounding box.
Implements Triangulation.
Definition at line 70 of file DualEdgeTriangulation.h.
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Returns the smallest x-coordinate value of the bounding box.
Implements Triangulation.
Definition at line 72 of file DualEdgeTriangulation.h.
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Tests, if the bounding box of the halfedge with index i intersects the specified bounding box. The main purpose for this method is the drawing of the triangulation.
Definition at line 212 of file DualEdgeTriangulation.h.
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Inserts an edge and makes sure, everything is OK with the storage of the edge. The number of the HalfEdge is returned.
Definition at line 1132 of file DualEdgeTriangulation.cpp.
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Inserts a forced segment between the points with the numbers p1 and p2 into the triangulation and returns the number of a HalfEdge belonging to this forced edge or -100 in case of failure.
Definition at line 1140 of file DualEdgeTriangulation.cpp.
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Performs a consistency check, remove this later.
Implements Triangulation.
Definition at line 49 of file DualEdgeTriangulation.cpp.
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Returns true, if the point with coordinates x and y is inside the convex hull and false otherwise.
Implements Triangulation.
Definition at line 2488 of file DualEdgeTriangulation.cpp.
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Adds points to make the triangles better shaped (algorithm of ruppert)
Implements Triangulation.
Definition at line 1624 of file DualEdgeTriangulation.cpp.
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Saves the triangulation features to a feature sink.
The sink must be setup to accept LineString features, with fields matching those returned by triangulationFields().
Implements Triangulation.
Definition at line 2978 of file DualEdgeTriangulation.cpp.
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Sets the color of the breaklines.
Implements Triangulation.
Definition at line 1525 of file DualEdgeTriangulation.cpp.
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Definition at line 49 of file DualEdgeTriangulation.h.
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Sets the color of the normal edges.
Implements Triangulation.
Definition at line 1515 of file DualEdgeTriangulation.cpp.
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Sets the behavior of the triangulation in case of crossing forced lines.
Implements Triangulation.
Definition at line 1510 of file DualEdgeTriangulation.cpp.
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Sets the color of the forced edges.
Implements Triangulation.
Definition at line 1520 of file DualEdgeTriangulation.cpp.
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Sets an interpolator object.
Implements Triangulation.
Definition at line 1530 of file DualEdgeTriangulation.cpp.
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Inserts a new point on the halfedge with number 'edge'. The position can have a value from 0 to 1 (e.g. 0.5 would be in the middle). The return value is the number of the new inserted point. tin is the triangulation, which should be used to calculate the elevation of the inserted point.
Definition at line 3081 of file DualEdgeTriangulation.cpp.
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Reads the dual edge structure of a taff file.
Saves the dual edge structure to a taff file Swaps the edge which is closest to the point with x and y coordinates (if this is possible)
Implements Triangulation.
Definition at line 2854 of file DualEdgeTriangulation.cpp.
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Calculates the minimum angle, which would be present, if the specified halfedge would be swapped.
Definition at line 3041 of file DualEdgeTriangulation.cpp.
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Returns true, if it is possible to swap an edge, otherwise false(concave quad or edge on (or outside) the convex hull)
Definition at line 2314 of file DualEdgeTriangulation.cpp.
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Divides a polygon in a triangle and two polygons and calls itself recursively for these two polygons. 'poly' is a pointer to a list with the numbers of the edges of the polygon, 'free' is a pointer to a list of free halfedges, and 'mainedge' is the number of the edge, towards which the new triangle is inserted. Mainedge has to be the same as poly->begin(), otherwise the recursion does not work.
Definition at line 2351 of file DualEdgeTriangulation.cpp.
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Definition at line 174 of file DualEdgeTriangulation.h.
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Default value for the number of storable HalfEdges at the beginning.
Definition at line 116 of file DualEdgeTriangulation.h.
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Default value for the number of storable points at the beginning.
Definition at line 112 of file DualEdgeTriangulation.h.
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Threshold for the leftOfTest to handle numerical instabilities.
Security to prevent endless loops in 'baseEdgeOfTriangle'. It there are more iteration then this number, the point will not be inserted
Definition at line 138 of file DualEdgeTriangulation.h.
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Color to paint the breaklines.
Definition at line 128 of file DualEdgeTriangulation.h.
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Pointer to the decorator using this triangulation. It it is used directly, mDecorator equals this.
Definition at line 130 of file DualEdgeTriangulation.h.
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Color to paint the normal edges.
Definition at line 124 of file DualEdgeTriangulation.h.
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Number of an edge which does not point to the virtual point. It continuously updated for a fast search.
Definition at line 150 of file DualEdgeTriangulation.h.
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Number of an edge on the outside of the convex hull. It is updated in method 'baseEdgeOfTriangle' to enable insertion of points outside the convex hull.
Definition at line 152 of file DualEdgeTriangulation.h.
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If an inserted point is exactly on an existing edge, 'baseEdgeOfTriangle' returns -20 and sets the variable 'mEdgeWithPoint'.
Definition at line 154 of file DualEdgeTriangulation.h.
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Member to store the behavior in case of crossing forced segments.
Definition at line 122 of file DualEdgeTriangulation.h.
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Color to paint the forced edges.
Definition at line 126 of file DualEdgeTriangulation.h.
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Stores pointers to the HalfEdges.
Definition at line 118 of file DualEdgeTriangulation.h.
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Stores pointers to all points in the triangulations (including the points contained in the lines)
Definition at line 114 of file DualEdgeTriangulation.h.
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Association to an interpolator object.
Definition at line 120 of file DualEdgeTriangulation.h.
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If a point has been inserted twice, its number is stored in this member.
Definition at line 158 of file DualEdgeTriangulation.h.
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If an instability occurs in 'baseEdgeOfTriangle', mUnstableEdge is set to the value of the current edge.
Definition at line 156 of file DualEdgeTriangulation.h.
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X-coordinate of the upper right corner of the bounding box.
Definition at line 104 of file DualEdgeTriangulation.h.
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X-coordinate of the lower left corner of the bounding box.
Definition at line 106 of file DualEdgeTriangulation.h.
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Y-coordinate of the upper right corner of the bounding box.
Definition at line 108 of file DualEdgeTriangulation.h.
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Y-coordinate of the lower left corner of the bounding box.
Definition at line 110 of file DualEdgeTriangulation.h.