Zone2 is a certain defined area of a triangulation. More...

#include <Zone2.h>

Public Member Functions
Zone2 *	convertToBoundedZone ()
	Convert a zone to a bounded zone. More...

void	debug (const char *name="")
	Development function.

void	exportZone (FadeExport &fadeExport, bool bWithCustomIndices) const
	Export triangles from a zone. More...

double	getArea25D () const
	Get 2.5D Area. More...

double	getArea2D () const
	Get 2D Area. More...

void	getBorderEdges (std::vector< Edge2 > &vBorderEdgesOut) const
	Get border edges. More...

void	getBoundaryEdges (std::vector< Edge2 > &vEdges) const
	Compute the boundary edges. More...

void	getBoundarySegments (std::vector< Segment2 > &vSegments) const
	Compute the boundary segments. More...

Bbox2	getBoundingBox () const
	Compute the bounding box.

void	getComponentPolygons (std::vector< CompPolygon > &vCompPolygons) const
	Get connected components and their boundary polygons. More...

ConstraintGraph2 *	getConstraintGraph () const
	Get the associated constraint. More...

void	getConstraintGraphs (std::vector< ConstraintGraph2 * > &vConstraintGraphs_) const
	Get the associated constraint graphs.

size_t	getNumberOfTriangles () const
	Get the number of triangles. More...

void	getTriangles (std::vector< Triangle2 * > &vTriangles_) const
	Get the triangles of the zone. More...

void	getVertices (std::vector< Point2 * > &vVertices_) const
	Get the vertices of the zone.

ZoneLocation	getZoneLocation () const
	Get the zone location. More...

size_t	numberOfConstraintGraphs () const
	Get a the number of ConstraintGraph2 objects. More...

bool	save (const char *filename)
	Save the zone. More...

bool	save (std::ostream &stream)
	Save the zone. More...

void	show (const char *postscriptFilename, bool bShowFull, bool bWithConstraints) const
	Postscript visualization. More...

void	show (Visualizer2 *pVisualizer, bool bShowFull, bool bWithConstraints) const
	Postscript visualization. More...

void	showGeomview (const char filename, const char color) const
	Geomview visualization. More...

void	showGeomview (Visualizer3 pVis, const char color) const
	Geomview visualization. More...

void	slopeValleyRidgeOptimization (OptimizationMode om=OPTMODE_BETTER)
	Optimize Slopes, Valleys and Ridges. More...

void	smoothing (int numIterations=2)
	Smoothing. More...

void	statistics (const char *s) const

void	subscribe (MsgType msgType, MsgBase *pMsg)
	Register a message receiver. More...

void	unifyGrid (double tolerance)

void	unsubscribe (MsgType msgType, MsgBase *pMsg)
	Unregister a message receiver. More...

void	writeObj (const char *outFilename) const
	Write the zone to .obj Writes the triangles of the present Zone2 to an .obj file (The *.obj format represents a 3D scene). More...

Protected Member Functions
Zone2 &	operator= (const Zone2 &)

Friends
Zone2 *	peelOffIf (Zone2 pZone, bool bAvoidSplit, PeelPredicateTS pPredicate)
	Peel off border triangles. More...

Zone2 *	peelOffIf (Zone2 pZone, UserPredicateT pPredicate, bool bVerbose)
	Peel off border triangles (deprecated) More...

Zone2 *	zoneDifference (Zone2 pZone0, Zone2 pZone1)
	Compute the difference of two zones. More...

Zone2 *	zoneIntersection (Zone2 pZone0, Zone2 pZone1)
	Compute the intersection of two zones. More...

Zone2 *	zoneSymmetricDifference (Zone2 pZone0, Zone2 pZone1)
	Compute the symmetric difference of two zones. More...

Zone2 *	zoneUnion (Zone2 pZone0, Zone2 pZone1)
	Compute the union of two zones. More...

Detailed Description

See also: http://www.geom.at/example4-zones-defined-areas-in-triangulations/; http://www.geom.at/boolean-operations/; createZone in the Fade2D class

Member Function Documentation

◆ convertToBoundedZone()

Zone2* GEOM_FADE25D::Zone2::convertToBoundedZone ( )

The mesh generation algorithms refine() and refineAdvanced() require a zone object that is bounded by constraint segments. This is always the case for zones with zoneLocation ZL_INSIDE but other types of zones may be unbounded. For convenience this method is provided to create a bounded zone from a possibly unbounded one.

Returns: a pointer to a new Zone2 object with zoneLocation ZL_RESULT_BOUNDED or a pointer to the present zone if this->getZoneLocation() is ZL_INSIDE.

◆ exportZone()

void GEOM_FADE25D::Zone2::exportZone	(	FadeExport &	fadeExport,
		bool	bWithCustomIndices
	)		const

Parameters

fadeExport	is a struct that will hold the requested triangulation data
bWithCustomIndices	determines whether the custom indices of the points are also stored

◆ getArea25D()

double GEOM_FADE25D::Zone2::getArea25D ( ) const

Returns the 2.5D area of the zone.

Note: The getArea() method is deprecated and replaced by getArea2D() and getArea25D()

◆ getArea2D()

double GEOM_FADE25D::Zone2::getArea2D ( ) const

Returns the 2D area of the zone.

Note: The getArea() method is deprecated and replaced by getArea2D() and getArea25D()

◆ getBorderEdges()

void GEOM_FADE25D::Zone2::getBorderEdges ( std::vector< Edge2 > & vBorderEdgesOut ) const

Returns: : the CCW oriented border edges of the zone

◆ getBoundaryEdges()

void GEOM_FADE25D::Zone2::getBoundaryEdges ( std::vector< Edge2 > & vEdges ) const

Outputs the boundary edges of the zone. Edge2 elements are always ccw-oriented but the edges are not returned in any specific order.

◆ getBoundarySegments()

void GEOM_FADE25D::Zone2::getBoundarySegments ( std::vector< Segment2 > & vSegments ) const

Outputs the boundary segments of the zone. These are ccw-oriented but not returned in any specific order.

◆ getComponentPolygons()

void GEOM_FADE25D::Zone2::getComponentPolygons ( std::vector< CompPolygon > & vCompPolygons ) const

This method subdivides the zone into connected components. For each connected components it then returns a CompPolygon object consisting of the triangles, their outer boundary polygon and the hole polygons. Edges are represented by a triangle and an index and they are always counterclockwise (ccw) around their triangle. Thus the outer boundary polygon is also ccw-oriented while the polygons of inner holes are cw-oriented.

◆ getConstraintGraph()

ConstraintGraph2* GEOM_FADE25D::Zone2::getConstraintGraph ( ) const

Returns: a pointer to the ConstraintGraph2 object which defines the zone.
or NULL for ZL_RESULT-, ZL_GROW and ZL_GLOBAL_-zones.

◆ getNumberOfTriangles()

size_t GEOM_FADE25D::Zone2::getNumberOfTriangles ( ) const

Warning: This method is fast but O(n), so don't call it frequently in a loop.

◆ getTriangles()

void GEOM_FADE25D::Zone2::getTriangles ( std::vector< Triangle2 * > & vTriangles_ ) const

This command fetches the existing triangles of the zone.

Note: Fade_2D::void applyConstraintsAndZones() must be called after the last insertion of points and constraints.; that the lifetime of data from the Fade2D datastructures does exceed the lifetime of the Fade2D object.

◆ getZoneLocation()

ZoneLocation GEOM_FADE25D::Zone2::getZoneLocation ( ) const

Returns: ZL_INSIDE if the zone applies to the triangles inside one or more ConstraintGraph2 objects
ZL_OUTSIDE if the zone applies to the outside triangles
ZL_GLOBAL if the zone applies (dynamically) to all triangles
ZL_RESULT if the zone is the result of a set operation
ZL_GROW if the zone is specified by a set of constraint graphs and an inner point

An ouside zone and in inside zone

◆ numberOfConstraintGraphs()

size_t GEOM_FADE25D::Zone2::numberOfConstraintGraphs ( ) const

A Zone2 object might be defined by zero, one or more ConstraintGraph2 objects.

◆ save() [1/2]

bool GEOM_FADE25D::Zone2::save ( const char * filename )

This command saves the present Zone2 to a binary file. Any constraint edges and custom indices in the domain are retained.

Parameters

[in] filename is the output filename

Returns: whether the operation was successful

Note: A Delaunay triangulation is convex without holes but this may not hold for the zone to be saved. Thus extra triangles may be saved to fill concavities. These extra-triangles will belong to the Fade_2D instance but not to the Zone2 object when reloaded.

See also: save(std::ostream& stream). Use the similar command Fade_2D::saveZones(const char* file, std::vector<Zone2*>& vZones) to store more than just one zone. Use Fade_2D::saveTriangulation() to store all triangles of the triangulation plus any specified zones. Use Fade_2D::load() to reload the data from such files.

◆ save() [2/2]

bool GEOM_FADE25D::Zone2::save ( std::ostream & stream )

This command saves the present Zone2 to an ostream. Any constraint edges and custom indices in the domain are retained.

Parameters

stream is the output stream

Returns: whether the operation was successful

Note: A Delaunay triangulation is convex without holes but this may not hold for the zone to be saved. Thus extra triangles may be saved to fill concavities. These extra-triangles will belong to the Fade_2D instance but not to the Zone2 object when reloaded.

See also: Use the similar command Fade_2D::saveZones(const char* file, std::vector<Zone2*>& vZones) to store more than just one zone. Use Fade_2D::saveTriangulation() to store all triangles of the triangulation plus any specified zones. Use Fade_2D::load() to reload the data from such files.

◆ show() [1/2]

void GEOM_FADE25D::Zone2::show	(	const char *	postscriptFilename,
		bool	bShowFull,
		bool	bWithConstraints
	)		const

Parameters

postscriptFilename	is the name of the output file.
bShowFull	specifies if only the zone or the full triangulation shall be drawn
bWithConstraints	specifies if constraint edges shall be drawn

◆ show() [2/2]

void GEOM_FADE25D::Zone2::show	(	Visualizer2 *	pVisualizer,
		bool	bShowFull,
		bool	bWithConstraints
	)		const

Parameters

pVisualizer is a pointer to an existing Visualizer2 object.

Note: You must call pVisualizer->writeFile() before program end

Parameters

bShowFull	specifies if only the zone or the full triangulation shall be drawn
bWithConstraints	specifies if constraint edges shall be drawn

◆ showGeomview() [1/2]

void GEOM_FADE25D::Zone2::showGeomview	(	const char *	filename,
		const char *	color
	)		const

Parameters

filename	is the name of the output file.
color	is a string ("red green blue alpha"), e.g., "1.0 0.0 0.0 1.0"*

◆ showGeomview() [2/2]

void GEOM_FADE25D::Zone2::showGeomview	(	Visualizer3 *	pVis,
		const char *	color
	)		const

Parameters

pVis	points to a Visualizer3 object
color	is a string ("red green blue alpha"), e.g., "1.0 0.0 0.0 1.0"*

◆ slopeValleyRidgeOptimization()

void GEOM_FADE25D::Zone2::slopeValleyRidgeOptimization ( OptimizationMode om = OPTMODE_BETTER )

A pure Delaunay triangulation takes only the x and y coordinates into account. However, for terrain scans, it is important to consider the z coordinate as well, otherwise ridges, valleys and rivers will look unnatural. This method leaves the points constant, but uses edge flips to change the connectivity, making the surface smoother overall.

Parameters

om	is the optimization mode: OPTMODE_NORMAL is the fastest. OPTMODE_BETTER provides significantly better results while still taking a moderate amount of time. OPTMODE_BEST delivers the best results, but also has a significantly higher time requirement. This method supports the progress-bar mechanism.

Note: Flipping edges makes the triangulation non-delaunay, i.e. the empty-circle-property is then no longer given. Improving the smoothness of the surface by edge flips also means degrading the interior angles of the triangles (to a certain degree).

◆ smoothing()

void GEOM_FADE25D::Zone2::smoothing ( int numIterations = 2 )

This method applies weighted laplacian smoothing to the vertices. It keeps boundary points and internal points belonging to constraint-edges constant. Nevertheless it is guaranteed that moving the vertices does not lead to self-intersections. This method is very fast, but for larger models it still supports the progress bar mechanism.

Parameters

numIterations specifies the number of smoothing passes.

◆ statistics()

void GEOM_FADE25D::Zone2::statistics ( const char * s ) const

Statistics

Prints statistics to stdout.

◆ subscribe()

void GEOM_FADE25D::Zone2::subscribe	(	MsgType	msgType,
		MsgBase *	pMsg
	)

Parameters

msgType	is the type of message the subscriber shall receive, e.g. MSG_PROGRESS or MSG_WARNING
pMsg	is a pointer to a custom class derived from MsgBase

◆ unifyGrid()

void GEOM_FADE25D::Zone2::unifyGrid ( double tolerance )

Unify Grid

A Delaunay triangulation is not unique when when 2 or more triangles lie on a common circle. As a consequence the four corners of a rectangle can be triangulated in two different ways: Either the diagonal proceeds from the lower left to the upper right corner or it connects the other two corners. Both solutions are valid and an arbitrary one is applied when points are triangulated. To improve the repeatability and for reasons of visual appearance this method unifies such diagonals to point from the lower left to the upper right corner (or in horizontal direction).

Parameters

tolerance is 0 when only exact cases of more than 3 points on a common circumcircle shall be changed. But in practice input data can be disturbed by noise and tiny rounding errors such that grid points are not exactly on a grid. The numeric error is computed as $error=\frac{abs(diagonalA-diagonalB)}{max(diagonalA,diagonalB)}$ . and tolerance is an upper threshold to allow modification despite such tiny inaccuracies. Use with caution, such flips break the empty circle property and this may or may not fit your setting.

◆ unsubscribe()

void GEOM_FADE25D::Zone2::unsubscribe	(	MsgType	msgType,
		MsgBase *	pMsg
	)

Parameters

msgType	is the type of message the subscriber shall not receive anymore
pMsg	is a pointer to a custom class derived from MsgBase

◆ writeObj()

void GEOM_FADE25D::Zone2::writeObj ( const char * outFilename ) const

Parameters

outFilename is the output filename

Friends And Related Function Documentation

◆ peelOffIf [1/2]

Zone2* peelOffIf	(	Zone2 *	pZone,
		bool	bAvoidSplit,
		PeelPredicateTS *	pPredicate
	)

friend

Parameters

pZone	is the input zone
bAvoidSplit	if true, then the algorithm removes a triangle only if it does not break the zone into independent components.
pPredicate	is a user-defined predicate that decides if a triangle shall be removed.

Returns: a new zone containing a subset of the triangles of pZone or NULL when no triangles remain.

Attention: Check whether NULL is returned!

◆ peelOffIf [2/2]

Zone2* peelOffIf	(	Zone2 *	pZone,
		UserPredicateT *	pPredicate,
		bool	bVerbose
	)

friend

This function is DEPRECATED but kept for backwards compatibility. The new and better function is: peelOffIf(Zone2* pZone, bool bAvoidSplit,PeelPredicateTS* pPredicate)

Parameters

pZone
pPredicate
bVerbose

Returns: a new zone containing a subset of the triangles of pZone or NULL when no triangles remain.

◆ zoneDifference

Zone2* zoneDifference	(	Zone2 *	pZone0,
		Zone2 *	pZone1
	)

friend

Returns: a new zone containing the triangles of *pZone0 minus the ones of *pZone1

Note: pZone0 and pZone1 must belong to the same Fade_2D object.

◆ zoneIntersection

Zone2* zoneIntersection	(	Zone2 *	pZone0,
		Zone2 *	pZone1
	)

friend

Returns: a new zone containing the intersection of *pZone0 and *pZone1

Note: pZone0 and pZone1 must belong to the same Fade_2D object.

◆ zoneSymmetricDifference

Zone2* zoneSymmetricDifference	(	Zone2 *	pZone0,
		Zone2 *	pZone1
	)

friend

Returns: a new zone containing the triangles that are present in one of the zones but not in the other one.

Note: pZone0 and pZone1 must belong to the same Fade_2D object.

◆ zoneUnion

Zone2* zoneUnion	(	Zone2 *	pZone0,
		Zone2 *	pZone1
	)

friend

Returns: a new zone containing the union of the triangles of *pZone0 and *pZone1

Note: pZone0 and pZone1 must belong to the same Fade_2D object.

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

Zone2.h

Public Member Functions

Protected Member Functions

Friends

Detailed Description

Member Function Documentation

◆ convertToBoundedZone()

◆ exportZone()

◆ getArea25D()

◆ getArea2D()

◆ getBorderEdges()

◆ getBoundaryEdges()

◆ getBoundarySegments()

◆ getComponentPolygons()

◆ getConstraintGraph()

◆ getNumberOfTriangles()

◆ getTriangles()

◆ getZoneLocation()

◆ numberOfConstraintGraphs()

◆ save() [1/2]

◆ save() [2/2]

◆ show() [1/2]

◆ show() [2/2]

◆ showGeomview() [1/2]

◆ showGeomview() [2/2]

◆ slopeValleyRidgeOptimization()

◆ smoothing()

◆ statistics()

◆ subscribe()

◆ unifyGrid()

◆ unsubscribe()

◆ writeObj()

Friends And Related Function Documentation

◆ peelOffIf [1/2]

◆ peelOffIf [2/2]

◆ zoneDifference

◆ zoneIntersection

◆ zoneSymmetricDifference

◆ zoneUnion