GEOM_FADE25D::ConstraintSegment2 Class Reference

A ConstraintSegment2 represents a constraint edge between two vertices of a Delaunay triangulation. More...

#include <ConstraintSegment2.h>

Public Member Functions
CLASS_DECLSPEC void	getChildrenAndSplitPoint (ConstraintSegment2 *&pCSeg0, ConstraintSegment2 *&pCSeg1, Point2 *&pSplitPoint)
	Retrieves the two direct children and the split point. More...
CLASS_DECLSPEC void	getChildrenRec (std::vector< ConstraintSegment2 * > &vChildConstraintSegments)
	Retrieves all children of this constraint segment recursively. More...
ConstraintInsertionStrategy	getCIS () const
	Retrieves the constraint insertion strategy (CIS) of this segment. More...
CLASS_DECLSPEC Point2 *	getSrc () const
	Get the first endpoint of the constraint segment. More...
CLASS_DECLSPEC Point2 *	getTrg () const
	Get the second endpoint of the constraint segment. More...
CLASS_DECLSPEC Point2 *	insertAndSplit (const Point2 &splitPoint)
	Splits a constraint segment at a specified point. More...
CLASS_DECLSPEC bool	isAlive () const
	Checks if the segment is alive. More...
bool	operator< (const ConstraintSegment2 &pOther) const
	Comparison operator for sorting segments. More...

Public Attributes
int	label

Static Public Attributes
static int	runningLabel

Protected Attributes
bool	bAlive
ConstraintInsertionStrategy	cis
Point2 *	p0
Point2 *	p1
std::vector< ConstraintSegment2 * >	vChildren
std::vector< ConstraintSegment2 * >	vParents

Friends
class	ConstraintGraph2
class	ConstraintMgr
CLASS_DECLSPEC friend std::ostream &	operator<< (std::ostream &stream, const ConstraintSegment2 &cSeg)

Detailed Description

A Constraint Edge in a Constrained Delaunay triangulation

• A ConstraintSegment2 represents a constraint edge between two vertices (Point2 objects) of a Fade_2D instance.
• It can belong to multiple ConstraintGraph2 objects, and thus it does not carry any orientation information. Instead, the ConstraintGraph2 objects it belongs to can provide its orientation.
• A ConstraintSegment2 can be split. In this case it is dead and has two children (which can be the case recursively).

Member Function Documentation

getChildrenAndSplitPoint()

CLASS_DECLSPEC void GEOM_FADE25D::ConstraintSegment2::getChildrenAndSplitPoint	(	ConstraintSegment2 *&	pCSeg0,
		ConstraintSegment2 *&	pCSeg1,
		Point2 *&	pSplitPoint
	)

This method retrieves the two child segments that result from splitting this ConstraintSegment2 as well as the point where the split occurred.

Parameters

pCSeg0	A pointer to the first child ConstraintSegment2.
pCSeg1	A pointer to the second child ConstraintSegment2.
pSplitPoint	A pointer to the vertex at which the split occurred.

getChildrenRec()

CLASS_DECLSPEC void GEOM_FADE25D::ConstraintSegment2::getChildrenRec

(

std::vector< ConstraintSegment2 * > &

vChildConstraintSegments

)

This method recursively collects all child ConstraintSegment2s of the current one that are still alive, meaning they have not been marked as "dead" due to being split.

Parameters

vChildConstraintSegments

A vector that will be populated with the child segments.

getCIS()

ConstraintInsertionStrategy GEOM_FADE25D::ConstraintSegment2::getCIS

(

)

const

This function returns the constraint insertion strategy of the present ConstraintSegment2. CIS_CONSTRAINED_DELAUNAY is the only supported strategy. Other possible values are deprecated in favor of newer techniques.

Returns

The ConstraintInsertionStrategy of this segment.

getSrc()

CLASS_DECLSPEC Point2* GEOM_FADE25D::ConstraintSegment2::getSrc

(

)

const

Returns

A pointer to the first endpoint (Point2 object).

getTrg()

CLASS_DECLSPEC Point2* GEOM_FADE25D::ConstraintSegment2::getTrg

(

)

const

Returns

A pointer to the second endpoint (Point2 object).

insertAndSplit()

CLASS_DECLSPEC Point2* GEOM_FADE25D::ConstraintSegment2::insertAndSplit

(

const Point2 &

splitPoint

)

This method splits the ConstraintSegment2 at the given splitPoint. After the operation, the current ConstraintSegment2 is marked as "dead" and has two child segments.

Parameters

[in]

splitPoint

The point at which to split the segment.

Returns

A pointer to the inserted Point2 (the splitPoint), or NULL if the operation fails.

Note

Always use this method to split a ConstraintSegment2. Attempting to split the segment by simply inserting the splitPoint (e.g., using Fade_2D::insert(splitPoint)) will fail if the splitPoint and the two endpoints of the ConstraintSegment2 are not exactly collinear e.g., due to floating-point precision limitations. In contrast, this method accepts a non-collinear splitPoint as long as it has an orthogonal projection onto the segment.

isAlive()

CLASS_DECLSPEC bool GEOM_FADE25D::ConstraintSegment2::isAlive

(

)

const

This function checks whether the current ConstraintSegment2 object is "alive" or "dead."

Returns

Returns true if the segment is alive, false otherwise.

operator<()

bool GEOM_FADE25D::ConstraintSegment2::operator< ( const ConstraintSegment2 &  pOther ) const

inline

This operator compares two ConstraintSegment2 objects for sorting segments. The comparison is based on the pointers to their endpoints (p0 and p1), not the length of the ConstraintSegment2.

Parameters

pOther

Another ConstraintSegment2 to compare.

Returns

true if the current segment is less than the other segment, false otherwise.

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

• ConstraintSegment2.h