HalfEdgeList Class Reference

#include <HalfEdgeList.h>

Collaboration diagram for HalfEdgeList:

Public Member Functions
	HalfEdgeList (void)
	~HalfEdgeList (void)
void	addToList (DCELHalfEdge *newEdge)
void	removeFromList (DCELHalfEdge *edge)
DCELHalfEdge *	addTwinTo (DCELHalfEdge *edge, DCELHalfEdge *LaggingTwin)
	GETTTING THE HALF EDGE LIST. More...
DCELFace *	addEdgeBetween (DCELVertex *v1, DCELVertex *v2, DCELFace *face)
	GETTTING THE HALF EDGE LIST. More...

Public Attributes
DCELHalfEdge *	head
DCELHalfEdge *	tail
int	globalEdgeCount

Protected Attributes
bool	status

Constructor & Destructor Documentation

HalfEdgeList::HalfEdgeList

(

void

)

                               : globalEdgeCount(0), head(NULL), tail(NULL), status(false)
{
}

HalfEdgeList::~HalfEdgeList

(

void

)

{
}

Member Function Documentation

DCELFace * HalfEdgeList::addEdgeBetween	(	DCELVertex *	v1,
		DCELVertex *	v2,
		DCELFace *	face
	)

GETTTING THE HALF EDGE LIST.

Hepler For Handling End Vertex. Walk around the path and add vertices that are in the Hal Edge Vetices List

{
    DCELHalfEdge* walker = face->edge;
    while (1) {
        if (walker->next->origin == v1)
            break;
        walker = walker->next;
    }

    DCELHalfEdge* halfEdge = new DCELHalfEdge();
    halfEdge->origin = v2;
    halfEdge->meta = ++globalEdgeCount;
    halfEdge->next = walker->next;
    
    DCELHalfEdge* twinWalker = face->edge;
    while (1) {
        if (twinWalker->next->origin == v2)
            break;
        twinWalker = twinWalker->next;
    }

    DCELHalfEdge* twinEdge = new DCELHalfEdge();
    twinEdge->origin = v1;
    twinEdge->meta = ++globalEdgeCount;
    twinEdge->next = twinWalker->next;
    
    walker->next = twinEdge;
    twinWalker->next = halfEdge;
    
    halfEdge->twin = twinEdge;
    twinEdge->twin = halfEdge;


    DCELFace* firstHalf = new DCELFace();
    firstHalf->edge = halfEdge;
    walker = halfEdge;
    do {
        walker->face = firstHalf;
        walker = walker->next;
    } while(walker != halfEdge);

    DCELFace* secHalf = new DCELFace();
    secHalf->edge = twinEdge;
    twinEdge->face = secHalf;
    walker = twinEdge;
    do {
        walker->face = secHalf;
        walker = walker->next;
    } while(walker != twinEdge);

    secHalf->next = firstHalf;
    return secHalf;
}

void HalfEdgeList::addToList

(

DCELHalfEdge *

newEdge

)

{
    newEdge->meta = ++globalEdgeCount;

    if (head)
    {
        tail->next = newEdge;
        tail = newEdge;
    }
    else {
        head = newEdge;
        tail = newEdge;
    }
}

DCELHalfEdge * HalfEdgeList::addTwinTo	(	DCELHalfEdge *	edge,
		DCELHalfEdge *	LaggingTwin
	)

GETTTING THE HALF EDGE LIST.

Adding a twin

                                                                                   {
    DCELHalfEdge *twinEdge = new DCELHalfEdge();
    twinEdge->meta = ++globalEdgeCount;
    twinEdge->twin = edge;
    if (LaggingTwin) {
        LaggingTwin->origin = twinEdge->twin->origin;
        twinEdge->next = LaggingTwin;
    }
    edge->twin = twinEdge;
    return twinEdge;
}

void HalfEdgeList::removeFromList

(

DCELHalfEdge *

edge

)

{
    edge->getPrev()->next = edge->twin->next;
    edge->twin->getPrev()->next = edge->next;
    delete edge->twin;
    delete edge;
}

Member Data Documentation

int HalfEdgeList::globalEdgeCount

DCELHalfEdge* HalfEdgeList::head

bool HalfEdgeList::status

protected

DCELHalfEdge* HalfEdgeList::tail

---

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

• DCEL/HalfEdgeList.h