org.jcae.mesh.amibe.ds
Class HalfEdge

java.lang.Object
  org.jcae.mesh.amibe.ds.AbstractHalfEdge
      org.jcae.mesh.amibe.ds.HalfEdge

All Implemented Interfaces:

java.io.Serializable

public class HalfEdge
extends AbstractHalfEdge
implements java.io.Serializable

Half-edge data structure. This is a straightforward implementation of AbstractHalfEdge, an half-edge is represented by a local number (between 0 and 2) and a triangle. It has a link to the next edge in the same triangle, and to its symmetric edge.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.jcae.mesh.amibe.ds.AbstractHalfEdge

BOUNDARY, int3, MARKED, NONMANIFOLD, OUTER, QUAD, SWAPPED, traits, traitsBuilder

Constructor Summary

HalfEdge(HalfEdgeTraitsBuilder htb, TriangleHE tri, byte localNumber, byte attributes)

Method Summary

Vertex	apex() Returns apex of this edge.
double	area() Returns the area of triangle bound to this edge.
protected boolean	canCollapse(Vertex v) Checks whether an edge can be contracted into a given vertex.
boolean	checkNewRingNormals(double[] newpt) Checks that triangles are not inverted if origin vertex is moved.
double	checkSwap3D(double minCos) Checks the dihedral angle of an edge.
double	checkSwap3D(double minCos, double maxLength)
void	clearAttributes(int attr) Resets attributes of this edge.
protected HalfEdge	collapse(Mesh m, Vertex v) Contracts an edge.
void	copy(HalfEdge that)
Vertex	destination() Returns end vertex of this edge.
java.util.Iterator<AbstractHalfEdge>	fanIterator() Returns an iterator over triangle fans connected to this edge.
int	getAttributes()
int	getLocalNumber() Returns edge local number.
Triangle	getTri() Returns triangle tied to this edge.
void	glue(AbstractHalfEdge e) Sets the edge tied to this object.
boolean	hasAttributes(int attr) Checks if some attributes of this edge are set.
boolean	hasSymmetricEdge() Tells whether edge is connected to a symmetric edge.
HalfEdge	next() Moves counterclockwise to following edge.
AbstractHalfEdge	next(AbstractHalfEdge that) Moves counterclockwise to following edge.
HalfEdge	nextApexLoop() Moves counterclockwise to the following edge which has the same apex.
HalfEdge	nextOrigin() Moves counterclockwise to the following edge which has the same origin.
AbstractHalfEdge	nextOrigin(AbstractHalfEdge that) Moves counterclockwise to the following edge which has the same origin.
HalfEdge	nextOriginLoop() Moves counterclockwise to the following edge which has the same origin.
HalfEdge	notOriented()
Vertex	origin() Returns start vertex of this edge.
HalfEdge	prev() Moves counterclockwise to previous edge.
AbstractHalfEdge	prev(AbstractHalfEdge that) Moves counterclockwise to previous edge.
void	setApex(Vertex v) Sets apex of this edge.
void	setAttributes(int attr) Sets attributes of this edge.
void	setDestination(Vertex v) Sets end vertex of this edge.
void	setNext(HalfEdge e) Sets next link.
void	setOrigin(Vertex v) Sets start vertex of this edge.
protected HalfEdge	split(Mesh m, Vertex v) Splits an edge.
protected HalfEdge	swap() Swaps an edge.
HalfEdge	sym() Moves to symmetric edge.
AbstractHalfEdge	sym(AbstractHalfEdge that) Moves to symmetric edge.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

HalfEdge

public HalfEdge(HalfEdgeTraitsBuilder htb,
                TriangleHE tri,
                byte localNumber,
                byte attributes)

Method Detail

getTri

public final Triangle getTri()

Returns triangle tied to this edge.

Specified by:

getTri in class AbstractHalfEdge

Returns:

triangle tied to this edge

getLocalNumber

public final int getLocalNumber()

Returns edge local number.

Specified by:

getLocalNumber in class AbstractHalfEdge

Returns:

edge local number

getAttributes

public final int getAttributes()

glue

public final void glue(AbstractHalfEdge e)

Sets the edge tied to this object.

Specified by:

glue in class AbstractHalfEdge

Parameters:

e - the edge tied to this object

notOriented

public final HalfEdge notOriented()

hasSymmetricEdge

public final boolean hasSymmetricEdge()

Tells whether edge is connected to a symmetric edge.

Specified by:

hasSymmetricEdge in class AbstractHalfEdge

Returns:

true if edge has a symmetric edge, false otherwise.

sym

public final HalfEdge sym()

Moves to symmetric edge.

Specified by:

sym in class AbstractHalfEdge

Returns:

current instance after its transformation

sym

public final AbstractHalfEdge sym(AbstractHalfEdge that)

Moves to symmetric edge. Make that instance be a copy of current instance, move it to its symmetric edge and return this instance. Current instance is not modified.

Specified by:

sym in class AbstractHalfEdge

Parameters:

that - instance where transformed edge is stored

Returns:

argument after its transformation

next

public final HalfEdge next()

Moves counterclockwise to following edge.

Specified by:

next in class AbstractHalfEdge

Returns:

current instance after its transformation

next

public final AbstractHalfEdge next(AbstractHalfEdge that)

Moves counterclockwise to following edge. Make that instance be a copy of current instance, move it counterclockwise to next edge and return this instance. Current instance is not modified.

Specified by:

next in class AbstractHalfEdge

Parameters:

that - instance where transformed edge is stored

Returns:

argument after its transformation

prev

public final HalfEdge prev()

Moves counterclockwise to previous edge.

Specified by:

prev in class AbstractHalfEdge

Returns:

current instance after its transformation

prev

public final AbstractHalfEdge prev(AbstractHalfEdge that)

Moves counterclockwise to previous edge. Make that instance be a copy of current instance, move it counterclockwise to previous edge and return this instance. Current instance is not modified.

Specified by:

prev in class AbstractHalfEdge

Parameters:

that - instance where transformed edge is stored

Returns:

argument after its transformation

nextOrigin

public final HalfEdge nextOrigin()

Moves counterclockwise to the following edge which has the same origin.

Specified by:

nextOrigin in class AbstractHalfEdge

Returns:

current instance after its transformation

nextOrigin

public final AbstractHalfEdge nextOrigin(AbstractHalfEdge that)

Moves counterclockwise to the following edge which has the same origin. Make that instance be a copy of current instance, move it counterclockwise to the following edge which has the same origin and return this instance. Current instance is not modified.

Specified by:

nextOrigin in class AbstractHalfEdge

Parameters:

that - instance where transformed edge is stored

Returns:

argument after its transformation

setOrigin

public final void setOrigin(Vertex v)

Sets start vertex of this edge.

Parameters:

v - start vertex of this edge

setDestination

public final void setDestination(Vertex v)

Sets end vertex of this edge.

Parameters:

v - end vertex of this edge

setApex

public final void setApex(Vertex v)

Sets apex of this edge.

Parameters:

v - apex of this edge

setNext

public final void setNext(HalfEdge e)

Sets next link.

hasAttributes

public final boolean hasAttributes(int attr)

Checks if some attributes of this edge are set.

Specified by:

hasAttributes in class AbstractHalfEdge

Parameters:

attr - attributes to check

Returns:

true if this HalfEdge has one of these attributes set, false otherwise

setAttributes

public final void setAttributes(int attr)

Sets attributes of this edge.

Specified by:

setAttributes in class AbstractHalfEdge

Parameters:

attr - attributes of this edge

clearAttributes

public final void clearAttributes(int attr)

Resets attributes of this edge.

Specified by:

clearAttributes in class AbstractHalfEdge

Parameters:

attr - attributes of this edge to clear out

origin

public final Vertex origin()

Returns start vertex of this edge.

Specified by:

origin in class AbstractHalfEdge

Returns:

start vertex of this edge

destination

public final Vertex destination()

Returns end vertex of this edge.

Specified by:

destination in class AbstractHalfEdge

Returns:

end vertex of this edge

apex

public final Vertex apex()

Returns apex of this edge.

Specified by:

apex in class AbstractHalfEdge

Returns:

apex of this edge

nextOriginLoop

public final HalfEdge nextOriginLoop()

Moves counterclockwise to the following edge which has the same origin. If a boundary is reached, loop backward until another boundary is found and start again from there.

Specified by:

nextOriginLoop in class AbstractHalfEdge

Returns:

current instance after its transformation

nextApexLoop

public final HalfEdge nextApexLoop()

Moves counterclockwise to the following edge which has the same apex. If a boundary is reached, loop backward until another boundary is found and start again from there.

checkSwap3D

public final double checkSwap3D(double minCos)

Checks the dihedral angle of an edge. Warning: this method uses temp[0], temp[1], temp[2] and temp[3] temporary arrays.

Parameters:

minCos - if the dot product of the normals to adjacent triangles is lower than minCos, then -1.0 is returned.

Returns:

the minimum quality of the two triangles generated by swapping this edge.

checkSwap3D

public final double checkSwap3D(double minCos,
                                double maxLength)

swap

protected final HalfEdge swap()

Swaps an edge.

Specified by:

swap in class AbstractHalfEdge

Returns:

swapped edge, origin and apical vertices are the same as in original edge

Throws:

java.lang.IllegalArgumentException - if edge is on a boundary or belongs to an outer triangle.

See Also:

Mesh.edgeSwap(org.jcae.mesh.amibe.ds.AbstractHalfEdge)

area

public double area()

Returns the area of triangle bound to this edge.

Specified by:

area in class AbstractHalfEdge

Returns:

triangle area Warning: this method uses temp[0], temp[1] and temp[2] temporary arrays.

canCollapse

protected final boolean canCollapse(Vertex v)

Checks whether an edge can be contracted into a given vertex.

Specified by:

canCollapse in class AbstractHalfEdge

Parameters:

v - the resulting vertex

Returns:

true if this edge can be contracted into the single vertex n, false otherwise

See Also:

Mesh.canCollapseEdge(org.jcae.mesh.amibe.ds.AbstractHalfEdge, org.jcae.mesh.amibe.ds.Vertex)

checkNewRingNormals

public final boolean checkNewRingNormals(double[] newpt)

Checks that triangles are not inverted if origin vertex is moved.

Specified by:

checkNewRingNormals in class AbstractHalfEdge

Parameters:

newpt - the new position to be checked

Returns:

false if the new position produces an inverted triangle, true otherwise. Warning: this method uses temp[0], temp[1], temp[2] and temp[3] temporary arrays.

collapse

protected final HalfEdge collapse(Mesh m,
                                  Vertex v)

Contracts an edge.

Specified by:

collapse in class AbstractHalfEdge

Parameters:

m - mesh

v - the resulting vertex

Returns:

edge starting from n and with the same apex

Throws:

java.lang.IllegalArgumentException - if edge belongs to an outer triangle, because there would be no valid return value. User must then run this method against symmetric edge, this is not done automatically.

See Also:

Mesh.edgeCollapse(org.jcae.mesh.amibe.ds.AbstractHalfEdge, org.jcae.mesh.amibe.ds.Vertex)

split

protected final HalfEdge split(Mesh m,
                               Vertex v)

Splits an edge. This is the opposite of collapse(org.jcae.mesh.amibe.ds.Mesh, org.jcae.mesh.amibe.ds.Vertex).

Specified by:

split in class AbstractHalfEdge

Parameters:

m - mesh

v - vertex being inserted

Returns:

edge starting from origin and pointing to n

See Also:

Mesh.vertexSplit(org.jcae.mesh.amibe.ds.AbstractHalfEdge, org.jcae.mesh.amibe.ds.Vertex)

fanIterator

public final java.util.Iterator<AbstractHalfEdge> fanIterator()

Returns an iterator over triangle fans connected to this edge. If edge is manifold, this iterator contains a single value, which is this edge. But if it is non-manifold and bound to n triangles, this iterator returns successively the n edges contained in these triangles and connected to the same endpoints.

Specified by:

fanIterator in class AbstractHalfEdge

Returns:

iterator over triangle fans connected to this edge

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

copy

public final void copy(HalfEdge that)