org.jcae.mesh.amibe.ds
Class VirtualHalfEdge

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

Direct Known Subclasses:

VirtualHalfEdge2D

public class VirtualHalfEdge
extends AbstractHalfEdge

A handle to abstract half-edge instances. When triangles are instances of TriangleVH class, adjacency relations are contained within triangles. This VirtualHalfEdge class is a handle to an edge, it has a link to a triangle and contains a local number. When a VirtualHalfEdge instance is traversing the mesh, its reference is not modified, but its instance variables are updated. In order to prevent object allocations, we try to reuse VirtualHalfEdge objects as much as we can.

Field Summary

protected int	attributes Attributes of this edge.
protected int	localNumber Local number of this edge in this triangle.
protected TriangleVH	tri Triangle connected to this edge.

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

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

Constructor Summary

VirtualHalfEdge()
Sole constructor.

VirtualHalfEdge(Triangle t, int o)
Creates an object to handle data about a triangle.

Method Summary

Vertex	apex() Returns apex of this edge.
double	area() Returns the area of triangle bound to this edge.
void	bind(TriangleVH t) Sets triangle tied to this object, and resets localNumber.
void	bind(TriangleVH t, int l) Sets the triangle tied to this object, and the localNumber.
protected boolean	canCollapse(Vertex n) Checks whether an edge can be contracted.
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 VirtualHalfEdge	collapse(Mesh m, Vertex v) Contracts an edge.
double	computeNormal3D() Computes the normal of this triangle.
double	computeNormal3DT() Computes the normal of an edge, in the triangle plane.
protected static void	copyOTri(VirtualHalfEdge src, VirtualHalfEdge dest) Copies a VirtualHalfEdge instance into another VirtualHalfEdge instance.
Vertex	destination() Returns end vertex of this edge.
java.util.Iterator<AbstractHalfEdge>	fanIterator() Returns an iterator over triangle fans connected to this edge.
int	getLocalNumber() Returns edge local number.
double[]	getTempVector() Returns the temporary array TempD.
Triangle	getTri() Returns triangle tied to this edge.
void	glue(AbstractHalfEdge sym) Sets adjacency relations between two triangles.
boolean	hasAttributes(int attr) Checks if some attributes of this edge are set.
boolean	hasSymmetricEdge() Tells whether edge is connected to a symmetric edge.
boolean	isMutable() Checks whether an edge can be modified.
VirtualHalfEdge	next() Moves counterclockwise to following edge.
VirtualHalfEdge	next(AbstractHalfEdge that) Moves counterclockwise to following edge.
VirtualHalfEdge	nextOrigin() Moves counterclockwise to the following edge which has the same origin.
VirtualHalfEdge	nextOrigin(AbstractHalfEdge that) Moves counterclockwise to the following edge which has the same origin.
VirtualHalfEdge	nextOriginLoop() Moves counterclockwise to the following edge which has the same origin.
protected static void	nextOTri(VirtualHalfEdge o, VirtualHalfEdge that) Copies a VirtualHalfEdge instance and move it counterclockwise to following edge.
Vertex	origin() Returns start vertex of this edge.
VirtualHalfEdge	prev() Moves counterclockwise to previous edge.
VirtualHalfEdge	prev(AbstractHalfEdge that) Moves counterclockwise to previous edge.
protected static void	prevOTri(VirtualHalfEdge o, VirtualHalfEdge that) Copies a VirtualHalfEdge instance and move it counterclockwise to previous edge.
protected void	pullAttributes()
protected void	pushAttributes()
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	setOrigin(Vertex v) Sets start vertex of this edge.
protected VirtualHalfEdge	split(Mesh m, Vertex v) Splits an edge.
protected VirtualHalfEdge	swap() Swaps an edge.
VirtualHalfEdge	sym() Moves to symmetric edge.
VirtualHalfEdge	sym(AbstractHalfEdge that) Moves to symmetric edge.
protected static void	symOTri(VirtualHalfEdge o, VirtualHalfEdge that) Copies a VirtualHalfEdge instance and move to its symmetric edge.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

tri

protected TriangleVH tri

Triangle connected to this edge.

localNumber

protected int localNumber

Local number of this edge in this triangle.

attributes

protected int attributes

Attributes of this edge.

Constructor Detail

VirtualHalfEdge

public VirtualHalfEdge()

Sole constructor.

VirtualHalfEdge

public VirtualHalfEdge(Triangle t,
                       int o)

Creates an object to handle data about a triangle.

Parameters:

t - geometrical triangle

o - a number between 0 and 2 determining an edge

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

bind

public final void bind(TriangleVH t)

Sets triangle tied to this object, and resets localNumber.

Parameters:

t - triangle tied to this object

bind

public final void bind(TriangleVH t,
                       int l)

Sets the triangle tied to this object, and the localNumber.

Parameters:

t - triangle tied to this object

l - local number

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 VirtualHalfEdge 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

pushAttributes

protected final void pushAttributes()

pullAttributes

protected final void pullAttributes()

isMutable

public final boolean isMutable()

Checks whether an edge can be modified.

Returns:

false if edge is a boundary or outside the mesh, true otherwise.

sym

public final VirtualHalfEdge sym()

Moves to symmetric edge.

Specified by:

sym in class AbstractHalfEdge

Returns:

current instance after its transformation

sym

public final VirtualHalfEdge 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 VirtualHalfEdge next()

Moves counterclockwise to following edge.

Specified by:

next in class AbstractHalfEdge

Returns:

current instance after its transformation

next

public final VirtualHalfEdge 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 VirtualHalfEdge prev()

Moves counterclockwise to previous edge.

Specified by:

prev in class AbstractHalfEdge

Returns:

current instance after its transformation

prev

public final VirtualHalfEdge 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 VirtualHalfEdge 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 VirtualHalfEdge 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

nextOriginLoop

public final VirtualHalfEdge 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. Note: outer triangles are taken into account in this loop, because this is sometimes needed, as in VirtualHalfEdge2D.removeDegenerated(). They have to be explicitly filtered out by testing hasAttributes(OUTER).

Specified by:

nextOriginLoop in class AbstractHalfEdge

Returns:

current instance after its transformation

copyOTri

protected static final void copyOTri(VirtualHalfEdge src,
                                     VirtualHalfEdge dest)

Copies a VirtualHalfEdge instance into another VirtualHalfEdge instance.

Parameters:

src - VirtualHalfEdge being duplicated

dest - already allocated VirtualHalfEdge where data are copied

symOTri

protected static final void symOTri(VirtualHalfEdge o,
                                    VirtualHalfEdge that)

Copies a VirtualHalfEdge instance and move to its symmetric edge.

Parameters:

o - source VirtualHalfEdge

that - already allocated VirtualHalfEdge where data are copied

nextOTri

protected static final void nextOTri(VirtualHalfEdge o,
                                     VirtualHalfEdge that)

Copies a VirtualHalfEdge instance and move it counterclockwise to following edge.

Parameters:

o - source VirtualHalfEdge

that - already allocated VirtualHalfEdge where data are copied

prevOTri

protected static final void prevOTri(VirtualHalfEdge o,
                                     VirtualHalfEdge that)

Copies a VirtualHalfEdge instance and move it counterclockwise to previous edge.

Parameters:

o - source VirtualHalfEdge

that - already allocated VirtualHalfEdge where data are copied

origin

public Vertex origin()

Returns start vertex of this edge.

Specified by:

origin in class AbstractHalfEdge

Returns:

start vertex of this edge

destination

public Vertex destination()

Returns end vertex of this edge.

Specified by:

destination in class AbstractHalfEdge

Returns:

end vertex of this edge

apex

public Vertex apex()

Returns apex of this edge.

Specified by:

apex in class AbstractHalfEdge

Returns:

apex of this edge

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

glue

public final void glue(AbstractHalfEdge sym)

Sets adjacency relations between two triangles.

Specified by:

glue in class AbstractHalfEdge

Parameters:

sym - the edge tied to this object

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.

computeNormal3DT

public double computeNormal3DT()

Computes the normal of an edge, in the triangle plane. This vector is not normalized, it has the same length as this edge. The result is stored in the tempD temporary array.

Returns:

triangle area Warning: this method uses tempD, tempD1 and tempD2 temporary arrays.

See Also:

getTempVector()

computeNormal3D

public double computeNormal3D()

Computes the normal of this triangle. The result is stored in the tempD temporary array.

Returns:

triangle area Warning: this method uses tempD, tempD1 and tempD2 temporary arrays.

See Also:

getTempVector()

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 tempD, tempD1 and tempD2 temporary arrays.

getTempVector

public double[] getTempVector()

Returns the temporary array TempD.

checkSwap3D

public final double checkSwap3D(double minCos)

Checks the dihedral angle of an edge.

Parameters:

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

Returns:

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

checkSwap3D

public final double checkSwap3D(double minCos,
                                double maxLength)

swap

protected final VirtualHalfEdge 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)

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 work[0] and work[1] temporary arrays.

canCollapse

protected final boolean canCollapse(Vertex n)

Checks whether an edge can be contracted.

Specified by:

canCollapse in class AbstractHalfEdge

Parameters:

n - the resulting vertex

Returns:

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

See Also:

Warning: this method uses work[0], work[1] and work[2] temporary arrays.

collapse

protected final VirtualHalfEdge 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 VirtualHalfEdge split(Mesh m,
                                      Vertex v)

Splits an edge. This is the opposite of collapse.

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