#include <ntetrahedron.h>
Public Member Functions | |
NTetrahedron () | |
Creates a new tetrahedron with empty description and no faces joined to anything. | |
NTetrahedron (const std::string &desc) | |
Creates a new tetrahedron with the given description and no faces joined to anything. | |
virtual | ~NTetrahedron () |
Destroys this tetrahedron. | |
const std::string & | getDescription () const |
Returns the text description associated with this tetrahedron. | |
void | setDescription (const std::string &desc) |
Sets the text description associated with this tetrahedron. | |
NTetrahedron * | getAdjacentTetrahedron (int face) const |
Returns the tetrahedron glued to the given face of this tetrahedron, or 0 if the given face is on the triangulation boundary. | |
NPerm | getAdjacentTetrahedronGluing (int face) const |
Returns a permutation representing the correspondence between vertices of this tetrahedron and vertices of the tetrahedron glued to the given face of this tetrahedron. | |
int | getAdjacentFace (int face) const |
Examines the tetrahedron glued to the given face of this tetrahedron and returns the corresponding face of that tetrahedron. | |
bool | hasBoundary () const |
Determines if this tetrahedron has any faces that are boundary faces. | |
void | joinTo (int myFace, NTetrahedron *you, NPerm gluing) |
Joins the given face of this tetrahedron to another tetrahedron. | |
NTetrahedron * | unjoin (int myFace) |
Unglues the given face of this tetrahedron from whatever is joined to it. | |
void | isolate () |
Undoes any face gluings involving this tetrahedron. | |
NComponent * | getComponent () const |
Returns the triangulation component to which this tetrahedron belongs. | |
NVertex * | getVertex (int vertex) const |
Returns the vertex in the triangulation skeleton corresponding to the given vertex of this tetrahedron. | |
NEdge * | getEdge (int edge) const |
Returns the edge in the triangulation skeleton corresponding to the given edge of this tetrahedron. | |
NFace * | getFace (int face) const |
Returns the face in the triangulation skeleton corresponding to the given face of this tetrahedron. | |
NPerm | getEdgeMapping (int edge) const |
The edge in the skeleton corresponding to the requested edge of this tetrahedron is examined, and a permutation mapping vertices (0,1) of the skeleton edge to the corresponding vertices of this tetrahedron is returned. | |
NPerm | getFaceMapping (int face) const |
The face in the skeleton corresponding to the requested face of this tetrahedron is examined, and a permutation mapping vertices (0,1,2) of the skeleton face to the corresponding vertices of this tetrahedron is returned. | |
int | orientation () const |
Returns the orientation of this tetrahedron in the triangulation. | |
void | writeTextShort (std::ostream &out) const |
Writes this object in short text format to the given output stream. | |
Friends | |
class | NTriangulation |
Allow access to private members. |
With each tetrahedron is stored various pieces of information regarding the overall skeletal structure and component structure of the triangulation. This information will be allocated, calculated and deallocated by the NTriangulation object containing the corresponding tetrahedra.
Whenever the gluings of tetrahedra are altered, the external routine responsible for changing the gluings (the routine that calls joinTo() and unjoin()) must call NTriangulation::gluingsHaveChanged() for the triangulation containing the tetrahedra concerned; this will ensure that skeletal information and other properties of the triangulation are recalculated when necessary.
regina::NTetrahedron::NTetrahedron | ( | ) |
Creates a new tetrahedron with empty description and no faces joined to anything.
regina::NTetrahedron::NTetrahedron | ( | const std::string & | desc | ) |
Creates a new tetrahedron with the given description and no faces joined to anything.
desc | the description to give the new tetrahedron. |
regina::NTetrahedron::~NTetrahedron | ( | ) | [inline, virtual] |
Destroys this tetrahedron.
const std::string & regina::NTetrahedron::getDescription | ( | ) | const [inline] |
Returns the text description associated with this tetrahedron.
void regina::NTetrahedron::setDescription | ( | const std::string & | desc | ) | [inline] |
Sets the text description associated with this tetrahedron.
Note that descriptions need not be unique, and may be empty.
desc | the new description to assign to this tetrahedron. |
NTetrahedron * regina::NTetrahedron::getAdjacentTetrahedron | ( | int | face | ) | const [inline] |
Returns the tetrahedron glued to the given face of this tetrahedron, or 0 if the given face is on the triangulation boundary.
face | the face of this tetrahedron to examine. This should be between 0 and 3 inclusive, where face i is opposite vertex i of the tetrahedron. |
NPerm regina::NTetrahedron::getAdjacentTetrahedronGluing | ( | int | face | ) | const [inline] |
Returns a permutation representing the correspondence between vertices of this tetrahedron and vertices of the tetrahedron glued to the given face of this tetrahedron.
If we call the returned permutation p
, then for each vertex v
of this tetrahedron, p[v]
will be the vertex of the adjacent tetrahedron that is identified with v
according to the gluing along the given face of this tetrahedron.
face | the face of this tetrahedron whose gluing we will examine. This should be between 0 and 3 inclusive, where face i is opposite vertex i of the tetrahedron. |
int regina::NTetrahedron::getAdjacentFace | ( | int | face | ) | const [inline] |
Examines the tetrahedron glued to the given face of this tetrahedron and returns the corresponding face of that tetrahedron.
That is, the returned face of the adjacent tetrahedron is glued to the given face of this tetrahedron.
face | the face of this tetrahedron whose gluing we will examine. This should be between 0 and 3 inclusive, where face i is opposite vertex i of the tetrahedron. |
bool regina::NTetrahedron::hasBoundary | ( | ) | const |
Determines if this tetrahedron has any faces that are boundary faces.
true
if and only if this tetrahedron has any boundary faces. void regina::NTetrahedron::joinTo | ( | int | myFace, | |
NTetrahedron * | you, | |||
NPerm | gluing | |||
) |
Joins the given face of this tetrahedron to another tetrahedron.
The other tetrahedron involved will be automatically updated.
The face of the other tetrahedron that will be glued to the given face of this tetrahedron is not currently glued to anything.
If the other tetrahedron involved is this tetrahedron, we are not attempting to glue a face to itself.
myFace | the face of this tetrahedron that will be glued to the given other tetrahedron. This should be between 0 and 3 inclusive, where face i is opposite vertex i of the tetrahedron. | |
you | the tetrahedron (possibly this one) that will be glued to the given face of this tetrahedron. | |
gluing | a permutation describing the mapping of vertices by which the two tetrahedra will be joined. Each vertex v of this tetrahedron that lies on the given face will be identified with vertex gluing[v] of tetrahedron you . In addition, the face of you that will be glued to the given face of this tetrahedron will be face number gluing[myFace] . |
NTetrahedron* regina::NTetrahedron::unjoin | ( | int | myFace | ) |
Unglues the given face of this tetrahedron from whatever is joined to it.
The other tetrahedron involved (possibly this one) will be automatically updated.
myFace | the face of this tetrahedron whose gluing we will undo. This should be between 0 and 3 inclusive, where face i is opposite vertex i of the tetrahedron. |
void regina::NTetrahedron::isolate | ( | ) |
Undoes any face gluings involving this tetrahedron.
Any other tetrahedra involved will be automatically updated.
NComponent * regina::NTetrahedron::getComponent | ( | ) | const [inline] |
Returns the triangulation component to which this tetrahedron belongs.
NVertex * regina::NTetrahedron::getVertex | ( | int | vertex | ) | const [inline] |
Returns the vertex in the triangulation skeleton corresponding to the given vertex of this tetrahedron.
vertex | the vertex of this tetrahedron to examine. This should be between 0 and 3 inclusive. |
NEdge * regina::NTetrahedron::getEdge | ( | int | edge | ) | const [inline] |
Returns the edge in the triangulation skeleton corresponding to the given edge of this tetrahedron.
edge | the edge of this tetrahedron to examine. This should be between 0 and 5 inclusive. |
NFace * regina::NTetrahedron::getFace | ( | int | face | ) | const [inline] |
Returns the face in the triangulation skeleton corresponding to the given face of this tetrahedron.
face | the face of this tetrahedron to examine. This should be between 0 and 3 inclusive, where face i lies opposite vertex i . |
NPerm regina::NTetrahedron::getEdgeMapping | ( | int | edge | ) | const [inline] |
The edge in the skeleton corresponding to the requested edge of this tetrahedron is examined, and a permutation mapping vertices (0,1) of the skeleton edge to the corresponding vertices of this tetrahedron is returned.
Thus, for each i=0,1
and each tetrahedron containing this skeleton edge, getEdgeMapping(...)[i]
will refer to vertices that are all identified to each other along the skeleton edge concerned.
Furthermore, following the ordered edges defined by the images of (2,3) under the returned permutations will produce an ordered chain circling the skeleton edge. That is, if tetrahedra A
and B
are adjacent along the edge concerned and also at vertex V, then if A.getEdgeMapping(...)[3]
refers to V, we will have B.getEdgeMapping(...)[2]
referring to V also, and B
will appear immediately after A
in the list of embeddings stored in the corresponding NEdge object. See NEdge::getEmbeddings() for further details.
edge | the edge of this tetrahedron to examine. This should be between 0 and 5 inclusive. |
NPerm regina::NTetrahedron::getFaceMapping | ( | int | face | ) | const [inline] |
The face in the skeleton corresponding to the requested face of this tetrahedron is examined, and a permutation mapping vertices (0,1,2) of the skeleton face to the corresponding vertices of this tetrahedron is returned.
Thus, for each i=0,1,2
and all tetrahedra containing this skeleton face, getFaceMapping(...)[i]
will refer to vertices that are all identified to each other along the skeleton face concerned.
face | the face of this tetrahedron to examine. This should be between 0 and 3 inclusive. |
int regina::NTetrahedron::orientation | ( | ) | const [inline] |
Returns the orientation of this tetrahedron in the triangulation.
The orientation of each tetrahedron is always +1 or -1. In an orientable component of a triangulation, adjacent tetrahedra have the same orientations if one could be transposed onto the other without reflection, and they have opposite orientations if a reflection would be required. In a non-orientable component, orientations are still +1 and -1 but no further guarantees can be made.
void regina::NTetrahedron::writeTextShort | ( | std::ostream & | out | ) | const [inline, virtual] |
Writes this object in short text format to the given output stream.
The output should fit on a single line and no newline should be written.
out | the output stream to which to write. |
Implements regina::ShareableObject.
friend class NTriangulation [friend] |
Allow access to private members.