Regina Calculation Engine
Public Member Functions | Static Public Member Functions
regina::NPillowTwoSphere Class Reference

Represents a 2-sphere made from two faces glued together along their three edges. More...

#include <npillowtwosphere.h>

Inheritance diagram for regina::NPillowTwoSphere:
regina::ShareableObject regina::boost::noncopyable

List of all members.

Public Member Functions

NPillowTwoSphereclone () const
 Returns a newly created clone of this structure.
NFacegetFace (int index) const
 Returns one of the two faces whose boundaries are joined.
NPerm getFaceMapping () const
 Returns a permutation describing how the boundaries of the two faces are joined.
void writeTextShort (std::ostream &out) const
 Writes this object in short text format to the given output stream.

Static Public Member Functions

static NPillowTwoSphereformsPillowTwoSphere (NFace *face1, NFace *face2)
 Determines if the two given faces together form a pillow 2-sphere.

Detailed Description

Represents a 2-sphere made from two faces glued together along their three edges.

The two faces must be distinct and the three edges of each face must also be distinct. Neither of the faces may be boundary faces. These two faces together form an embedded 2-sphere in the triangulation (with the exception that two or three points of the sphere corresponding to the face vertices may be identified).

This 2-sphere can be cut along and the two resulting 2-sphere boundaries filled in with 3-balls, and the resulting triangulation has the same number of tetrahedra as the original. If the original 2-sphere was separating, the resulting triangulation will contain the two terms of the corresponding connected sum.


Member Function Documentation

NPillowTwoSphere* regina::NPillowTwoSphere::clone ( ) const

Returns a newly created clone of this structure.

Returns:
a newly created clone.
static NPillowTwoSphere* regina::NPillowTwoSphere::formsPillowTwoSphere ( NFace face1,
NFace face2 
) [static]

Determines if the two given faces together form a pillow 2-sphere.

Precondition:
The two given faces are distinct.
Parameters:
face1the first face to examine.
face2the second face to examine.
Returns:
a newly created structure containing details of the pillow 2-sphere, or null if the given faces do not form a pillow 2-sphere.
NFace * regina::NPillowTwoSphere::getFace ( int  index) const [inline]

Returns one of the two faces whose boundaries are joined.

Parameters:
indexspecifies which of the two faces to return; this must be either 0 or 1.
Returns:
the corresponding face.
NPerm regina::NPillowTwoSphere::getFaceMapping ( ) const [inline]

Returns a permutation describing how the boundaries of the two faces are joined.

The permutation will map vertices (0,1,2) of getFace(0) to vertices (0,1,2) of getFace(1). The map will represent how the vertices of the faces are identified by the three edge gluings.

Returns:
a permutation describing how the face boundaries are joined.
void regina::NPillowTwoSphere::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.

Python:
The parameter out does not exist; standard output will be used.
Parameters:
outthe output stream to which to write.

Implements regina::ShareableObject.


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

Copyright © 1999-2009, Ben Burton
This software is released under the GNU General Public License.
For further information, or to submit a bug or other problem, please contact Ben Burton (bab@debian.org).