A vertex record in a DCEL data structure. A vertex is always associated with a point. However, the vertex record only stores a pointer to the associated point, and the actual Point
object is stored elsewhere.
A vertex usually has several halfedges incident to it, such that it is possible to access one of these halfedges directly and to traverse all incident halfedges around the vertex. However, the DCEL may also contain isolated vertices that have no incident halfedges. In this case, the vertex stores an isolated vertex-information record, indicating the face that contains this vertex in its interior.
- See also
ArrangementDcel
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ArrangementDcelHalfedge
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ArrangementDcelIsolatedVertex
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All functions below also have const counterparts, returning non-mutable pointers or references:
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bool | is_isolated () const |
| returns whether the vertex is isolated (has no incident halfedges).
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Halfedge * | halfedge () |
| returns an incident halfedge that has v as its target. More...
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Isolated_vertex * | isolated_vertex () |
| returns the isolated vertex-information record. More...
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bool | has_null_point () const |
| returns whether the vertex is not associated with a valid point (i.e. it lies at infinity).
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Point & | point () |
| returns the associated point. More...
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Arr_parameter_space | parameter_space_in_x () const |
| returns the placement of the \( x\)-coordinate in the parameter space, that is, either the left boundary-side, the interior, or the right boundary-side.
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Arr_parameter_space | parameter_space_in_y () const |
| returns the placement of the \( y\)-coordinate in the parameter space, that is, either the bottom boundary-side, the interior, or the top boundary-side.
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