%\RCSdef{\RCSTriangulationRev}{$Id$} %\RCSdefDate{\RCSTriangulationDate}{$Date$} \ccRefChapter{Triangulations\label{chap:triangulation_ref}} \ccChapterAuthor{Samuel Hornus \and Olivier Devillers} A triangulation is a pure simplicial complex, connected and without singularities. Its faces are such that two of them either do not intersect or share a common face. The basic triangulation class of \cgal\ is primarily designed to represent the triangulations of a set of points $A$ in $\R^d$. It can be viewed as a partition of the convex hull of $A$ into simplices whose vertices are the points of $A$. Together with the unbounded cells having the convex hull boundary as its frontier, the triangulation forms a partition of $\R^d$. In order to deal only with full dimensional simplices (full cells), which is convenient for many applications, the space outside the convex hull is subdivided into simplices by considering that each convex hull facet is incident to an infinite cell having as vertex an auxiliary vertex called the infinite vertex. In that way, each facet is incident to exactly two cells and special cases at the boundary of the convex hull are simple to deal with. A triangulation is a collection of vertices and cells that are linked together through incidence and adjacency relations. Each cell gives access to its its incident vertices and to its its adjacent cells. Each vertex gives access to one of its incident cells. The vertices of a cell are indexed in positive orientation, the positive orientation being defined by the orientation of the underlying Euclidean space $\R^d$. The neighbors of a cell are also indexed in such a way that the neighbor indexed by $i$ is opposite to the vertex with the same index. \section{Reference Pages Sorted by Type} \subsection{Concepts} \subsubsection*{Triangulation data structure} \ccRefConceptPage{TriangulationDataStructure} The above concept is also abbreviated as \ccc{TDS}. It defines three types, \ccc{Vertex}, \ccc{Full_cell} and \ccc{Face}, that must respectively fulfill the following concepts: \ccRefConceptPage{TriangulationDSVertex}\\ \ccRefConceptPage{TriangulationDSFullCell}\\ \ccRefConceptPage{TriangulationFace} The above first two concepts are also abbreviated respectively as \ccc{TDSVertex} and \ccc{TDSFullCell}. \subsubsection*{(Geometric) triangulations} \ccRefConceptPage{TriangulationTraits}\\ \ccRefConceptPage{DelaunayTriangulationTraits}\\ %\ccRefConceptPage{RegularTriangulationTraits} \ccRefConceptPage{TriangulationVertex}\\ \ccRefConceptPage{TriangulationFullCell} The above concepts are also abbreviated respectively as \ccc{TrTraits}, \ccc{DTTraits}, %\ccc{RTTraits}, \ccc{TrVertex} and \ccc{TrFullCell}. \subsection{Classes} \subsubsection*{Triangulation data structure} \ccRefIdfierPage{CGAL::Triangulation_data_structure}\\ \ccRefIdfierPage{CGAL::Triangulation_ds_vertex}\\ \ccRefIdfierPage{CGAL::Triangulation_ds_full_cell} \ccRefIdfierPage{CGAL::Triangulation_face} \subsubsection*{(Geometric) triangulations} \ccRefIdfierPage{CGAL::Triangulation}\\ \ccRefIdfierPage{CGAL::Delaunay_triangulation} %\ccRefIdfierPage{CGAL::Regular_triangulation} \ccRefIdfierPage{CGAL::Triangulation_vertex}\\ \ccRefIdfierPage{CGAL::Triangulation_full_cell} \subsection{Enums} \ccRefIdfierPage{CGAL::Triangulation::Locate_type}