tlp::PlanarityTest Class Reference

#include <PlanarityTest.h>

Static Public Member Functions
static std::list< edge >	getObstructionsEdges (Graph *graph)
static bool	isPlanar (Graph *graph)
static bool	isPlanarEmbedding (const Graph *graph)
static bool	planarEmbedding (Graph *graph)

Detailed Description

performs tests to check whether a graph is planar. From wikipedia: "A planar graph is a graph that can be embedded in the plane, i.e., it can be drawn on the plane in such a way that its edges intersect only at their endpoints."

Definition at line 37 of file PlanarityTest.h.

Member Function Documentation

getObstructionsEdges()

static std::list<edge> tlp::PlanarityTest::getObstructionsEdges ( Graph *  graph )

static

Computes a list of edges that prevent the graph from being planar (i.e. part of the minor of K3,3 or K5).

Parameters

graph

The graph on which to compute the obstruction edges.

Returns

:list< tlp::edge, std::allocator< tlp::edge > > The obstruction edges.

isPlanar()

static bool tlp::PlanarityTest::isPlanar ( Graph *  graph )

static

Checks whether the graph is planar (i.e. the graph can be drawn on the plane in such a way that no edges cross each other).

Parameters

graph

The graph to check for planarity.

Returns

bool True if the graph is planar, false otherwise.

Note

The graph is made biconnected to ease (?) the computation.

isPlanarEmbedding()

static bool tlp::PlanarityTest::isPlanarEmbedding ( const Graph *  graph )

static

Checks if the graph is plane (or a planar embedding). A planar graph can be drawn such as no edges cross each other, a plane graph is drawn such as no edges cross each other.

Returns true if the current embedding of the graph is planar, false otherwise.

Parameters

graph

The graph to check for a planar e;bedding.

Returns

bool True if the graph is a planar embedding, false otherwise.

planarEmbedding()

static bool tlp::PlanarityTest::planarEmbedding ( Graph *  graph )

static

Makes a planar graph a planar embedding, i.e. makes a graph so that no edges cross each other if it is known to be possible. This modifies the order of the edges around the nodes.

Parameters

graph

The graph to make a planar embedding of.

Returns

bool True if the graph is planar, false otherwise.