# OpenGraph DrawingFramework

v. 2022.02 (Dogwood)

ogdf::PlanarizationGridLayout Class Reference

The planarization grid layout algorithm. More...

#include <ogdf/planarity/PlanarizationGridLayout.h>

Inheritance diagram for ogdf::PlanarizationGridLayout:

## Public Member Functions

PlanarizationGridLayout ()
Creates an instance of planarization layout and sets options to default values. More...

~PlanarizationGridLayout ()

Optional parameters
double pageRatio () const
Returns the current setting of option pageRatio. More...

void pageRatio (double ratio)
Sets the option pageRatio to ratio. More...

Module options
void setCrossMin (CrossingMinimizationModule *pCrossMin)
Sets the module option for crossing minimization. More...

void setPlanarLayouter (GridLayoutPlanRepModule *pPlanarLayouter)
Sets the module option for the planar grid layout algorithm. More...

void setPacker (CCLayoutPackModule *pPacker)
Sets the module option for the arrangement of connected components. More...

Further information
int numberOfCrossings () const
Returns the number of crossings in computed layout. More...

Public Member Functions inherited from ogdf::GridLayoutModule
GridLayoutModule ()
Initializes a grid layout module. More...

virtual ~GridLayoutModule ()

virtual void call (GraphAttributes &GA) override final
Calls the grid layout algorithm (general call). More...

void callGrid (const Graph &G, GridLayout &gridLayout)
Calls the grid layout algorithm (call for GridLayout). More...

const IPointgridBoundingBox () const

double separation () const
Returns the current setting of the minimum distance between nodes. More...

void separation (double sep)
Sets the minimum distance between nodes. More...

Public Member Functions inherited from ogdf::LayoutModule
LayoutModule ()
Initializes a layout module. More...

virtual ~LayoutModule ()

void operator() (GraphAttributes &GA)
Computes a layout of graph GA. More...

## Protected Member Functions

virtual void doCall (const Graph &G, GridLayout &gridLayout, IPoint &boundingBox) override
Implements the algorithm call. More...

## Private Attributes

std::unique_ptr< CrossingMinimizationModulem_crossMin
The module for computing a planar subgraph. More...

int m_nCrossings
The number of crossings in the computed layout. More...

std::unique_ptr< CCLayoutPackModulem_packer
The module for arranging connected components. More...

double m_pageRatio
The desired page ratio. More...

std::unique_ptr< GridLayoutPlanRepModulem_planarLayouter
The module for computing a planar grid layout. More...

Protected Attributes inherited from ogdf::GridLayoutModule
IPoint m_gridBoundingBox
The computed bounding box of the grid layout. More...

## Detailed Description

The planarization grid layout algorithm.

The class PlanarizationGridLayout represents a customizable implementation of the planarization approach for drawing graphs. The class uses a planar grid layout algorithm as a subroutine and allows to generate a usual layout or a grid layout.

The implementation used in PlanarizationGridLayout is based on the following publication:

C. Gutwenger, P. Mutzel: An Experimental Study of Crossing Minimization Heuristics. 11th International Symposium on Graph Drawing 2003, Perugia (GD '03), LNCS 2912, pp. 13-24, 2004.

### Optional parameters

OptionTypeDefaultDescription
pageRatiodouble1.0 Specifies the desired ration of width / height of the computed layout. It is currently only used when packing connected components.

### Module options

The various phases of the algorithm can be exchanged by setting module options allowing flexible customization. The algorithm provides the following module options:

OptionTypeDefaultDescription
crossMinCrossingMinimizationModuleSubgraphPlanarizer The module used for the crossing minimization step.
planarLayouterGridLayoutPlanRepModuleMixedModelLayout The planar layout algorithm used to compute a planar layout of the planarized representation resulting from the crossing minimization step.
packerCCLayoutPackModuleTileToRowsCCPacker The packer module used for arranging connected components.

Definition at line 91 of file PlanarizationGridLayout.h.

## ◆ PlanarizationGridLayout()

 ogdf::PlanarizationGridLayout::PlanarizationGridLayout ( )

Creates an instance of planarization layout and sets options to default values.

## ◆ ~PlanarizationGridLayout()

 ogdf::PlanarizationGridLayout::~PlanarizationGridLayout ( )
inline

Definition at line 97 of file PlanarizationGridLayout.h.

## ◆ doCall()

 virtual void ogdf::PlanarizationGridLayout::doCall ( const Graph & G, GridLayout & gridLayout, IPoint & boundingBox )
overrideprotectedvirtual

Implements the algorithm call.

A derived algorithm must implement this method and return the computed grid layout in gridLayout.

Parameters
 G is the input graph. gridLayout is assigned the computed grid layout. boundingBox returns the bounding box of the grid layout. The lower left corner of the bounding box is always (0,0), thus this IPoint defines the upper right corner as well as the width and height of the grid layout.

Implements ogdf::GridLayoutModule.

## ◆ numberOfCrossings()

 int ogdf::PlanarizationGridLayout::numberOfCrossings ( ) const
inline

Returns the number of crossings in computed layout.

Definition at line 162 of file PlanarizationGridLayout.h.

## ◆ pageRatio() [1/2]

 double ogdf::PlanarizationGridLayout::pageRatio ( ) const
inline

Returns the current setting of option pageRatio.

This option specifies the desired ration width / height of the computed layout. It is currently only used for packing connected components.

Definition at line 110 of file PlanarizationGridLayout.h.

## ◆ pageRatio() [2/2]

 void ogdf::PlanarizationGridLayout::pageRatio ( double ratio )
inline

Sets the option pageRatio to ratio.

Definition at line 115 of file PlanarizationGridLayout.h.

## ◆ setCrossMin()

 void ogdf::PlanarizationGridLayout::setCrossMin ( CrossingMinimizationModule * pCrossMin )
inline

Sets the module option for crossing minimization.

Definition at line 125 of file PlanarizationGridLayout.h.

## ◆ setPacker()

 void ogdf::PlanarizationGridLayout::setPacker ( CCLayoutPackModule * pPacker )
inline

Sets the module option for the arrangement of connected components.

The planarization layout algorithm draws each connected component of the input graph seperately, and then arranges the resulting drawings using a packing algorithm.

Definition at line 151 of file PlanarizationGridLayout.h.

## ◆ setPlanarLayouter()

 void ogdf::PlanarizationGridLayout::setPlanarLayouter ( GridLayoutPlanRepModule * pPlanarLayouter )
inline

Sets the module option for the planar grid layout algorithm.

The planar layout algorithm is used to compute a planar layout of the planarized representation resulting from the crossing minimization step. Planarized representation means that edge crossings are replaced by dummy nodes of degree four, so the actual layout algorithm obtains a planar graph as input. By default, the planar layout algorithm produces an orthogonal drawing.

Definition at line 140 of file PlanarizationGridLayout.h.

## ◆ m_crossMin

 std::unique_ptr ogdf::PlanarizationGridLayout::m_crossMin
private

The module for computing a planar subgraph.

Definition at line 174 of file PlanarizationGridLayout.h.

## ◆ m_nCrossings

 int ogdf::PlanarizationGridLayout::m_nCrossings
private

The number of crossings in the computed layout.

Definition at line 184 of file PlanarizationGridLayout.h.

## ◆ m_packer

 std::unique_ptr ogdf::PlanarizationGridLayout::m_packer
private

The module for arranging connected components.

Definition at line 180 of file PlanarizationGridLayout.h.

## ◆ m_pageRatio

 double ogdf::PlanarizationGridLayout::m_pageRatio
private

The desired page ratio.

Definition at line 182 of file PlanarizationGridLayout.h.

## ◆ m_planarLayouter

 std::unique_ptr ogdf::PlanarizationGridLayout::m_planarLayouter
private

The module for computing a planar grid layout.

Definition at line 177 of file PlanarizationGridLayout.h.

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