GRID: An Interactive Tool for Computing Orthogonal Drawings With the Minimum Number of Bends

In this paper we present a new interactive tool for computing orthogonal grid drawings of planar graphs. The tool is based on GDToolkit, an object-oriented library of classes for handling graphs and computing their layout. GDToolkit is built on LEDA (an efficient library of data types and algorithms) and currently implements three orthogonal layout methods. Especially, we provide a new branch-and-bound algorithm choosing a planar embedding in order to minimise the number of bends. The enumeration schema of the branch-and-bound algorithm is based on the GDToolkit SPQR-tree class (as far as we know, the only existing SPQR-tree implementation). The tool offers an interactive graphical interface to the branch-and-bound algorithm, which allows to edit the embedding, to execute the algorithm step by step and to view partial results. It also gives quality measures on the drawing, and quantitative measures on the algoritm's performance.