News

We have released the first update of the gml2pic utility, which adds support for rendering edges as curved lines using Bézier curves and circular arcs. These curves are automatically computed from the given polylines in the GML file; see excerpt from a drwaing of unix-history-time.gml on the right.

The new features are as follows:

• Automatic generation of curved lines from the given polyline in the GML file. You can chose between quadratic and cubic Bézier curves and circular arcs (options -curve and -curvedLength).
• Support for additional node templates (i.e. node shapes): hexagon, rhombus, and trapeze.
• Support for using file patterns when calling gml2pic, e.g. you can now write gml2pic graph*.gml for processing all graphs fulfilling the pattern g*.gml.
• You can now specify an additional margin around the drawing (option -margin).
• There is now an option for determining the amount of output, so you can chose between no output at all (useful when running a script) or some informative output (option -msg-level).
• The binaries in the Windows installer package are now statically linked against Qt, so there is no need anymore to distribute Qt DLLs (this shrinks the size of the .msi).

You can download the new version v1.1 on gml2pic's homepage.

Today, we released our first internal project based on OGDF. The program gml2pic is a command line utility for converting a drawing stored as GML file into graphics file, like e.g. a JPEG or PDF file. It works perfectly together with OGDF and allows to view layouts produced by OGDF layout algorithms in an easy way. Simply store the layout as GML file and call gml2pic for this file. The program also supports various graphical attributes (similar as GDE) like colors and line styles, different fonts and even rich text. Here are some highlights:

• supports GML file format extensions as used by OGDF and GDE
• drawing of nodes, edges, and clusters
• supports line styles, colors, and width for nodes, edges, and clusters
• flexible drawing of arrow heads scaled with respect to line width, with correct anchoring at node bounding boxes
• drawing of rich text with formatting of font, style, color, and alignment
• various bitmap formats (PNG, JPEG, TIFF), freely scalable bitmap size
• anti-aliasing of lines and text in bitmap graphics
• true vector graphics (SVG, PDF, EPS) with correct bounding boxes

Please have a look at gml2pic's homepage for further information. You will also find various examples there that have been produced by gml2pic.

There are also new forums at the OGDF forums page, where you can discuss anything related to programs and projects that use OGDF.

Today, we released the new version v2010.10 (Sassafras) of OGDF! This release brings various new algorithms and features. The most important highlights are:

• Basic multithreading support and a completely revised memory management, including a thread-safe pool-memory allocator.
• New hierarchical graph layout method using upward planarization (class UpwardPlanarization); outperforms traditional Sugiyama-based methods with respect to crossings by far.
• New multilevel layout algorithm (FastMultipoleMultilevelEmbedder), based on the multipole method, well-separated pair decomposition, and a new quad-tree space partitioning (Martin Gronemann's Diploma thesis); makes use of SSE and multicore processors and is significantly faster than FMMMLayout.
• New modular framework for multilevel graph layout (class ModularMultilevelMixer) with various options for coarsening, placement, and single-level layout.
• New force-directed layout algorithms: Kamada-Kawai (class SpringEmbedderKK) and stress majorization (class StressMajorization).
• Added support for OGML graph file format.
• Exact algorithms for computing maximum planar and maximum c-planar subgraphs (classes MaximumPlanarSubgraph and MaximumCPlanarSubgraph).
• Support for latest versions of Visual Studio and g++ compilers.

For a complete list of changes, please refer to the version history and Sassafras' change-log.

To continue the tradition, the OGDF team has won again a first prize at this year's Graph Drawing conference in Konstanz, Germany. This time, the topic of the online challenge was to minimize the length of the longest edge in planar orthogonal drawings of 4-planar graphs. Prof. Mutzel used Martin Gronemann's Gryphon graph editor (unfortunately not publicly available yet) and a little moral support from last year's winner Hoi-Ming Wong. We're looking forward to see some more competition in next year's challenge, since this time only one team participated in the automatic category.

The OGDF team of TU Dortmund wins again the GD 2009 challenge in automatic upward crossing minimization at the Graph Drawing conference in Chicago, USA. We congratulate Hoi-Ming Wong and Karsten Klein for winning the first prize!

The OGDF team of TU Dortmund wins the GD 2008 challenge in automatic upward crossing minimization at the Graph Drawing conference in Heraklion, Crete. The winning software used ogdf's upward planarization algorithm, to be available in ogdf's upcoming Sassafras release, and achieved a perfect score of 6 out of 6 points. The competition also included the commercial software by Tom Sawyer as well as AT&T's GraphViz.

The second public release of OGDF has been released today. This release focuses on improved usability, but also contains new functionality. Highlights of the new release are:

• A new algorithm for planar augmentation with fixed embedding, and extended functionality for drawing graphs with a given planar embedding.
• A new class DualGraph for representing the geometric dual graph of a combinatorial embedding.
• Sugiyama layout now produces drawings with given node ranks that are also respected across different connected components.
• Hashing functions can now be passed as template parameters; the implementation of two-dimensional hash-arrays has been revised and allows now using different types for each index. Array-based classes have now an optional template parameter for the index type.
• Unified naming conventions and interfaces; significantly improved documentation.
• Improved build system, including support for compiling with Osi Coin in Visual Studio and creating projects for Visual Studio 2003.
• The library is now licensed under GPL v2 or v3 (you have the choice) with special exceptions allowing to link against LP-solver libraries.

Please refer to the change-log for further details.

The first hotfix v.2007.09_a for Jacaranda has been released and is available at the download page. It fixes a bug that occurs when using OGDF with Coin.

The first public release of OGDF (v.2007.09, Codename “Jacaranda”) goes online, including this website, forum, and doxygen-documentation.