foxglove

OGDF » Release Notes » Foxglove

OGDF Foxglove (2025.10)

Released 2025-10-27.

This release contains many significant improvements to core functionality, including a unified Graph::insert and NodeArrays/EdgeArrays that store their data in std::vectors. Moreover, we enhanced the build process by, e.g., properly enabling multi-config builds and packaging via CPack. However, as a result, this release also comes with several notable breaking changes. For example, OGDF now requires C++17. Thus, we strongly suggest to read the porting guide.

Note that to simplify access to the OGDF, we also plan to publish an OGDF docker image and to improve support of C++ package managers in the future.

Noteworthy changes:

• build:
  • OGDF now requires C++17 features
  • improved compatibility with Windows MinGW, Apple silicon, and CGAL 6
  • fixes for linking user code with out-of-source OGDF builds
  • aligned symbol visibility on Windows and Unix
  • updated install declaration using GNUInstallDirs
  • enabled multi-config builds (i.e., parallel debug and release builds)
    • debug binaries and libs are now marked with -debug
  • enabled packaging via CPack
• core functionality:
  • new unified and versatile Graph::insert implementation:
    • variants to insert subgraphs via iterators, lists, filter functions
    • options for notifying observers and keeping embedding or node/edge IDs
    • replaces Graph::copy(), Graph::construct*(), Graph::assign(), and GraphCopy(Simple)::init*()
  • new RegisteredArray:
    • as underlying class for NodeArray, EdgeArray, FaceArray etc.
    • now uses std::vector instead of ogdf::Array for data storage
    • new NodeArrayP etc. to wrap non-movable objects in std::unique_ptr
    • new invertRegisteredArray to transfer XArray<Y> into YArray<X>
  • new RegisteredSet:
    • as underlying class for NodeSet, FaceSet, ClusterSet
    • automatically removes members that are deleted from the resp. registry
    • always allows for efficient size()
    • new EdgeSet and AdjEntrySet
  • new Observer and Observable:
    • as underlying class for GraphObserver, RegisteredSets etc.
    • new (Graph)Observer::registrationChanged()
    • new ClusterGraphObserver::clustersCleared()
  • GraphCopy and GraphCopySimple:
    • now with common superclass GraphCopyBase
    • new GraphCopyBase::setOriginalGraph() replacing createEmpty()
    • new GraphCopySimple::copyEmbeddingToOriginal()
    • new generic copyEmbedding()
  • ClusterGraph:
    • new ClusterGraph::representsConnectedCombEmbedding()
    • new ClusterGraph::planarizeClusterBorderCrossings()
    • new ClusterGraph::adjAvailable()
    • new cluster->isDescendant()
• graph algorithms:
  • new algorithms for Min-Weight Perfect Matching (MWPM):
    • MatchingModule
    • MatchingBlossom
    • MatchingBlossomV
    • MatchingImplementation as the current best OGDF MWPM algorithm
  • new node coloring heuristics:
    • NodeColoringModule
    • NodeColoringBergerRompel
    • NodeColoringBoppanaHalldorsson
    • NodeColoringHalldorsson
    • NodeColoringJohnson
    • NodeColoringRecursiveLargestFirst
    • NodeColoringSequential
    • NodeColoringSimple
    • NodeColoringWigderson
  • new PCTree for planarity testing
  • new Synchronized Planarity functionality:
    • SyncPlan for modeling and solving SyncPlan instances
    • ClusterPlanarityModule for computing cluster-planar embeddings
    • SyncPlanClusterPlanarityModule
    • randomSyncPlanInstance() generator
    • randomSEFEInstanceBy...() generators
• graph decomposition:
  • new FourBlockTree for construction and traversal of 4-block trees
  • new parameter for connectedComponents() to get comp representatives
  • new CCsInfo::nodes(int cc) and CCsInfo::edges(int cc)
  • new access methods for member vars of BCTree and DynamicSPQRForest
  • new operator<< for nodes of BCTree and DynamicSPQRForest
• graph generators:
  • new randomProperMaximalLevelPlaneGraph()
  • new pruneEdges() to enforce a maximum edge number
  • new graph operations join(), intersection(), and complement()
  • reworked cluster generators:
    • old randomClusterPlanarGraph renamed randomCConnectedClustering()
    • old randomClusterGraph renamed randomClustering()
    • new randomClusterPlanarGraph
    • new randomPlanarClustering
• layouts:
  • TreeLayout now works on non-arborescence forests
  • SimpleCCPacker now correctly preserves edge bends
  • ComponentSplitterLayout now correctly preserves edge bends
• memory allocation:
  • PoolMemoryAllocator::defrag() renamed defragGlobal()
  • new PoolMemoryAllocator::defragThread()
  • new PoolMemoryAllocator::get{Global,Thread}FreeListSizes()
  • new OGDFAllocator for use with containers of the C++ standard lib
• miscellaneous:
  • HiddenEdgeSet now has begin(), end(), and empty()
  • new Graph::sort(node v, ITER begin, ITER end) to adapt rotation systems
  • new indent parameter for Logger::lout()
    • new Logger::setIndent(), Logger::indent(), Logger::dedent()
  • SvgPrinter now correctly connects arrow heads to the edge's target
• OGDF development:
  • documentation now powered by Netlify
  • new CODE_OF_CONDUCT.md
  • new utility OGDF_-macros for declaring c'tors and assignment operators
  • new OGDF_IF_DBG macro for single-line statements in debug mode
  • new indent_comments.py for formatting comments
  • new style/test_all.sh for unified style check
  • usage of include-what-you-use
  • new make_release.sh for easier release management

This release contains (big and small) contributions by Antoine Lambert, Dominik Potulski, Felix F Xu, Gregor Diatzko, Jan-Niklas Buckow, Joshua Sangmeister, Lily Wang, Max Ilsen, Simon Dominik "Niko" Fink, and Sven Strickroth. Thanks a lot to all contributors!