In a planar L-drawing of a directed graph (digraph) each edge e is represented as a polyline composed of a vertical segment starting at the tail of e and a horizontal segment ending at the head of e. Distinct edges may overlap, but not cross. Our main focus is on bimodal graphs, i.e., digraphs admitting a planar embedding in which the incoming and outgoing edges around each vertex are contiguous. We show that every plane bimodal graph without 2-cycles admits a planar L-drawing. This includes the class of upward-plane graphs. Finally, outerplanar digraphs admit a planar L-drawing – although they do not always have a bimodal embedding – but not necessarily with an outerplanar embedding.
Angelini, P., Chaplick, S., Cornelsen, S., DA LOZZO, G. (2020). Planar L-Drawings of Bimodal Graphs. In Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) (pp.205-219). Springer Science and Business Media Deutschland GmbH [10.1007/978-3-030-68766-3_17].