Top-Down Drawings of Compound Graphs

TL;DR

This work proposes top-down layout, which utilizes scale to hide low-level details at high zoom levels, so the entire high-level view can fit into the viewport and remain readable, while the ability to zoom in to see the details is still maintained.

Abstract

Bottom-up layout algorithms for compound graphs are suitable for presenting the microscale view of models and are often used in model-driven engineering. However, they have difficulties at the macroscale where maintaining the overview of large models becomes challenging. We propose top-down layout, which utilizes scale to hide low-level details at high zoom levels. The entire high-level view can fit into the viewport and remain readable, while the ability to zoom in to see the details is still maintained. Top-down layout is an abstract high-level layout process that can be used in conjunction with classic layout algorithms to produce visually compelling and readable diagrams of large compound graphs.

Figures (8)

• Figure 1: Comparison of bottom-up and top-down layout for a compound graph. In this case, the graph is an SCChart that represents a railway wagon.
• Figure 2: Different cases of Topdownpacking.
• Figure 3: Comparison of the bottom-up layout and three different top-down layout configurations for the Controller example SCChart.
• Figure 4: Conversion from $z$-level to diagram scale.
• Figure 5: Illustration of the scale calculations that are done in top-down layouts.