GLIDE [chapter]

Kathy Ryall
2002 Lecture Notes in Computer Science  
The glide (Graph Layout Interactive Diagram Editor) system (first presented at GD'96 [4]) improves on general constraint-based approaches to drawing and layout by supporting only a small set of "macro" constraints, known as VOFs (visual organization features). They are specifically suited to graph drawing, contributing both aesthetic and semantic information. To date, glide remains the only interactive graph drawing tool to support the use of VOFs or similar constructs. More recent work [1][3]
more » ... as begun to investigate the importance of visual organization in graph drawing. Areas of Application Glide is intended for interactive drawing of small graphs, most often used in publications or presentations. By exploiting the advanced techniques that have been developed by both the graph-drawing or constraint-based-layout communities, glide supports the exquisite symmetries, spacings, and alignments that graphic designers utilize in professional-grade work. Layout Algorithms and Layout Features Glide is based on constraints, but ones that are designed specifically for drawing graphs, not general graphics. These "macro" constraints, or Visual Organization Features (VOFs) [2] , and their application in glide are described more fully in [5] . In glide, VOFs can be applied and removed interactively. Furthermore, the tool enforces syntactic constraints, such as preventing nodes overlapping other nodes/edges. The VOF and syntactic constraints are enforced by a generalized spring algorithm. Glide converts each VOF instance into a set of constraints. The physical simulation of the resulting mass-spring model is continuously animated, indicating to the user the influence of the chosen VOFs. The user may move nodes and groups of nodes while the simulation proceeds in order to aid the system in finding better global solutions to the implicit constraint-satisfaction problem. The use of a constraint-satisfaction scheme (mass-spring simulation) that is intuitive and predictable, rather than one better at finding global solutions, is deliberate. Glide is intended to support a user and the computer in jointly solving the layout problem. For this purpose predictability, simplicity, and the compelling nature of the animation are more important than global optimality.
doi:10.1007/3-540-45848-4_55 fatcat:q2ukcvaftfbyreojpgu6vgnluy