Graphs are useful tools for solving many problems in real worlds. Moreover, their visualization is helpful to understand the structures of problems. Therefore, it becomes popular to construct a geometric representation of a graph so called graph drawing. In this thesis, we present a convenient environment for developing graph drawing algorithms. The environment, Degas(Development Environment for Graph Drawing Algorithms) consists of 3 parts: a graph drawing library system, an algorithm animation system, and a graphic user interface.
The graph drawing library system has a hierarchical structure due to the complex nature of graph data types and their relations to drawing algorithms. In order to support this structure, our library system is constructed using object-oriented paradigm. In the library system, we define graph data types including a geometric information and implement basic graph operations such as vertex ordering and dual graph construction to support graph drawing. We also provide an algorithm animation system. Algorithm animation is a technique for visualizing the stepwise results of an algorithm. Therefore, the animated drawing algorithms are helpful to understand how to draw a graph by the algorithm and may motivate new idea for graph drawing. The algorithm animation system also can be used as a debugger to find logical errors of drawing algorithms. In order to visualize geometric representations generated by graph drawing algorithms, GUI(Graphic User Interface) is indispensable. Degas not only provides a convenient user interface to create and modify a graph but also supports graph visualization. Examples are given to illustrated how to use Degas to develop graph drawing algorithms.
