An enhanced grammatical approach for graph drawing

Abstract

With the development of computer-aided design, visual languages have been widely used as formal methods to represent various types of graphical models. Accordingly, many grammar systems have been proposed for the specification of visual languages. However, apart from shape grammar, most grammars focus on the abstract structures of the languages and ignore the semantic modeling of graph drawing. Furthermore, shape grammar supports generation rather than parsing, with its limited application scope. To address these problems, this paper proposes an enhanced grammar system based on Coordinate Graph Grammar (CGG). Different from traditional grammars, the enhanced system defines a new type of grammatical rule named shape rules to transform graphs into shapes by shape applications. In each shape application, the assertion set describes the range of validity, and shapes can be generated by translation, zoom, and rotation to a set of rule-based coordinates. With the combinations of shape applications and L-applications, the node-edge graph and drawn outline could both be specified, building a bridge between abstract structures and physical layouts of visual languages. An example is given to illustrate the application of the enhanced system in industrial design, where a Bauhaus-style baby cradle is generated by the combination of shape applications and L-applications.