An Object-Oriented Model for the Hierarchical Composition of Letterforms in Computer-Aided Typeface Design

The scope of this paper is to present an object-oriented model for the hierarchical composition of letterforms within the typeface design process. The model is oriented towards traditional type design techniques as those are most likely to be accepted by the designer community. Moreover, the model is stroke-based in order to reflect the process of drawing letterforms most naturally. Style is kept consistent by a constraint mechanism, which becomes very powerful by constraining stroke properties instead of outline control points. Especially, non-linear dependencies in style can be expressed as well. The hierarchical approach allows for the propagation of style attributes, affecting all derived letterforms sharing the same attributes. With some minor changes, totally different typefaces can be generated from existing ones, significantly speeding up the type design process. Since the presented model is closely related to traditional type design techniques, it is suitable to serve as a des ign paradigm for computer aided typeface design systems. The model is not restricted to a certain class of characters. Especially, it may be used for the design of non-latin characters as well.