A user interface for simulating calligraphic pens and brushes

Abstract

CAD and graphics packages running on microcomputers are becoming increasingly popular for applications such as business charts, engineering designs, and computer art. Such packages typically provide a choice of different line styles and widths for creating drawings and images. Text is usually created using the fonts provided by the packages. Variations from the pre-defined line styles and fonts are allowed but are usually defined in an awkward, pixel by pixel process. Certain drawing and writing implements, specifically calligraphic pens and brushes, do not migrate naturally to a raster-display, keyboard-entry, mouse-dragging environment. This paper describes a user interface being developed at the University of North Florida Center for Human-Machine Studies to simulate calligraphic pens and brushes for use in a low cost environment, namely, a microcomputer equipped with a mouse device. This is the environment chosen simply because of its availability and also due to lack of a low cost (or even a high cost) input device that allows a natural simulation of painting or drawing with calligraphic pens and brushes. The interface along with underlying algorithms and data structures is described. Some example characters and “art work” are also presented. The objective of the interface is to allow the production of such characters and “art work” using the concept of a more natural “brush stroke” rather than a pixel-by-pixel or manual-outline and painting process.