Interactive Graphics Using MathLink

Interactive graphics effectively expresses the dynamic structure of a model, and helps improve the intuitive understanding of concepts in the sciences. Also it can be used as a user-interface tool. Currently, Mathematica graphics is not interactive but static and merely a side effect of computation. It is not possible to select a part of a graphic using the mouse, nor can one make interactive dynamic relationships between graphical elements. The graphics system introduced here is a MathLink program for creating interactive graphical objects which the user can manipulate. In this program, all graphics elements--point, line, curve, and text--are represented as objects which can be manipulated by mouse; all graphics are manipulated by a kernel evaluation; and the relationship between objects can be defined as Mathematica functions. This paper outlines the system and discusses its design and implementation.