The architecture and implementation of CPN2000, a post-WIMP graphical application

We have developed an interface for editing and simulating Coloured Petri Nets based on toolglasses, marking menus and bi-manual interaction, in order to understand how novel interaction techniques could be supported by a new generation of user interface toolkits. The architecture of CPN2000 is based on three components: the Document Structure stores all the persistent data in the system; the Display Structure represents the contents of the screen and implements rendering and hit detection algorithms; and the Input Structure uses "instruments" to manage interaction. The rendering engine is based on OpenGL and a number of techniques have been developed to take advantage of 3D accelerated graphics for a 2D application. Performance data show that high frame rates have been achieved with off-theshelf hardware even with a non-optimized redisplay. This work paves the way towards a post-WIMP UI toolkit.