DiamondSpin is a toolkit for the efficient prototyping of and experimentation with multi-person, concurrent interfaces for interactive shared displays. In this paper, we identify the fundamental functionality that tabletop user interfaces should embody, then present the toolkit's architecture and API. DiamondSpin provides a novel real-time polar to Cartesian transformation engine that has enabled new, around-the-table interaction metaphors to be implemented. DiamondSpin allows arbitrary document positioning and orientation on a tabletop surface. Polygonal tabletop layouts such as rectangular, octagonal, and circular tabletops can easily be constructed. DiamondSpin also supports multiple work areas within the same digital tabletop. Multi-user operations are offered through multi-threaded input event streams, multiple active objects, and multiple concurrent menus. We also discuss insights on tabletop interaction issues we have observed from a set of applications built with DiamondSpin.
['Chia Shen', 'Frédéric Vernier', 'Clifton Forlines', 'Meredith Ringel']
DiamondSpin: an extensible toolkit for around-the-table interaction