The Construction of a Predictive Collision 2D Game Engine

This paper discusses the construction of a game engine which is based around the principle of discrete event simulation. This work is interesting as it uses a predictive time of collision rather than a frame based approach. The key design decisions made and the tools used during the construction of the predictive game engine (PGE) are described. The objects modelled in the game engine are rigid circles and polyhedra which may have an orbit rotational velocity, a positional velocity and acceleration. Equations calculating the time of next collision between two circles, a line and a circle and two lines are given. If orbit rotation is excluded, the two circles expansion is simple as the output from maxima is only twelve lines, conversely when orbit rotation is included the output exceeds 835 lines. The input formula to maxima used for detecting the time of collisions between moving polyhedra are presented alongside a tool to automatically import the expanded formula into program code.