World

A world is represented by a 3-dimensional array. Each space in a world consists of a stack of a terrain type, an optional thing, and an optional agent. A world is rendered as one layer at a time, where the layer is defined by the z-coordinate in the array (i.e. int[x][y][z]), and the area shown is a subset of the (x,y) plane centered around a display center point. An instance of Genhat must have exactly one world.