Hi,
couldn’t you just use a ContinuousSpace instance? You can use the projections whenever you move_agent! to be sure that it is moved to its appropriate location.
There is no explicit support for shape files or for continuous coordinate systems outside the Euclidean space at the moment, but making a new space type is rather straightforward: Developer Docs · Agents.jl.
(I do not know about Gama, hope someone else can comment on that)