I always use classes for this type of programming (well, all types of programming) to wrap up all the parameters and pass them around as a single variable. In this case maybe two classes if parameters and constraints are distinct.
If you are not familiar with classes then structs will also do the job, especially if you aren't needing to add functions to what would be the parameters class.
I would strongly advise against global variables, in all cases, but probably especially so if you are nesting function calls.
