The code in main.cpp has been split into respective modules. This is so that main.cpp is not clouded with code other than main.
In other words, things that deal with the automation routine is placed in automation.cpp and the user control code is placed int usercontrol.cpp.
This enables code to be read and somewhat more importantly navigated more easily. What results is better debugging and whatnot.
When compiling the compile will basically copy and paste all the references into their respective places.
In other words, the code that is generated is basically the previous monolithic(everything in one place little to no compartmentalization) form. The execution will not be hindered by the stack calls to the functions because when compiled the functions will most likely not be there.
There exists a mechanism called "Inline functions" which functions work like #includes. This results in a larger binary executable but faster execution. Note that the "monolithic" form would basically look like the code at the stage of compilation where inline functions are inserted.
I set the motor definitions as constants since they appear to have no intention of modificiation during the execution. It is common c++ fact that compile-time constants(constants whose values are set during compilation) are fast.
Basically, from my understanding, because C and C++ are converted into assembly, the section.data-which holds constants-doesn't have to worry about information changing which means faster data access.
_The code's functionality has not been changed at all and nothing with the Robot's behavior has been changed. What has been changed is only the formatting of the code. It is like having a pdf, and moving the same content into website formatting. The content is the same. _