Large Scale C++ design

[Jan Wassenberg]

Cleanups inspired by book of same name (am currently reading it).

I think cleaning up our code to reduce inter-module dependencies is quite important. It promises to reduce compile time, simplify releases of parts ripped out of our codebase (e.g. a limited actor viewer), and overall make the code easier to modify (without having to wonder: "hm, what all does this break?").

First idea: sdl is dragged into 6 of 7 of our static library components - ugh! This would be mostly avoidable by just forward-declaring SDL_Event. Unfortunately it is declared as a union (bad design!!), so that is impossible. Simple solution: wrap it in a struct and forward-declare that.[done]

Use pImpl to hide implementation details of simulation classes. Specifically: boost dependency, which is dragged into network as well.

• wrap sys detect stuff in struct at least
• remove globals.h - replace with InputRepeater
• move enums from header scope into class, e.g. Paint::ORANGE
• Remove X-Macros. As nifty as they are, unfortunately they are a barrier to static code analysis and VisualAssist.

This means: make apphooks.h and glext_funcs.h regular headers (with standard function decls), adding a note on what all needs to be done to add a new function. Since using those functions is more frequent than adding a new one, this makes sense overall.

However, I am still undecided about doing the same for liberrors.h. Splitting that up into separate header files would avoid a full recompile when adding errors, but would complicate the errcode -> descriptive string mapping and (more importantly) no longer be type safe. The current approach of one big enum containing all error values triggers warnings when someone returns 0 instead of INFO_OK; that would no longer be possible after splitting up into separate headers (because specific modules like VFS with their own error codes would want to use generic ones like TIMED_OUT or OK often) Done - errors are now in ERR namespace and split over multiple headers (thanks, Philip, for the excellent idea!). Type safety is still possible via Lint's "strong typing".

[Jan Wassenberg]

(In [4252]) # sweng forward declare SDL_event. remove SDL dependency of network code. refs #140

[Jan Wassenberg]

• wrap sys detect stuff in struct at least
• remove globals.h - replace with InputRepeater
• move enums from header scope into class, e.g. Paint::ORANGE
• Remove X-Macros. As nifty as they are, unfortunately they are a barrier to static code analysis and VisualAssist.

This means: make apphooks.h and glext_funcs.h regular headers (with standard function decls), adding a note on what all needs to be done to add a new function. Since using those functions is more frequent than adding a new one, this makes sense overall. However, I am still undecided about doing the same for liberrors.h. Splitting that up into separate header files would avoid a full recompile when adding errors, but would complicate the errcode -> descriptive string mapping and (more importantly) no longer be type safe. The current approach of one big enum containing all error values triggers warnings when someone returns 0 instead of INFO_OK; that would no longer be possible after splitting up into separate headers (because specific modules like VFS with their own error codes would want to use generic ones like TIMED_OUT or OK often)

[Jan Wassenberg]

Work on error codes complete (forgot to ref this ticket, doh)