Nearly Automatic Function Registration

Deyja · 2005-06-14T05:41:26

I had a giant function in my project that did nothing but call asIScriptEngine::RegisterGlobalFunction over and over. This bugged me. My current solution is still less than perfect, but, IMHO, much better. It does not require some other cpp file to include every header that happens to contain a function I need bound to angelscript. It allows me to say in the cpp file the function is defined in 'Hey, bind this with AS!'. It works by inserting code to be executed before main() begins into the program using the constructor of a static object. This code builds a list of functions to be registered using the command pattern. Right now, it only supports global functions, but could be easily expanded. AutoBind.h #ifndef JM_SERVER_AUTOBIND_H #define JM_SERVER_AUTOBIND_H #include <angelscript.h> #define REG_NUM __LINE__ //Normally, the preprocessor pastes tokens before expanding them. REG_CAT gets around //that problem by delaying concatanation until after expansion. I don't know how it //works; I took this trick from boost. #define REG_CAT(a,b) REG_CAT_I(a,b) #define REG_CAT_I(a,b) REG_CAT_II(a ## b) #define REG_CAT_II(a) a //Must be in a CPP file. Inserts a call to AutoBind::BindGlobalFunction at program //startup. Hides identifiers in anonymous namespace - safe across compilation units. #define REGISTER_GLOBAL_FUNCTION(AS_STR,FUNC) namespace { class REG_CAT(RGF,REG_NUM) { public: REG_CAT(RGF,REG_NUM)() { AutoBind::BindGlobalFunction(AS_STR,FUNC); } }; REG_CAT(RGF,REG_NUM) REG_CAT(RGF_instance_,REG_NUM) ; }; namespace AutoBind { void Bind(asIScriptEngine*); class Binder { public: virtual void bind(asIScriptEngine*) = 0; }; void PushBinder(Binder*); template <typename T> class TBinder : public Binder { public: std::string in_as; T fptr; TBinder(const std::string& str, T fp) : in_as(str), fptr(fp) {} virtual void bind(asIScriptEngine* engine) { engine->RegisterGlobalFunction(in_as.c_str(),fptr,asCALL_CDECL); } }; //Use the function argument to determine the type of the function pointer and generate //the proper TBinder object template <typename T> void BindGlobalFunction(const std::string& str, T fp) { PushBinder(new TBinder<T>(str,fp)); } }; #endif AutoBind.cpp #include "AutoBind.h" #include <list> namespace { typedef std::list<AutoBind::Binder*> BinderList; BinderList& GetBinder() //Static creation method { static BinderList binders; return binders; } }; void AutoBind::PushBinder(AutoBind::Binder* b) { GetBinder().push_back(b); } void AutoBind::Bind(asIScriptEngine* engine) { while (!GetBinder().empty()) { GetBinder().front()->bind(engine); delete GetBinder().front(); GetBinder().pop_front(); } } usage #include "AutoBind.h" void Function() {} REGISTER_GLOBAL_FUNCTION("void Function()",asFUNCTION(Function)); int main() { //initiate script engine... AutoBind::Bind(pointer_to_script_engine); }

AngelCode Affiliates

Started by Deyja June 09, 2005 07:36 PM

12 comments, last by Deyja 19 years, 5 months ago

AlphaDog

122

June 13, 2005 08:22 PM

LOL.. That's good advice. I know I have looked at code on the day after to wonder what the hell I was thinking.. I have a one pint coding limit.. :)

Have you looked at the Wave preprocessor:

http://spirit.sourceforge.net/repository/applications/wave.html

You probably have, but I thought I would mention it anyway.

[size=1]'Behold! It is not over unknown seas but back over well-known years that your quest must go; back to the bright strange things of infancy and the quick sun-drenched glimpses of magic that old scenes brought to wide young eyes.'

Deyja

Author

920

June 13, 2005 08:26 PM

No I hadn't seen it. Bah on it. I'll use mine, because I wrote it, even if this one his better. I might change my mind when I'm less full of Captain Morgan.

http://jemgine.omnisu.com