From aff28653dad7d78c09b3a9aa721bf232bd32ae80 Mon Sep 17 00:00:00 2001 From: Glenn Maynard Date: Mon, 20 Jun 2005 03:54:51 +0000 Subject: [PATCH] Rearrange Lua types. Instead of each class registering all of the functions of its base classes, set __index in the methods table to point to the base class's methods table. This has a few important advantages. First and most importantly, types don't need access to the Luna type of their base to derive from it, so these definitions don't have to be in the headers, and probably don't need to be templated. Second, you can say: function Actor:queue_rotate() self:linear(0.5) self:rotationz( 180 ) end OnCommand=x,100;queue_rotate This partially worked previously, but wasn't inherited; a function defined for Actor wouldn't work for BitmapText. (changes that use this in a few minutes) --- stepmania/src/LuaBinding.cpp | 89 ++++++++++++++++++++++++++++++++++++ stepmania/src/LuaBinding.h | 60 ++++++++++++++++++------ 2 files changed, 135 insertions(+), 14 deletions(-) create mode 100644 stepmania/src/LuaBinding.cpp diff --git a/stepmania/src/LuaBinding.cpp b/stepmania/src/LuaBinding.cpp new file mode 100644 index 0000000000..5f882cd139 --- /dev/null +++ b/stepmania/src/LuaBinding.cpp @@ -0,0 +1,89 @@ +#include "global.h" +#include "LuaBinding.h" + +void CreateGlobalTable( lua_State *L, const CString &szName ) +{ + lua_pushstring( L, szName ); + lua_rawget( L, LUA_GLOBALSINDEX ); + if( !lua_isnil(L, -1) ) + return; + + lua_pop( L, 1 ); + lua_newtable( L ); + lua_pushstring( L, szName ); + lua_pushvalue( L, -2 ); + lua_rawset( L, LUA_GLOBALSINDEX ); +} + +/* + * Get a userdata, and check that it's either szType or a type + * derived from szType, by walking the __index chain. + */ +bool CheckType( lua_State *L, int narg, const char *szType ) +{ + int iTop = lua_gettop(L); + lua_pushvalue( L, narg ); + + narg = lua_gettop(L); + while(1) + { + /* If the object on the stack has no metatable, it has no type; fail. */ + if( !lua_getmetatable(L, narg) ) + { + lua_settop( L, iTop ); + return false; + } + int iMetatable = lua_gettop(L); + + /* Look up the type name. */ + lua_pushstring( L, "__type" ); + lua_rawget( L, iMetatable ); + const char *szActualType = lua_tostring( L, -1 ); + + if( szActualType != NULL && !strcmp(szActualType, szType) ) + { + /* The type matches. */ + lua_settop( L, iTop ); + return true; + } + + /* The type doesn't match. Does the metatable have __index? */ + lua_pushstring( L, "__index" ); + lua_rawget( L, iMetatable ); + if( lua_isnil(L, -1) ) + { + /* There's no __index. The type doesn't match. */ + lua_settop( L, iTop ); + return false; + } + + /* Start over with __index. */ + lua_replace( L, narg ); + lua_pop( L, 1 ); + } +} + +/* + * (c) 2005 Glenn Maynard + * All rights reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, and/or sell copies of the Software, and to permit persons to + * whom the Software is furnished to do so, provided that the above + * copyright notice(s) and this permission notice appear in all copies of + * the Software and that both the above copyright notice(s) and this + * permission notice appear in supporting documentation. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF + * THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS + * INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT + * OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS + * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR + * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ diff --git a/stepmania/src/LuaBinding.h b/stepmania/src/LuaBinding.h index 18dc28cac3..eb65c1d873 100644 --- a/stepmania/src/LuaBinding.h +++ b/stepmania/src/LuaBinding.h @@ -27,26 +27,27 @@ struct RegType int (*mfunc)(T *p, lua_State *L); }; +void CreateGlobalTable( lua_State *L, const CString &szName ); +bool CheckType( lua_State *L, int narg, const char *szType ); + template class Luna { typedef struct { T *pT; } userdataType; + public: - + static void Register(lua_State *L) { - lua_newtable(L); + /* Create the methods table, if it doesn't already exist. */ + CreateGlobalTable( L, m_sClassName ); + int methods = lua_gettop(L); + /* Create a metatable for the userdata objects. */ luaL_newmetatable(L, m_sClassName); int metatable = lua_gettop(L); - // store method table in globals so that - // scripts can add functions written in Lua. - lua_pushstring(L, m_sClassName); - lua_pushvalue(L, methods); - lua_settable(L, LUA_GLOBALSINDEX); - lua_pushliteral(L, "__metatable"); lua_pushvalue(L, methods); lua_settable(L, metatable); // hide metatable from Lua getmetatable() @@ -72,15 +73,41 @@ public: lua_pushcclosure(L, thunk, 1); lua_settable(L, methods); } - + + /* Create a metatable for the methods table. */ + lua_newtable( L ); + int methods_metatable = lua_gettop(L); + + // Hide the metatable. + lua_pushliteral( L, "__metatable" ); + lua_pushstring( L, "(hidden)" ); + lua_settable( L, methods_metatable ); + + if( strcmp(m_sBaseClassName, "none") ) + { + // If this type has a base class, set the __index of this type + // to the base class. If the base class doesn't exist, we probably + // were called before the Register() of the base class; we'll fill + // it in when we get to it. + lua_pushliteral( L, "__index" ); + CreateGlobalTable( L, m_sBaseClassName ); + lua_settable( L, methods_metatable ); + } + + lua_pushliteral( L, "__type" ); + lua_pushstring( L, m_sClassName ); + lua_settable( L, methods_metatable ); + + /* Set and pop the methods metatable. */ + lua_setmetatable( L, methods ); + lua_pop(L, 2); // drop metatable and method table } // get userdata from Lua stack and return pointer to T object static T *check( lua_State *L, int narg, bool bIsSelf = false ) { - userdataType *pUserdata = static_cast( luaL_checkudata(L, narg, m_sClassName) ); - if( pUserdata == NULL ) + if( !CheckType(L, narg, m_sClassName) ) { if( bIsSelf ) luaL_typerror( L, narg, m_sClassName ); @@ -88,6 +115,7 @@ public: LuaHelpers::TypeError( L, narg, m_sClassName ); } + userdataType *pUserdata = static_cast( lua_touserdata(L, narg) ); return pUserdata->pT; // pointer to T object } @@ -135,7 +163,8 @@ public: s_pvMethods = new RegTypeVector; } private: - static const char m_sClassName[]; + static const char *m_sClassName; + static const char *m_sBaseClassName; static int tostring_T (lua_State *L) { @@ -148,9 +177,12 @@ private: } }; - #define LUA_REGISTER_CLASS( T ) \ - template<> const char Luna::m_sClassName[] = #T; \ + LUA_REGISTER_DERIVED_CLASS( T, none ) + +#define LUA_REGISTER_DERIVED_CLASS( T, B ) \ + template<> const char *Luna::m_sClassName = #T; \ + template<> const char *Luna::m_sBaseClassName = #B; \ template<> Luna::RegTypeVector* Luna::s_pvMethods = NULL; \ static Luna##T registera; \ void T::PushSelf( lua_State *L ) { Luna##T::Push( L, this ); } \