- attempt to save and load scenario info in saved games

source/shared_lib/sources/lua/lua_script.cpp

@@ -140,6 +140,117 @@ void LuaScript::DumpGlobals()
 	}
 }
 
+void LuaScript::saveGame(XmlNode *rootNode) {
+	std::map<string,string> mapTagReplacements;
+
+	LuaHandle *L = luaState;
+	// push the first key (nil = beginning of table)
+	lua_pushnil(L);
+
+	// lua_next will:
+	// 1 - pop the key
+	// 2 - push the next key
+	// 3 - push the value at that key
+	// ... so the key will be at index -2 and the value at index -1
+	while (lua_next(L, LUA_GLOBALSINDEX) != 0) {
+		// get type of key and value
+		int key_type = lua_type(L, -2);
+		int value_type = lua_type(L, -1);
+
+		// support only string keys
+		// globals aren't likely to have a non-string key, but just to be certain ...
+		if (key_type != LUA_TSTRING) {
+			lua_pop(L, 1); // pop the value so that the top contains the key for the next iteration
+			continue;
+		}
+
+		// support only number, boolean and string values
+		if (value_type != LUA_TNUMBER &&
+			value_type != LUA_TBOOLEAN &&
+			value_type != LUA_TSTRING) {
+			lua_pop(L, 1); // again, pop the value before going to the next loop iteration
+			continue;
+		}
+
+		// get the key as a string
+		string key_string = lua_tostring(L, -2); // no copy required - we already know this is a string
+
+		// do not support variables that start with '_'
+		// lua has some predefined values like _VERSION. They all start with underscore
+
+		if (!key_string.size()) { // this again is highly unlikely, but still ...
+			lua_pop(L, 1);
+			continue;
+		}
+		if (key_string[0] == '_') {
+			lua_pop(L, 1);
+			continue;
+		}
+
+		string value_string;
+
+		// convert the value to a string. This depends on its type
+		switch (value_type) {
+		case LUA_TSTRING:
+		case LUA_TNUMBER:
+			// numbers can be converted to strings
+
+			// get the value as a string (this requires a copy because traversing tables
+			// uses the top of the stack as an index. If conversion from a number to string
+			// happens, the top of the stack will be altered and the table index will become invalid)
+			lua_pushvalue(L, -1);
+			value_string = lua_tostring(L, -1);
+			lua_pop(L, 1);
+			break;
+		case LUA_TBOOLEAN:
+			value_string = lua_toboolean(L, -1) == 0 ? "false" : "true";
+			break;
+		}
+
+		// enclose the value in "" if it is a string
+		if (value_type == LUA_TSTRING) {
+			value_string = "\"" + value_string + "\"";
+		}
+
+		// resulting line. Somehow save this and when you need to restore it, just
+		// call luaL_dostring with that line.
+		//SaveLine(key_string + " = " + value_string);		// Pop the value so the index remains on top of the stack for the next iteration
+		//printf("Found global LUA var: %s = %s\n",key_string.c_str(),value_string.c_str());
+		XmlNode *luaScriptNode = rootNode->addChild("LuaScript");
+		luaScriptNode->addAttribute("variable",key_string, mapTagReplacements);
+		luaScriptNode->addAttribute("value",value_string, mapTagReplacements);
+		luaScriptNode->addAttribute("value_type",intToStr(value_type), mapTagReplacements);
+
+		lua_pop(L, 1);
+	}
+}
+
+void LuaScript::loadGame(const XmlNode *rootNode) {
+	const XmlNode *luaScriptNode = rootNode;
+
+	vector<XmlNode *> luaScriptNodeList = rootNode->getChildList("LuaScript");
+	for(unsigned int i = 0; i < luaScriptNodeList.size(); ++i) {
+		XmlNode *node = luaScriptNodeList[i];
+
+		string variable = node->getAttribute("variable")->getValue();
+		int value_type = node->getAttribute("value_type")->getIntValue();
+
+		switch (value_type) {
+			case LUA_TSTRING:
+				lua_pushstring( luaState, node->getAttribute("value")->getValue().c_str() );
+				break;
+			case LUA_TNUMBER:
+				lua_pushnumber( luaState, node->getAttribute("value")->getIntValue() );
+				break;
+			case LUA_TBOOLEAN:
+				lua_pushboolean( luaState, node->getAttribute("value")->getIntValue() );
+				break;
+		}
+
+		lua_setglobal( luaState, variable.c_str() );
+	}
+}
+
 LuaScript::~LuaScript() {
 	Lua_STREFLOP_Wrapper streflopWrapper;