Add: [Script] Framework for loading/saving selected ScriptObject

cmake/scripts/SquirrelExport.cmake

@@ -347,7 +347,7 @@ foreach(LINE IN LISTS SOURCE_LINES)
         string(APPEND SQUIRREL_EXPORT "\nvoid SQ${API_CLS}_Register(Squirrel *engine)")
         string(APPEND SQUIRREL_EXPORT "\n{")
         string(APPEND SQUIRREL_EXPORT "\n	DefSQClass<${CLS}, ScriptType::${APIUC}> SQ${API_CLS}(\"${API_CLS}\");")
-        if("${SUPER_CLS}" STREQUAL "Text" OR "${SUPER_CLS}" STREQUAL "ScriptObject")
+        if("${SUPER_CLS}" STREQUAL "Text")
             string(APPEND SQUIRREL_EXPORT "\n	SQ${API_CLS}.PreRegister(engine);")
         else()
             string(APPEND SQUIRREL_EXPORT "\n	SQ${API_CLS}.PreRegister(engine, \"${API_SUPER_CLS}\");")

src/saveload/saveload.h

@@ -399,6 +399,7 @@ enum SaveLoadVersion : uint16_t {
 
 	SLV_ENCODED_STRING_FORMAT,              ///< 350  PR#13499 Encoded String format changed.
 	SLV_PROTECT_PLACED_HOUSES,              ///< 351  PR#13270 Houses individually placed by players can be protected from town/AI removal.
+	SLV_SCRIPT_SAVE_INSTANCES,              ///< 352  PR#13556 Scripts are allowed to save instances.
 
 	SL_MAX_VERSION,                         ///< Highest possible saveload version
 };

src/script/api/script_includes.hpp.in

@@ -9,7 +9,17 @@
 
 ${SQUIRREL_INCLUDES}
 
+static SQInteger ${APIUC}ObjectConstructor(HSQUIRRELVM vm)
+{
+	return sq_throwerror(vm, "${APIUC}Object is not instantiable");
+}
+
 void SQ${APIUC}_RegisterAll(Squirrel *engine)
 {
+	DefSQClass<ScriptObject, ScriptType::${APIUC}> SQ${APIUC}Object("${APIUC}Object");
+	SQ${APIUC}Object.PreRegister(engine);
+	SQ${APIUC}Object.DefSQAdvancedStaticMethod(engine, &${APIUC}ObjectConstructor, "constructor");
+	SQ${APIUC}Object.PostRegister(engine);
+
 ${SQUIRREL_REGISTER}
 }

src/script/api/script_object.hpp

@@ -84,6 +84,22 @@ protected:
 		static ScriptInstance *active;  ///< The global current active instance.
 	};
 
+	/**
+	 * Save this object.
+	 * Must push 2 elements on the stack:
+	 *  - the name (classname without "Script") of the object (OT_STRING)
+	 *  - the data for the object (any supported types)
+	 * @return True iff saving this type is supported.
+	 */
+	virtual bool SaveObject(HSQUIRRELVM) { return false; }
+
+	/**
+	 * Load this object.
+	 * The data for the object must be pushed on the stack before the call.
+	 * @return True iff loading this type is supported.
+	 */
+	virtual bool LoadObject(HSQUIRRELVM) { return false; }
+
 public:
 	/**
 	 * Store the latest result of a DoCommand per company.

src/script/script_instance.cpp

@@ -480,6 +480,27 @@ static const SaveLoad _script_byte[] = {
 			return true;
 		}
 
+		case OT_INSTANCE:{
+			if (!test) {
+				_script_sl_byte = SQSL_INSTANCE;
+				SlObject(nullptr, _script_byte);
+			}
+			SQInteger top = sq_gettop(vm);
+			try {
+				ScriptObject *obj = static_cast<ScriptObject *>(Squirrel::GetRealInstance(vm, -1, "Object"));
+				if (!obj->SaveObject(vm)) throw std::exception();
+				if (sq_gettop(vm) != top + 2) throw std::exception();
+				if (sq_gettype(vm, -2) != OT_STRING || !SaveObject(vm, -2, max_depth - 1, test)) throw std::exception();
+				if (!SaveObject(vm, -1, max_depth - 1, test)) throw std::exception();
+				sq_settop(vm, top);
+				return true;
+			} catch (...) {
+				ScriptLog::Error("You tried to save an unsupported type. No data saved.");
+				sq_settop(vm, top);
+				return false;
+			}
+		}
+
 		default:
 			ScriptLog::Error("You tried to save an unsupported type. No data saved.");
 			return false;
@@ -588,7 +609,7 @@ bool ScriptInstance::IsPaused()
 		case SQSL_INT: {
 			int64_t value;
 			SlCopy(&value, 1, IsSavegameVersionBefore(SLV_SCRIPT_INT64) ? SLE_FILE_I32 | SLE_VAR_I64 : SLE_INT64);
-			if (data != nullptr) data->push_back((SQInteger)value);
+			if (data != nullptr) data->push_back(static_cast<SQInteger>(value));
 			return true;
 		}
 
@@ -602,24 +623,29 @@ bool ScriptInstance::IsPaused()
 
 		case SQSL_ARRAY:
 		case SQSL_TABLE: {
-			if (data != nullptr) data->push_back((SQSaveLoadType)_script_sl_byte);
+			if (data != nullptr) data->push_back(static_cast<SQSaveLoadType>(_script_sl_byte));
 			while (LoadObjects(data));
 			return true;
 		}
 
 		case SQSL_BOOL: {
 			SlObject(nullptr, _script_byte);
-			if (data != nullptr) data->push_back((SQBool)(_script_sl_byte != 0));
+			if (data != nullptr) data->push_back(static_cast<SQBool>(_script_sl_byte != 0));
 			return true;
 		}
 
 		case SQSL_NULL: {
-			if (data != nullptr) data->push_back((SQSaveLoadType)_script_sl_byte);
+			if (data != nullptr) data->push_back(static_cast<SQSaveLoadType>(_script_sl_byte));
+			return true;
+		}
+
+		case SQSL_INSTANCE: {
+			if (data != nullptr) data->push_back(static_cast<SQSaveLoadType>(_script_sl_byte));
 			return true;
 		}
 
 		case SQSL_ARRAY_TABLE_END: {
-			if (data != nullptr) data->push_back((SQSaveLoadType)_script_sl_byte);
+			if (data != nullptr) data->push_back(static_cast<SQSaveLoadType>(_script_sl_byte));
 			return false;
 		}
 
@@ -663,6 +689,31 @@ bool ScriptInstance::IsPaused()
 					sq_pushnull(this->vm);
 					return true;
 
+				case SQSL_INSTANCE: {
+					SQInteger top = sq_gettop(this->vm);
+					LoadObjects(this->vm, this->data);
+					const SQChar *buf;
+					sq_getstring(this->vm, -1, &buf);
+					Squirrel *engine = static_cast<Squirrel *>(sq_getforeignptr(this->vm));
+					std::string class_name = fmt::format("{}{}", engine->GetAPIName(), buf);
+					sq_pushroottable(this->vm);
+					sq_pushstring(this->vm, class_name);
+					if (SQ_FAILED(sq_get(this->vm, -2))) throw Script_FatalError(fmt::format("'{}' doesn't exist", class_name));
+					sq_pushroottable(vm);
+					if (SQ_FAILED(sq_call(this->vm, 1, SQTrue, SQFalse))) throw Script_FatalError(fmt::format("Failed to instantiate '{}'", class_name));
+					HSQOBJECT res;
+					sq_getstackobj(vm, -1, &res);
+					sq_addref(vm, &res);
+					sq_settop(this->vm, top);
+					sq_pushobject(vm, res);
+					sq_release(vm, &res);
+					ScriptObject *obj = static_cast<ScriptObject *>(Squirrel::GetRealInstance(vm, -1, "Object"));
+					LoadObjects(this->vm, this->data);
+					if (!obj->LoadObject(vm)) throw Script_FatalError(fmt::format("Failed to load '{}'", class_name));
+					sq_pop(this->vm, 1);
+					return true;
+				}
+
 				case SQSL_ARRAY_TABLE_END:
 					return false;
 

src/script/script_instance.hpp

@@ -32,6 +32,7 @@ private:
 		SQSL_TABLE           = 0x03, ///< The following data is an table.
 		SQSL_BOOL            = 0x04, ///< The following data is a boolean.
 		SQSL_NULL            = 0x05, ///< A null variable.
+		SQSL_INSTANCE        = 0x06, ///< The following data is an instance.
 		SQSL_ARRAY_TABLE_END = 0xFF, ///< Marks the end of an array or table, no data follows.
 	};
 

src/script/squirrel.hpp

@@ -23,6 +23,7 @@ struct ScriptAllocator;
 
 class Squirrel {
 	friend class ScriptAllocatorScope;
+	friend class ScriptInstance;
 
 private:
 	typedef void (SQPrintFunc)(bool error_msg, const std::string &message);