Godot 4 源码分析 - 获取脚本

获取属性列表

今天搂草打兔，取得了脚本内容

因为已能取得属性值，那就再进一步，取得属性名列表

if (SameText(drGet.propertyName, "propertyNames", DRGRAPH_FLAG_CASESENSITIVE)) {
	List<PropertyInfo> *p_list = new List<PropertyInfo>;
	bool p_reversed = true;
	destObject->get_property_list(p_list, p_reversed);
	cofs << "OK";
	for (List<PropertyInfo>::Iterator it = p_list->begin(); it != p_list->end(); ++it) {
		Variant value = destObject->get(it->name);
		cofs << str_format(U"%s[%s] = %s", it->name.utf8().get_data(),
			VarType2String(it->type).c_str(), value.operator String().utf8().get_data());
	}
	delete p_list;
	cofs << GetObjectHint(destObject);	
}

相应地，可以取得函数名列表、子对象列表

if (SameText(drGet.propertyName, "methodNames", DRGRAPH_FLAG_CASESENSITIVE)) {
	List<MethodInfo> *p_list = new List<MethodInfo>;
	destObject->get_method_list(p_list);
	cofs << "OK";
	for (List<MethodInfo>::Iterator it = p_list->begin(); it != p_list->end(); ++it) {
		String content = it->name + "(";
		for (List<PropertyInfo>::Iterator iter = it->arguments.begin(); iter != it->arguments.end(); ++iter) {
			if (iter != it->arguments.begin())
				content += ", ";
			content += str_format("%s %s", VarType2String(iter->type).c_str(), iter->name.utf8().get_data()).c_str();
		}
		content += ")";
		cofs << content;
	}
	delete p_list;
	cofs << GetObjectHint(destObject);	
}
if (SameText(drGet.propertyName, "childNames", DRGRAPH_FLAG_CASESENSITIVE)) {
	if (Node *node = dynamic_cast<Node *>(destObject)) {
		int count = node->get_child_count();
		for (int i = 0; i < count; ++i) {
			Node *subNode = node->get_child(i);
			cofs << str_format(U"%s[%s]", subNode->get_name().operator String().utf8().get_data(),
					subNode->get_class_name().operator String().utf8().get_data());
		}
		cofs << GetObjectHint(destObject);
	}
}

其中，获取对象信息(GetObjectHint)是期望能显示对象的一些相应信息

#define CAST(T, ptr) dynamic_cast<T>(static_cast<T>(ptr))
std::string GetObjectHint(void* ptr) {
	String result = U"未处理对象";
	if (Object *object = CAST(Object *, ptr)) {
		result = str_format(U" ---==== [%s]类型对象 0X%08x ====---", object->get_class_name().operator String().utf8().get_data(), int(ptr));
		if (Node *node = CAST(Node *, ptr)) {
			String path = node->get_name();
			Node *parent = node->get_parent();
			while (parent) {
				path = parent->get_name().operator String() + U"." + path;
				parent = parent->get_parent();
			}
			result += U"：\n\t\t\t\t\t\t路径信息：";
			result += path + U"\n\t\t\t\t\t\t子对象信息：";
			int count = node->get_child_count();
			for (int i = 0; i < count; ++i) {
				Node *subNode = node->get_child(i);
				result += str_format(U" %s[%s]", String2std(subNode->get_name().operator String()).c_str(),
						String2std(subNode->get_class_name().operator String()).c_str());
			}
		}
	} else if (Engine *engine = CAST(Engine *, ptr)) {
		result = str_format(U"[Engine]类型对象 0X%08x", int(ptr));
	}
	return String2std(result);
}

测试一下，取得根节点(Book)的所有属性名： Book.propertyNames

261. 15:58:53:368 > 【主线程】 > [Pipe.发送] > 发送数据中内容[DrGraph.78: Request - wait 1000 ms]: 
	[int]类型 > 值 = 2
	[UnicodeString]类型 > 值 = Book
	[UnicodeString]类型 > 值 = propertyNames
262. 15:58:53:614 > 【主线程】 > [Pipe.Read] > 发送数据[DrGraph.78: Request - wait 1000 ms]成功返回 2396 字节... > PIPE响应中内容[godot -> DrGraph.78: Response - no return]: 
	[int]类型 > 值 = 3
	[UnicodeString]类型 > 值 = OK
	[UnicodeString]类型 > 值 = book.gd[NIL] = <null>
	[UnicodeString]类型 > 值 = singlePage[BOOL] = false
	[UnicodeString]类型 > 值 = middleBarWidth[INT] = 0
	[UnicodeString]类型 > 值 = shader_rect[OBJECT] = ShaderRect:<ColorRect#26944209309>
	[UnicodeString]类型 > 值 = currentPageMode[BOOL] = false
	[UnicodeString]类型 > 值 = currentAreaType[INT] = 5
	[UnicodeString]类型 > 值 = triggleAreaMoment[INT] = 745493
	[UnicodeString]类型 > 值 = currentPageIndex[INT] = 30
	[UnicodeString]类型 > 值 = pageCount[INT] = 100
	[UnicodeString]类型 > 值 = pageImgPath[STRING] = res://Pages/
	[UnicodeString]类型 > 值 = leftMouseDownMoment[INT] = 0
	[UnicodeString]类型 > 值 = underAutoTurnPage[BOOL] = false
	[UnicodeString]类型 > 值 = leftMouseDownPos[VECTOR2] = (0, 0)
	[UnicodeString]类型 > 值 = dllStream[OBJECT] = <DllStream#67024979098>
	[UnicodeString]类型 > 值 = AutoTurnObject[OBJECT] = <RefCounted#-9223372009692462686>
	[UnicodeString]类型 > 值 = Node2D[NIL] = <null>
	[UnicodeString]类型 > 值 = Transform[NIL] = <null>
	[UnicodeString]类型 > 值 = position[VECTOR2] = (0, 0)
	[UnicodeString]类型 > 值 = rotation[FLOAT] = 0
	[UnicodeString]类型 > 值 = rotation_degrees[FLOAT] = 0
	[UnicodeString]类型 > 值 = scale[VECTOR2] = (1, 1)
	[UnicodeString]类型 > 值 = skew[FLOAT] = 0
	[UnicodeString]类型 > 值 = transform[TRANSFORM2D] = [X: (1, 0), Y: (0, 1), O: (0, 0)]
	[UnicodeString]类型 > 值 = global_position[VECTOR2] = (0, 0)
	[UnicodeString]类型 > 值 = global_rotation[FLOAT] = 0
	[UnicodeString]类型 > 值 = global_rotation_degrees[FLOAT] = 0
	[UnicodeString]类型 > 值 = global_scale[VECTOR2] = (1, 1)
	[UnicodeString]类型 > 值 = global_skew[FLOAT] = 0
	[UnicodeString]类型 > 值 = global_transform[TRANSFORM2D] = [X: (1, 0), Y: (0, 1), O: (0, 0)]
	[UnicodeString]类型 > 值 = CanvasItem[NIL] = <null>
	[UnicodeString]类型 > 值 = Visibility[NIL] = <null>
	[UnicodeString]类型 > 值 = visible[BOOL] = true
	[UnicodeString]类型 > 值 = modulate[COLOR] = (1, 1, 1, 1)
	[UnicodeString]类型 > 值 = self_modulate[COLOR] = (1, 1, 1, 1)
	[UnicodeString]类型 > 值 = show_behind_parent[BOOL] = false
	[UnicodeString]类型 > 值 = top_level[BOOL] = false
	[UnicodeString]类型 > 值 = clip_children[INT] = 0
	[UnicodeString]类型 > 值 = light_mask[INT] = 1
	[UnicodeString]类型 > 值 = visibility_layer[INT] = 1
	[UnicodeString]类型 > 值 = Ordering[NIL] = <null>
	[UnicodeString]类型 > 值 = z_index[INT] = 0
	[UnicodeString]类型 > 值 = z_as_relative[BOOL] = true
	[UnicodeString]类型 > 值 = y_sort_enabled[BOOL] = false
	[UnicodeString]类型 > 值 = Texture[NIL] = <null>
	[UnicodeString]类型 > 值 = texture_filter[INT] = 0
	[UnicodeString]类型 > 值 = texture_repeat[INT] = 0
	[UnicodeString]类型 > 值 = Material[NIL] = <null>
	[UnicodeString]类型 > 值 = material[OBJECT] = <Object#null>
	[UnicodeString]类型 > 值 = use_parent_material[BOOL] = false
	[UnicodeString]类型 > 值 = Node[NIL] = <null>
	[UnicodeString]类型 > 值 = _import_path[NODE_PATH] = 
	[UnicodeString]类型 > 值 = name[STRING_NAME] = Book
	[UnicodeString]类型 > 值 = unique_name_in_owner[BOOL] = false
	[UnicodeString]类型 > 值 = scene_file_path[STRING] = res://book.tscn
	[UnicodeString]类型 > 值 = owner[OBJECT] = <Object#null>
	[UnicodeString]类型 > 值 = multiplayer[OBJECT] = <SceneMultiplayer#-9223372011168857674>
	[UnicodeString]类型 > 值 = Process[NIL] = <null>
	[UnicodeString]类型 > 值 = process_mode[INT] = 0
	[UnicodeString]类型 > 值 = process_priority[INT] = 0
	[UnicodeString]类型 > 值 = Editor Description[NIL] = <null>
	[UnicodeString]类型 > 值 = editor_description[STRING] = 
	[UnicodeString]类型 > 值 = script[OBJECT] = <GDScript#-9223372010984308353>
	[UnicodeString]类型 > 值 =  ---==== [Node2D]类型对象 0X4d7c5600 ====---：
						路径信息：root.Book
						子对象信息： LeftPage[Sprite2D] RightPage[Sprite2D] ShaderRect[ColorRect] LeftButton[Button] RightButton[Button] AutoTurnTimer[Timer] DrGraph[Node]

看到script属性：[UnicodeString]类型 > 值 = script[OBJECT] = <GDScript#-9223372010984308353>

那就再取得Book.script.propertyNames来看下，结果发现返回了脚本内容

仔细一看，是属性 script/source 的值。那就单独看一下该属性： Book.script.script/source，果然得到相应脚本内容

倒是有点意思，属性名称为 script/source

源码分析

在源码中查找 script/source，在gdscript.cpp中有两处，应该是这个

void GDScript::_get_property_list(List<PropertyInfo> *p_properties) const {
	p_properties->push_back(PropertyInfo(Variant::STRING, "script/source", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL));
}

原来GDScript对象返回属性名称列表时，就添加了这么一个玩意

这样取属性名称列表时，就有一个名为 script/source 的属性

下来看看get该属性时具体有哪些动作，调试跟进

Variant Object::get(const StringName &p_name, bool *r_valid) const {
	Variant ret;

	if (script_instance) {
		if (script_instance->get(p_name, ret)) {
			if (r_valid) {
				*r_valid = true;
			}
			return ret;
		}
	}
	if (_extension && _extension->get) {
// C style pointer casts should never trigger a compiler warning because the risk is assumed by the user, so GCC should keep quiet about it.
#if defined(__GNUC__) && !defined(__clang__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wignored-qualifiers"
#endif

		if (_extension->get(_extension_instance, (const GDExtensionStringNamePtr)&p_name, (GDExtensionVariantPtr)&ret)) {
			if (r_valid) {
				*r_valid = true;
			}
			return ret;
		}
#if defined(__GNUC__) && !defined(__clang__)
#pragma GCC diagnostic pop
#endif
	}

	// Try built-in getter.
	{
		if (ClassDB::get_property(const_cast<Object *>(this), p_name, ret)) {
			if (r_valid) {
				*r_valid = true;
			}
			return ret;
		}
	}

	if (p_name == CoreStringNames::get_singleton()->_script) {
		ret = get_script();
		if (r_valid) {
			*r_valid = true;
		}
		return ret;
	}

	const Variant *const *V = metadata_properties.getptr(p_name);

	if (V) {
		ret = **V;
		if (r_valid) {
			*r_valid = true;
		}
		return ret;

	} else {
#ifdef TOOLS_ENABLED
		if (script_instance) {
			bool valid;
			ret = script_instance->property_get_fallback(p_name, &valid);
			if (valid) {
				if (r_valid) {
					*r_valid = true;
				}
				return ret;
			}
		}
#endif
		// Something inside the object... :|
		bool success = _getv(p_name, ret);
		if (success) {
			if (r_valid) {
				*r_valid = true;
			}
			return ret;
		}

		if (r_valid) {
			*r_valid = false;
		}
		return Variant();
	}
}

具体是在 bool success = _getv(p_name, ret); 中处理，直接在GDScript::_get中实质处理

bool GDScript::_get(const StringName &p_name, Variant &r_ret) const {
	{
		const GDScript *top = this;
		while (top) {
			{
				HashMap<StringName, Variant>::ConstIterator E = top->constants.find(p_name);
				if (E) {
					r_ret = E->value;
					return true;
				}
			}

			{
				HashMap<StringName, Ref<GDScript>>::ConstIterator E = subclasses.find(p_name);
				if (E) {
					r_ret = E->value;
					return true;
				}
			}
			top = top->_base;
		}

		if (p_name == GDScriptLanguage::get_singleton()->strings._script_source) {
			r_ret = get_source_code();
			return true;
		}
	}

	return false;
}

调试可知，在constants中，保存了各常量信息[key / value]

 而subclasses中保存了自定义的结构(类)

 最终在get_source_code函数中，直接返回source

String GDScript::get_source_code() const {
	return source;
}

也就是脚本文本内容。

就这。

获取脚本中变量值

从上面可看到属性获取逻辑，在script/source属性获取过程中，检查了constants和subclasses，那试试能否获取其中的变量值

发送Book.script.AREA_OUT，结果成功

自定义结构

继续测试自定义结构

发送Book.script.TAutoTurn，结果返回为对象： <GDScript#-9223372010833313372>

279. 16:18:07:517 > 【主线程】 > [Pipe.发送] > 发送数据中内容[DrGraph.87: Request - wait 1000 ms]: 
	[int]类型 > 值 = 2
	[UnicodeString]类型 > 值 = Book.script
	[UnicodeString]类型 > 值 = TAutoTurn
280. 16:18:07:617 > 【主线程】 > [Pipe.Read] > 发送数据[DrGraph.87: Request - wait 1000 ms]成功返回 168 字节... > PIPE响应中内容[godot -> DrGraph.87: Response - no return]: 
	[int]类型 > 值 = 3
	[UnicodeString]类型 > 值 = OK
	[UnicodeString]类型 > 值 = <GDScript#-9223372010833313372>

检查该对象属性名列表

281. 16:18:21:175 > 【主线程】 > [Pipe.发送] > 发送数据中内容[DrGraph.88: Request - wait 1000 ms]: 
	[int]类型 > 值 = 2
	[UnicodeString]类型 > 值 = Book.script.TAutoTurn
	[UnicodeString]类型 > 值 = propertyNames
282. 16:18:21:272 > 【主线程】 > [Pipe.Read] > 发送数据[DrGraph.88: Request - wait 1000 ms]成功返回 423 字节... > PIPE响应中内容[godot -> DrGraph.88: Response - no return]: 
	[int]类型 > 值 = 3
	[UnicodeString]类型 > 值 = OK
	[UnicodeString]类型 > 值 = GDScript[NIL] = <null>
	[UnicodeString]类型 > 值 = script/source[STRING] = 
	[UnicodeString]类型 > 值 = Script[NIL] = <null>
	[UnicodeString]类型 > 值 = source_code[STRING] = 
	[UnicodeString]类型 > 值 = Resource[NIL] = <null>
	[UnicodeString]类型 > 值 = Resource[NIL] = <null>
	[UnicodeString]类型 > 值 = resource_local_to_scene[BOOL] = false
	[UnicodeString]类型 > 值 = resource_path[STRING] = 
	[UnicodeString]类型 > 值 = resource_name[STRING] = 
	[UnicodeString]类型 > 值 = RefCounted[NIL] = <null>
	[UnicodeString]类型 > 值 =  ---==== [GDScript]类型对象 0X4d771310 ====---：
						路径信息：
						子对象信息：

也有script/source、source_code属性，不过好象没内容，测试也还是真没内容返回

 但能取得这些信息，感觉已经足够用的了