[Unity插件]Lua行为树(七)：行为树嵌套

在上一篇的基础上，可以测试下行为树的嵌套，所谓的行为树嵌套，就是在一棵行为树下的某一个分支，接入另一棵行为树。

以下面这棵行为树为例：

TestBehaviorTree2.lua

 TestBehaviorTree2 = BTBehaviorTree:New();

 local this = TestBehaviorTree2;
 this.name = "TestBehaviorTree2";

 function this:New()
     local o = {};
     setmetatable(o, self);
     self.__index = self;
     self:Init();
     return o;
 end

 function this:Init()
     local repeater = BTRepeater:New();
     local sequence = BTSequence:New();
     local log = BTLog:New("This is a other tree!!!");
     local log2 = BTLog:New("This is a other tree 2!!!");

     self:SetStartTask(repeater);

     repeater:AddChild(sequence);

     sequence:AddChild(log);
     sequence:AddChild(log2);
 end

TestBehaviorTree.lua

 TestBehaviorTree = BTBehaviorTree:New();

 local this = TestBehaviorTree;
 this.name = "TestBehaviorTree";

 function this:New()
     local o = {};
     setmetatable(o, self);
     self.__index = self;
     self:Init();
     return o;
 end

 function this:Init()
     local repeater = BTRepeater:New();
     local selector = BTSelector:New();
     local sequence = BTSequence:New();
     local isNullOrEmpty = BTIsNullOrEmpty:New("");
     local log = BTLog:New("This is a empty string!!!");
     local tree2 = TestBehaviorTree2:New();

     self:SetStartTask(repeater);

     repeater:AddChild(selector);

     selector:AddChild(sequence);
     selector:AddChild(tree2);

     sequence:AddChild(isNullOrEmpty);
     sequence:AddChild(log);
 end

打印如下：

上面的执行结果是没有问题的，由此可见，将BTBehaviorTree当作节点，然后嵌套在行为树中是可行的。不过通过上面的打印，可以发现嵌套树先被打印，然后总树才被打印，而且嵌套树的层级也是不对的。

对于打印错误，这是节点添加顺序造成的问题，因此不应该在设置节点或者添加节点时进行打印，应该在整棵数构成完成后进行打印。

对于层级不对，可以在添加嵌套树后更新嵌套树下的节点层级。

Enum.lua

 --节点状态
 BTTaskStatus = {
     Inactive = ,    --尚未执行
     Failure = ,     --返回失败
     Success = ,     --返回成功
     Running = ,     --执行中
 }

 --节点类型
 BTTaskType = {
     Root = ,
     Action = ,
     Composite = ,
     Conditional = ,
     Decorator = ,
 }

BTBehaviorManager.lua

 BTBehaviorManager = {};

 local this = BTBehaviorManager;
 this.printTreeStr = "";

 function this.RunTree(tree)
     this.bTree = tree;
     this.OnUpdate();
 end

 function this.OnUpdate()
     local status = this.bTree:OnUpdate();
     while (status == BTTaskStatus.Running) do
         status = this.bTree:OnUpdate();
     end
 end

 --深度优先，打印树结构
 function this.PrintTree(task)
     this.printTreeStr = "";
     this.AddToPrintTreeStr(task);
     print(this.printTreeStr);
 end

 function this.AddToPrintTreeStr(task)
     local taskType = task.taskType;

     this.printTreeStr = this.printTreeStr .. task:ToString() .. "\n";

     if (taskType == BTTaskType.Root) then
         this.AddToPrintTreeStr(task.startTask);
     elseif (taskType == BTTaskType.Composite or taskType == BTTaskType.Decorator) then
         for i=,#task.childTasks do
             this.AddToPrintTreeStr(task.childTasks[i]);
         end
     else

     end
 end

BTBehaviorTree.lua

 --[[
 树的根节点
 --]]
 BTBehaviorTree = BTTask:New();

 local this = BTBehaviorTree;
 this.taskType = BTTaskType.Root;

 function this:New()
     local o = {};
     setmetatable(o, self);
     self.__index = self;
     return o;
 end

 --设置起始节点
 function this:SetStartTask(task)
     task.root = self;
     task.parent = self;
     task.layer = self.layer + ;
     self.startTask = task;
 end

 --更新子节点层级
 function this:UpdateLayer()
     self:UpdateChildLayer(self.startTask);
 end

 function this:UpdateChildLayer(task)
     local taskType = task.taskType;
     task.layer = task.root.layer + task.layer - ;

     if (taskType == BTTaskType.Root) then
         self:UpdateChildLayer(task.startTask);
     elseif (taskType == BTTaskType.Composite or taskType == BTTaskType.Decorator) then
         for i=,#task.childTasks do
             self:UpdateChildLayer(task.childTasks[i]);
         end
     else

     end
 end

 function this:OnUpdate()
     if (self.startTask) then
         return self.startTask:OnUpdate();
     end
 end

打印如下：