[Unity插件]Lua行为树(六)：打印树结构

经过前面的文章，已经把行为树中的四种基本类型节点介绍了下。接下来可以整理一下，打印一下整棵行为树。注意点如下：

1.可以把BTBehaviorTree也当作一种节点，这样就可以方便地进行行为树嵌套了

2.可以在BTBehaviorTree中的SetStartTask、BTParentTask中的AddChild，即在设置节点和添加节点时对节点的信息进行打印

以下面这棵行为树为例：

BTTask.lua

 BTTask = {};

 local this = BTTask;

 function this:New()
     local o = {};
     setmetatable(o, self);
     self.__index = self;
     o.executionStatus = BTTaskStatus.Inactive;   --该节点的执行状态
     o.root = nil;                                 --根节点
     o.parent = nil;                               --父节点
     o.layer = ;                                 --第几层
     o.index = ;                                 --父节点下的第几个节点
     o.name = "BTTask";                           --该节点名字
     return o;
 end

 function this:ToString()
     local root = "root:";
     if (self.root) then
         root = root .. self.root.name;
     else
         root = root .. "nil";
     end

     local parent = "parent:";
     if (self.parent) then
         parent = parent .. self.parent.name;
     else
         parent = parent .. "nil";
     end

     local layer = "layer:" .. self.layer;
     local index = "index:" .. self.index;
     local name = "name:" .. self.name;

     print(root .. " " .. parent .. " " .. layer .. " " .. index .. " " .. name);
 end

BTParentTask.lua

 BTParentTask = BTTask:New();

 local this = BTParentTask;

 function this:New()
     local o = {};
     setmetatable(o, self);
     self.__index = self;
     o.currentChildIndex = ;  --当前运行到第几个子节点
     o.currentChildTask = nil; --当前运行的子节点
     o.childTasks = {};        --子节点列表
     return o;
 end

 --添加子节点
 function this:AddChild(task)
     local index = #self.childTasks + ;
     task.index = index;
     task.layer = self.layer + ;
     task.parent = self;
     task.root = self.root;
     self.childTasks[index] = task;

     if (BTBehaviorManager.isPrintTaskInfo) then
         print(task:ToString());
     end
 end

 --是否有子节点
 function this:HasChild()
     if (#self.childTasks > ) then
         return true;
     else
         return false;
     end
 end

 --获取子节点数目
 function this:GetChildCount()
     return #self.childTasks;
 end

 --获取下一个要执行的子节点
 function this:GetNextChild()
     if (#self.childTasks >= (self.currentChildIndex + )) then
         self.currentChildIndex = self.currentChildIndex + ;
         return self.childTasks[self.currentChildIndex];
     end
     return nil;
 end

 --重置
 function this:Reset()
     self.currentChildIndex = ;
     self.currentChildTask = nil;
 end

BTBehaviorTree.lua

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

 local this = BTBehaviorTree;

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

 function this:SetStartTask(task)
     task.root = self;
     task.parent = self;
     task.layer = self.layer + ;
     self.startTask = task;

     if (BTBehaviorManager.isPrintTaskInfo) then
         print(task:ToString());
     end
 end

 function this:OnUpdate()
     if (self.startTask) then
         return self.startTask:OnUpdate();
     end
 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 log2 = BTLog:New("This is not a empty string");

     self:SetStartTask(repeater);

     repeater:AddChild(selector);

     selector:AddChild(sequence);
     selector:AddChild(log2);

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

打印如下：