[Unity插件]Lua行为树(十二)：行为树管理

之前运行的行为树，都是一颗总树，那么实际上会有很多的总树，因此需要对行为树进行管理。

BTBehaviorManager.lua

 BTBehaviorManager = {};

 local this = BTBehaviorManager;
 this.isEachFrameCall = false;--是否是每帧调用
 this.printTreeStr = "";
 this.trees = {};

 function this.RunTree()
     if (isEachFrameCall) then
     else
         while (true) do
             local isAllFinish = this.OnUpdate();
             if (isAllFinish) then
                 break;
             end
         end
     end
 end

 function this.OnUpdate()
     local count = ;

     for i=,#this.trees do
         local tree = this.trees[i];
         if (tree.executionStatus == BTTaskStatus.Inactive) then --第一次执行
             print("第一次执行:" .. tree.name);
             tree:OnUpdate();
         elseif (tree.executionStatus == BTTaskStatus.Running) then --第二次以及以后执行
             print("第二次以及以后执行:" .. tree.name);
             tree:OnUpdate();
         else
             count = count + ;
         end
     end

     if (count == #this.trees) then
         return true;
     else
         return false;
     end
 end

 --添加行为树
 function this.AddTree(task)
     table.insert(this.trees, task);
 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

说明：

1.因为是运行在Sublime环境下的，所以这里使用while循环模拟每帧调用

2.关于AddTree和OnUpdate是否会冲突的问题。AddTree会增加trees的长度，但是在lua中for的三个表达式在循环开始前一次性求值，以后不再进行求值。比如#this.trees这个表达式只会在循环开始前执行一次，其结果用在后面的循环中。也就是说，如果在for循环过程中执行了AddTree方法，新增的元素会添加在后面，不会影响for循环的。

测试：

1.多行为树执行

TestBehaviorTree.lua

 TestBehaviorTree = BTBehaviorTree:New();

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

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

 function this:Init()
     local parallel = BTParallel:New();
     local action = self:GetBTActionUniversal();
     local action2 = self:GetBTActionUniversal2();

     self:SetStartTask(parallel);

     parallel:AddChild(action);
     parallel:AddChild(action2);
 end

 function this:GetBTActionUniversal()
     local count = ;
     local a = function ()
         if (count <= ) then
             count = count + ;
             print("");
             return BTTaskStatus.Running;
         else
             return BTTaskStatus.Success;
         end
     end
     local universal = BTActionUniversal:New(nil, a);
     return universal;
 end

 function this:GetBTActionUniversal2()
     local universal = BTActionUniversal:New(nil, function ()
         return BTTaskStatus.Success;
     end);
     return universal;
 end

TestBehaviorTree2.lua

 TestBehaviorTree2 = BTBehaviorTree:New();

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

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

TestMain.lua

 require "BehaviorTree/Core/Init"
 require "BehaviorTree/Test/TestBehaviorTree"
 require "BehaviorTree/Test/TestBehaviorTree2"

 local tree = TestBehaviorTree:New();
 local tree2 = TestBehaviorTree2:New();
 tree.name = "tree";
 tree2.name = "tree2";
 BTBehaviorManager.AddTree(tree);
 BTBehaviorManager.AddTree(tree2);
 BTBehaviorManager.RunTree();

输出如下：

2.for循环中添加行为树

TestBehaviorTree3.lua

 TestBehaviorTree3 = BTBehaviorTree:New();

 local this = TestBehaviorTree3;
 this.name = "TestBehaviorTree3";

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

 function this:Init()
     local repeater = BTRepeater:New();
     local log = BTLog:New("This is TestBehaviorTree3 tree!!!");

     self:SetStartTask(repeater);

     repeater:AddChild(log);
 end

BTBehaviorManager.lua

 BTBehaviorManager = {};

 local this = BTBehaviorManager;
 this.isEachFrameCall = false;--是否是每帧调用
 this.printTreeStr = "";
 this.trees = {};

 function this.RunTree()
     if (isEachFrameCall) then
     else
         while (true) do
             local isAllFinish = this.OnUpdate();
             if (isAllFinish) then
                 break;
             end
         end
     end
 end

 local temp = false;

 function this.OnUpdate()
     local count = ;

     for i=,#this.trees do
         if (not temp) then
             temp = true;
             require "BehaviorTree/Test/TestBehaviorTree3"
             local tree3 = TestBehaviorTree3:New();
             tree3.name = "tree3";
             this.AddTree(tree3);
         end

         local tree = this.trees[i];
         if (tree.executionStatus == BTTaskStatus.Inactive) then --第一次执行
             print("第一次执行:" .. tree.name);
             tree:OnUpdate();
         elseif (tree.executionStatus == BTTaskStatus.Running) then --第二次以及以后执行
             print("第二次以及以后执行:" .. tree.name);
             tree:OnUpdate();
         else
             count = count + ;
         end
     end

     print("------------------------------");

     if (count == #this.trees) then
         return true;
     else
         return false;
     end
 end

 --添加行为树
 function this.AddTree(task)
     table.insert(this.trees, task);
 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

输出如下。可以看到，在第一帧时，添加了行为树tree3，但是并不影响tree和tree2的执行，而在第二帧以及以后的帧时，tree3也开始执行了。