[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。