[Unity插件]Lua行为树(五)：装饰节点Repeater

Repeater：重复执行子节点，直到一定次数

特点如下：

1.执行次数可以是无限循环，也可以是固定次数

2.一般来说，子节点的执行返回状态不会影响Repeater节点，但可以设置当子节点返回失败时，结束执行Repeater节点

Repeater的继承关系如下：

Repeater->Decorator->ParentTask->Task

因为继承装饰节点，所以其子节点只能有一个

Repeater.cs

 namespace BehaviorDesigner.Runtime.Tasks
 {
     [TaskDescription(@"The repeater task will repeat execution of its child task until the child task has been run a specified number of times. " +
                       "It has the option of continuing to execute the child task even if the child task returns a failure.")]
     [HelpURL("http://www.opsive.com/assets/BehaviorDesigner/documentation.php?id=37")]
     [TaskIcon("{SkinColor}RepeaterIcon.png")]
     public class Repeater : Decorator
     {
         [Tooltip("The number of times to repeat the execution of its child task")]
         public SharedInt count = ;
         [Tooltip("Allows the repeater to repeat forever")]
         public SharedBool repeatForever;
         [Tooltip("Should the task return if the child task returns a failure")]
         public SharedBool endOnFailure;

         // The number of times the child task has been run.
         private int executionCount = ;
         // The status of the child after it has finished running.
         private TaskStatus executionStatus = TaskStatus.Inactive;

         public override bool CanExecute()
         {
             // Continue executing until we've reached the count or the child task returned failure and we should stop on a failure.
             return (repeatForever.Value || executionCount < count.Value) && (!endOnFailure.Value || (endOnFailure.Value && executionStatus != TaskStatus.Failure));
         }

         public override void OnChildExecuted(TaskStatus childStatus)
         {
             // The child task has finished execution. Increase the execution count and update the execution status.
             executionCount++;
             executionStatus = childStatus;
         }

         public override void OnEnd()
         {
             // Reset the variables back to their starting values.
             executionCount = ;
             executionStatus = TaskStatus.Inactive;
         }

         public override void OnReset()
         {
             // Reset the public properties back to their original values.
             count = ;
             endOnFailure = true;
         }
     }
 }

BTDecorator.lua

 BTDecorator = BTParentTask:New();

 local this = BTDecorator;

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

 function this:GetChild()
     if (self:GetChildCount() ~= ) then
         return nil;
     end
     return self.childTasks[];
 end

BTRepeater.lua

 BTRepeater = BTDecorator:New();

 local this = BTRepeater;

 function this:New(count, endOnFailure)
     local o = {};
     setmetatable(o, self);
     self.__index = self;
     o.executionStatus = BTTaskStatus.Inactive;
     o.count = count or -;                       --执行次数，-1为循环执行
     o.endOnFailure = endOnFailure or false;      --子节点返回Failure时，是否结束
     o.executionCount = ;                        --当前执行次数
     return o;
 end

 function this:OnUpdate()
     if (not self.currentChildTask) then
         self.currentChildTask = self:GetChild();
         if (not self.currentChildTask) then
             return BTTaskStatus.Failure;
         end
     end

     local canExecute = false;
     if (((self.count == -) or (self.executionCount < self.count)) and
         ((not self.endOnFailure) or (self.endOnFailure and self.executionStatus ~= BTTaskStatus.Failure))) then
         canExecute = true;
     end

     if (canExecute) then
         self.executionStatus = self.currentChildTask:OnUpdate();
         self.executionCount = self.executionCount + ;
     end

     if (self.endOnFailure and self.executionStatus == BTTaskStatus.Failure) then
         self:Reset();
         return BTTaskStatus.Success;
     elseif (self.executionCount == self.count) then
         self:Reset();
         return BTTaskStatus.Success;
     else
         return BTTaskStatus.Running;
     end
 end

 function this:Reset()
     self.executionStatus = BTTaskStatus.Inactive;
     self.executionCount = ;
     BTParentTask.Reset(self);
 end

测试：

 TestBehaviorTree = BTBehaviorTree:New();

 local this = TestBehaviorTree;

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

 function this:Init()
     --1.一定的执行次数
     local repeater = BTRepeater:New();
     local log = BTLog:New("This is a BTRepeater test");
     repeater:AddChild(log);

     --2.循环执行
     --[[local repeater = BTRepeater:New();
     local log = BTLog:New("This is a BTRepeater test");
     repeater:AddChild(log);--]]

     --3.endOnFailure false
     --[[local repeater = BTRepeater:New(3);
     local sequence = BTSequence:New();
     local log = BTLog:New("First Child");
     local isNullOrEmpty = BTIsNullOrEmpty:New("123");
     local log2 = BTLog:New("This is a empty string");
     sequence:AddChild(log);
     sequence:AddChild(isNullOrEmpty);
     sequence:AddChild(log2);
     repeater:AddChild(sequence);--]]

     --4.endOnFailure true
     --[[local repeater = BTRepeater:New(3, true);
     local sequence = BTSequence:New();
     local log = BTLog:New("First Child");
     local isNullOrEmpty = BTIsNullOrEmpty:New("123");
     local log2 = BTLog:New("This is a empty string");
     sequence:AddChild(log);
     sequence:AddChild(isNullOrEmpty);
     sequence:AddChild(log2);
     repeater:AddChild(sequence);--]]

     this:PushTask(repeater);
 end

第一个输出：

第二个输出(循环执行)：

第三个输出：

第四个输出：