[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 = 1;
        [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 = 0;
        // 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 = 0;
            executionStatus = TaskStatus.Inactive;
        }

        public override void OnReset()
        {
            // Reset the public properties back to their original values.
            count = 0;
            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() ~= 1) then
        return nil;
    end
    return self.childTasks[1];
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 -1;                       --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 = 0;                        --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 == -1) 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 + 1;
    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 = 0;
    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(5);
    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：