[Unity插件]Lua行为树(七)：行为树嵌套

在上一篇的基础上，可以测试下行为树的嵌套，所谓的行为树嵌套，就是在一棵行为树下的某一个分支，接入另一棵行为树。

以下面这棵行为树为例：

 

TestBehaviorTree2.lua

TestBehaviorTree2 = BTBehaviorTree:New();

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

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

function this:Init()
    local repeater = BTRepeater:New(2);
    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

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(2);
    local selector = BTSelector:New();
    local sequence = BTSequence:New();
    local isNullOrEmpty = BTIsNullOrEmpty:New("123");
    local log = BTLog:New("This is a empty string!!!");
    local tree2 = TestBehaviorTree2:New();

    self:SetStartTask(repeater);

    repeater:AddChild(selector);

    selector:AddChild(sequence);
    selector:AddChild(tree2);

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

打印如下：

上面的执行结果是没有问题的，由此可见，将BTBehaviorTree当作节点，然后嵌套在行为树中是可行的。不过通过上面的打印，可以发现嵌套树先被打印，然后总树才被打印，而且嵌套树的层级也是不对的。

对于打印错误，这是节点添加顺序造成的问题，因此不应该在设置节点或者添加节点时进行打印，应该在整棵数构成完成后进行打印。

对于层级不对，可以在添加嵌套树后更新嵌套树下的节点层级。

Enum.lua

--节点状态
BTTaskStatus = {
    Inactive = 1,    --尚未执行
    Failure = 2,     --返回失败
    Success = 3,     --返回成功
    Running = 4,     --执行中
}

--节点类型
BTTaskType = {
    Root = 0,
    Action = 1,
    Composite = 2,
    Conditional = 3,
    Decorator = 4,
}

BTBehaviorManager.lua

BTBehaviorManager = {};

local this = BTBehaviorManager;
this.printTreeStr = "";

function this.RunTree(tree)
    this.bTree = tree;
    this.OnUpdate();
end

function this.OnUpdate()
    local status = this.bTree:OnUpdate();
    while (status == BTTaskStatus.Running) do
        status = this.bTree:OnUpdate();
    end
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() .. "
";

    if (taskType == BTTaskType.Root) then    
        this.AddToPrintTreeStr(task.startTask);
    elseif (taskType == BTTaskType.Composite or taskType == BTTaskType.Decorator) then
        for i=1,#task.childTasks do
            this.AddToPrintTreeStr(task.childTasks[i]);
        end
    else
        
    end
end

BTBehaviorTree.lua

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

local this = BTBehaviorTree;
this.taskType = BTTaskType.Root;

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

--设置起始节点
function this:SetStartTask(task)
    task.root = self;
    task.parent = self;
    task.layer = self.layer + 1;
    self.startTask = task;
end

--更新子节点层级
function this:UpdateLayer()
    self:UpdateChildLayer(self.startTask);
end

function this:UpdateChildLayer(task)
    local taskType = task.taskType;
    task.layer = task.root.layer + task.layer - 1;

    if (taskType == BTTaskType.Root) then    
        self:UpdateChildLayer(task.startTask);
    elseif (taskType == BTTaskType.Composite or taskType == BTTaskType.Decorator) then
        for i=1,#task.childTasks do
            self:UpdateChildLayer(task.childTasks[i]);
        end
    else
        
    end    
end

function this:OnUpdate()
    if (self.startTask) then
        return self.startTask:OnUpdate();
    end
end

打印如下：