[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 = 0;

    for i=1,#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 + 1;
        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() .. "
";

    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

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 = 1;
    local a = function ()
        if (count <= 3) then
            count = count + 1;
            print("22");
            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(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

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(2);
    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 = 0;

    for i=1,#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 + 1;
        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() .. "
";

    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

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。