[Unity插件]Lua行为树(四)：条件节点和行为节点

条件节点和行为节点，这两种节点本身的设计比较简单，项目中编写行为树节点一般就是扩展这两种节点，而Decorator和Composite节点只需要使用内置的就足够了。

它们的继承关系如下：

Conditional->Task

Action->Task

代码如下：

BTAction.lua

BTAction = BTTask:New();

local this = BTAction;

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

BTConditional.lua

BTConditional = BTTask:New();

local this = BTConditional;

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

BTLog.lua

--[[
参考BehaviorDesigner-Action-Log
--]]
BTLog = BTAction:New();

local this = BTLog;

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

function this:OnUpdate()
    print(self.text);
    return BTTaskStatus.Success;
end

BTIsNullOrEmpty.lua

--[[
参考BehaviorDesigner-Conditional-IsNullOrEmpty
--]]
BTIsNullOrEmpty = BTConditional:New();

local this = BTIsNullOrEmpty;

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

function this:OnUpdate()
    if (not self.text or self.text == "") then
        return BTTaskStatus.Success;
    else
        return BTTaskStatus.Failure;
    end
end

TestBehaviorTree.lua

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()
    local sequence = BTSequence:New();
    local isNullOrEmpty = BTIsNullOrEmpty:New("");
    local log = BTLog:New("This is a empty string");
    sequence:AddChild(isNullOrEmpty);
    sequence:AddChild(log);
    this:PushTask(sequence);
end

输出如下：