一个简单的游戏框架：Lua相关

一个简单的游戏框架：Lua相关

代码：https://github.com/HushengStudent/myGameFramework

目前游戏开发中，普遍使用Unity+Lua的形式，为了热更新的目的，所以Lua在游戏开发中基本属于必不可少了，本文旨在简单介绍在Unity开发中，Lua的常见简单使用：

1.Lua"类"的实现

Lua中实现"类"，主要是通过元表实现的，我们简单参考cocos2d-x lua-bulding源码中，"类"的实现:

Class.lua:

function class(classname, ...)
    local cls = {__cname = classname}

    local supers = {...}
    for _, super in ipairs(supers) do
        local superType = type(super)
        assert(superType == "nil" or superType == "table" or superType == "function",
        string.format("class() - create class \"%s\" with invalid super class type \"%s\"",
        classname, superType))

        if superType == "function" then
            assert(cls.__create == nil,
            string.format("class() - create class \"%s\" with more than one creating function",
            classname));
            -- if super is function, set it to __create
            cls.__create = super
        elseif superType == "table" then
            if super[".isclass"] then
                -- super is native class
                assert(cls.__create == nil,
                string.format("class() - create class \"%s\" with more than one creating function or native class",
                classname));
                cls.__create = function() return super:create() end
            else
                -- super is pure lua class
                cls.__supers = cls.__supers or {}
                cls.__supers[#cls.__supers + 1] = super
                if not cls.super then
                    -- set first super pure lua class as class.super
                    cls.super = super
                end
            end
        else
            error(string.format("class() - create class \"%s\" with invalid super type",
            classname), 0)
        end
    end

    cls.__index = cls
    if not cls.__supers or #cls.__supers == 1 then
        setmetatable(cls, {__index = cls.super})
    else
        setmetatable(cls, {__index = function(_, key)
            local supers = cls.__supers
            for i = 1, #supers do
                local super = supers[i]
                if super[key] then return super[key] end
            end
        end})
    end

    if not cls.ctor then
        -- add default constructor
        cls.ctor = function() end
    end
    cls.new = function(...)
        local instance
        if cls.__create then
            instance = cls.__create(...)
        else
            instance = {}
        end
        setmetatableindex(instance, cls)
        instance.class = cls
        instance:ctor(...)
        return instance
    end
    cls.create = function(_, ...)
        return cls.new(...)
    end

    return cls
end

local setmetatableindex_
setmetatableindex_ = function(t, index)
    if type(t) == "userdata" then
        local peer = tolua.getpeer(t)
        if not peer then
            peer = {}
            tolua.setpeer(t, peer)
        end
        setmetatableindex_(peer, index)
    else
        local mt = getmetatable(t)
        if not mt then mt = {} end
        if not mt.__index then
            mt.__index = index
            setmetatable(t, mt)
        elseif mt.__index ~= index then
            setmetatableindex_(mt, index)
        end
    end
end
setmetatableindex = setmetatableindex_

lua类的使用，比如我们建一个类GameManager：

GameManager = class("GameManager")

function GameManager:ctor() end

function GameManager:GetManagerName()
    log("GameManager")
end

2.Lua常用工具方法

以下常用Lua工具方法，也是参考cocos2d-x lua-bulding源码：

---table's number
function table.nums(t)
    local count = 0
    for k, v in pairs(t) do
        count = count + 1
    end
    return count
end

---table's keys
function table.keys(hashtable)
    local keys = {}
    for k, v in pairs(hashtable) do
        keys[#keys + 1] = k
    end
    return keys
end

---table's values
function table.values(hashtable)
    local values = {}
    for k, v in pairs(hashtable) do
        values[#values + 1] = v
    end
    return values
end

---
function table.merge(dest, src)
    for k, v in pairs(src) do
        dest[k] = v
    end
end

---
function table.walk(t, fn)
    for k,v in pairs(t) do
        fn(v, k)
    end
end

---string split
function string.split(input, delimiter)
    input = tostring(input)
    delimiter = tostring(delimiter)
    if (delimiter=='') then return false end
    local pos,arr = 0, {}
    -- for each divider found
    for st,sp in function() return string.find(input, delimiter, pos, true) end do
        table.insert(arr, string.sub(input, pos, st - 1))
        pos = sp + 1
    end
    table.insert(arr, string.sub(input, pos))
    return arr
end

---table dump
function table.dump(t)
    for k, v in pairs(t) do
        logGreen("--->>>key:"..tostring(k).." --->>>value:"..tostring(v))
    end
end

3.Lua其他相关

C#中ulong传递到Lua使用string；

lua面向对象编程中，属性使用点号，方法使用冒号；

Lua网络，事件系统，定时器等将在介绍tolua时介绍；

Lua注意两种表的遍历方式；

Lua GC；