Cocos2d-x Lua：Label文本自动换行实现

开发环境：Cocos2dx 3.17
开发语言：lua
我们在开发过程中，经常会遇到字符串过长，显示的时候超出范围，这时我们可以设置Label自动换行

function FunSetLinefeed( strText, nLineWidth )		--文本，行宽
	--读取每个字符做中文英文判断，并且记录大小
	local nStep = 1
	local index = 1
	local ltabTextSize = {}
	while true do
		c = string.sub(strText, nStep, nStep)
		b = string.byte(c)
 
		if b > 128 then
			ltabTextSize[index] = 3
			nStep = nStep + 3
			index = index + 1
		else
			ltabTextSize[index] = 1
			nStep = nStep + 1
			index = index + 1
		end
 
		if nStep > #strText then
			break
		end
	end
	
	--将字符按照限定行宽进行分组
	local nLineCount = 1
	local nBeginPos = 1
	local lptrCurText = nil
	local ltabText = {}
	local nCurSize = 0
	for i = 1, index - 1 do
		nCurSize = nCurSize + ltabTextSize[i]
		if nCurSize > nLineWidth and nLineCount< math.ceil(#strText/nLineWidth) then
			nCurSize = nCurSize - ltabTextSize[i]
			ltabText[nLineCount] = string.sub( strText, nBeginPos, nBeginPos + nCurSize - 1 )
			nBeginPos = nBeginPos + nCurSize
			nCurSize = ltabTextSize[i]
			nLineCount = nLineCount + 1
		end
        if nLineCount == math.ceil(#strText/nLineWidth) then
			ltabText[nLineCount] = string.sub( strText, nBeginPos, #strText)
        end
	end
	-- for i = 1, nLineCount - 1 do 
    for i = 1, nLineCount  do 
		if lptrCurText == nil then
			lptrCurText = ltabText[i]
		else
			lptrCurText = lptrCurText .. "\n" .. ltabText[i]
		end
	end
	return lptrCurText
end