cocos2d-x + lua 处理触屏事件

来源：互联网发布：吉林大学网络教育学费编辑：程序博客网时间：2024/05/16 18:33

(1) 使用方法如下

local function onTouchBegan(x, y)endlocal function onTouchMoved(x, y)endlocal function onTouchEnded(x, y)endlocal function onTouch(eventType, x, y)    if eventType == "begin" then        return onTouchBegan(x, y)    elseif eventType == "moved" CCTOUCHMOVED then        return onTouchMoved(x, y)    else        return onTouchEnded(x, y)    endend--注册触摸函数layer:registerScriptTouchHandler(onTouch)--设置成可触摸layer:setIsTouchEnabled(true)

(2)原理如下

一，其实就是在touch事件派发到layer的时候执行一个lua的函数。

这个函数也就是

local function onTouch(eventType, x, y)
    if eventType == "begin" then
        return onTouchBegan(x, y)
    elseif eventType == "moved" CCTOUCHMOVED then
        return onTouchMoved(x, y)
    else
        return onTouchEnded(x, y)
    end
end

二，在cclayer中注册此函数

layer:registerScriptTouchHandler(onTouch)

void CCLayer::registerScriptTouchHandler(int nHandler, bool bIsMultiTouches, int nPriority, bool bSwallowsTouches){    unregisterScriptTouchHandler(); //将函数名注册到CCTouchScriptHandlerEntry中    m_pScriptTouchHandlerEntry = CCTouchScriptHandlerEntry::create(nHandler, bIsMultiTouches, nPriority, bSwallowsTouches);    m_pScriptTouchHandlerEntry->retain();}

三，当cclayer响应ccTouchBegin时，有如下代码

if (kScriptTypeNone != m_eScriptType)
{ //如果使用了脚本语言，就解析上面注册的ScriptTouchHandler
return excuteScriptTouchHandler(CCTOUCHBEGAN, pTouch) == 0 ? false : true;
}

excuteScriptTouchHandler调用了executeLayerTouchEvent解析lua函数

四，执行lua函数

int CCLuaEngine::executeLayerTouchEvent(CCLayer* pLayer, int eventType, CCTouch *pTouch){    CCTouchScriptHandlerEntry* pScriptHandlerEntry = pLayer->getScriptTouchHandlerEntry();    if (!pScriptHandlerEntry) return 0;    //从CCTouchScriptHandlerEntry取得函数名    int nHandler = pScriptHandlerEntry->getHandler();    if (!nHandler) return 0;        switch (eventType)    {        case CCTOUCHBEGAN:            m_stack->pushString("began");            break;                    case CCTOUCHMOVED:            m_stack->pushString("moved");            break;                    case CCTOUCHENDED:            m_stack->pushString("ended");            break;                    case CCTOUCHCANCELLED:            m_stack->pushString("cancelled");            break;                    default:            return 0;    }        const CCPoint pt = CCDirector::sharedDirector()->convertToGL(pTouch->getLocationInView());    m_stack->pushFloat(pt.x);    m_stack->pushFloat(pt.y);    //解析函数，传递了3个参数，分别是eventType,x,y    int ret = m_stack->executeFunctionByHandler(nHandler, 3);    m_stack->clean();    return ret;}这样就完成了触屏事件在lua中的处理