cocos2dx

记录cocos2dx的学习历程和遇到的坑。 版本4.0

坐标系问题

• 对于精灵，坐标系从左下开始向右上增长，x轴从左向右。例如 sprite->setPosition(Vec2(0, 0)); 设置精灵为左下角。
• 对于鼠标，坐标系从左上方开始向右下增长，x轴从左向右。例如 Point pt = e->getLocation(); pt={0,0}代表鼠标位于左上角。

鼠标控制事件

对于鼠标事件，cocos官方文档中对于4.0版本中还未更新。我们可以同过如下方式实现鼠标对于精灵的控制。

static bool mouse_down = false;
auto myMouseListener = EventListenerMouse::create();
myMouseListener->onMouseDown = [=](Event* event)
{
    EventMouse* e = (EventMouse*)event;
    Point pt = e->getLocation();
    pt.y = visibleSize.height - pt.y;
    Rect rect = charac->getBoundingBox();
    //log("point x:%f,y%f", pt.x, pt.y);

    if (rect.containsPoint(pt))
    {
      //  log("rect x:%f,y%f", rect.origin.x, rect.origin.y);
        mouse_down = true;
        charac->setPosition(pt);

    }
   
};
myMouseListener->onMouseUp = [=](Event* event)
{
    mouse_down = false;
};
//鼠标移动
myMouseListener->onMouseMove = [=](Event* event)
{
    EventMouse* e = (EventMouse*)event;
    Point pt = e->getLocation();
    pt.y = visibleSize.height - pt.y;

    if (mouse_down )
    {
       charac->setPosition( pt);
    }
};
_eventDispatcher->addEventListenerWithSceneGraphPriority(myMouseListener, this);

setUserObject

在使用setUserObject传值时，对应的参数要new，否则会出现莫名其妙的bug。