osg鼠标缩放

osg鼠标缩放

bool handle(const osgGA::GUIEventAdapter &ea, osgGA::GUIActionAdapter &us) 
{
    // 得到x的初始屏幕坐标
    float mouseX = ea.getX();
    // 得到y的初始屏幕坐标
    float mouseY = ea.getY();
    // 判断事件类型
    switch (ea.getEventType()) 
    {
    case (osgGA::GUIEventAdapter::EventType::SCROLL):
        //osgGA::GUIEventAdapter::ScrollingMotion  scrollingMotionObj=ea.getScrollingMotion();
        if (ea.getScrollingMotion() == osgGA::GUIEventAdapter::ScrollingMotion::SCROLL_UP)
        {
            camera_scale = camera_scale + 0.1f;
        }
        if (ea.getScrollingMotion() == osgGA::GUIEventAdapter::ScrollingMotion::SCROLL_DOWN)
        {
            camera_scale = camera_scale - 0.1f;
        }
        std::cout << "camera_scale:" << camera_scale << std::endl;
        return false;
    default:
        return false;
    }
}      

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