问Qt QOpenGLWidget wheelEvent奇怪的行为

EN

class Curve2DOpenGLWidget : public QOpenGLWidget, protected QOpenGLFunctions_3_3_Core {
Q_OBJECT   
public:

    Curve2DOpenGLWidget( QWidget* parent = nullptr );
    ~Curve2DOpenGLWidget();  

    void initializeGL() override;
    void resizeGL(int width, int height) override;
    void paintGL() override;
    void NativePaintGL();

protected:
    void mousePressEvent(QMouseEvent *event) override;
    void mouseReleaseEvent(QMouseEvent *event) override;
    void mouseMoveEvent(QMouseEvent *event) override;
    void wheelEvent(QWheelEvent *event) override;

};

void Curve2DOpenGLWidget::wheelEvent( QWheelEvent* event ) {
    QOpenGLWidget::wheelEvent(event);
    float numStep = (event->angleDelta().y() / 8) / 15;
    m_camera.MoveFront(numStep * 0.1f);
}