上一篇文章中的视频展示了模型的旋转、平移和缩放的运行结果图。下面是具体的实现：

首先在*****View.h中定义一下成员变量：

protected:
	//三维场景转换模式
	enum CurrentAction3d
	{
		CurAction3d_Nothing,
		CurAction3d_DynamicPanning, //平移
		CurAction3d_DynamicZooming, //缩放
		CurAction3d_DynamicRotation //旋转
	};
	Standard_Integer m_x_max;    //记录鼠标平移坐标X
	Standard_Integer m_y_max;    //记录鼠标平移坐标Y
	float m_scale;    //记录滚轮缩放比例 
	CurrentAction3d m_current_mode; //三维场景转换模式(平移\缩放\旋转)
	bool leftMouseBtn = false; //记录鼠标左键状态
	bool midMouseBtn = false;  //记录鼠标中键状态
	CPoint mouseDownPT;    //控制旋转角度
	CPoint m_Pt;

接着在*****View的类向导中添加鼠标消息响应：

添加完成之后，会出现六个成员函数：

public:
	
	afx_msg void OnMouseMove(UINT nFlags, CPoint point);
	afx_msg BOOL OnMouseWheel(UINT nFlags, short zDelta, CPoint pt);
	afx_msg void OnLButtonDown(UINT nFlags, CPoint point);
	afx_msg void OnLButtonUp(UINT nFlags, CPoint point);
	afx_msg void OnMButtonDown(UINT nFlags, CPoint point);
	afx_msg void OnMButtonUp(UINT nFlags, CPoint point);

至此，成员变量和成员函数添加完毕。

接下来进行变量初始化和函数的实现：

在*****View.h的构造函数COCCmfcMDIView::COCCmfcMDIView() noexcept 进行变量的初始化

COCCmfcMDIView::COCCmfcMDIView() noexcept
{
	// TODO: 在此处添加构造代码
	mouseDownPT.x = 0;
	mouseDownPT.y = 0;

	m_Pt.x = 0;
	m_Pt.y = 0;
	m_scale = 1.0;
}

下面进行鼠标响应事件的实现：

1. afx_msg void OnLButtonDown(UINT nFlags, CPoint point);的实现

void COCCmfcMDIView::OnLButtonDown(UINT nFlags, CPoint point)
{
	// TODO: 在此添加消息处理程序代码和/或调用默认值
	m_current_mode = CurAction3d_DynamicRotation;
	mouseDownPT = point;
	myView->StartRotation(point.x, point.y);
	leftMouseBtn = true;
	CView::OnLButtonDown(nFlags, point);
}

2. afx_msg void OnLButtonUp(UINT nFlags, CPoint point);的实现

void COCCmfcMDIView::OnLButtonUp(UINT nFlags, CPoint point)
{
    // TODO: 在此添加消息处理程序代码和/或调用默认值
    m_current_mode = CurAction3d_Nothing;
    if (leftMouseBtn==true)
    {
        leftMouseBtn = false;
    }
    CView::OnLButtonUp(nFlags, point);
}

3. afx_msg void OnMButtonDown(UINT nFlags, CPoint point);的实现

//鼠标中键按下事件初始操作
void COCCmfcMDIView::OnMButtonDown(UINT nFlags, CPoint point)
{
	// TODO: 在此添加消息处理程序代码和/或调用默认值
	m_current_mode = CurAction3d_DynamicPanning;
	mouseDownPT = point;
	m_x_max = point.x; //记录平移时起始X位置
	m_y_max = point.y; //记录平移时起始Y位置
	midMouseBtn = true;
	CView::OnMButtonDown(nFlags, point);
}

4. afx_msg void OnMButtonUp(UINT nFlags, CPoint point);的实现

void COCCmfcMDIView::OnMButtonUp(UINT nFlags, CPoint point)
{
	// TODO: 在此添加消息处理程序代码和/或调用默认值
	m_current_mode = CurAction3d_Nothing;
	if (midMouseBtn==true)
	{
		midMouseBtn == false;
	}
	CView::OnMButtonUp(nFlags, point);
}

5. afx_msg void OnMouseMove(UINT nFlags, CPoint point);的实现

void COCCmfcMDIView::OnMouseMove(UINT nFlags, CPoint point)
{
	// TODO: 在此添加消息处理程序代码和/或调用默认值

	CView::OnMouseMove(nFlags, point);
	
	switch (m_current_mode)
	{

	case COCCmfcMDIView::CurAction3d_DynamicPanning:
		//执行平移
		myView->Pan(point.x - m_x_max, m_y_max-point.y);
		m_x_max = point.x;
		m_y_max = point.y;
		break;
	
	case COCCmfcMDIView::CurAction3d_DynamicRotation:
		//执行旋转
		myView->Rotation(point.x, point.y);
		break;
	}
	
}

6. afx_msg BOOL OnMouseWheel(UINT nFlags, short zDelta, CPoint pt);的实现

BOOL COCCmfcMDIView::OnMouseWheel(UINT nFlags, short zDelta, CPoint pt)
{
	// TODO: 在此添加消息处理程序代码和/或调用默认值
	static float upLimit = 10.0f;
	static float downLimit = 0.04f;
	static float fUp = 1.1f;
	static float fDown = 0.9f;
	m_Pt = pt;
	myView->StartZoomAtPoint(pt.x, pt.y);   //在鼠标光标的点处进行放大
	if (zDelta > 0 && m_scale <= upLimit)
	{
		m_scale *= fUp;
		myView->ZoomAtPoint(0, 0, 10, 0);
	}
	else if (zDelta<0 && m_scale>downLimit)
	{
		m_scale *= fDown;
		myView->ZoomAtPoint(0, 0, -10, 0);

	}
	
	return CView::OnMouseWheel(nFlags, zDelta, pt);
}

至此，完成了的模型的旋转、平移、缩放功能 ！！！！！！！！！！！