【转】 《基于MFC的OpenGL编程》Part 6 Keyboard and Mouse Control

在上一篇的基础上加入对键盘和鼠标的事件处理程序，以便用其来控制3D物体的旋转和移动。
1,首先在CCY457OpenGLView类中为WM_KEYDOWN, WM_LBUTTONDOWN, WM_LBUTTONUP 和 WM_MOUSEMOVE四个事件加入事件处理函数。

2,在CCY457OpenGLView.h中加入下列用于控制旋转和移动的变量：并在构造函数中初始化：

GLfloat m_xAngle;

GLfloat m_yAngle;

GLfloat m_xPos;

GLfloat m_yPos;

CPoint m_MouseDownPoint;

CCY457OpenGLView::CCY457OpenGLView()

{

m_xPos = 0.0f;

m_yPos = 0.0f;

m_xAngle = 0.0f;

m_yAngle = 0.0f;

}

3，加入绘制代码：

void COpenGLView::RenderScene ()

{

glLoadIdentity();

glTranslatef(m_xPos, m_yPos, -5.0f);

glRotatef(m_xAngle, 1.0f,0.0f,0.0f);

glRotatef(m_yAngle, 0.0f,1.0f,0.0f);

glutWireCube(1.0f);

}

4，为四个事件处理函数加入控制代码

void COpenGLView::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags)

{

// TODO: Add your message handler code here and/or call default

switch (nChar)

{

case VK_UP: m_yPos = m_yPos + 0.1f;

break;

case VK_DOWN: m_yPos = m_yPos - 0.1f;

break;

case VK_LEFT: m_xPos = m_xPos - 0.1f;

break;

case VK_RIGHT: m_xPos = m_xPos + 0.1f;

break;

default: MessageBox("Press the arrow keys only");

break;

}

InvalidateRect(NULL,FALSE);

CView::OnKeyDown(nChar, nRepCnt, nFlags);

}

void COpenGLView::OnLButtonDown(UINT nFlags, CPoint point)

{

// TODO: Add your message handler code here and/or call default

m_MouseDownPoint=point;

SetCapture();

CView::OnLButtonDown(nFlags, point);

}

void COpenGLView::OnLButtonUp(UINT nFlags, CPoint point)

{

// TODO: Add your message handler code here and/or call default

m_MouseDownPoint=CPoint(0,0);

ReleaseCapture();

CView::OnLButtonUp(nFlags, point);

}

void COpenGLView::OnMouseMove(UINT nFlags, CPoint point)

{

// TODO: Add your message handler code here and/or call default

// Check if we have captured the mouse

if (GetCapture()==this)

{

//Increment the object rotation angles

m_xAngle+=(point.y-m_MouseDownPoint.y)/3.6;

m_yAngle+=(point.x-m_MouseDownPoint.x)/3.6;

//Redraw the view

InvalidateRect(NULL,FALSE);

//Set the mouse point

m_MouseDownPoint=point;

};

CView::OnMouseMove(nFlags, point);

}