OpenGL在MFC中的使用总结（一）

标签：mfc   opengl   

把OnPreCreate改写成如下所示：

<span style="font-size:14px;">BOOL COpenGLDemoView::PreCreateWindow(CREATESTRUCT& cs)
{
    // TODO: Modify the Window class or styles here by modifying
    //  the CREATESTRUCT cs
    cs.style |= (WS_CLIPCHILDREN | WS_CLIPSIBLINGS);
    return CView::PreCreateWindow(cs);
}</span>

　　2.定义窗口的像素格式

产生一个RC的第一步是定义窗口的像素格式。像素格式决定窗口着所显示的图形在内存中是如何表示的。由像素格式控制的参数包括：颜色深度、缓冲模式和所支持的绘画接口。在下面将有对这些参数的设置。我们先在COpenGLDemoView的类中添加一个保护型的成员函数BOOL SetWindowPixelFormat(HDC hDC)（用鼠标右键添加）和保护型的成员变量：int m_GLPixelIndex;

并编辑其中的代码如下：

<span style="font-size:14px;">BOOL COpenGLDemoView::SetWindowPixelFormat(HDC hDC)
{
	//定义窗口的像素格式
    PIXELFORMATDESCRIPTOR pixelDesc=
    {
        sizeof(PIXELFORMATDESCRIPTOR),
        1,
        PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|
        PFD_DOUBLEBUFFER|PFD_SUPPORT_GDI,
        PFD_TYPE_RGBA,
        24,
        0,0,0,0,0,0,
        0,
        0,
        0,
        0,0,0,0,
        32,
        0,
        0,
        PFD_MAIN_PLANE,
        0,
        0,0,0
    };

    this->m_GLPixelIndex = ChoosePixelFormat(hDC,&pixelDesc);
    if(this->m_GLPixelIndex==0)
    {
        this->m_GLPixelIndex = 1;
        if(DescribePixelFormat(hDC,this->m_GLPixelIndex,sizeof(PIXELFORMATDESCRIPTOR),&pixelDesc)==0)
        {
            return FALSE;
        }
    }

    if(SetPixelFormat(hDC,this->m_GLPixelIndex,&pixelDesc)==FALSE)
    {
        return FALSE;
    }
    return TRUE;
｝</span>

　　通常的OpenGL发行版本并不包括所有的标志(flag)。wFlags能接收以下标志：

　　一旦初始化完我们的结构，我们就想知道与要求最相近的系统象素格式。我们可以这样做：

<span style="font-size:14px;">BOOL COpenGLDemoView::CreateViewGLContext(HDC hDC)
{
    this->m_hGLContext = wglCreateContext(hDC);
    if(this->m_hGLContext==NULL)
    {//创建失败
        return FALSE;
    }


    if(wglMakeCurrent(hDC,this->m_hGLContext)==FALSE)
    {//选为当前RC失败
        return FALSE;
    }
    return TRUE;
} </span>

<span style="font-size:14px;">int COpenGLDemoView::OnCreate(LPCREATESTRUCT lpCreateStruct) 
{
    if (CView::OnCreate(lpCreateStruct) == -1)
        return -1;
    
    // TODO: Add your specialized creation code here
    HWND hWnd = this->GetSafeHwnd();    
    HDC hDC = ::GetDC(hWnd);
    if(this->SetWindowPixelFormat(hDC)==FALSE)
    {
        return 0;
    }
    if(this->CreateViewGLContext(hDC)==FALSE)
    {
        return 0;
    }
    return 0;
}　<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);"> </span></span>

<span style="font-size:14px;">void COpenGLDemoView::OnDestroy() 
{
    CView::OnDestroy();
    
    // TODO: Add your message handler code here
    if(wglGetCurrentContext()!=NULL)
    {
        wglMakeCurrent(NULL,NULL);
    }
    if(this->m_hGLContext!=NULL)
    {
        wglDeleteContext(this->m_hGLContext);
        this->m_hGLContext = NULL;
    }
}　　 </span>

<span style="font-size:14px;">COpenGLDemoView::COpenGLDemoView()
{
    // TODO: add construction code here
    this->m_GLPixelIndex = 0;
    this->m_hGLContext = NULL;
}</span>

<span style="font-size:14px;">void COpenGLDemoView::OnSize(UINT nType, int cx, int cy) 
{
    CView::OnSize(nType, cx, cy);
    
    // TODO: Add your message handler code here
    GLsizei width,height;
    GLdouble aspect;
    width = cx;
    height = cy;
    if(cy==0)
    {
        aspect = (GLdouble)width;
    }
    else
    {
        aspect = (GLdouble)width/(GLdouble)height;
    }
    glViewport(0,0,width,height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0,500.0*aspect,0.0,500.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}　　</span>

<span style="font-size:14px;">void COpenGLDemoView::OnPaint() 
{
    CPaintDC dc(this); // device context for painting
    
    // TODO: Add your message handler code here
    
    // Do not call CView::OnPaint() for painting messages


    glLoadIdentity();
    glClear(GL_COLOR_BUFFER_BIT);
    glBegin(GL_POLYGON);
        glColor4f(1.0f,0.0f,0.0f,1.0f);
        glVertex2f(100.0f,50.0f);
        glColor4f(0.0f,1.0f,0.0f,1.0f);
        glVertex2f(450.0f,400.0f);
        glColor4f(0.0f,0.0f,1.0f,1.0f);
        glVertex2f(450.0f,50.0f);
    glEnd();
    glFlush();
}</span>

这个程序的运行结果是黑色背景下的一个绚丽多彩的三角形。

(1) 

(2)

(3)

 我们得告诉OpenGL在后台缓存中画图，在视类的OnSize()的最后一行加入：glDrawBuffer (GL_BACK)；

(4)

 最后我们得把后台缓存的内容换到前台缓存中，在视类的OnPaint()的最后一行加入：SwapBuffers(dc.m_ ps.hdc)。

OpenGL在MFC中的使用总结（一）,布布扣,bubuko.com

OpenGL在MFC中的使用总结（一）

标签：mfc   opengl   

原文地址：http://blog.csdn.net/sin_geek/article/details/38731319