在多文档应用程序中使用OpenGL绘图

 

1、在视图类的头文件中添加两个成员变量：

   1: public:

   2:     int m_GLPixelIndex;

   3:     HGLRC m_hGLContext;

2、在视图类的构造函数中对这两个成员进行初始化：

   1: m_GLPixelIndex = 0;

   2: m_hGLContext = NULL;

3、在视图类声明中添加两个成员函数：

   1: BOOL SetWindowPixelFormat(HDC hDC);

   2: BOOL CreateViewGLContext(HDC hDC);

4、在视图类的实现文件中添加这两个成员函数的实现：

   1: BOOL CXXXView::CreateViewGLContext(HDC hDC)

   2: {

   3:     m_hGLContext = wglCreateContext(hDC);

   4:  

   5:     if(m_hGLContext==NULL)

   6:         return FALSE;

   7:  

   8:     if(wglMakeCurrent(hDC,m_hGLContext)==FALSE)

   9:         return FALSE;

  10:  

  11:     return TRUE;    

  12: }

以及

   1: BOOL CXXXView::SetWindowPixelFormat(HDC hDC)

   2: {

   3:     PIXELFORMATDESCRIPTOR pixelDesc;

   4:  

   5:     pixelDesc.nSize = sizeof(PIXELFORMATDESCRIPTOR);

   6:     pixelDesc.nVersion = 1;

   7:  

   8:     pixelDesc.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL |

   9:         PFD_DOUBLEBUFFER | PFD_STEREO_DONTCARE;

  10:  

  11:     pixelDesc.iPixelType = PFD_TYPE_RGBA;

  12:     pixelDesc.cColorBits = 32;

  13:     pixelDesc.cRedBits = 8;

  14:     pixelDesc.cRedShift = 16;

  15:     pixelDesc.cGreenBits = 8;

  16:     pixelDesc.cGreenShift = 8;

  17:     pixelDesc.cBlueBits = 8;

  18:     pixelDesc.cBlueShift = 0;

  19:     pixelDesc.cAlphaBits = 0;

  20:     pixelDesc.cAlphaShift = 0;

  21:     pixelDesc.cAccumBits = 64;

  22:     pixelDesc.cAccumRedBits = 16;

  23:     pixelDesc.cAccumGreenBits = 16;

  24:     pixelDesc.cAccumBlueBits = 16;

  25:     pixelDesc.cAccumAlphaBits = 0;

  26:     pixelDesc.cDepthBits = 32;

  27:     pixelDesc.cStencilBits = 8;

  28:     pixelDesc.cAuxBuffers = 0;

  29:     pixelDesc.iLayerType = PFD_MAIN_PLANE;

  30:     pixelDesc.bReserved = 0;

  31:     pixelDesc.dwLayerMask = 0;

  32:     pixelDesc.dwVisibleMask = 0;

  33:     pixelDesc.dwDamageMask = 0;

  34:  

  35:     m_GLPixelIndex = ChoosePixelFormat(hDC,&pixelDesc);

  36:     if(m_GLPixelIndex == 0) // Choose default

  37:     {

  38:         m_GLPixelIndex = 1;

  39:         if(DescribePixelFormat(hDC,m_GLPixelIndex,

  40:             sizeof(PIXELFORMATDESCRIPTOR),&pixelDesc)==0)

  41:             return FALSE;

  42:     }

  43:  

  44:     if(!SetPixelFormat(hDC,m_GLPixelIndex,&pixelDesc))

  45:         return FALSE;

  46:  

  47:     return TRUE;

  48: }

在视图类的OnCreate成员函数中添加：

   1: HWND hWnd = GetSafeHwnd();

   2: HDC hDC = ::GetDC(hWnd);

   3:  

   4: if(SetWindowPixelFormat(hDC)==FALSE)

   5:     return -1;

   6:  

   7: if(CreateViewGLContext(hDC)==FALSE)

   8:     return -1;

添加OnPaint消息响应函数，在函数中加入：

   1: HWND hWnd = GetSafeHwnd();

   2: HDC hDC = ::GetDC(hWnd);

   3: wglMakeCurrent(dc.m_ps.hdc,m_hGLContext);

   4:  

   5: ....

   6:  

   7: // Double buffer

   8: SwapBuffers(dc.m_ps.hdc);

   9: glFlush();

  10:  

  11: // release

  12: ::ReleaseDC(hWnd,hDC);

添加OnSize消息响应函数。这里的内容可以根据需要进行修改：

   1: glViewport(0,0,(GLsizei)cx,(GLsizei)cy);

   2: glMatrixMode(GL_PROJECTION);

   3: glLoadIdentity();

   4: gluPerspective(60.0,(GLfloat)cx/(GLfloat)cy,0.1,100.0);

   5: glMatrixMode(GL_MODELVIEW);

   6: glLoadIdentity();

添加虚函数OnActivateView，在其中添加：

   1: HWND hWnd = GetSafeHwnd();

   2: HDC hDC = ::GetDC(hWnd);

   3: wglMakeCurrent(hDC,m_hGLContext);

   4: ::ReleaseDC(hWnd,hDC);

添加WM_DESTROY消息响应函数，在其中添加：

   1: if(wglGetCurrentContext() != NULL)

   2:     wglMakeCurrent(NULL,NULL);

   3:  

   4: if(m_hGLContext != NULL)

   5: {

   6:     wglDeleteContext(m_hGLContext);

   7:     m_hGLContext = NULL;

   8: }

Over。