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How to enable openGL in a win32++ application

2010-07-27
2021-07-10
  • lin tun ren

    lin tun ren - 2010-07-27

    I have referenced a MFC based with opengl enabled application,
    I develope a tiny system which needs 3d graphy,and I select openGL,
    How can I enable it into WIn32++ based programs?

     
  • David

    David - 2010-07-28

    Hi,

    OpenGL will work much the same way as DirectX in Win32++.  Start with the DirectX sample and observe how the message loop is overridden in CDXApp::MessageLoop. We will need to do the same thing to support OpenGL.

    What follows below is a sample OpenGL from the Windows Platform SDK documentation. Note how it calls the drawScene in the message loop, just like the Win32++ uses Render.

    I assume it will be relatively straight forward to port this OpenGL program now to Win32++, but if you need further assistance, please get back to me.

    Best regards,
    David

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    /*
    * Example of a Win32 OpenGL program. 
    * The OpenGL code is the same as that used in 
    * the X Window System sample
    */
    #include <windows.h>
    #include <GL/gl.h>
    #include <GL/glu.h>

    /* Windows globals, defines, and prototypes */
    CHAR szAppName="Win OpenGL";
    HWND  ghWnd;
    HDC   ghDC;
    HGLRC ghRC;

    #define SWAPBUFFERS SwapBuffers(ghDC)
    #define BLACK_INDEX     0
    #define RED_INDEX       13
    #define GREEN_INDEX     14
    #define BLUE_INDEX      16
    #define WIDTH           300
    #define HEIGHT          200

    LONG WINAPI MainWndProc (HWND, UINT, WPARAM, LPARAM);
    BOOL bSetupPixelFormat(HDC);

    /* OpenGL globals, defines, and prototypes */
    GLfloat latitude, longitude, latinc, longinc;
    GLdouble radius;

    #define GLOBE    1
    #define CYLINDER 2
    #define CONE     3

    GLvoid resize(GLsizei, GLsizei);
    GLvoid initializeGL(GLsizei, GLsizei);
    GLvoid drawScene(GLvoid);
    void polarView( GLdouble, GLdouble, GLdouble, GLdouble);

    int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
    {
        MSG        msg;
        WNDCLASS   wndclass;

        /* Register the frame class */
        wndclass.style         = 0;
        wndclass.lpfnWndProc   = (WNDPROC)MainWndProc;
        wndclass.cbClsExtra    = 0;
        wndclass.cbWndExtra    = 0;
        wndclass.hInstance     = hInstance;
        wndclass.hIcon         = LoadIcon (hInstance, szAppName);
        wndclass.hCursor       = LoadCursor (NULL,IDC_ARROW);
        wndclass.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
        wndclass.lpszMenuName  = szAppName;
        wndclass.lpszClassName = szAppName;

        if (!RegisterClass (&wndclass) )
            return FALSE;

        /* Create the frame */
        ghWnd = CreateWindow (szAppName,
                 "Generic OpenGL Sample",
             WS_OVERLAPPEDWINDOW | WS_CLIPSIBLINGS | WS_CLIPCHILDREN,
                 CW_USEDEFAULT,
                 CW_USEDEFAULT,
                 WIDTH,
                 HEIGHT,
                 NULL,
                 NULL,
                 hInstance,
                 NULL);

        /* make sure window was created */
        if (!ghWnd)
            return FALSE;

        /* show and update main window */
        ShowWindow (ghWnd, nCmdShow);

        UpdateWindow (ghWnd);

        /* animation loop */
        while (1) {
            /*
             *  Process all pending messages
             */

            while (PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE) == TRUE)
            {
                if (GetMessage(&msg, NULL, 0, 0) )
                {
                    TranslateMessage(&msg);
                    DispatchMessage(&msg);
                } else {
                    return TRUE;
                }
            }
            drawScene();
        }
    }

    /* main window procedure */
    LONG WINAPI MainWndProc (
        HWND    hWnd,
        UINT    uMsg,
        WPARAM  wParam,
        LPARAM  lParam)
    {
        LONG    lRet = 1;
        PAINTSTRUCT    ps;
        RECT rect;

        switch (uMsg) {

        case WM_CREATE:
            ghDC = GetDC(hWnd);
            if (!bSetupPixelFormat(ghDC))
                PostQuitMessage (0);

            ghRC = wglCreateContext(ghDC);
            wglMakeCurrent(ghDC, ghRC);
            GetClientRect(hWnd, &rect);
            initializeGL(rect.right, rect.bottom);
            break;

        case WM_PAINT:
            BeginPaint(hWnd, &ps);
            EndPaint(hWnd, &ps);
            break;

        case WM_SIZE:
            GetClientRect(hWnd, &rect);
            resize(rect.right, rect.bottom);
            break;

        case WM_CLOSE:
            if (ghRC)
                wglDeleteContext(ghRC);
            if (ghDC)
                ReleaseDC(hWnd, ghDC);
            ghRC = 0;
            ghDC = 0;

            DestroyWindow (hWnd);
            break;

        case WM_DESTROY:
            if (ghRC)
                wglDeleteContext(ghRC);
            if (ghDC)
                ReleaseDC(hWnd, ghDC);

            PostQuitMessage (0);
            break;
        
        case WM_KEYDOWN:
            switch (wParam) {
            case VK_LEFT:
                longinc += 0.5F;
                break;
            case VK_RIGHT:
                longinc -= 0.5F;
                break;
            case VK_UP:
                latinc += 0.5F;
                break;
            case VK_DOWN:
                latinc -= 0.5F;
                break;
            }

        default:
            lRet = DefWindowProc (hWnd, uMsg, wParam, lParam);
            break;
        }

        return lRet;
    }

    BOOL bSetupPixelFormat(HDC hdc)
    {
        PIXELFORMATDESCRIPTOR pfd, *ppfd;
        int pixelformat;

        ppfd = &pfd;

        ppfd->nSize = sizeof(PIXELFORMATDESCRIPTOR);
        ppfd->nVersion = 1;
        ppfd->dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | 
                            PFD_DOUBLEBUFFER;
        ppfd->dwLayerMask = PFD_MAIN_PLANE;
        ppfd->iPixelType = PFD_TYPE_COLORINDEX;
        ppfd->cColorBits = 8;
        ppfd->cDepthBits = 16;
        ppfd->cAccumBits = 0;
        ppfd->cStencilBits = 0;

        pixelformat = ChoosePixelFormat(hdc, ppfd);

        if ( (pixelformat = ChoosePixelFormat(hdc, ppfd)) == 0 )
        {
            MessageBox(NULL, "ChoosePixelFormat failed", "Error", MB_OK);
            return FALSE;
        }

        if (SetPixelFormat(hdc, pixelformat, ppfd) == FALSE)
        {
            MessageBox(NULL, "SetPixelFormat failed", "Error", MB_OK);
            return FALSE;
        }

        return TRUE;
    }

    /* OpenGL code */

    GLvoid resize( GLsizei width, GLsizei height )
    {
        GLfloat aspect;

        glViewport( 0, 0, width, height );

        aspect = (GLfloat) width / height;

        glMatrixMode( GL_PROJECTION );
        glLoadIdentity();
        gluPerspective( 45.0, aspect, 3.0, 7.0 );
        glMatrixMode( GL_MODELVIEW );
    }    

    GLvoid createObjects()
    {
        GLUquadricObj *quadObj;

        glNewList(GLOBE, GL_COMPILE);
            quadObj = gluNewQuadric ();
            gluQuadricDrawStyle (quadObj, GLU_LINE);
            gluSphere (quadObj, 1.5, 16, 16);
        glEndList();

        glNewList(CONE, GL_COMPILE);
            quadObj = gluNewQuadric ();
            gluQuadricDrawStyle (quadObj, GLU_FILL);
            gluQuadricNormals (quadObj, GLU_SMOOTH);
            gluCylinder(quadObj, 0.3, 0.0, 0.6, 15, 10);
        glEndList();

        glNewList(CYLINDER, GL_COMPILE);
            glPushMatrix ();
            glRotatef ((GLfloat)90.0, (GLfloat)1.0, (GLfloat)0.0, (GLfloat)0.0);
            glTranslatef ((GLfloat)0.0, (GLfloat)0.0, (GLfloat)-1.0);
            quadObj = gluNewQuadric ();
            gluQuadricDrawStyle (quadObj, GLU_FILL);
            gluQuadricNormals (quadObj, GLU_SMOOTH);
            gluCylinder (quadObj, 0.3, 0.3, 0.6, 12, 2);
            glPopMatrix ();
        glEndList();
    }

    GLvoid initializeGL(GLsizei width, GLsizei height)
    {
        GLfloat     maxObjectSize, aspect;
        GLdouble    near_plane, far_plane;

        glClearIndex( (GLfloat)BLACK_INDEX);
        glClearDepth( 1.0 );

        glEnable(GL_DEPTH_TEST);

        glMatrixMode( GL_PROJECTION );
        aspect = (GLfloat) width / height;
        gluPerspective( 45.0, aspect, 3.0, 7.0 );
        glMatrixMode( GL_MODELVIEW );

        near_plane = 3.0;
        far_plane = 7.0;
        maxObjectSize = 3.0F;
        radius = near_plane + maxObjectSize/2.0;

        latitude = 0.0F;
        longitude = 0.0F;
        latinc = 6.0F;
        longinc = 2.5F;

        createObjects();
    }

    void polarView(GLdouble radius, GLdouble twist, GLdouble latitude,
               GLdouble longitude)
    {
        glTranslated(0.0, 0.0, -radius);
        glRotated(-twist, 0.0, 0.0, 1.0);
        glRotated(-latitude, 1.0, 0.0, 0.0);
        glRotated(longitude, 0.0, 0.0, 1.0);     

    }

    GLvoid drawScene(GLvoid)
    {
        glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

        glPushMatrix();

            latitude += latinc;
            longitude += longinc;

            polarView( radius, 0, latitude, longitude );

            glIndexi(RED_INDEX);
            glCallList(CONE);

            glIndexi(BLUE_INDEX);
            glCallList(GLOBE);

        glIndexi(GREEN_INDEX);
            glPushMatrix();
                glTranslatef(0.8F, -0.65F, 0.0F);
                glRotatef(30.0F, 1.0F, 0.5F, 1.0F);
                glCallList(CYLINDER);
            glPopMatrix();

        glPopMatrix();

        SWAPBUFFERS;
    }

     
  • x-flow

    x-flow - 2021-07-09

    Great project BTW.
    I found you can enable OpenGL following these instructions.

     
  • David

    David - 2021-07-10

    Thanks for your feedback. I'm glad you found the instructions useful.

     

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