Irrlicht 3D Engine: Tutorial 14: Win32 Window

| Irrlicht 3D Engine |

Tutorial 14: Win32 Window

This example only runs under MS Windows and demonstrates that Irrlicht can render inside a win32 window. MFC and .NET Windows.Forms windows are possible, too.

In the beginning, we create a windows window using the windows API. I'm not going to explain this code, because it is windows specific. See the MSDN or a windows book for details.

    #include <irrlicht.h>
    #ifndef _IRR_WINDOWS_
    #error Windows only example
    #else
    #include <windows.h> // this example only runs with windows
    #include <iostream>
    #include "driverChoice.h"

    using namespace irr;

    #pragma comment(lib, "irrlicht.lib")

    HWND hOKButton;
    HWND hWnd;

    static LRESULT CALLBACK CustomWndProc(HWND hWnd, UINT message,
            WPARAM wParam, LPARAM lParam)
    {
        switch (message)
        {
        case WM_COMMAND:
            {
                HWND hwndCtl = (HWND)lParam;
                int code = HIWORD(wParam);

                if (hwndCtl == hOKButton)
                {
                    DestroyWindow(hWnd);
                    PostQuitMessage(0);
                    return 0;
                }
            }
            break;
        case WM_DESTROY:
            PostQuitMessage(0);
            return 0;

        }

        return DefWindowProc(hWnd, message, wParam, lParam);
    }

Now ask for the driver and create the Windows specific window.

    int main()
    {
        // ask user for driver
        video::E_DRIVER_TYPE driverType=driverChoiceConsole();
        if (driverType==video::EDT_COUNT)
            return 1;

        printf("Select the render window (some dead window may exist too):\n"\
            " (a) Window with button (via CreationParam)\n"\
            " (b) Window with button (via beginScene)\n"\
            " (c) Own Irrlicht window (default behavior)\n"\
            " (otherKey) exit\n\n");

        char key;
        std::cin >> key;
        if (key != 'a' && key != 'b' && key != 'c')
            return 1;

        HINSTANCE hInstance = 0;
        // create dialog

        const char* Win32ClassName = "CIrrlichtWindowsTestDialog";

        WNDCLASSEX wcex;
        wcex.cbSize         = sizeof(WNDCLASSEX);
        wcex.style          = CS_HREDRAW | CS_VREDRAW;
        wcex.lpfnWndProc    = (WNDPROC)CustomWndProc;
        wcex.cbClsExtra     = 0;
        wcex.cbWndExtra     = DLGWINDOWEXTRA;
        wcex.hInstance      = hInstance;
        wcex.hIcon          = NULL;
        wcex.hCursor        = LoadCursor(NULL, IDC_ARROW);
        wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW);
        wcex.lpszMenuName   = 0;
        wcex.lpszClassName  = Win32ClassName;
        wcex.hIconSm        = 0;

        RegisterClassEx(&wcex);

        DWORD style = WS_SYSMENU | WS_BORDER | WS_CAPTION |
            WS_CLIPCHILDREN | WS_CLIPSIBLINGS | WS_MAXIMIZEBOX | WS_MINIMIZEBOX | WS_SIZEBOX;

        int windowWidth = 440;
        int windowHeight = 380;

        hWnd = CreateWindow( Win32ClassName, "Irrlicht Win32 window example",
            style, 100, 100, windowWidth, windowHeight,
            NULL, NULL, hInstance, NULL);

        RECT clientRect;
        GetClientRect(hWnd, &clientRect);
        windowWidth = clientRect.right;
        windowHeight = clientRect.bottom;

        // create ok button

        hOKButton = CreateWindow("BUTTON", "OK - Close", WS_CHILD | WS_VISIBLE | BS_TEXT,
            windowWidth - 160, windowHeight - 40, 150, 30, hWnd, NULL, hInstance, NULL);

        // create some text

        CreateWindow("STATIC", "This is Irrlicht running inside a standard Win32 window.\n"\
            "Also mixing with MFC and .NET Windows.Forms is possible.",
            WS_CHILD | WS_VISIBLE, 20, 20, 400, 40, hWnd, NULL, hInstance, NULL);

        // create window to put irrlicht in

        HWND hIrrlichtWindow = CreateWindow("BUTTON", "",
                WS_CHILD | WS_VISIBLE | BS_OWNERDRAW,
                50, 80, 320, 220, hWnd, NULL, hInstance, NULL);
        video::SExposedVideoData videodata((key=='b')?hIrrlichtWindow:0);

So now that we have some window, we can create an Irrlicht device inside of it. We use Irrlicht createEx() function for this. We only need the handle (HWND) to that window, set it as windowsID parameter and start up the engine as usual. That's it.

        // create irrlicht device in the button window

        irr::SIrrlichtCreationParameters param;
        param.DriverType = driverType;
        if (key=='a')
            param.WindowId = reinterpret_cast<void*>(hIrrlichtWindow);

        irr::IrrlichtDevice* device = irr::createDeviceEx(param);
        if (!device)
            return 1;

        // setup a simple 3d scene

        irr::scene::ISceneManager* smgr = device->getSceneManager();
        video::IVideoDriver* driver = device->getVideoDriver();

        if (driverType==video::EDT_OPENGL)
        {
            HDC HDc=GetDC(hIrrlichtWindow);
            PIXELFORMATDESCRIPTOR pfd={0};
            pfd.nSize=sizeof(PIXELFORMATDESCRIPTOR);
            int pf = GetPixelFormat(HDc);
            DescribePixelFormat(HDc, pf, sizeof(PIXELFORMATDESCRIPTOR), &pfd);
            pfd.dwFlags |= PFD_DOUBLEBUFFER | PFD_SUPPORT_OPENGL | PFD_DRAW_TO_WINDOW;
            pfd.cDepthBits=16;
            pf = ChoosePixelFormat(HDc, &pfd);
            SetPixelFormat(HDc, pf, &pfd);
            videodata.OpenGLWin32.HDc = HDc;
            videodata.OpenGLWin32.HRc=wglCreateContext(HDc);
            wglShareLists((HGLRC)driver->getExposedVideoData().OpenGLWin32.HRc, (HGLRC)videodata.OpenGLWin32.HRc);
        }
        scene::ICameraSceneNode* cam = smgr->addCameraSceneNode();
        cam->setTarget(core::vector3df(0,0,0));

        scene::ISceneNodeAnimator* anim =
            smgr->createFlyCircleAnimator(core::vector3df(0,15,0), 30.0f);
        cam->addAnimator(anim);
        anim->drop();

        scene::ISceneNode* cube = smgr->addCubeSceneNode(20);

        cube->setMaterialTexture(0, driver->getTexture("../../media/wall.bmp"));
        cube->setMaterialTexture(1, driver->getTexture("../../media/water.jpg"));
        cube->setMaterialFlag( video::EMF_LIGHTING, false );
        cube->setMaterialType( video::EMT_REFLECTION_2_LAYER );

        smgr->addSkyBoxSceneNode(
        driver->getTexture("../../media/irrlicht2_up.jpg"),
        driver->getTexture("../../media/irrlicht2_dn.jpg"),
        driver->getTexture("../../media/irrlicht2_lf.jpg"),
        driver->getTexture("../../media/irrlicht2_rt.jpg"),
        driver->getTexture("../../media/irrlicht2_ft.jpg"),
        driver->getTexture("../../media/irrlicht2_bk.jpg"));

        // show and execute dialog

        ShowWindow(hWnd , SW_SHOW);
        UpdateWindow(hWnd);

        // do message queue

Now the only thing missing is the drawing loop using IrrlichtDevice::run(). We do this as usual. But instead of this, there is another possibility: You can also simply use your own message loop using GetMessage, DispatchMessage and whatever. Calling Device->run() will cause Irrlicht to dispatch messages internally too. You need not call Device->run() if you want to do your own message dispatching loop, but Irrlicht will not be able to fetch user input then and you have to do it on your own using the window messages, DirectInput, or whatever.

        while (device->run())
        {
            driver->beginScene(true, true, 0, videodata);
            smgr->drawAll();
            driver->endScene();
        }

The alternative, own message dispatching loop without Device->run() would look like this:

MSG msg; while (true) { if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) { TranslateMessage(&msg); DispatchMessage(&msg);

if (msg.message == WM_QUIT) break; }

advance virtual time device->getTimer()->tick();

draw engine picture driver->beginScene(true, true, 0, (key=='c')?hIrrlichtWindow:0); smgr->drawAll(); driver->endScene(); }

        device->closeDevice();
        device->drop();

        return 0;
    }
    #endif // if windows

That's it, Irrlicht now runs in your own windows window.