I am following along with a program by doing an exercise in the book "beginning programming" in chapter 5. The exercise tells me to modify the code below to change the size of the screen resolution. I changed the screen width and height to 600 and 400 but got pop up window message "error creating Direct3D Device." Could someone tell me if I am doing this correctly or is it something with my compiler. I am using vb.net 2005 on a hp dv8125nr laptop graphics card: ATI Radeon Express 200M // Beginning Game Programming // Chapter 5 // Direct3D_Fullscreen program //header files to include #include <windows.h> #include <d3d9.h> #include <time.h> //application title #define APPTITLE "Direct3D_Fullscreen" //macros to read the keyboard asynchronously #define KEY_DOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0) #define KEY_UP(vk_code)((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0) //screen resolution #define SCREEN_WIDTH 640 // I changed screen and height to 600 and 400 but got an error? #define SCREEN_HEIGHT 480 //forward declarations LRESULT WINAPI WinProc(HWND,UINT,WPARAM,LPARAM); ATOM MyRegisterClass(HINSTANCE); int Game_Init(HWND); void Game_Run(HWND); void Game_End(HWND); //Direct3D objects LPDIRECT3D9 d3d = NULL; LPDIRECT3DDEVICE9 d3ddev = NULL; //window event callback function LRESULT WINAPI WinProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam ) { switch( msg ) { case WM_DESTROY: Game_End(hWnd); PostQuitMessage(0); return 0; } return DefWindowProc( hWnd, msg, wParam, lParam ); } //helper function to set up the window properties ATOM MyRegisterClass(HINSTANCE hInstance) { //create the window class structure WNDCLASSEX wc; wc.cbSize = sizeof(WNDCLASSEX); //fill the struct with info wc.style = CS_HREDRAW | CS_VREDRAW; wc.lpfnWndProc = (WNDPROC)WinProc; wc.cbClsExtra = 0; wc.cbWndExtra = 0; wc.hInstance = hInstance; wc.hIcon = NULL; wc.hCursor = LoadCursor(NULL, IDC_ARROW); wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH); wc.lpszMenuName = NULL; wc.lpszClassName = APPTITLE; wc.hIconSm = NULL; //set up the window with the class info return RegisterClassEx(&wc); } //entry point for a Windows program int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { // declare variables MSG msg; // register the class MyRegisterClass(hInstance); // initialize application //note--got rid of initinstance HWND hWnd; //create a new window hWnd = CreateWindow( APPTITLE, //window class APPTITLE, //title bar WS_EX_TOPMOST | WS_VISIBLE | WS_POPUP, //window style pg 88 CW_USEDEFAULT, //x position of window CW_USEDEFAULT, //y position of window SCREEN_WIDTH, //width of the window SCREEN_HEIGHT, //height of the window NULL, //parent window NULL, //menu hInstance, //application instance NULL); //window parameters //was there an error creating the window? if (!hWnd) return FALSE; //display the window ShowWindow(hWnd, nCmdShow); UpdateWindow(hWnd); //initialize the game if (!Game_Init(hWnd)) return 0; // main message loop int done = 0; while (!done) { if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) { //look for quit message if (msg.message == WM_QUIT) done = 1; //decode and pass messages on to WndProc TranslateMessage(&msg); DispatchMessage(&msg); } else //process game loop (else prevents running after window is closed) Game_Run(hWnd); } return msg.wParam; } // Function Definitions ------------------------------------------------// int Game_Init(HWND hwnd) { //initialize Direct3D d3d = Direct3DCreate9(D3D_SDK_VERSION); if (d3d == NULL) { MessageBox(hwnd, "Error initializing Direct3D", "Error", MB_OK); return 0; } //set Direct3D presentation parameters D3DPRESENT_PARAMETERS d3dpp; ZeroMemory(&d3dpp, sizeof(d3dpp)); d3dpp.Windowed = FALSE; d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD; d3dpp.BackBufferFormat = D3DFMT_X8R8G8B8; d3dpp.BackBufferCount = 1; d3dpp.BackBufferWidth = SCREEN_WIDTH; d3dpp.BackBufferHeight = SCREEN_HEIGHT; d3dpp.hDeviceWindow = hwnd; //create Direct3D device d3d->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hwnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &d3ddev); if (d3ddev == NULL) { MessageBox(hwnd, "Error creating Direct3D device", "Error", MB_OK); return 0; } //set random number seed srand(time(NULL)); //return okay return 1; } void Game_Run(HWND hwnd) { //make sure the Direct3D device is valid if (d3ddev == NULL) return; //clear the backbuffer to black d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,80,80), 1.0f, 0); //start rendering if (d3ddev->BeginScene()) { //do something //stop rendering d3ddev->EndScene(); } //display the back buffer on the screen d3ddev->Present(NULL, NULL, NULL, NULL); //check for escape key (to exit program) if (KEY_DOWN(VK_ESCAPE)) PostMessage(hwnd, WM_DESTROY, 0, 0); } void Game_End(HWND hwnd) { //release the Direct3D device if (d3ddev != NULL) d3ddev->Release(); //release the Direct3D object if (d3d != NULL) d3d->Release(); }

Thanks for the info, I understand now.