Jeff Molofee - NeHe's OpenGL Tutorials

glBegin(GL_QUADS);

// Front Face

glNormal3f( 0.0f, 0.0f, 1.0f);

glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f);

glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);

glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, –1.0f, 1.0f);

glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, –1.0f, 1.0f);

// Back Face

glNormal3f( 0.0f, 0.0f,-1.0f);

glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, –1.0f);

glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, –1.0f);

glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, –1.0f, –1.0f);

glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, –1.0f, –1.0f);

// Top Face

glNormal3f( 0.0f, 1.0f, 0.0f);

glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, –1.0f);

glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, –1.0f);

glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f);

glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 1.0f);

// Bottom Face

glNormal3f( 0.0f,-1.0f, 0.0f);

glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, –1.0f, 1.0f);

glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, –1.0f, 1.0f);

glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, –1.0f, –1.0f);

glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, –1.0f, –1.0f);

// Right Face

glNormal3f( 1.0f, 0.0f, 0.0f);

glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, –1.0f, –1.0f);

glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, –1.0f);

glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f);

glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, –1.0f, 1.0f);

// Left Face

glNormal3f(-1.0f, 0.0f, 0.0f);

glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, –1.0f, –1.0f);

glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, –1.0f, 1.0f);

glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);

glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, –1.0f);

glEnd();

xrot+=0.3f;

yrot+=0.2f;

zrot+=0.4f;

}

The KillGLWindow() code has a few changes. You'll notice the code to switch from fullscreen mode back to your desktop is now at the top of KillGLWindow(). If the user ran the program in fullscreen mode, the first thing we do when we kill the window is try to switch back to the desktop resolution. If the quick way fails to work, we reset the screen using the information stored in DMsaved. This should restore us to our orignal desktop settings.

GLvoid KillGLWindow(GLvoid) // Properly Kill The Window

{

if (fullscreen) // Are We In Fullscreen Mode?

{

if (!ChangeDisplaySettings(NULL, CDS_TEST)) { // If The Shortcut Doesn't Work

ChangeDisplaySettings(NULL, CDS_RESET); // Do It Anyway (To Get The Values Out Of The Registry)

ChangeDisplaySettings(&DMsaved, CDS_RESET); // Change Resolution To The Saved Settings

} else // Not Fullscreen

{

ChangeDisplaySettings(NULL,CDS_RESET); // Do Nothing

}

ShowCursor(TRUE); // Show Mouse Pointer

}

if (hRC) // Do We Have A Rendering Context?

{

if (!wglMakeCurrent(NULL, NULL)) // Are We Able To Release The DC And RC Contexts?

{

MessageBox(NULL, "Release Of DC And RC Failed.", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);

}

if (!wglDeleteContext(hRC)) // Are We Able To Delete The RC?

{

MessageBox(NULL, "Release Rendering Context Failed.", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);

}

hRC=NULL; // Set RC To NULL

}

if (hDC && !ReleaseDC(hWnd,hDC)) // Are We Able To Release The DC

{

MessageBox(NULL, "Release Device Context Failed.", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);

hDC=NULL; // Set DC To NULL

}

if (hWnd && !DestroyWindow(hWnd)) // Are We Able To Destroy The Window?

{

MessageBox(NULL, "Could Not Release hWnd.", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);

hWnd=NULL; // Set hWnd To NULL

}

if (!UnregisterClass("OpenGL", hInstance)) // Are We Able To Unregister Class

{

MessageBox(NULL, "Could Not Unregister Class.", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);

hInstance=NULL; // Set hInstance To NULL

}

}

I've made some changes in CreateGLWindow. The changes will hopefully elimintate alot of the problems people are having when they switch to and from from fullscreen mode. I've included the first part of CreateGLWindow() so you can easily follow through the code.

BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag) {

GLuint PixelFormat; // Holds The Results After Searching For A Match

WNDCLASS wc; // Windows Class Structure

DWORD dwExStyle; // Window Extended Style

DWORD dwStyle; // Window Style

fullscreen=fullscreenflag; // Set The Global Fullscreen Flag

hInstance = GetModuleHandle(NULL); // Grab An Instance For Our Window

wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; // Redraw On Size, And Own DC For Window.

wc.lpfnWndProc = (WNDPROC) WndProc; // WndProc Handles Messages

wc.cbClsExtra = 0; // No Extra Window Data

wc.cbWndExtra = 0; // No Extra Window Data

wc.hInstance = hInstance; // Set The Instance

wc.hIcon = LoadIcon(NULL, IDI_WINLOGO); // Load The Default Icon

wc.hCursor = LoadCursor(NULL, IDC_ARROW); // Load The Arrow Pointer

wc.hbrBackground = NULL; // No Background Required For GL

wc.lpszMenuName = NULL; // We Don't Want A Menu

wc.lpszClassName = "OpenGL"; // Set The Class Name

The big change here is that we now save the current desktop resolution, bit depth, etc. before we switch to fullscreen mode. That way when we exit the program, we can set everything back exactly how it was. The first line below copies the display settings into the DMsaved Device Mode structure. Nothing else has changed, just one new line of code.

EnumDisplaySettings(NULL, ENUM_CURRENT_SETTINGS, &DMsaved); // Save The Current Display State (NEW)

if (fullscreen) // Attempt Fullscreen Mode?

{

DEVMODE dmScreenSettings; // Device Mode

memset(&dmScreenSettings, 0, sizeof(dmScreenSettings)); // Makes Sure Memory's Cleared

dmScreenSettings.dmSize = sizeof(dmScreenSettings); // Size Of The Devmode Structure

dmScreenSettings.dmPelsWidth = width; // Selected Screen Width

dmScreenSettings.dmPelsHeight = height; // Selected Screen Height

dmScreenSettings.dmBitsPerPel = bits; // Selected Bits Per Pixel

dmScreenSettings.dmFields = DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;