#include <windows.h>
#include <gl\gl.h>
#include <gl\glu.h>
#include <gl\glaux.h>

#pragma comment(lib, "opengl32.lib")
#pragma comment(lib, "glu32.lib")
#pragma comment(lib, "glaux.lib")

bool active = TRUE;
bool keys[256];

HGLRC           hRC		=	NULL;
HDC             hDC		=	NULL;
HWND            hWnd	=	NULL;
HINSTANCE       hInstance;

LRESULT	CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

void killWindow(void)
{
	ChangeDisplaySettings(NULL, 0);
	ShowCursor(TRUE);

	if(hRC)
	{
		if(!wglMakeCurrent(NULL, NULL))
		{
			MessageBox(NULL, "Release Of DC And RC Failed", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
		}

		if(!wglDeleteContext(hRC))
		{
			MessageBox(NULL, "Release Rendering Context Failed", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
		}
		hRC = NULL;
	}

	if(hDC && !ReleaseDC(hWnd, hDC))
	{
		MessageBox(NULL, "Release Device Context Failed", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
		hDC = NULL;
	}

	if(hWnd && !DestroyWindow(hWnd))
	{
		MessageBox(NULL, "Could Not Release hWnd", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
		hWnd = NULL;
	}

	if(!UnregisterClass("Space", hInstance))
	{
		MessageBox(NULL, "Could Not Unregister Class", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
		hInstance = NULL;
	}

}

bool createWindow()
{	
	WNDCLASS Window;	
	int pixelFormat;

	DWORD dwExStyle;

	hInstance				= GetModuleHandle(NULL);
	Window.style			= CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
	Window.lpfnWndProc		= (WNDPROC) WndProc;
	Window.cbClsExtra		= 0;
	Window.cbWndExtra		= 0;
	Window.hInstance		= hInstance;
	Window.hIcon			= LoadIcon(NULL, IDI_WINLOGO);
	Window.hCursor			= LoadCursor(NULL, IDC_ARROW);
	Window.hbrBackground	= NULL;
	Window.lpszMenuName		= NULL;
	Window.lpszClassName	= "Space";

	if(!RegisterClass(&Window))
	{
		MessageBox(NULL, "Failed To Register The Window Class", "ERROR", MB_OK | MB_ICONEXCLAMATION);		
		return FALSE;
	}

	dwExStyle = WS_EX_APPWINDOW;
	ShowCursor(FALSE);

	if(!(hWnd = CreateWindowEx(dwExStyle,	
							   "Space",
							   "Space Quest",
							   WS_POPUP,
							   0, 0,
							   800, 600,
							   NULL,
							   NULL,
							   hInstance,
							   NULL)))
	{	
		killWindow();	
		MessageBox(NULL, "Window Creation Error", "ERROR", MB_OK | MB_ICONEXCLAMATION);		
		return FALSE;	
	}

	DEVMODE newSettings;
	EnumDisplaySettings(NULL, 0, &newSettings);
	newSettings.dmPelsWidth  = 800;
	newSettings.dmPelsHeight = 600;
	newSettings.dmBitsPerPel = 16;
	newSettings.dmFields	 = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;

	if (ChangeDisplaySettings(&newSettings, CDS_FULLSCREEN) 
		!= DISP_CHANGE_SUCCESSFUL)
	return FALSE;

	static PIXELFORMATDESCRIPTOR pfd =	{
										 sizeof(PIXELFORMATDESCRIPTOR),	
										 1,	
										 PFD_DRAW_TO_WINDOW |
										 PFD_SUPPORT_OPENGL |
										 PFD_DOUBLEBUFFER,
										 PFD_TYPE_RGBA,	
										 16,
										 0, 0, 0, 0, 0, 0,
										 0,	
										 0,	
										 0,	
										 0, 0, 0, 0,
										 16,
										 0,	
										 0,	
										 PFD_MAIN_PLANE,
										 0,	
										 0, 0, 0
	};

	if (!(hDC = GetDC(hWnd)))
	{
		killWindow();
		MessageBox(NULL, "Can't Create A GL Device Context", "ERROR", MB_OK | MB_ICONEXCLAMATION);
		return FALSE;
	}

	if (!(pixelFormat = ChoosePixelFormat(hDC, &pfd)))
	{
		killWindow();
		MessageBox(NULL, "Can't Find A Suitable PixelFormat", "ERROR",MB_OK | MB_ICONEXCLAMATION);
		return FALSE;
	}

	if(!SetPixelFormat(hDC, pixelFormat, &pfd))
	{
		killWindow();
		MessageBox(NULL, "Can't Set The PixelFormat", "ERROR", MB_OK | MB_ICONEXCLAMATION);
		return FALSE;
	}

	if (!(hRC = wglCreateContext(hDC)))
	{
		killWindow();
		MessageBox(NULL, "Can't Create A GL Rendering Context", "ERROR", MB_OK | MB_ICONEXCLAMATION);
		return FALSE;
	}

	if(!wglMakeCurrent(hDC, hRC))
	{
		killWindow();
		MessageBox(NULL, "Can't Activate The GL Rendering Context", "ERROR", MB_OK | MB_ICONEXCLAMATION);
		return FALSE;
	}

	ShowWindow(hWnd, SW_SHOW);
	SetForegroundWindow(hWnd);
	SetFocus(hWnd);

	return TRUE;
}

LRESULT CALLBACK WndProc(HWND	hWnd,
						 UINT	uMsg,
						 WPARAM	wParam,	
						 LPARAM	lParam)
{
	switch (uMsg)
	{
		case WM_ACTIVATE:
		{
			if (!HIWORD(wParam))
			{
				active = TRUE;
			}
			else
			{
				active = FALSE;
			}

			return 0;
		}

		case WM_SYSCOMMAND:
		{
			switch (wParam)
			{
				case SC_SCREENSAVE:
				case SC_MONITORPOWER:
				return 0;
			}
			break;
		}

		case WM_CLOSE:
		{
			PostQuitMessage(0);
			return 0;
		}

		case WM_KEYDOWN:
		{
			keys[wParam] = TRUE;
			return 0;
		}

		case WM_KEYUP:
		{
			keys[wParam] = FALSE;
			return 0;
		}
	}

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

int WINAPI WinMain(HINSTANCE hInstance,
				   HINSTANCE hPrevInstance,
				   LPSTR lpCmdLine,
				   int nShowCmd)
{
	MSG		msg;
	bool	escape = FALSE;

	if (!createWindow())
	{
		return 0;
	}

	while(!escape)
	{
		if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
		{
			if (msg.message == WM_QUIT)
			{
				escape = TRUE;
			}
			else
			{
				TranslateMessage(&msg);
				DispatchMessage(&msg);
			}
		}
		else
		{
			if (active)
			{
				if (keys[VK_ESCAPE])
				{
					escape = TRUE;
				}
				else
				{
					SwapBuffers(hDC);
				}
			}
		}
	}
	killWindow();
	return (msg.wParam);	
}