// funkcje obslugi okna windowsa, opengla, 
// na poczatek mniej istotne
#include <windows.h>
#include <gl\gl.h>



extern bool	keys[256];
extern bool	active;

extern LRESULT	CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
extern HDC hDC;
extern HGLRC hRC;
extern HWND hWnd;
extern HINSTANCE hInstance;

extern int UstawiamyGL(GLsizei width, GLsizei height);
GLvoid KillGLWindow(GLvoid);
 
BOOL CreateGLWindow(char* title, int width, int height, int bits)
{
	GLuint		PixelFormat;			
	WNDCLASS	wc;						
	DWORD		dwExStyle;				
	DWORD		dwStyle;				
	RECT		WindowRect;				
	WindowRect.left=(long)0;			
	WindowRect.right=(long)width;		
	WindowRect.top=(long)0;				
	WindowRect.bottom=(long)height;

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

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

	dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;
	dwStyle=WS_OVERLAPPEDWINDOW;
	

	AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);

	if (!(hWnd=CreateWindowEx(	dwExStyle,"OpenGL",	title, dwStyle | WS_CLIPSIBLINGS | WS_CLIPCHILDREN,	0, 0, WindowRect.right-WindowRect.left,	WindowRect.bottom-WindowRect.top, NULL,	NULL, hInstance, NULL)))
	{
		KillGLWindow();	
		MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;	
	}

	static	PIXELFORMATDESCRIPTOR pfd=	
	{ sizeof(PIXELFORMATDESCRIPTOR), 1, PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL |	PFD_DOUBLEBUFFER, PFD_TYPE_RGBA, bits, 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)))						
	{
		KillGLWindow();							
		MessageBox(NULL,"Can't Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;							
	}

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

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

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

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

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

	if (!UstawiamyGL(width, height))							
	{
		KillGLWindow();				
		MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;						
	}

	return TRUE;							
}

GLvoid KillGLWindow(GLvoid)
{
	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("OpenGL",hInstance))
	{
		MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		hInstance=NULL;
	}
}


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;						
		}

		case WM_SIZE:						
		{
			UstawiamyGL(LOWORD(lParam),HIWORD(lParam));
			return 0;								
		}
	}

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