maze.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

draw_wall(i, j, dir, hDC)                                   /* draw a single wall */
     int i, j, dir;
	 HDC hDC;
{
  switch (dir) {
  case 0:
  	MoveToEx(hDC, border_x + grid_width * i, border_y + grid_height * j, NULL);
	(void) LineTo(hDC, border_x + grid_width * (i+1),
	              border_y + grid_height * j);
    break;
  case 1:
	MoveToEx(hDC, border_x + grid_width * (i+1), border_y + grid_height * j,
	         NULL);
	(void) LineTo(hDC, border_x + grid_width * (i+1),
	              border_y + grid_height * (j+1));
    break;
  case 2:
	MoveToEx(hDC, border_x + grid_width * i, border_y + grid_height * (j+1),
	         NULL);
	(void) LineTo(hDC, border_x + grid_width * (i+1),
	              border_y + grid_height * (j+1));
    break;
  case 3:
	MoveToEx(hDC, border_x + grid_width * i, border_y + grid_height * j,
	         NULL);
	(void) LineTo(hDC, border_x + grid_width * i,
	              border_y + grid_height * (j+1));
    break;
  }
}

static void
begin_solve_maze()                             /* solve it with graphical feedback */
{
  static long grayPattern[] = {
	0x55555555,
	0xaaaaaaaa,
	0x55555555,
	0xaaaaaaaa,
	0x55555555,
	0xaaaaaaaa,
	0x55555555,
	0xaaaaaaaa
  };
  static RGBQUAD argbq[] = {
  	{ 0, 0, 255, 0 },
	{ 255, 255, 255, 0 }
  };
  BITMAPINFO *pbmi;

  hDC = GetDC(hWnd);
  pbmi = malloc(sizeof(BITMAPINFOHEADER) + sizeof(argbq) + sizeof(grayPattern));
  pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
  pbmi->bmiHeader.biWidth = 8;
  pbmi->bmiHeader.biHeight = 8;
  pbmi->bmiHeader.biPlanes = 1;
  pbmi->bmiHeader.biBitCount = 1;
  pbmi->bmiHeader.biCompression = BI_RGB;
  (void) memcpy(pbmi->bmiColors, argbq, sizeof(argbq));
  (void) memcpy(pbmi->bmiColors + 2, grayPattern, sizeof(grayPattern));
#if 0
  /* FIXME Pattern brushes not yet implemented in ReactOS */
  hBrushDead = CreateDIBPatternBrushPt(pbmi, DIB_RGB_COLORS);
#else
  hBrushDead = CreateSolidBrush(RGB(255, 0, 0));
#endif
//  hBrushDead = CreateHatchBrush(HS_DIAGCROSS, RGB(255, 0, 0));
  free(pbmi);
  hBrushLiving = CreateSolidBrush(RGB(0, 255, 0));

  /* plug up the surrounding wall */
  maze[start_x][start_y] |= (WALL_TOP >> start_dir);
  maze[end_x][end_y] |= (WALL_TOP >> end_dir);

  /* initialize search path */
  pathi = 0;
  path[pathi].x = end_x;
  path[pathi].y = end_y;
  path[pathi].dir = -1;
}

static int
solve_maze()                             /* solve it with graphical feedback */
{
  int ret;
  int action_done;

  do {
    action_done = 1;
    if ( ++path[pathi].dir >= 4 ) {
      pathi--;
      draw_solid_square( (int)(path[pathi].x), (int)(path[pathi].y),
	  	       (int)(path[pathi].dir), hDC, hBrushDead);
      ret = 0;
    }
    else if ( ! (maze[path[pathi].x][path[pathi].y] &
	  	(WALL_TOP >> path[pathi].dir))  &&
	     ( (pathi == 0) || ( (path[pathi].dir !=
		  	    (int)(path[pathi-1].dir+2)%4) ) ) ) {
      enter_square(pathi, hDC, hBrushLiving);
      pathi++;
      if ( maze[path[pathi].x][path[pathi].y] & START_SQUARE ) {
	    DeleteObject(hBrushLiving);
	    DeleteObject(hBrushDead);
	    ReleaseDC(hWnd, hDC);
          ret = 1;
      } else {
        ret = 0;
      }
    } else {
      action_done = 0;
    }
  } while (! action_done);

  return ret;
}


static void
enter_square(int n, HDC hDC, HBRUSH hBrush)  /* move into a neighboring square */
{
  draw_solid_square( (int)path[n].x, (int)path[n].y,
		    (int)path[n].dir, hDC, hBrush);

  path[n+1].dir = -1;
  switch (path[n].dir) {
  case 0: path[n+1].x = path[n].x;
    path[n+1].y = path[n].y - 1;
    break;
  case 1: path[n+1].x = path[n].x + 1;
    path[n+1].y = path[n].y;
    break;
  case 2: path[n+1].x = path[n].x;
    path[n+1].y = path[n].y + 1;
    break;
  case 3: path[n+1].x = path[n].x - 1;
    path[n+1].y = path[n].y;
    break;
  }
}

static void
start_timer(HWND hWnd, int iTimeout)
{
	waiting = TRUE;
	SetTimer(hWnd, 1, iTimeout, NULL);
}

/****************************************************************************

	FUNCTION: WinMain(HINSTANCE, HINSTANCE, LPSTR, int)

	PURPOSE: calls initialization function, processes message loop

	COMMENTS:

		Windows recognizes this function by name as the initial entry point
		for the program.  This function calls the application initialization
		routine, if no other instance of the program is running, and always
		calls the instance initialization routine.  It then executes a message
		retrieval and dispatch loop that is the top-level control structure
		for the remainder of execution.  The loop is terminated when a WM_QUIT
		message is received, at which time this function exits the application
		instance by returning the value passed by PostQuitMessage().

		If this function must abort before entering the message loop, it
		returns the conventional value NULL.

****************************************************************************/
int APIENTRY WinMain(
	HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
	LPSTR lpCmdLine,
	int nCmdShow)
{
	MSG msg;
	HDC hDC;

	if (!hPrevInstance) {       	/* Other instances of app running? */
			if (!InitApplication(hInstance)) { /* Initialize shared things */
			return (FALSE);     	/* Exits if unable to initialize */
		}
	}

	/* Perform initializations that apply to a specific instance */

	if (!InitInstance(hInstance, nCmdShow)) {
		return (FALSE);
	}

	waiting = FALSE;
	state = 1;

	/* Acquire and dispatch messages until a WM_QUIT message is received. */

	while (0 != state) {
		if (waiting) {
			(void) WaitMessage();
		}
		while (0 != state && PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
			if (WM_QUIT == msg.message) {
				state = 0;
			} else {
				DispatchMessage(&msg); /* Dispatches message to window */
			}
		}
    		switch (state) {
    		case 1:
      			initialize_maze();
			state = 2;
      			break;
	    	case 2:
			hDC = GetDC(hWnd);
			SendMessage(hWnd, WM_ERASEBKGND, (WPARAM) hDC, (LPARAM) 0);
			draw_maze_border(hWnd, hDC);
			ReleaseDC(hWnd, hDC);
			state = 3;
      			break;
	    	case 3:
			create_maze();
			state = 4;
			break;
	    	case 4:
			start_timer(hWnd, pre_solve_delay);
			state = 5;
			break;
		case 5:
			if (! waiting) {
				state = 6;
			}
			break;
    		case 6:
			begin_solve_maze();
			if (0 != solve_delay) {
				start_timer(hWnd, solve_delay);
				state = 7;
			} else {
				state = 8;
			}
			break;
		case 7:
			if (! waiting) {
				state = 8;
			}
			break;
		case 8:
			if (! solve_maze()) {
				if (0 != solve_delay) {
					start_timer(hWnd, solve_delay);
					state = 7;
				}
			} else {
				state = 9;
			}
			break;
		case 9:
			start_timer(hWnd, post_solve_delay);
			state = 10;
			break;
		case 10:
			if (! waiting) {
				state = 11;
			}
			break;
		case 11:
			state = 1;
			break;
		}
	}

	return (msg.wParam); /* Returns the value from PostQuitMessage */
}


/****************************************************************************

	FUNCTION: InitApplication(HINSTANCE)

	PURPOSE: Initializes window data and registers window class

	COMMENTS:

		This function is called at initialization time only if no other
		instances of the application are running.  This function performs
		initialization tasks that can be done once for any number of running
		instances.

		In this case, we initialize a window class by filling out a data
		structure of type WNDCLASS and calling the Windows RegisterClass()
		function.  Since all instances of this application use the same window
		class, we only need to do this when the first instance is initialized.


****************************************************************************/

static BOOL InitApplication(HINSTANCE hInstance)
{
	WNDCLASS  wc;

	// Fill in window class structure with parameters that describe the
	// main window.

	wc.style         = CS_HREDRAW | CS_VREDRAW;// Class style(s).
	wc.lpfnWndProc   = (WNDPROC)WndProc;       // Window Procedure
	wc.cbClsExtra    = 0;                      // No per-class extra data.
	wc.cbWndExtra    = 0;                      // No per-window extra data.
	wc.hInstance     = hInstance;              // Owner of this class
	wc.hIcon         = LoadIcon (hInstance, szAppName); // Icon name from .RC
	wc.hCursor       = LoadCursor(NULL, (LPCTSTR) IDC_ARROW);// Cursor
	wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);// Default color
	wc.lpszMenuName  = NULL;                    // No menu
	wc.lpszClassName = szAppName;              // Name to register as

	// Register the window class and return success/failure code.
	return (RegisterClass(&wc));
}


/****************************************************************************

	FUNCTION:  InitInstance(HINSTANCE, int)

	PURPOSE:  Saves instance handle and creates main window

	COMMENTS:

		This function is called at initialization time for every instance of
		this application.  This function performs initialization tasks that
		cannot be shared by multiple instances.

		In this case, we save the instance handle in a static variable and
		create and display the main program window.

****************************************************************************/

static BOOL InitInstance(
	HINSTANCE          hInstance,
	int             nCmdShow)
{
	/* Save the instance handle in static variable, which will be used in
	   many subsequence calls from this application to Windows. */

	hInst = hInstance; /* Store instance handle in our global variable */

	/* Create a main window for this application instance. */

	hWnd = CreateWindow(
		szAppName,	     	/* See RegisterClass() call. */
		szTitle,	     	/* Text for window title bar. */
		WS_OVERLAPPEDWINDOW,/* Window style. */
		0, 0, CW_USEDEFAULT, CW_USEDEFAULT, /* Use default positioning */
		NULL,		     	/* Overlapped windows have no parent. */
		NULL,		     	/* Use the window class menu. */
		hInstance,	     	/* This instance owns this window. */
		NULL		     	/* We don't use any data in our WM_CREATE */
	);

	// If window could not be created, return "failure"
	if (!hWnd) {
		return (FALSE);
	}

	// Make the window visible; update its client area; and return "success"
	ShowWindow(hWnd, nCmdShow); // Show the window
	UpdateWindow(hWnd);         // Sends WM_PAINT message

	return (TRUE);              // We succeeded...

}

static BOOL
OnCreate(HWND hWnd, LPCREATESTRUCT lpCreateStruct)
{
	RECT rc;
	int size;

	srand((unsigned) time(NULL));

#if 0
	/* FIXME GetPrivateProfileInt not yet implemented in ReactOS */
	size = GetPrivateProfileInt("maze", "gridsize", 0, "maze.ini");
	pre_solve_delay = GetPrivateProfileInt("maze", "predelay", 5000,
	                                       "maze.ini");
	post_solve_delay = GetPrivateProfileInt("maze", "postdelay", 5000,
	                                        "maze.ini");
	solve_delay = GetPrivateProfileInt("maze", "solvedelay", 10,
	                                   "maze.ini");
#else
	size = 10;
	pre_solve_delay = 5000;
	post_solve_delay = 5000;
	solve_delay = 20;
#endif

  	if (size < 2) {
  		size = 7 + (rand() % 30);
	}
  	grid_width = grid_height = size;
    bw = (size > 6 ? 3 : (size-1)/2);

	GetClientRect(hWnd, &rc);
	set_maze_sizes(rc.right - rc.left, rc.bottom - rc.top);

	return TRUE;
}

void OnTimer(HWND hwnd, UINT id)
{
	waiting = FALSE;
}

/****************************************************************************

	FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)

	PURPOSE:  Processes messages

	MESSAGES:

	WM_DESTROY    - destroy window

	COMMENTS:

****************************************************************************/

LRESULT CALLBACK WndProc(
		HWND hWnd,         // window handle
		UINT message,      // type of message
		WPARAM wParam,     // additional information
		LPARAM lParam)     // additional information
{
	PAINTSTRUCT ps;

	switch (message) {
		case WM_CREATE:
			OnCreate(hWnd, (LPCREATESTRUCT) lParam);
			break;
		case WM_PAINT:
			BeginPaint(hWnd, &ps);
			state = 1;
			EndPaint(hWnd, &ps);
		case WM_TIMER:
			OnTimer(hWnd, wParam);
			break;
		case WM_DESTROY:  // message: window being destroyed
			PostQuitMessage(0);
			break;

		default:          // Passes it on if unproccessed
			return (DefWindowProc(hWnd, message, wParam, lParam));
	}
	return (0);
}