Conway's Life

#define   STRICT
#include  <windows.h>
#include  <stdio.h>

#define   LIFE                      1
#define   DEATH                     0
#define   COLUMNS                   100
#define   ROWS                      100
#define   TILEWIDTH                 8
#define   TILEHEIGHT                8
#define   TIMER                     100 // milliseconds

#define   TOGGLEGO                  1001
#define   CLEAR                     1002

#define   DRAW                      WM_USER + 1

class CField
{
private:
   char  F1[COLUMNS][ROWS];
   char  F2[COLUMNS][ROWS];

public:
   char  *Source;
   char  *Dest;
   RECT  rect[COLUMNS][ROWS];

   CField(void)
   {
      this->Source   = *F1;
      this->Dest     = *F2;
      for(int x = 0; x < COLUMNS; x ++)
      {
         for(int y = 0; y < ROWS; y ++)
         {
            SetRect(&rect[x][y], (x+1) * TILEWIDTH, (y+1) * TILEHEIGHT, (x+2) * TILEWIDTH - 1, (y+2) * TILEHEIGHT - 1);
            F1[x][y] = 0;
            F2[x][y] = 0;
         }
      }
   }

   BOOL GetCellValue(int x, int y)
   {
      return *(this->Source + ((y * ROWS) + x) * sizeof(char));
   }

   void SetSourceCellValue(int x, int y, BOOL bVal)
   {
      *(this->Source + ((y * ROWS) + x) * sizeof(char)) = bVal;
   }

   void SetDestCellValue(int x, int y, BOOL bVal)
   {
      *(this->Dest + ((y * ROWS) + x) * sizeof(char)) = bVal;
   }

   void ToggleCell(POINT *p)
   {
      int   x, y;
      for(x = 0; x < COLUMNS; x ++)
      {
         for(y = 0; y < ROWS; y ++)
         {
            if(PtInRect(&rect[x][y], *p))
            {
               SetSourceCellValue(x, y, 1 - GetCellValue(x, y));
               return;
            }
         }
      }
   }

   void CalcField(void)
   {
      char *temp;
      for(int x = 0; x < COLUMNS; x ++)
      {
         for(int y = 0; y < ROWS; y ++)
         {
            int   iNeighbours = 0;
            int   iXStart;
            int   iXStop;
            int   ix;

            iXStart = x - 1 + (x == 0);
            iXStop  = x + 2 - (x == COLUMNS);
            
            for(ix = iXStart; ix < iXStop; ix ++)
            {
               iNeighbours += GetCellValue(ix, y);
               if(y > 0)
               {
                  iNeighbours += GetCellValue(ix, y-1);
               }
               if(y < ROWS)
               {
                  iNeighbours += GetCellValue(ix, y+1);
               }
            }
            iNeighbours -= GetCellValue(x, y);

            SetDestCellValue(x, y, (BOOL)(GetCellValue(x, y) && (iNeighbours == 2) || (iNeighbours == 3)));
         }
      }
      // Swap pointers
      temp = this->Source;
      this->Source = this->Dest;
      this->Dest = temp;
   }
};

//    -------------
//    | 0 | 1 | 2 |
//    -------------
//    | 3 | X | 4 |
//    -------------
//    | 5 | 6 | 7 |
//
//    Death
//    If an occupied cell has 0, 1, 4, 5, 6, 7, or 8 occupied neighbors, the organism dies (0, 1: of loneliness; 4 thru 8: of overcrowding).

//    Survival
//    If an occupied cell has two or three neighbors, the organism survives to the next generation.

//    Birth
//    If an unoccupied cell has three occupied neighbors, it becomes occupied.

LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{
   CREATESTRUCT            *cs;
   PAINTSTRUCT             ps;
   int                     x, y;
   static char             MenuText[2][6] = {"GO", "STOP"};
   static int              iWidth, iHeight;
   static HBRUSH           hBrush[2], hBkGndBrush;
   static HPEN             hPen;
   static HDC              hdcMem;
   static HBITMAP          hBitmap = NULL;
   static BOOL             bGo = FALSE;
   static CField           *field;
   HMENU                   hMenu;
   static RECT             rect;
   POINT                   p;
   HDC                     hdc;

   switch (iMsg)
   {
   case WM_CREATE :
      cs = (LPCREATESTRUCT)lParam;

      field = new CField();

      hPen = CreatePen(1, 1, RGB(200, 200, 200));
      hBrush[0]   = CreateSolidBrush(RGB(64, 64, 64));
      hBrush[1]   = CreateSolidBrush(RGB(64, 255, 64));
      hBkGndBrush = CreateSolidBrush(RGB(192, 192, 192));

      iWidth   = (COLUMNS+2) * TILEWIDTH + 5;
      iHeight  = (ROWS+2) * TILEHEIGHT + 50;

      hdc      = GetDC(hwnd);
      hdcMem   = CreateCompatibleDC(hdc);
      ReleaseDC(hwnd, hdc);

      // init tiles
      GetClientRect(GetDesktopWindow(), &rect);
      MoveWindow(hwnd, ((rect.right/2) - (iWidth/2)), ((rect.bottom/2) - (iHeight/2)), iWidth, iHeight, TRUE);
      break;

   case WM_KEYUP:
      if(!bGo && wParam == VK_SPACE)
      {
         PostMessage(hwnd, DRAW, 0, 0);
      }
      break;

   case WM_RBUTTONUP :
      p.x = LOWORD(lParam);
      p.y = HIWORD(lParam);
      hMenu = CreatePopupMenu();
      AppendMenu (hMenu, MF_STRING, TOGGLEGO, MenuText[bGo]);
      if(!bGo)
      {
         AppendMenu (hMenu, MF_STRING, CLEAR, "Clear Screen");
      }
      ClientToScreen (hwnd, (LPPOINT)&p);
      TrackPopupMenu (hMenu, 0, p.x, p.y, 0, hwnd, NULL);
      DestroyMenu (hMenu);
      break;

   case WM_LBUTTONUP :
      if(!bGo)
      {
         p.x = LOWORD(lParam);
         p.y = HIWORD(lParam);
         field->ToggleCell(&p);
         PostMessage(hwnd, DRAW, 0, 0);
      }
      break;

   case WM_SIZE :
      if(hBitmap != NULL)
      {
         DeleteObject(hBitmap);
      }
      GetClientRect(hwnd, &rect);
      hdc      = GetDC(hwnd);
      hBitmap    = CreateCompatibleBitmap(hdc, rect.right, rect.bottom);
      SelectObject(hdcMem, hBitmap);
      ReleaseDC(hwnd, hdc);
      break;

   case WM_COMMAND :
      switch(LOWORD(wParam))
      {
         case TOGGLEGO :
            if(bGo)
            {
               KillTimer(hwnd, 1);
               bGo = FALSE;
            }
            else
            {
               SetTimer(hwnd, 1, TIMER, NULL);
               bGo = TRUE;
            }
            break;

         case CLEAR :
            if(!bGo)
            {
               for(x = 0; x < COLUMNS; x ++)
               {
                  for(y = 0; y < ROWS; y ++)
                  {
                     field->SetSourceCellValue(x, y, FALSE);
                  }
               }
            }
            PostMessage(hwnd, DRAW, 0, 0);
            break;
      }
      break;

   case WM_ERASEBKGND :
      return FALSE;

   case WM_TIMER :
      field->CalcField();
      PostMessage(hwnd, DRAW, 0, 0);
      break;

   case DRAW :
      FillRect(hdcMem, &rect, hBkGndBrush);

      SelectObject(hdcMem, hPen);
      for(x = 0; x < COLUMNS; x ++)
      {
         for(y = 0; y < ROWS; y ++)
         {
            RECT r;
            CopyRect(&r, &field->rect[x][y]);
            FillRect(hdcMem, &field->rect[x][y], hBrush[field->GetCellValue(x,y)]);
         }
      }

      hdc = GetDC(hwnd);
      BitBlt(hdc, 0, 0, rect.right, rect.bottom, hdcMem, 0, 0, SRCCOPY);
      ReleaseDC(hwnd, hdc);
      break;

   case WM_PAINT :
      FillRect(hdcMem, &rect, hBkGndBrush);

      SelectObject(hdcMem, hPen);
      for(x = 0; x < COLUMNS; x ++)
      {
         for(y = 0; y < ROWS; y ++)
         {
            FillRect(hdcMem, &field->rect[x][y], hBrush[field->GetCellValue(x, y)]);
         }
      }

      BeginPaint(hwnd, &ps);
      BitBlt(ps.hdc, 0, 0, rect.right, rect.bottom, hdcMem, 0, 0, SRCCOPY);
      EndPaint(hwnd, &ps);
      break;

   case WM_CLOSE :
      DestroyWindow(hwnd);
      break;

   case WM_DESTROY :
      DeleteObject(hBrush[0]);
      DeleteObject(hBrush[1]);
      DeleteObject(hBkGndBrush);
      DeleteObject(hPen);

      PostQuitMessage(0);
      break;
   }
   return DefWindowProc(hwnd, iMsg, wParam, lParam);
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
   HWND        hwnd;
   MSG         msg;
   WNDCLASS    wndclass;
   char        szAppName[] = "Conway's Life";

   wndclass.style         = 0;
   wndclass.lpfnWndProc   = WndProc;
   wndclass.cbClsExtra    = 0;
   wndclass.cbWndExtra    = 0;
   wndclass.hInstance     = hInstance;
   wndclass.hIcon         = LoadIcon(hInstance, szAppName);
   wndclass.hCursor       = LoadCursor(NULL, IDC_ARROW);
   wndclass.hbrBackground = (HBRUSH)(COLOR_BTNFACE + 1);
   wndclass.lpszMenuName  = szAppName;
   wndclass.lpszClassName = szAppName;
   RegisterClass(&wndclass);

   hwnd = CreateWindow(szAppName,
      szAppName,
      WS_CAPTION | WS_SYSMENU | WS_VISIBLE,
      200, 200, 500, 500,
      NULL, NULL, hInstance, szCmdLine);

   while (GetMessage(&msg, NULL, 0, 0))
   {
      TranslateMessage(&msg);
      DispatchMessage(&msg);
   }
   return (int)msg.wParam;
}