/*-------------------------------------------------
   CHECKER1.C -- Mouse Hit-Test Demo Program No. 1
                 (c) Charles Petzold, 1996
  -------------------------------------------------*/

#include <windows.h>

#define DIVISIONS 5
#define MoveTo(hdc, x, y) MoveToEx (hdc, x, y, NULL)

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

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR  szCmdLine, int iCmdShow)
     {
     static char szAppName[] = "Checker1" ;
     HWND        hwnd ;
     MSG         msg ;
     WNDCLASSEX  wndclass ;

	 wndclass.cbSize        = sizeof (wndclass) ;
     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = WndProc ;
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = LoadIcon (NULL, IDI_APPLICATION) ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
     wndclass.lpszMenuName  = NULL ;
     wndclass.lpszClassName = szAppName ;
	 wndclass.hIconSm       = LoadIcon (NULL, IDI_APPLICATION) ;

     RegisterClassEx (&wndclass) ;

     hwnd = CreateWindow (szAppName, "Checker1 Mouse Hit-Test Demo",
                          WS_OVERLAPPEDWINDOW,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          NULL, NULL, hInstance, NULL) ;

     ShowWindow (hwnd, iCmdShow) ;
     UpdateWindow (hwnd) ;

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

LRESULT CALLBACK WndProc (HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
     {
     static BOOL fState[DIVISIONS][DIVISIONS] ;
     static int  cxBlock, cyBlock ;
     HDC         hdc ;
     PAINTSTRUCT ps ;
     RECT        rect ;
     int         x, y ;

     switch (iMsg)
          {
          case WM_SIZE :
               cxBlock = LOWORD (lParam) / DIVISIONS ;
               cyBlock = HIWORD (lParam) / DIVISIONS ;
               return 0 ;

          case WM_LBUTTONDOWN :
               x = LOWORD (lParam) / cxBlock ;
               y = HIWORD (lParam) / cyBlock ;

               if (x < DIVISIONS && y < DIVISIONS)
                    {
                    fState [x][y] ^= 1 ;

                    rect.left   = x * cxBlock ;
                    rect.top    = y * cyBlock ;
                    rect.right  = (x + 1) * cxBlock ;
                    rect.bottom = (y + 1) * cyBlock ;

                    InvalidateRect (hwnd, &rect, FALSE) ;
                    }
               else
                    MessageBeep (0) ;
               return 0 ;

          case WM_PAINT :
               hdc = BeginPaint (hwnd, &ps) ;

               for (x = 0 ; x < DIVISIONS ; x++)
                    for (y = 0 ; y < DIVISIONS ; y++)
                         {
                         Rectangle (hdc, x * cxBlock, y * cyBlock,
                                   (x + 1) * cxBlock, (y + 1) * cyBlock) ;

                         if (fState [x][y])
                              {
                              MoveTo (hdc,  x    * cxBlock,  y    * cyBlock) ;
                              LineTo (hdc, (x+1) * cxBlock, (y+1) * cyBlock) ;
                              MoveTo (hdc,  x    * cxBlock, (y+1) * cyBlock) ;
                              LineTo (hdc, (x+1) * cxBlock,  y    * cyBlock) ;
                              }
                         }
               EndPaint (hwnd, &ps) ;
               return 0 ;

          case WM_DESTROY :
               PostQuitMessage (0) ;
               return 0 ;
          }
     return DefWindowProc (hwnd, iMsg, wParam, lParam) ;
     }
