Win32 Battleship game enigma?

I'm writing a program at the moment that is a windows battleship game, where you play against the computer. The problem is that I can't think of a way to get the co-ordinates of the "grid", so that the computer can understand the user input. Is the best way to simply make lots of buttons and then assign them all identifiers, so that the user can click where they want to "shoot". By the way, at the moment, I'm not using any special libs, just the win32 api.

You could just set it up as a 2D array. Then when the user clicks on the screen you could translate the mouse coordinates to array indices. You might do something like, when the user clicks and holds, highlight whichever grid he is about to select and when he releases, select it.

I understand what you mean, but I'm not too sure about how to do what you say. Could you post a little example code please so that I can see how to do it

Caption bar will display the (column,row) of the cell clicked.

Code:

#include <windows.h>

#define MATRIX_WIDTH  5
#define MATRIX_HEIGHT 4
#define CELL_WIDTH    100
#define CELL_HEIGHT   100

LRESULT CALLBACK WndProc( HWND hwnd,UINT msg,WPARAM wParam,LPARAM lParam )
{
  static char   matrix[MATRIX_WIDTH][MATRIX_HEIGHT];
  static HBRUSH brush = (HBRUSH)GetStockObject(BLACK_BRUSH);
  
  switch(msg)  
  {
    case WM_PAINT:
    {
      PAINTSTRUCT ps;
      RECT        rc;
      HDC         hdc;
      
      hdc = BeginPaint( hwnd, &ps );    
      
      for( int row = 0; row < MATRIX_HEIGHT; ++row )
      {
        for( int column = 0; column < MATRIX_WIDTH; ++column )
        {
          rc.left   = column  * CELL_WIDTH;
          rc.top    = row     * CELL_HEIGHT;
          rc.right  = rc.left + CELL_WIDTH;
          rc.bottom = rc.top  + CELL_HEIGHT;

          FrameRect( hdc, &rc, brush );
        }
      }
      
      EndPaint ( hwnd, &ps );
      
      return 0;        
    }
    
    case WM_LBUTTONDOWN:
    {
      int x = LOWORD(lParam);
      int y = HIWORD(lParam);
      
      char buffer[100];
      wsprintf( buffer, "You clicked in column %d, row %d", 
                x/CELL_WIDTH, y/CELL_HEIGHT );
      SetWindowText( hwnd, buffer );
      
      return 0; 
    }

    case WM_DESTROY:
    {
      PostQuitMessage ( 0 ); 
    }

    default: return DefWindowProc(hwnd,msg,wParam,lParam);
  }
}

int WINAPI WinMain( HINSTANCE hInst, HINSTANCE hPrev, LPSTR args, int nShow )
{
  WNDCLASS wc = {0};
  wc.lpszClassName = TEXT( "Minimum" );
  wc.hInstance     = hInst ;
  wc.hbrBackground = GetSysColorBrush(COLOR_3DFACE);
  wc.lpfnWndProc   = WndProc ;
  wc.hCursor       = LoadCursor(0,IDC_ARROW);
  
  RegisterClass(&wc);

  RECT rc = { 0, 0, MATRIX_WIDTH * CELL_WIDTH, MATRIX_HEIGHT * CELL_HEIGHT };
  AdjustWindowRect( &rc, WS_POPUP|WS_VISIBLE|WS_CAPTION|WS_SYSMENU, FALSE );    
  
  HWND hwnd = CreateWindow(wc.lpszClassName,TEXT("Click on a cell."),
                           WS_POPUP|WS_VISIBLE|WS_CAPTION|WS_SYSMENU ,
                           0,0,rc.right-rc.left,rc.bottom-rc.top,0,0,hInst,0);
                           
  
  MSG  msg ;  
  while( GetMessage(&msg,0,0,0) > 0 ) {
    TranslateMessage(&msg);
    DispatchMessage(&msg);
  }
  return (int)msg.wParam;
}

the simplest way is two comboboxes (One for X and one for Y) and a button to tell that the user has finished selecting from the combos.

You can stack both combos easily (at the start of the app) with a loop and they will retain the last selection.

But I (as a user) would prefer the grid. I would try to move the code from the WM_PAINT handler though. Try looking at 'double buffering', should find many code snippets here.

Code:

HBRUSH hbrSelectedCell=CreateSolidBrush(COLORREF(255,0,0));//red brush
for( int row = 0; row < MATRIX_HEIGHT; ++row )
      {
        for( int column = 0; column < MATRIX_WIDTH; ++column )
        {
          rc.left   = column  * CELL_WIDTH;
          rc.top    = row     * CELL_HEIGHT;
          rc.right  = rc.left + CELL_WIDTH;
          rc.bottom = rc.top  + CELL_HEIGHT;
          //highlight the selected cell
          if((row==Selected_Row)&&(column==Selected_Col))
                FrameRect(hdc,&rc,hbrSelectedCell)
          else
                FrameRect( hdc, &rc, brush );
        }
      }
DeleteObject(hbrSelectedCell);//clean up GDI. Not selected into DC so can just delete

That code is just what I wanted, but how would you limit the area that the grid fills so that it only fills a part of the window, not the entire window? Thanks for the code, much appriciated

but how would you limit the area that the grid fills so that it only fills a part of the window, not the entire window?

Change the following lines in WinMain.

Code:

  RECT rc = { 0, 0, MATRIX_WIDTH * CELL_WIDTH, MATRIX_HEIGHT * CELL_HEIGHT };
  AdjustWindowRect( &rc, WS_POPUP|WS_VISIBLE|WS_CAPTION|WS_SYSMENU, FALSE );    
  
  HWND hwnd = CreateWindow(wc.lpszClassName,TEXT("Click on a cell."),
                           WS_POPUP|WS_VISIBLE|WS_CAPTION|WS_SYSMENU ,
                           0,0,rc.right-rc.left,rc.bottom-rc.top,0,0,hInst,0);

I used AdjustWindowRect to make it so that the size of the window's client area is the same as the matrix. If you do not wish this to happen, remove the AdjustWindowRect line and give your own width and height values to CreateWindow (bolded).

And to change the size of the matrix, adjust the #defines at the top of the source code.

Thank you very much for your help, I'll look at the source code and learn from it. At least I know how to make a grid now, so I don't have to program in a few hundred little buttons on the screen, that would take ages