Thread: KEY_PRESSED error

Code:

if (KEY_DOWN(VK_ESCAPR))
  {
  PostMessage(main_window_handle, WM_DESTROY,0,0);
  }

I get an error that says KEY_DOWN and main_window_handle are not declared. Are they suppost to be???

Got any other code or is that it?

Yes! Define them...

Code:

#define KEY_DOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)
#define KEY_UP(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 0 : 1)

HWND main_window_handle; //make sure you set this to hwnd passed to WinMain later...

Code:

if (KEY_DOWN(VK_ESCAPR))
//wrong

if (KEY_DOWN(VK_ESCAPE))
 //right

Code:

//make sure you set this to hwnd passed to WinMain later...

so how would I do that? Thoe following is my WinMain

Code:

int WINAPI WinMain(HINSTANCE hinstance,
                               HINSTANCE hprevinstance,
	               LPSTR lpcmdline,
	               int ncmdshow)
{

WNDCLASSEX winclass; // this will hold the class we create
HWND	   hwnd;	 // generic window handle
MSG		   msg;// generic message

// first fill in the window class stucture
winclass.cbSize         = sizeof(WNDCLASSEX);
winclass.style			= CS_DBLCLKS | CS_OWNDC | 
                          CS_HREDRAW | CS_VREDRAW;
winclass.lpfnWndProc	= WindowProc;
winclass.cbClsExtra		= 0;
winclass.cbWndExtra		= 0;
winclass.hInstance		= hinstance;
winclass.hIcon			= LoadIcon(NULL, IDI_APPLICATION);
winclass.hCursor		= LoadCursor(NULL, IDC_ARROW);
winclass.hbrBackground	= (HBRUSH)GetStockObject(DKGRAY_BRUSH);
winclass.lpszMenuName	= NULL;
winclass.lpszClassName	= WINDOW_CLASS_NAME;
winclass.hIconSm        = LoadIcon(NULL, "G3D.ICO");

// register the window class
if (!RegisterClassEx(&winclass))
	return(0);

// create the window
if (!(hwnd = CreateWindowEx(0, // extended style
                            WINDOW_CLASS_NAME,   // class
						    "Geo 3D Game Engine V1.0 Alpha -- By Ryan ****** ©", // title
						    WS_OVERLAPPEDWINDOW | WS_VISIBLE,
					 	    0,0,	    // initial x,y
						    800,600,  // initial width, height
						    NULL,	    // handle to parent 
						    NULL,	    // handle to menu
						    hinstance,// instance of this application
						    NULL)))	// extra creation parms
return(0);


//Calls Game Initilizastion
int Game_Init();



// enter main event loop
while(1)
  {
  if (PeekMessage(&msg, NULL,0,0,PM_REMOVE))
      {
      //Test if this is a quit.
      if (msg.message == WM_QUIT)
      break;
      
      //Translate any accelerator keys
      TranslateMessage(&msg);
      
      //Send message to window proc.
      DispatchMessage(&msg);
      } //end IF(PeekMessage);




// Calls Game_Shutdown
int Game_Shutdown();
}// end while(1);

//Call Game_Shutdown
int Game_Shutdown();

//Return to windows
return(msg.wParam);

}//end WinMain

Where is the code that causes the error?

look at Jawibs post above.



~Trooper

No, I mean, you haven't actually posted up the code and it's context that actually causes the error. Posting up a few lines isn't enough, I need to know what function it's in and what other code is there. Just post your entire code.

okay here's the .cpp file


~Trooper

Code:

case WM_CREATE: 
        {
	// do initialization stuff here
	main_window_handle=hwnd;
                return(0);
        }

That's where I'd put it. I think WM_CREATE is just about the earliest place you can put the code, except maybe WM_NCCREATE.

Code:

if (!(hwnd = CreateWindowEx(0, // extended style
                            WINDOW_CLASS_NAME,   // class
						    "Geo 3D Game Engine V1.0 Alpha -- By Ryan ****** ©", // title
						    WS_OVERLAPPEDWINDOW | WS_VISIBLE,
					 	    0,0,	    // initial x,y
						    800,600,  // initial width, height
						    NULL,	    // handle to parent 
						    NULL,	    // handle to menu
						    hinstance,// instance of this application
						    NULL)))	// extra creation parms
return(0);

You could probably put it right after you create the window

Placing it in the WM_NCCREATE handler would come before that, Jawib. A lot happens before CreateWindowEx() returns.

But that would be even before the message pump begins, handling your WM_NCCREATE message. Unless CreateWindowEx() calls your message handler on its own?

Ummmmmmmmmm.........

you could put it here

if (!(main_window_handle = CreateWindowEx(0, WINDOW_CLASS_NAME,

That's probably the best place to put it really. If you also initialize the variable with NULL in the first place, then you can be assured that whenever you use the handle, it will either point to a window that has been created and is valid, or it will be NULL, in which case it'll just get flagged as invalid. If you were to place the assignment in WM_NCCREATE, and by chance some function used the handle before WM_CREATE returned, you might have some problems.

So I guess novacain is right. Do the following:

Code:

//at the top of the file
HWND main_window_handle=NULL; 
.
.
.
int WINAPI WinApi(...)
{
.
.
.
main_window_handle=CreateWindowEx(...);
if (!main_window_handle)
       exit(1);

This way, main_window_handle does not have the window handle until WM_CREATE returns, which is a good thing IMO.