Multiple Monitor Support Code

Multiple Monitor Support Code
by David Stubbs

This code allows the user to select which video card to use if there are more than one present.


static GUID          *gpSelectedDriverGUID;

BOOL WINAPI Callback(
  GUID FAR *lpGUID,
  LPSTR     lpDriverDescription,
  LPSTR     lpDriverName,
  LPVOID    lpContext,
  HMONITOR  hm
)
{
   char    buffer[256];

   if (lpGUID)
   {
      wsprintf(buffer, "Use the %hs video card?", lpDriverDescription);
      if (MessageBoxEx(NULL, buffer, "Avoidance", MB_YESNO, NULL) ==  IDYES)
      {
         gpSelectedDriverGUID=lpGUID;
         return DDENUMRET_CANCEL;
      }
   }
   return DDENUMRET_OK;
}

And to use the routine in your code:


DirectDrawEnumerateExA(Callback, NULL, DDENUM_ATTACHEDSECONDARYDEVICES |
      DDENUM_NONDISPLAYDEVICES | DDENUM_DETACHEDSECONDARYDEVICES);
if (!gpSelectedDriverGUID)
   gpSelectedDriverGUID = NULL;

Then when creating the DirectDraw object just call it like this:


DirectDrawCreate(gpSelectedDriverGUID, &lpdd, NULL);

Discuss this article in the forums

Date this article was posted to GameDev.net: 8/15/2000
(Note that this date does not necessarily correspond to the date the article was written)

See Also:
General
Sweet Snippets