Samples/multimedia/directshow/baseclasses/ddmm.cpp

//------------------------------------------------------------------------------
// File: DDMM.cpp
//
// Desc: DirectShow base classes - implements routines for using DirectDraw
//       on a multimonitor system.
//
// Copyright (c) 1995-2001 Microsoft Corporation.  All rights reserved.
//------------------------------------------------------------------------------


#include <streams.h>
#include <ddraw.h>
#include "ddmm.h"

/*
 * FindDeviceCallback
 */
typedef struct {
	LPSTR   szDevice;
	GUID*   lpGUID;
	GUID    GUID;
	BOOL    fFound;
}   FindDeviceData;

BOOL CALLBACK FindDeviceCallback(__in_opt GUID* lpGUID, __in LPSTR szName, __in LPSTR szDevice, __in LPVOID lParam)
{
	FindDeviceData *p = (FindDeviceData*)lParam;

	if (lstrcmpiA(p->szDevice, szDevice) == 0) {
	    if (lpGUID) {
		p->GUID = *lpGUID;
		p->lpGUID = &p->GUID;
	    } else {
		p->lpGUID = NULL;
	    }
	    p->fFound = TRUE;
	    return FALSE;
	}
	return TRUE;
}


BOOL CALLBACK FindDeviceCallbackEx(__in_opt GUID* lpGUID, __in LPSTR szName, __in LPSTR szDevice, __in LPVOID lParam, HMONITOR hMonitor)
{
	FindDeviceData *p = (FindDeviceData*)lParam;

	if (lstrcmpiA(p->szDevice, szDevice) == 0) {
	    if (lpGUID) {
		p->GUID = *lpGUID;
		p->lpGUID = &p->GUID;
	    } else {
		p->lpGUID = NULL;
	    }
	    p->fFound = TRUE;
	    return FALSE;
	}
	return TRUE;
}


/*
 * DirectDrawCreateFromDevice
 *
 * create a DirectDraw object for a particular device
 */
IDirectDraw * DirectDrawCreateFromDevice(__in_opt LPSTR szDevice, PDRAWCREATE DirectDrawCreateP, PDRAWENUM DirectDrawEnumerateP)
{
	IDirectDraw*    pdd = NULL;
	FindDeviceData  find;

	if (szDevice == NULL) {
		DirectDrawCreateP(NULL, &pdd, NULL);
		return pdd;
	}

	find.szDevice = szDevice;
	find.fFound   = FALSE;
	DirectDrawEnumerateP(FindDeviceCallback, (LPVOID)&find);

	if (find.fFound)
	{
		//
		// In 4bpp mode the following DDraw call causes a message box to be popped
		// up by DDraw (!?!).  It's DDraw's fault, but we don't like it.  So we
		// make sure it doesn't happen.
		//
		UINT ErrorMode = SetErrorMode(SEM_FAILCRITICALERRORS);
		DirectDrawCreateP(find.lpGUID, &pdd, NULL);
		SetErrorMode(ErrorMode);
	}

	return pdd;
}


/*
 * DirectDrawCreateFromDeviceEx
 *
 * create a DirectDraw object for a particular device
 */
IDirectDraw * DirectDrawCreateFromDeviceEx(__in_opt LPSTR szDevice, PDRAWCREATE DirectDrawCreateP, LPDIRECTDRAWENUMERATEEXA DirectDrawEnumerateExP)
{
	IDirectDraw*    pdd = NULL;
	FindDeviceData  find;

	if (szDevice == NULL) {
		DirectDrawCreateP(NULL, &pdd, NULL);
		return pdd;
	}

	find.szDevice = szDevice;
	find.fFound   = FALSE;
	DirectDrawEnumerateExP(FindDeviceCallbackEx, (LPVOID)&find,
					DDENUM_ATTACHEDSECONDARYDEVICES);

	if (find.fFound)
	{
		//
		// In 4bpp mode the following DDraw call causes a message box to be popped
		// up by DDraw (!?!).  It's DDraw's fault, but we don't like it.  So we
		// make sure it doesn't happen.
		//
		UINT ErrorMode = SetErrorMode(SEM_FAILCRITICALERRORS);
		DirectDrawCreateP(find.lpGUID, &pdd, NULL);
		SetErrorMode(ErrorMode);
	}

	return pdd;
}