Sweden-Number/dlls/ddraw/ddcomimpl.h

37 lines
1.5 KiB
C

/* A few helpful macros for implementing COM objects.
*
* Copyright 2000 TransGaming Technologies Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#ifndef _DDCOMIMPL_H_
#define _DDCOMIMPL_H_
#include <stddef.h>
/* Given an interface pointer, returns the implementation pointer. */
#define ICOM_OBJECT(impltype, ifacename, ifaceptr) \
(impltype*)((ifaceptr) == NULL ? NULL \
: (char*)(ifaceptr) - offsetof(impltype, ifacename##_vtbl))
#define ICOM_THIS_FROM(impltype, ifacename, ifaceptr) \
impltype* This = ICOM_OBJECT(impltype, ifacename, ifaceptr)
#define COM_INTERFACE_CAST(impltype, ifnamefrom, ifnameto, ifaceptr) \
((ifaceptr) ? (ifnameto *)&(((impltype *)((char *)(ifaceptr) \
- offsetof(impltype, ifnamefrom##_vtbl)))->ifnameto##_vtbl) : NULL)
#endif /* _DDCOMIMPL_H_ */