//a c file. #include it in the XS file
static char szWINOLE[] = "Win32::OLE";

static const DWORD WINOLE_MAGIC = 0x12344321;
static const DWORD WINOLEENUM_MAGIC = 0x12344322;
static const DWORD WINOLEVARIANT_MAGIC = 0x12344323;
static const DWORD WINOLETYPELIB_MAGIC = 0x12344324;
static const DWORD WINOLETYPEINFO_MAGIC = 0x12344325;


#define COINIT_OLEINITIALIZE -1
#define COINIT_NO_INITIALIZE -2

typedef HRESULT (STDAPICALLTYPE FNCOINITIALIZEEX)(LPVOID, DWORD);
typedef void (STDAPICALLTYPE FNCOUNINITIALIZE)(void);
typedef HRESULT (STDAPICALLTYPE FNCOCREATEINSTANCEEX)
    (REFCLSID, IUnknown*, DWORD, COSERVERINFO*, DWORD, MULTI_QI*);

typedef HWND (WINAPI FNHTMLHELP)(HWND hwndCaller, LPCSTR pszFile,
				 UINT uCommand, DWORD dwData);

typedef struct _tagOBJECTHEADER OBJECTHEADER;

/* per interpreter variables */
typedef struct
{
    CRITICAL_SECTION CriticalSection;
    OBJECTHEADER *pObj;
    BOOL bInitialized;
    HV *hv_unique;

    /* DCOM function addresses are resolved dynamically */
    HINSTANCE hOLE32;
    FNCOINITIALIZEEX     *pfnCoInitializeEx;
    FNCOUNINITIALIZE     *pfnCoUninitialize;
    FNCOCREATEINSTANCEEX *pfnCoCreateInstanceEx;

    /* HTML Help Control loaded dynamically */
    HINSTANCE hHHCTRL;
    FNHTMLHELP *pfnHtmlHelp;

}   PERINTERP;

#ifdef PERL_IMPLICIT_CONTEXT
#    define dPERINTERP                                                 \
        SV **pinterp = hv_fetch(PL_modglobal, MY_VERSION,              \
                                sizeof(MY_VERSION)-1, FALSE);          \
        if (!pinterp || !*pinterp || !SvIOK(*pinterp))		       \
            warn(MY_VERSION ": Per-interpreter data not initialized"); \
        PERINTERP *pInterp = INT2PTR(PERINTERP*, SvIV(*pinterp))
#    define INTERP pInterp
#else
static PERINTERP Interp;
#   define dPERINTERP extern int errno
#   define INTERP (&Interp)
#endif

#define g_pObj            (INTERP->pObj)
#define g_bInitialized    (INTERP->bInitialized)
#define g_CriticalSection (INTERP->CriticalSection)
#define g_hv_unique       (INTERP->hv_unique)

#define g_hOLE32                (INTERP->hOLE32)
#define g_pfnCoInitializeEx     (INTERP->pfnCoInitializeEx)
#define g_pfnCoUninitialize     (INTERP->pfnCoUninitialize)
#define g_pfnCoCreateInstanceEx (INTERP->pfnCoCreateInstanceEx)

#define g_hHHCTRL               (INTERP->hHHCTRL)
#define g_pfnHtmlHelp           (INTERP->pfnHtmlHelp)

/* common object header */
typedef struct _tagOBJECTHEADER
{
    long lMagic;
    OBJECTHEADER *pNext;
    OBJECTHEADER *pPrevious;
#ifdef PERL_IMPLICIT_CONTEXT
    PERINTERP    *pInterp;
#endif
}   OBJECTHEADER;

#define OBJFLAG_DESTROYED 0x01
#define OBJFLAG_UNIQUE    0x02

typedef struct
{
    OBJECTHEADER header;

    UV flags;
    IDispatch *pDispatch;
    ITypeInfo *pTypeInfo;
    IEnumVARIANT *pEnum;
    void *pEventSink;

    HV *self;
    HV *hashTable;
    SV *destroy;

    unsigned short cFuncs;
    unsigned short cVars;
    unsigned int   PropIndex;

}   WINOLEOBJECT;

void PLCOM(pTHX_ SV * sv){
    WINOLEOBJECT *pObj;
	ISpVoice * SpVInterface;
	HRESULT hr;
	unsigned short vol;
    int dispatchpos = offsetof
(WINOLEOBJECT, pDispatch);
    pObj = (WINOLEOBJECT*)(SvIV(sv));
	if (pObj->header.lMagic != WINOLE_MAGIC || !(pObj->pDispatch)){
        croak("PLCOM: GetOleObject() Not a %s object", szWINOLE);
    }
	hr = pObj->pDispatch->lpVtbl->QueryInterface(pObj->pDispatch, &IID_ISpVoice, (void **)&SpVInterface);
    printf("from c QI pdispath=%p lpvtbl=%p QI=%p\n",
           pObj->pDispatch,
           pObj->pDispatch->lpVtbl,
           pObj->pDispatch->lpVtbl->QueryInterface);
    if(hr != S_OK) croak("QueryInterface Failed");
	hr = SpVInterface->lpVtbl->GetVolume(SpVInterface, &vol);
	if(hr != S_OK) croak("GetVolume Failed");
	vol--;
	hr = SpVInterface->lpVtbl->SetVolume(SpVInterface, vol);
	if(hr != S_OK) croak("SetVolume Failed");
	vol = 0;
	hr = SpVInterface->lpVtbl->GetVolume(SpVInterface, &vol);
	if(hr != S_OK) croak("GetVolume Failed");
    
    printf("from c GV pdispath=%p lpvtbl=%p GV=%p\n",
           SpVInterface,
           SpVInterface->lpVtbl,
           SpVInterface->lpVtbl->GetVolume);
    printf("from c SV pdispath=%p lpvtbl=%p SV=%p\n",
           SpVInterface,
           SpVInterface->lpVtbl,
           SpVInterface->lpVtbl->SetVolume);
	hr = SpVInterface->lpVtbl->Release(SpVInterface);
    0;
}

#####################################################################
//In the XS file

void
PLCOM(sv)
    SV * sv
PPCODE:
    PLCOM(aTHX_ sv);