sxc = sp->sxc;
pxAllocImgBuf(pxScreenPrivPtr sp){	pxImgBufPtr ib;#ifdef notyet	if (!sp->queueing)#endif		return (&sp->ib[sp->ibsel ^= 1]);#ifdef notyet	for (;;) {		ib = &sp->ib[0];		if (sp->sxc->sxc_done[ib->bufnum] != ib->ident)			break;		ib = &sp->ib[1];		if (sp->sxc->sxc_done[ib->bufnum] != ib->ident)			break;	}	return (ib);#endif}