pp->ident = (idgen += 2) | 1;
pp->ident = (idgen += 2);
pxPacketStart(pxScreenPrivPtr sp, pxPacketPtr pp, int hdrsz, int primsz){	u_int32_t *pb;	int sel;	PX_TRACE("pxPacketStart");	if (!sp->queueing)		sel = (sp->pbsel ^= 1);	else {		/* Allocate a buffer and assign it a unique ID. */		pp->ident = (idgen += 2) | 1;		pp->bufnum = sp->sxc->sxc_head;		sel = pp->bufnum;		sp->sxc->sxc_done[sel] = pp->ident;	}	pb = sp->buf + (sel * STIC_PACKET_SIZE) / sizeof(u_int32_t);	pp->head = pb;	pp->curpb = pb + hdrsz;	pp->hdrsz = hdrsz;	pp->primsz = primsz;	pp->primcnt = 0;	pp->maxprimcnt = min(255, (1024 - hdrsz) / primsz);	return (pb);}