NextPicture
status_t NextPicture(BPicture& picture, BPoint& p, BRect& r);
fStatus = pjp->NextPicture(fPictures[i], fPoints[i], fRects[i]);
while (pjp.NextPicture(picture, pos, rect) == B_OK) {
(rc = pjp->NextPicture(fPictures[i], fPoints[i], fRects[i])) == B_OK; i ++);