docs: function parse_PtgArea3d(blob, length, opts) {
  	var type = (blob[blob.l++] & 0x60) >> 5;
  	var ixti = blob.read_shift(2, 'i');
  	var w = 8;
  	if(opts) switch(opts.biff) {
  		case 5: blob.l += 12; w = 6; break;
  		case 12: w = 12; break;
  	}
  	var area = parse_RgceArea(blob, w, opts);
  	return [type, ixti, area];
  }