function [retval] = fd3(fid)
% [retval] = fd3(fid)
% read a 3 byte integer out of a file


%
% fread3.m
%
% Original Author: Bruce Fischl
%
% Copyright © 2011 The General Hospital Corporation (Boston, MA) "MGH"
%
% Terms and conditions for use, reproduction, distribution and contribution
% are found in the 'FreeSurfer Software License Agreement' contained
% in the file 'LICENSE' found in the FreeSurfer distribution, and here:
%
% https://surfer.nmr.mgh.harvard.edu/fswiki/FreeSurferSoftwareLicense
%
% Reporting: freesurfer@nmr.mgh.harvard.edu
%

b1 = fread(fid, 1, 'uchar') ;
b2 = fread(fid, 1, 'uchar') ;
b3 = fread(fid, 1, 'uchar') ;
retval = bitshift(b1, 16) + bitshift(b2,8) + b3 ;

