function outstruct = read_structs_from_bin_file(fid,typestruct)
% Matlab function to read a binary data file consisting of structs
% usage : outstruct = read_structs_from_bin_file2(fid,typestruct)
%
% inputs: fid:         file id obtained from fopen.m
%
%         typestruct:  structure to specify the type of each member,                      
%                      example:
%                      typestruct.<membername>.type='double';  %can be 'int' 'uint8' etc, see fread.m 
%
%                      if the member is an array, specify length as follows:
%                      typestruct.<membername>.length=1; 
%
%                      optionally you can specify skip, if the data is padded with some empty bytes, see fread.m documentation
%                      typestruct.<membername>.skip=4;     
%                      
%
% outputs: outstruct:  <1xn struct> where n is the number of times the
%                      struct was printed to the file
%
% Rob Hoogendijk, 2013


%get members of the struct
m=fieldnames(typestruct);
n=length(m);
%check properties of each member of the struct
%if skip not specified, set it to 0
%if length not specified, set it to 1
for field_i=1:n
    fname=m{field_i}; %string containing the field name
     if ~isfield(typestruct.(fname),'skip')                     
          typestruct.(fname).skip=0; 
     end
     if ~isfield(typestruct.(fname),'length')            
          typestruct.(fname).length=1; 
     end
end

%get data from file
entry_i=0;
outstruct=[];
while ~feof(fid)
    entry_i=entry_i+1;
    for field_i=1:n
        fname=m{field_i}; %string containing the field name
        size      = typestruct.(fname).length;
        skip      = typestruct.(fname).skip; 
        precision = typestruct.(fname).type;         
        [tmp,count]=fread(fid,size,precision,skip);%see fread.m documentation
        if(count>0)%to prevent creating an empty struct after the last data entry
            outstruct(entry_i).(fname)=tmp; 
        end
    end
end

end%function