You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: ptriproj.m
    path of file: ./repos/fieldtrip/private
    
    the code of the file until where you have to start completion: function [varargout] = ptriproj(varargin)

% PTRIPROJ projects a point onto the plane going through a triangle
%
% Use as
%   [proj, dist] = ptriproj(v1, v2, v3, r, flag)
% where v1, v2 and v3 are three vertices of the triangle, and r is 
% the point that is projected onto the plane spanned by the vertices
%
% the optional flag can be:
%   0 (default)  project the point anywhere on the complete plane
%   1            project the point within or on the edge of the triangle

% Copyright (C) 2002-2009, Robert Oostenveld
%
% This file is part of FieldTrip, see http://www.fieldtriptoolbox.org
% for the documentation and details.
%
%    FieldTrip is free software: you can redistribute it and/or modify
%    it under the terms of the GNU General Public License as published by
%    the Free Software Foundation, either version 3 of the License, or
%    (at your option) any later version.
%
%    FieldTrip is distributed in the hope that it will be useful,
%    but WITHOUT ANY WARRANTY; without even the implied warranty of
%    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%    GNU General Public License for more details.
%

    
function [varargout] = ptriproj(varargin)

% PTRIPROJ projects a point onto the plane going through a triangle
%
% Use as
%   [proj, dist] = ptriproj(v1, v2, v3, r, flag)
% where v1, v2 and v3 are three vertices of the triangle, and r is 
% the point that is projected onto the plane spanned by the vertices
%
% the optional flag can be:
%   0 (default)  project the point anywhere on the complete plane
%   1            project the point within or on the edge of the triangle

% Copyright (C) 2002-2009, Robert Oostenveld
%
% This file is part of FieldTrip, see http://www.fieldtriptoolbox.org
% for the documentation and details.
%
%    FieldTrip is free software: you can redistribute it and/or modify
%    it under the terms of the GNU General Public License as published by
%    the Free Software Foundation, either version 3 of the License, or
%    (at your option) any later version.
%
%    FieldTrip is distributed in the hope that it will be useful,
%    but WITHOUT ANY WARRANTY; without even the implied warranty of
%    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%    GNU General Public License for more details.
%
%    You should have received a copy of the GNU General Public License
%    along with FieldTrip. If not, see <http://www.gnu.org/licenses/>.
%
% $Id$

% compile the missing mex file on the fly
% remember the original working directory
pwdir = pwd;

% determine the name and full path of this function
funname = mfilename('fullpath');
mexsrc  = [funname '.c'];
[mexdir, mexname] = fileparts(funname);

try
  % try to compile the mex file on the fly
  ft_warning('trying to compile MEX file from %s', mexsrc);
  cd(mexdir);
  
  if ispc
    mex -I. -c geometry.c
    mex -I. -c ptriproj.c ; mex ptriproj.c ptriproj.obj geometry.obj
  else
    mex -I. -c geometry.c
    mex -I. -c ptriproj.c ; mex -o ptriproj ptriproj.o geometry.o
  end