function res = formatMeshOutput(nbArgs, vertices, edges, faces)
%FORMATMESHOUTPUT Format mesh output depending on nargout.
%
%   OUTPUT = formatMeshOutput(NARGOUT, VERTICES, EDGES, FACES)
%   Utilitary function to convert mesh data .
%   If NARGOUT is 0 or 1, return a matlab structure with fields vertices,
%   edges and faces.
%   If NARGOUT is 2, return a cell array with data VERTICES and FACES.
%   If NARGOUT is 3, return a cell array with data VERTICES, EDGES and
%   FACES. 
%
%   OUTPUT = formatMeshOutput(NARGOUT, VERTICES, FACES)
%   Same as before, but do not intialize EDGES in output. NARGOUT can not
%   be equal to 3.
%
%   Example
%     % Typical calling sequence (for a very basic mesh of only one face)
%     v = [0 0; 0 1;1 0;1 1];
%     e = [1 2;1 3;2 4;3 4];
%     f = [1 2 3 4];
% 
%     varargout = formatMeshOutput(nargout, v, e, f);
%
%   See also
%   meshes3d, parseMeshData
%
% ------
% Author: David Legland
% e-mail: david.legland@grignon.inra.fr
% Created: 2010-12-06,    using Matlab 7.9.0.529 (R2009b)
% Copyright 2010 INRA - Cepia Software Platform.

if nargin < 4
    faces = edges;
    edges = [];
end

switch nbArgs
    case {0, 1}
        % output is a data structure with fields vertices, edges and faces
        mesh.vertices = vertices;
        if ~isempty(edges)
            mesh.edges = edges;
        end
        mesh.faces = faces;
        res = {mesh};

    case 2
        % keep only vertices and faces
        res = cell(nbArgs, 1);
        res{1} = vertices;
        res{2} = faces;
        
    case 3
        % return vertices, edges and faces as 3 separate outputs
        res = cell(nbArgs, 1);
        res{1} = vertices;
        res{2} = edges;
        res{3} = faces;
        
    otherwise
        error('Can not manage more than 3 outputs');
end

