function varargout = fillPolygon3d(varargin)
%FILLPOLYGON3D Fill a 3D polygon specified by a list of vertex coords.
%
%   fillPolygon3d(COORD, COLOR)
%   packs coordinates in a single [N*3] array.
%   COORD can also be a cell array of polygon, in this case each polygon is
%   drawn using the same color.
%
%   fillPolygon3d(PX, PY, PZ, COLOR)
%   specifies coordinates in separate numeric vectors (either row or
%   columns)
%
%   fillPolygon3d(..., PARAM, VALUE)
%   allows to specify some drawing parameter/value pairs as for the plot
%   function.
%
%   H = fillPolygon3d(...) 
%   also returns a handle to the list of created patch objects. 
%
%   Example
%     t = linspace(0, 2*pi, 100)';
%     xt = 10 * cos(t);
%     yt = 5 * sin(t);
%     zt = zeros(100,1);
%     poly = [xt yt zt];
%     figure; hold on; axis equal; fillPolygon3d(poly, 'c'); 
%     drawPolygon3d(poly, 'linewidth', 2, 'color', 'k');
% 
%   See also 
%   polygons3d, drawPolygon3d, drawPolyline3d
%

% ------
% Author: David Legland
% E-mail: david.legland@inrae.fr
% Created: 2007-01-05
% Copyright 2007-2024 INRA - BIA PV Nantes - MIAJ Jouy-en-Josas

% Check if axes handle is specified
if isAxisHandle(varargin{1})
    hAx = varargin{1};
    varargin(1) = [];
else
    hAx = gca;
end

% check case we want to draw several curves, stored in a cell array
var1 = varargin{1};
if iscell(var1)
    hold on;
    h = [];
    for i = 1:length(var1(:))
        h = [h; fillPolygon3d(hAx, var1{i}, varargin{2:end})]; %#ok<AGROW>
    end
    if nargout>0
        varargout{1}=h;
    end
    return;
end

% extract vertex coordinates
if min(size(var1)) == 1
    % if first argument is a vector (either row or column), then assumes
    % first argument contains x coords, second argument contains y coords
    % and third one the z coords
    px = var1;
    if length(varargin) < 3
        error('geom3d:fillPolygon3d:Wrong number of arguments in fillPolygon3d');
    end
    py = varargin{2};
    pz = varargin{3};
    varargin = varargin(4:end);
else
    % first argument contains all three coordinates
    px = var1(:, 1);
    py = var1(:, 2);
    pz = var1(:, 3);
    varargin = varargin(2:end);
end

% extract color information
if isempty(varargin)
    color = 'c';
else
    color = varargin{1};
    varargin = varargin(2:end);
end

% fill the polygon
h = fill3(hAx, px, py, pz, color, varargin{:});

if nargout>0
    varargout{1}=h;
end
