function demoRevolutionSurface(varargin)
%DEMOREVOLUTIONSURFACE  One-line description here, please.
%   output = demoRevolutionSurface(input)
%
%   Example
%   demoRevolutionSurface
%
%   See also
%

% ------
% Author: David Legland
% e-mail: david.legland@inra.fr
% Created: 2007-04-20
% Copyright 2007 INRA - BIA PV Nantes - MIAJ Jouy-en-Josas.


%% Draw a torus with vertical axis as revolution axis

circle  = circleToPolygon([10 0 3], 50);
[x, y, t] = revolutionSurface(circle, linspace(0, 4*pi/3, 50));

figure;
surf(x, y, t);
axis equal;

 

function varargout = circleToPolygon(circle, varargin)
%CIRCLETOPOLYGON Convert a circle into a series of points
%
%   P = circleToPolygon(CIRC, N);
%   Converts the circle CIRC into an array of  (N+1)-by-2 of double,
%   containing x and y positions of vertices.
%   CIRC is given as [x0 y0 r], where x0 and y0 are coordinate of center,
%   and r is the radius. 
%   The resulting polygon is closed (first and last vertices are the same).
%
%   P = circleToPolygon(CIRCLE);
%   uses a default value of N=64 vertices.
%
%   Example
%   circle = circleToPolygon([10 0 5], 16);
%   figure;
%   drawPolygon(circle);
%
%   See also:
%   circles2d, polygons2d, circleArcToPolyline, ellipseToPolygon
%
%
% ---------
% author : David Legland 
% created the 06/04/2005.
% Copyright 2010 INRA - Cepia Software Platform.
%

% HISTORY
% 2007-04-20 return a closed polygon with N+1 vertices, use default N=64
% 2011-12-09 rename to 'circleToPolygon'

% determines number of points
N = 64;
if ~isempty(varargin)
    N = varargin{1};
end

% create circle
t = linspace(0, 2*pi, N+1)';
x = circle(1) + circle(3) * cos(t);
y = circle(2) + circle(3) * sin(t);

if nargout == 1
    varargout{1} = [x y];
elseif nargout == 2
    varargout{1} = x;
    varargout{2} = y;    
end
