1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
## Copyright (C) 2024 David Legland
## All rights reserved.
##
## Redistribution and use in source and binary forms, with or without
## modification, are permitted provided that the following conditions are met:
##
## 1 Redistributions of source code must retain the above copyright notice,
## this list of conditions and the following disclaimer.
## 2 Redistributions in binary form must reproduce the above copyright
## notice, this list of conditions and the following disclaimer in the
## documentation and/or other materials provided with the distribution.
##
## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ''AS IS''
## AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
## IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
## ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
## ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
## DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
## SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
## CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
## OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
##
## The views and conclusions contained in the software and documentation are
## those of the authors and should not be interpreted as representing official
## policies, either expressed or implied, of the copyright holders.
function [hull, inds] = convexHull(points, varargin)
%CONVEXHULL Convex hull of a set of points.
%
% POLY = convexHull(POINTS)
% Computes the convex hull of the set of points POINTS. This function is
% mainly a wrapper to the convhull function, that format the result to a
% polygon.
%
% [POLY, INDS] = convexHull(POINTS)
% Also returns the indices of convex hull vertices within the original
% array of points.
%
% ... = convexHull(POINTS, 'simplify', BOOL)
% specifies the 'simplify' option use dfor calling convhull. By default,
% the convexHull functions uses simplify equals to TRUE (contrary to the
% convhull function), resulting in a more simple convex polygon.
%
%
% Example
% % Draws the convex hull of a set of random points
% pts = rand(30,2);
% drawPoint(pts, '.');
% hull = convexHull(pts);
% hold on;
% drawPolygon(hull);
%
% % Draws the convex hull of a paper hen
% x = [0 10 20 0 -10 -20 -10 -10 0];
% y = [0 0 10 10 20 10 10 0 -10];
% poly = [x' y'];
% hull = convexHull(poly);
% figure; drawPolygon(poly);
% hold on; axis equal;
% drawPolygon(hull, 'm');
%
% See also
% polygons2d, convhull
%
% ------
% Author: David Legland
% E-mail: david.legland@inrae.fr
% Created: 2011-04-08, using Matlab 7.9.0.529 (R2009b)
% Copyright 2011-2023 INRA - Cepia Software Platform
% checkup on array size
if size(points, 1) < 3
hull = points;
inds = 1:size(points, 1);
return;
end
% parse simplify option
simplify = true;
if nargin > 2 && strcmpi(varargin{1}, 'simplify')
simplify = varargin{2};
end
% compute convex hull by calling the 'convhull' function
inds = convhull(points(:,1), points(:,2), 'simplify', simplify);
hull = points(inds, :);
|
