summaryrefslogtreecommitdiff
path: root/inst/polyjoin.m
blob: 7b54933751414c7ea3321a1143652cee2dab7291 (plain)
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
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
## Copyright (C) 2016 Amr Mohamed
## Copyright (C) 2017 Piyush Jain
## Copyright (C) 2017-2018 Philip Nienhuis
##
## This program 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.
##
## This program 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 this program.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*- 
## @deftypefn {} [@var{xo}, @var{yo}] = polyjoin (@var{xi}, @var{yi})
## @deftypefnx {} {@var{xyo} =} polyjoin (@var{xi})
## Convert cell arrays of multipart polygon coordinates to numeric
## vectors with polygon parts separated by NaNs.
##
## @var{xi} and @var{yi} are cell vectors where each cell contains a
## numeric vector of X and Y coordinates, resp.  Alternatively, @var{xi}
## can be a cell array wih each cell containing Nx2 or Nx3 matrices
## constituting XY or XYZ coordinates of polygon part vertices and yi
## can be omitted.
##
## @var{xo} and @var{yo} are vectors of X and Y coordinates of polygon
## vertices where polygon parts are separated by NaNs.  If @var{xi} and
## @var{yi} either were row vectors or contained row vectors, @var{xo}
## and @var{yo} will be returned as row vectors, otherwise as column
## vectors.
##
## If @var{xi} contained Nx2 or Nx3 matrices, @var{xo} will be a Nx2
## or Nx3 matrix where polygon parts are separetd by NaN rows.  @var{yo}
## will be empty.
##
## polyjoin ultimately calls function joinPolygons in the Geometry package.
##
## @end deftypefn

## Author: Philip Nienhuis <prnienhuis@users.sf.net>
## Created: 2017-11-19

function [xo, yo] = polyjoin (xi, yi)

  ## Input checks
  if (nargin < 1)
    print_usage ();
  elseif (! iscell (xi))
    error ("Octave:invalid-input-arg", ...
           "polyjoin: input cell array or vectors expected");
  elseif (nargin == 1 && (! iscell (xi) || 
          (isnumeric (xi{1}) && size (xi{1}, 2) < 2)))
    error ("Octave:invalid-input-arg", ...
           "polyjoin: Nx2 or Nx3 matrix expected for arg. #1");
  elseif (nargin > 1 && ! iscell (yi))
    error ("Octave:invalid-input-arg", ...
           "polyjoin: expected 2 cell arrays of coordinate vectors");
  elseif (nargin > 1 && nargout < 2)
    warning ("Octave:invalid-input-arg", ...
             ["polyjoin: nr. of input arguments doesn't match nr. of output" ...
             " arguments"]);
  endif

  ## Remember input vector orientation; does not apply to input matrices
  ir = 0;

  if (isvector (xi{1}))
    if (nargin == 1)
      yi = {};
    endif
    if (isrow (xi{1}))
      ## Transpose
      ir = 1;
      xi = cellfun (@transpose, xi, "uni", 0);
      yi = cellfun (@transpose, yi, "uni", 0);
    endif
    if (isrow (xi) && ! isscalar (xi))
      ir = 1;
      xi = xi';
      yi = yi';
    endif
    yo = joinPolygons (yi);
  else
    yo = [];
  endif

##  if (numel (xi) > 1)
    xo = joinPolygons (xi);
##  else
##    xo = cell2mat (xi);
##  endif

  if (ir)
    ## Convert back to row vectors
    xo = xo';
    yo = yo';
  endif

endfunction

%!demo
%! x = {[1 2]'; [3 4]'} 
%! y = {[10 20]'; [30 40]'}
%! [vecx, vecy] = polyjoin (x, y)

%!test
%! x = {[1 2]'; [3 4]'}; y = {[10 20]'; [30 40]'};
%! [vecx, vecy] = polyjoin (x, y);
%! assert (vecx, [1; 2; NaN; 3; 4]);
%! assert (vecy, [10; 20; NaN; 30; 40]);

%!test
%! x = {[1;2]; [3;4]; [3]}; y = {[10;20]; [30;40]; [10]};
%! [vecx, vecy] = polyjoin (x, y);
%! assert (vecx, [1; 2; NaN; 3; 4; NaN; 3]);
%! assert (vecy, [10; 20; NaN; 30; 40; NaN; 10]);

%!test
%! x = {[1 2 3]'; 4; [5 6 7 8 NaN 9]'};
%! y = {[9 8 7]'; 6; [5 4 3 2 NaN 1]'};
%! [vecx, vecy] = polyjoin (x, y);
%! assert (vecx, [1; 2; 3; NaN; 4; NaN; 5; 6; 7; 8; NaN; 9]);
%! assert (vecy, [9; 8; 7; NaN; 6; NaN; 5; 4; 3; 2; NaN; 1]);

## Test 2D input matrices
%!test
%! xyi = {[0 0; 0 10; 10, 10; 10, 0; 0, 0]; [1 5; 2 5; 2 6; 1 6; 1 5]};
%! xyo = polyjoin (xyi);
%! assert (polyjoin (xyi), [0 0; 0 10; 10 10; 10 0; 0 0; NaN, NaN; 1 5; 2 5; 2 6; 1 6; 1 5], eps);

## Test 3D input matrices
%!test
%! xyi = {[0 0 1; 0 10 2; 10, 10 3; 10, 0 2; 0, 0 1]; [1 5 1.5; 2 5 2; 2 6 2.5; 1 6 2; 1 5 1.5]};
%! xyo = polyjoin (xyi);
%! assert (polyjoin (xyi), [0 0 1; 0 10 2; 10 10 3; 10 0 2; 0 0 1; NaN, NaN NaN; 1 5 1.5; 2 5 2; 2 6 2.5; 1 6 2; 1 5 1.5], eps);

## Corner case of just one point
%!test
%! assert (polyjoin ({[2, 3]}), [2, 3], eps);

%!error <input cell array or vectors expected> polyjoin (1);
%!error <Nx2 or Nx3 matrix expected> polyjoin ({2});
%!error <Nx2 or Nx3 matrix expected> polyjoin ({2, 3});
%!error <expected 2 cell arrays> polyjoin ({1; 2}, [3 4]);
%!warning <nr. of input arguments doesn't match> polyjoin ({1; 2}, {3 4});