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compute_text_colour.hh
1 // Copyright (C) 2011 EPITA Research and Development Laboratory (LRDE)
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25 
26 #ifndef SCRIBO_IO_XML_INTERNAL_COMPUTE_TEXT_COLOUR_HH
27 # define SCRIBO_IO_XML_INTERNAL_COMPUTE_TEXT_COLOUR_HH
28 
32 
33 # include <mln/value/rgb8.hh>
34 # include <mln/value/int_u8.hh>
35 # include <mln/make/vec.hh>
36 # include <mln/norm/l2.hh>
37 
38 
39 namespace scribo
40 {
41 
42  namespace io
43  {
44 
45  namespace xml
46  {
47 
48  namespace internal
49  {
50 
51  using namespace mln;
52 
53  const char *
54  compute_text_colour(const value::rgb8& v);
55 
56 
57  struct color_t
58  {
60  const char *name;
61  float res;
62  };
63 
64 
65 # ifndef MLN_INCLUDE_ONLY
66 
67 
68  inline
69  const char *
70  compute_text_colour(const value::rgb8& v)
71  {
72  static color_t colors[] = {
73  { mln::make::vec(0, 0, 0), "black", 0 },
74  { mln::make::vec(255, 0, 0), "red", 0 },
75  { mln::make::vec(255, 255, 255), "white", 0 },
76  { mln::make::vec(0, 255, 0), "green", 0 },
77  { mln::make::vec(0, 0, 255), "blue", 0 },
78  { mln::make::vec(255, 255, 0), "yellow", 0 },
79  { mln::make::vec(255, 165, 0), "orange", 0 },
80  { mln::make::vec(255, 192, 203), "pink", 0 },
81  { mln::make::vec(192, 192, 192), "grey", 0 },
82  { mln::make::vec(64, 224, 208), "turquoise", 0 },
83  { mln::make::vec(75, 0, 130), "indigo", 0 },
84  { mln::make::vec(238, 130, 238), "violet", 0 },
85  { mln::make::vec(0, 255, 255), "cyan", 0 },
86  { mln::make::vec(255, 0, 255), "magenta", 0 },
87  { mln::make::vec(0, 0, 0), 0, 0 } // Invalid
88  };
89 
90  unsigned closest = 0;
91  for (unsigned i = 0; colors[i].name; ++i)
92  {
93  colors[i].res = norm::l2_distance(colors[i].v, v.to_equiv());
94  if (colors[closest].res > colors[i].res)
95  closest = i;
96  }
97 
98  return colors[closest].name;
99  }
100 
101 #endif // MLN_INCLUDE_ONLY
102 
103  } // end of namespace scribo::io::xml::internal
104 
105  } // end of namespace scribo::io::xml
106 
107  } // end of namespace scribo::io
108 
109 } // end of namespace scribo
110 
111 
112 #endif // ! SCRIBO_IO_XML_INTERNAL_COMPUTE_TEXT_COLOUR_HH