ceph/src/boost/libs/gil/test/extension/io/mandel_view.hpp

   1 //
   2 // Copyright 2013 Christian Henning
   3 //
   4 // Distributed under the Boost Software License, Version 1.0
   5 // See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt
   7 //
   8 #ifndef BOOST_GIL_IO_TEST_MANDEL_HPP
   9 #define BOOST_GIL_IO_TEST_MANDEL_HPP
  10
  11 #include <boost/gil.hpp>
  12
  13 using namespace std;
  14 using namespace boost;
  15 using namespace gil;
  16
  17 // Models a Unary Function
  18 template <typename P>   // Models PixelValueConcept
  19 struct mandelbrot_fn
  20 {
  21     using point_t = boost::gil::point_t;
  22     using const_t = mandelbrot_fn;
  23     using value_type = P;
  24     using reference = value_type;
  25     using const_reference = value_type;
  26     using argument_type = point_t;
  27     using result_type = reference;
  28     static constexpr bool is_mutable = false;
  29
  30     value_type                    _in_color,_out_color;
  31     point_t                       _img_size;
  32     static const int MAX_ITER=100;        // max number of iterations
  33
  34     mandelbrot_fn() {}
  35     mandelbrot_fn(const point_t& sz, const value_type& in_color, const value_type& out_color) : _in_color(in_color), _out_color(out_color), _img_size(sz) {}
  36
  37     std::ptrdiff_t width()  { return _img_size.x; }
  38     std::ptrdiff_t height() { return _img_size.y; }
  39
  40     result_type operator()(const point_t& p) const {
  41         // normalize the coords to (-2..1, -1.5..1.5)
  42         // (actually make y -1.0..2 so it is asymmetric, so we can verify some view factory methods)
  43         double t=get_num_iter(point<double>(p.x/(double)_img_size.x*3-2, p.y/(double)_img_size.y*3-1.0f));//1.5f));
  44         t=pow(t,0.2);
  45
  46         value_type ret;
  47         for (int k=0; k<num_channels<P>::value; ++k)
  48             ret[k]=(typename channel_type<P>::type)(_in_color[k]*t + _out_color[k]*(1-t));
  49         return ret;
  50     }
  51
  52 private:
  53     double get_num_iter(const point<double>& p) const {
  54         point<double> Z(0,0);
  55         for (int i=0; i<MAX_ITER; ++i) {
  56             Z = point<double>(Z.x*Z.x - Z.y*Z.y + p.x, 2*Z.x*Z.y + p.y);
  57             if (Z.x*Z.x + Z.y*Z.y > 4)
  58                 return i/(double)MAX_ITER;
  59         }
  60         return 0;
  61     }
  62 };
  63
  64 template< typename Pixel >
  65 struct mandel_view
  66 {
  67     using deref_t = mandelbrot_fn<Pixel>;
  68     using locator_t= virtual_2d_locator<deref_t, false>;
  69     using my_virt_view_t = image_view<locator_t>;
  70     using type = my_virt_view_t;
  71 };
  72
  73 template< typename Pixel >
  74 typename mandel_view< Pixel >::type create_mandel_view( unsigned int width
  75                                                       , unsigned int height
  76                                                       , const Pixel& in
  77                                                       , const Pixel& out
  78                                                       )
  79 {
  80     using view_t = typename mandel_view<Pixel>::type;
  81     using deref_t = typename mandel_view<Pixel>::deref_t;
  82     using locator_t = typename mandel_view<Pixel>::locator_t;
  83
  84     point_t dims( width, height );
  85     return view_t( dims
  86                  , locator_t( point_t( 0, 0 )
  87                             , point_t( 1, 1 )
  88                             , deref_t( dims
  89                                      , in
  90                                      , out
  91                                      )
  92                             )
  93                  );
  94 }
  95
  96 #endif // BOOST_GIL_IO_TEST_MANDEL_HPP