ceph/src/boost/libs/gil/example/mandelbrot.cpp

   1 //
   2 // Copyright 2005-2007 Adobe Systems Incorporated
   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 #include <boost/gil/image.hpp>
   9 #include <boost/gil/typedefs.hpp>
  10 #include <boost/gil/extension/io/jpeg.hpp>
  11
  12 // Example for convolve_rows() and convolve_cols() in the numeric extension
  13
  14 using namespace boost::gil;
  15
  16 // Models a Unary Function
  17 template <typename P>   // Models PixelValueConcept
  18 struct mandelbrot_fn
  19 {
  20     using point_t = boost::gil::point_t;
  21     using const_t = mandelbrot_fn;
  22     using value_type = P;
  23     using reference = value_type;
  24     using const_reference = value_type;
  25     using argument_type = point_t;
  26     using result_type = reference;
  27     static constexpr bool is_mutable =false;
  28
  29     value_type                    _in_color,_out_color;
  30     point_t                       _img_size;
  31     static const int MAX_ITER=100;        // max number of iterations
  32
  33     mandelbrot_fn() {}
  34     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) {}
  35
  36     result_type operator()(const point_t& p) const {
  37         // normalize the coords to (-2..1, -1.5..1.5)
  38         // (actually make y -1.0..2 so it is asymmetric, so we can verify some view factory methods)
  39         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));
  40         t=pow(t,0.2);
  41
  42         value_type ret;
  43         for (int k=0; k<num_channels<P>::value; ++k)
  44             ret[k]=(typename channel_type<P>::type)(_in_color[k]*t + _out_color[k]*(1-t));
  45         return ret;
  46     }
  47
  48 private:
  49     double get_num_iter(const point<double>& p) const {
  50         point<double> Z(0,0);
  51         for (int i=0; i<MAX_ITER; ++i) {
  52             Z = point<double>(Z.x*Z.x - Z.y*Z.y + p.x, 2*Z.x*Z.y + p.y);
  53             if (Z.x*Z.x + Z.y*Z.y > 4)
  54                 return i/(double)MAX_ITER;
  55         }
  56         return 0;
  57     }
  58 };
  59
  60 int main()
  61 {
  62     using deref_t = mandelbrot_fn<rgb8_pixel_t>;
  63     using point_t = deref_t::point_t;
  64     using locator_t = virtual_2d_locator<deref_t,false>;
  65     using my_virt_view_t = image_view<locator_t>;
  66
  67     boost::function_requires<PixelLocatorConcept<locator_t>>();
  68     gil_function_requires<StepIteratorConcept<locator_t::x_iterator>>();
  69
  70     point_t dims(200,200);
  71     my_virt_view_t mandel(dims, locator_t(point_t(0,0), point_t(1,1), deref_t(dims, rgb8_pixel_t(255,0,255), rgb8_pixel_t(0,255,0))));
  72     write_view("out-mandelbrot.jpg",mandel, jpeg_tag{});
  73
  74     return 0;
  75 }