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
mandelbrot_fnmandelbrot_fn33 mandelbrot_fn() {}
mandelbrot_fnmandelbrot_fn34 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
operator ()mandelbrot_fn36 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:
get_num_itermandelbrot_fn49 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
main()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 }
76