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
|
#include <imgen.h>
#include <cmath>
#include <algorithm>
#include <thread>
int minkowski_metric(double p, int refX, int refY, int x, int y) {
return static_cast<int>(std::nearbyint(
std::pow(
std::pow(std::abs(refX - x), p) + std::pow(std::abs(refY - y), p),
1.0 / p
)
));
}
int manhattan_metric(int refX, int refY, int x, int y) {
return minkowski_metric(1, refX, refY, x, y);
}
int euclidean_metric(int refX, int refY, int x, int y) {
return minkowski_metric(2, refX, refY, x, y);
}
void generate_minkowski_voronoi(
const double lower,
const double upper,
const double epsilon
) {
constexpr std::array<imgen::colored_vector, 9> ref{
imgen::colored_vector{ 0, 0, imgen::red() },
imgen::colored_vector{ 240, 200, imgen::green() },
imgen::colored_vector{-100, 230, imgen::blue() },
imgen::colored_vector{ 120, -100, imgen::yellow() },
imgen::colored_vector{ -42, -200, imgen::cyan() },
imgen::colored_vector{ 120, 40, imgen::magenta()},
imgen::colored_vector{-150, 50, imgen::silver() },
imgen::colored_vector{ 60, -128, imgen::maroon() },
imgen::colored_vector{-240, -20, imgen::olive() }
};
for ( double p = lower; p < upper; p = p + epsilon ) {
imgen::write_ppm(
"voronoi_" + std::to_string(p) + ".ppm",
512,
512,
[&ref, p](std::ptrdiff_t x, std::ptrdiff_t y) -> imgen::color {
std::array<int, 9> distances;
std::transform(
ref.begin(),
ref.end(),
distances.begin(),
[x, y, p](const imgen::colored_vector& pos) {
return minkowski_metric(p, std::get<0>(pos), std::get<1>(pos), x, y);
});
const auto& minimal_distance = std::min_element(
distances.begin(),
distances.end()
);
const imgen::colored_vector& nearest = ref[
std::distance(distances.begin(), minimal_distance)
];
if ( *minimal_distance <= 5 ) {
return imgen::color(0, 0, 0);
} else {
return std::get<2>(nearest);
}
}
);
}
}
int main(int, char*[]) {
std::thread worker1([](){ generate_minkowski_voronoi(0.8, 1.1, 0.002); });
std::thread worker2([](){ generate_minkowski_voronoi(1.102, 1.4, 0.002); });
std::thread worker3([](){ generate_minkowski_voronoi(1.402, 1.7, 0.002); });
std::thread worker4([](){ generate_minkowski_voronoi(1.702, 2.0, 0.002); });
worker1.join();
worker2.join();
worker3.join();
worker4.join();
}
|