1 use plotters::prelude::*;
2 use std::ops::Range;
3
main() -> Result<(), Box<dyn std::error::Error>>4 fn main() -> Result<(), Box<dyn std::error::Error>> {
5 let root =
6 BitMapBackend::new("plotters-doc-data/mandelbrot.png", (800, 600)).into_drawing_area();
7
8 root.fill(&WHITE)?;
9
10 let mut chart = ChartBuilder::on(&root)
11 .margin(20)
12 .x_label_area_size(10)
13 .y_label_area_size(10)
14 .build_cartesian_2d(-2.1f64..0.6f64, -1.2f64..1.2f64)?;
15
16 chart
17 .configure_mesh()
18 .disable_x_mesh()
19 .disable_y_mesh()
20 .draw()?;
21
22 let plotting_area = chart.plotting_area();
23
24 let range = plotting_area.get_pixel_range();
25
26 let (pw, ph) = (range.0.end - range.0.start, range.1.end - range.1.start);
27 let (xr, yr) = (chart.x_range(), chart.y_range());
28
29 for (x, y, c) in mandelbrot_set(xr, yr, (pw as usize, ph as usize), 100) {
30 if c != 100 {
31 plotting_area.draw_pixel((x, y), &HSLColor(c as f64 / 100.0, 1.0, 0.5))?;
32 } else {
33 plotting_area.draw_pixel((x, y), &BLACK)?;
34 }
35 }
36
37 Ok(())
38 }
39
mandelbrot_set( real: Range<f64>, complex: Range<f64>, samples: (usize, usize), max_iter: usize, ) -> impl Iterator<Item = (f64, f64, usize)>40 fn mandelbrot_set(
41 real: Range<f64>,
42 complex: Range<f64>,
43 samples: (usize, usize),
44 max_iter: usize,
45 ) -> impl Iterator<Item = (f64, f64, usize)> {
46 let step = (
47 (real.end - real.start) / samples.0 as f64,
48 (complex.end - complex.start) / samples.1 as f64,
49 );
50 return (0..(samples.0 * samples.1)).map(move |k| {
51 let c = (
52 real.start + step.0 * (k % samples.0) as f64,
53 complex.start + step.1 * (k / samples.0) as f64,
54 );
55 let mut z = (0.0, 0.0);
56 let mut cnt = 0;
57 while cnt < max_iter && z.0 * z.0 + z.1 * z.1 <= 1e10 {
58 z = (z.0 * z.0 - z.1 * z.1 + c.0, 2.0 * z.0 * z.1 + c.1);
59 cnt += 1;
60 }
61 return (c.0, c.1, cnt);
62 });
63 }
64 #[test]
entry_point()65 fn entry_point() {
66 main().unwrap()
67 }
68
