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Diffstat (limited to 'vendor/plotters/examples/mandelbrot.rs')
-rw-r--r-- | vendor/plotters/examples/mandelbrot.rs | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/vendor/plotters/examples/mandelbrot.rs b/vendor/plotters/examples/mandelbrot.rs new file mode 100644 index 000000000..413c319c6 --- /dev/null +++ b/vendor/plotters/examples/mandelbrot.rs @@ -0,0 +1,71 @@ +use plotters::prelude::*; +use std::ops::Range; + +const OUT_FILE_NAME: &'static str = "plotters-doc-data/mandelbrot.png"; +fn main() -> Result<(), Box<dyn std::error::Error>> { + let root = BitMapBackend::new(OUT_FILE_NAME, (800, 600)).into_drawing_area(); + + root.fill(&WHITE)?; + + let mut chart = ChartBuilder::on(&root) + .margin(20) + .x_label_area_size(10) + .y_label_area_size(10) + .build_cartesian_2d(-2.1f64..0.6f64, -1.2f64..1.2f64)?; + + chart + .configure_mesh() + .disable_x_mesh() + .disable_y_mesh() + .draw()?; + + let plotting_area = chart.plotting_area(); + + let range = plotting_area.get_pixel_range(); + + let (pw, ph) = (range.0.end - range.0.start, range.1.end - range.1.start); + let (xr, yr) = (chart.x_range(), chart.y_range()); + + for (x, y, c) in mandelbrot_set(xr, yr, (pw as usize, ph as usize), 100) { + if c != 100 { + plotting_area.draw_pixel((x, y), &HSLColor(c as f64 / 100.0, 1.0, 0.5))?; + } else { + plotting_area.draw_pixel((x, y), &BLACK)?; + } + } + + // To avoid the IO failure being ignored silently, we manually call the present function + root.present().expect("Unable to write result to file, please make sure 'plotters-doc-data' dir exists under current dir"); + println!("Result has been saved to {}", OUT_FILE_NAME); + + Ok(()) +} + +fn mandelbrot_set( + real: Range<f64>, + complex: Range<f64>, + samples: (usize, usize), + max_iter: usize, +) -> impl Iterator<Item = (f64, f64, usize)> { + let step = ( + (real.end - real.start) / samples.0 as f64, + (complex.end - complex.start) / samples.1 as f64, + ); + return (0..(samples.0 * samples.1)).map(move |k| { + let c = ( + real.start + step.0 * (k % samples.0) as f64, + complex.start + step.1 * (k / samples.0) as f64, + ); + let mut z = (0.0, 0.0); + let mut cnt = 0; + while cnt < max_iter && z.0 * z.0 + z.1 * z.1 <= 1e10 { + z = (z.0 * z.0 - z.1 * z.1 + c.0, 2.0 * z.0 * z.1 + c.1); + cnt += 1; + } + return (c.0, c.1, cnt); + }); +} +#[test] +fn entry_point() { + main().unwrap() +} |