Sierpinski pentagon: Difference between revisions
Added Rust solution
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See [http://rosettacode.org/mw/images/5/57/Perl6_pentaflake.svg 5th order pentaflake]
=={{header|Rust}}==
This code is based on the Java solution. The output is a file in SVG format.
<lang rust>// [dependencies]
// svg = "0.8.0"
fn sierpinski_pentagon(mut document : svg::Document, mut x : f64, mut y : f64,
mut side : f64, order: usize) -> svg::Document {
use svg::node::element::Path;
use svg::node::element::path::Data;
use std::f64::consts::PI;
let degrees72 = 0.4 * PI;
let mut angle = 3.0 * degrees72;
let scale_factor = 1.0/(2.0 + degrees72.cos() * 2.0);
if order == 1 {
let mut data = Data::new();
data = data.move_to((x, y));
for _ in 0..5 {
x += angle.cos() * side;
y -= angle.sin() * side;
angle += degrees72;
data = data.line_to((x, y));
}
data = data.close();
let path = Path::new()
.set("fill", "blue")
.set("stroke", "black")
.set("stroke-width", "1")
.set("d", data);
document = document.add(path);
} else {
side *= scale_factor;
let distance = side + side * degrees72.cos() * 2.0;
for _ in 0..5 {
x += angle.cos() * distance;
y -= angle.sin() * distance;
angle += degrees72;
document = sierpinski_pentagon(document, x, y, side, order - 1);
}
}
document
}
fn write_sierpinski_pentagon(file : &str, size : usize,
order : usize) -> std::io::Result<()> {
use svg::node::element::Rectangle;
use std::f64::consts::PI;
let margin = 5.0;
let radius = (size as f64)/2.0 - 2.0 * margin;
let side = radius * (0.2 * PI).sin() * 2.0;
let x = (size as f64)/2.0;
let y = 3.0 * margin;
let rect = Rectangle::new()
.set("width", "100%")
.set("height", "100%")
.set("fill", "white");
let mut document = svg::Document::new()
.set("width", size)
.set("height", size)
.add(rect);
document = sierpinski_pentagon(document, x, y, side, order);
svg::save(file, &document)
}
fn main() {
write_sierpinski_pentagon("sierpinski_pentagon.svg", 600, 5).unwrap();
}</lang>
=={{header|Scala}}==
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