64 lines
1.7 KiB
Text
64 lines
1.7 KiB
Text
// [dependencies]
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// svg = "0.8.0"
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const SQRT3_2: f64 = 0.86602540378444;
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fn sierpinski_triangle(
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mut document: svg::Document,
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mut x: f64,
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mut y: f64,
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mut side: f64,
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order: usize,
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) -> svg::Document {
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use svg::node::element::Polygon;
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if order == 1 {
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let mut points = Vec::new();
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points.push((x, y));
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y += side * SQRT3_2;
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x -= side * 0.5;
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points.push((x, y));
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x += side;
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points.push((x, y));
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let polygon = Polygon::new()
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.set("fill", "black")
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.set("stroke", "none")
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.set("points", points);
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document = document.add(polygon);
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} else {
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side *= 0.5;
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document = sierpinski_triangle(document, x, y, side, order - 1);
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y += side * SQRT3_2;
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x -= side * 0.5;
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document = sierpinski_triangle(document, x, y, side, order - 1);
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x += side;
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document = sierpinski_triangle(document, x, y, side, order - 1);
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}
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document
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}
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fn write_sierpinski_triangle(file: &str, size: usize, order: usize) -> std::io::Result<()> {
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use svg::node::element::Rectangle;
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let margin = 20.0;
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let side = (size as f64) - 2.0 * margin;
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let y = 0.5 * ((size as f64) - SQRT3_2 * side);
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let x = margin + side * 0.5;
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let rect = Rectangle::new()
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.set("width", "100%")
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.set("height", "100%")
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.set("fill", "white");
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let mut document = svg::Document::new()
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.set("width", size)
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.set("height", size)
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.add(rect);
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document = sierpinski_triangle(document, x, y, side, order);
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svg::save(file, &document)
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}
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fn main() {
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write_sierpinski_triangle("sierpinski_triangle.svg", 600, 8).unwrap();
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}
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