Code shared from the Rust Playground

playground.rs

#[derive(Debug, Clone)]
struct Rect {
    name: String,
    x: f64,
    y: f64,
    width: f64,
    height: f64,
}

fn subdivide_paper(rect: Rect, level: u32, max_level: u32) {
    println!(
        "{}: Position ({:.1}, {:.1}) | Size: {:.1}mm x {:.1}mm",
        rect.name, rect.x, rect.y, rect.width, rect.height
    );

    if level >= max_level {
        return;
    }

    let next_level = level + 1;
    
    // If width > height, cut vertically. Otherwise, cut horizontally.
    if rect.width > rect.height {
        let new_width = rect.width / 2.0;
        
        let left = Rect {
            name: format!("A{}", next_level),
            x: rect.x,
            y: rect.y,
            width: new_width,
            height: rect.height,
        };
        
        let _right = Rect {
            name: format!("A{}", next_level),
            x: rect.x + new_width,
            y: rect.y,
            width: new_width,
            height: rect.height,
        };

        // Recursively process one side to show the nested fractal path
        subdivide_paper(left, next_level, max_level);
        // (Optional) process right side if mapping the full grid
    } else {
        let new_height = rect.height / 2.0;
        
        let top = Rect {
            name: format!("A{}", next_level),
            x: rect.x,
            y: rect.y,
            width: rect.width,
            height: new_height,
        };
        
        let _bottom = Rect {
            name: format!("A{}", next_level),
            x: rect.x,
            y: rect.y + new_height,
            width: rect.width,
            height: new_height,
        };

        subdivide_paper(top, next_level, max_level);
    }
}

fn main() {
    // A0 Base dimensions in millimeters
    let a0 = Rect {
        name: "A0".to_string(),
        x: 0.0,
        y: 0.0,
        width: 841.0,
        height: 1189.0,
    };

    println!("--- ISO A-Series Fractal Tree ---");
    subdivide_paper(a0, 0, 8);
}