polys 0.4.2

A package for polygon geometry
Documentation 
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use std::f64::consts::PI;

use crate::tri::Tri;
use crate::Polygon;

/// Struct that represents a rectangle.
#[derive(Debug)]
pub struct Rect {
    pub width: f64,
    pub height: f64,
}

impl Rect {
    /// Returns a new Rect from given width *w* and height *h*.
    /// # Examples
    /// ```
    /// let rect = polys::Rect::new(12.0, 6.0);
    /// ```
    pub fn new(w: f64, h: f64) -> Option<Rect> {
        if w == 0.0 || h == 0.0 {
            None
        } else {
            Some(Rect {
                width: w,
                height: h,
            })
        }
    }

    /// Returns a new Rect where both width and height are set to given value *w*.
    /// # Examples
    /// ```
    /// let square = polys::Rect::square(12.0);
    /// ```
    pub fn square(w: f64) -> Option<Rect> {
        if w == 0.0 {
            None
        } else {
            Some(Rect {
                width: w,
                height: w,
            })
        }
    }

    /// Returns the triangle created by cutting the Rect through two opposite corners.
    /// # Examples
    /// ```
    /// use crate::polys::Polygon;
    ///
    /// let rect = polys::Rect::new(3.0, 4.0)
    ///     .expect("Cound not make Rect")
    ///     .split()
    ///     .expect("Could not convert to Tri");
    /// let tri = polys::Tri::new(3.0, 4.0, 5.0)
    ///     .expect("Could not make Tri");
    ///
    /// assert_eq!(rect.side3, tri.side3);
    /// ```
    pub fn split(&self) -> Option<Tri> {
        Tri::sas(self.width, self.height, PI / 2.0)
    }
}

impl Polygon for Rect {
    /// Gets the area of the Rect according to its width and height.
    /// # Examples
    /// ```
    /// use crate::polys::Polygon;
    ///
    /// let rect = polys::Rect::new(10.0, 5.0)
    ///     .expect("Could not make Rect");
    /// let area = rect.area().expect("Is none");
    /// assert_eq!(area, 50.0);
    /// ```
    fn area(&self) -> Option<f64> {
        Some(self.width * self.height)
    }

    /// Gets the perimeter of the Rect from its width and height.
    /// # Examples
    /// ```
    /// use crate::polys::Polygon;
    ///
    /// let rect = polys::Rect::new(10.0, 5.0)
    ///     .expect("Could not make Rect");
    /// let peri = rect.peri().expect("Is none");
    /// assert_eq!(peri, 30.0);
    /// ```
    fn peri(&self) -> Option<f64> {
        Some(2.0 * &self.width + 2.0 * &self.height)
    }

    /// Returns interior angles (all 90) in degrees.
    /// # Examples
    /// ```
    /// use crate::polys::Polygon;
    ///
    /// let rect = polys::Rect::new(10.0, 5.0)
    ///     .expect("Could not make Rect");
    /// let angles = rect.angles().expect("Is none");
    /// assert_eq!((angles)[0], 90.0);
    /// ```
    fn angles(&self) -> Option<Vec<f64>> {
        Some(vec![90.0; 4])
    }
}