pub struct CellAxis {
    min: f32,
    max: f32,
    num: u32,
    idx: u32
}

impl CellAxis {
    pub fn new(min: f32, len: f32, num: u32) -> Self {
        Self {
            min,
            max: min + len,
            num,
            idx: 0
        }
    }
}

impl Iterator for CellAxis {
    type Item = (f32, f32);

    fn next(&mut self) -> Option<Self::Item> {
        if self.idx < self.num {
            let beg: f32 = self.min + ((self.max - self.min) * self.idx as f32) / self.num as f32;
            let end: f32 = self.min + ((self.max - self.min) * (self.idx + 1) as f32) / self.num as f32;
            self.idx += 1;
           
            return Some((beg.trunc(), end.trunc()));
        }
        return None;
    }
}