venuss 0.0.2

Venus celestial simulation crate for the MilkyWay SolarSystem workspace
Documentation 
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pub fn solar_declination_deg(ls_deg: f64) -> f64 {
    let eps = crate::AXIAL_TILT_DEG.to_radians();
    let ls = ls_deg.to_radians();
    (eps.sin() * ls.sin()).asin().to_degrees()
}

pub struct SolarPosition {
    pub elevation_deg: f64,
    pub direction: [f64; 3],
}
impl SolarPosition {
    pub fn compute(ls_deg: f64, local_time_h: f64, lat_deg: f64, lon_deg: f64) -> Self {
        if !lon_deg.is_finite() {
            return Self {
                elevation_deg: f64::NAN,
                direction: [f64::NAN; 3],
            };
        }

        let decl = solar_declination_deg(ls_deg).to_radians();
        let hour = ((local_time_h - 12.0) * 15.0).to_radians();
        let lat = lat_deg.to_radians();
        let sin_elev = lat.sin() * decl.sin() + lat.cos() * decl.cos() * hour.cos();
        let elev = sin_elev.asin();
        Self {
            elevation_deg: elev.to_degrees(),
            direction: [0.0, elev.sin(), elev.cos()],
        }
    }
    pub fn is_above_horizon(&self) -> bool {
        self.elevation_deg > 0.0
    }
}