moons 0.0.2

Moon celestial simulation crate for the MilkyWay SolarSystem workspace
Documentation 
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#[derive(Debug, Clone, Copy, PartialEq)]
pub struct EarthView {
    pub earth_elevation_deg: f64,
    pub apparent_diameter_deg: f64,
    pub illuminated_fraction: f64,
}

impl EarthView {
    pub fn near_side_default() -> Self {
        Self {
            earth_elevation_deg: 89.0,
            apparent_diameter_deg: 1.9,
            illuminated_fraction: 0.65,
        }
    }

    pub fn is_visible(&self) -> bool {
        self.earth_elevation_deg > 0.0
    }
}

pub fn earthshine_gain(view: EarthView, surface_albedo: f64) -> f64 {
    if view.is_visible() {
        view.illuminated_fraction * view.apparent_diameter_deg * surface_albedo.max(0.0)
    } else {
        0.0
    }
}