#[derive(Debug, Clone, Copy, PartialEq)]
pub struct ElevationSample {
    pub latitude_deg: f64,
    pub longitude_deg: f64,
    pub elevation_m: f64,
}

pub fn sample_dem(latitude_deg: f64, longitude_deg: f64) -> ElevationSample {
    let xanadu_bias =
        if (-15.0..=15.0).contains(&latitude_deg) && (80.0..=140.0).contains(&longitude_deg) {
            1_200.0
        } else {
            0.0
        };
    let polar_lake_bias = if latitude_deg > 70.0 { -500.0 } else { 0.0 };
    let wave = latitude_deg.to_radians().sin() * 300.0 + longitude_deg.to_radians().cos() * 200.0;
    ElevationSample {
        latitude_deg,
        longitude_deg,
        elevation_m: xanadu_bias + polar_lake_bias + wave,
    }
}
