earths 0.0.1

High-fidelity Earth simulation engine — orbit, atmosphere, geology, hydrology, biosphere, terrain, lighting, rendering, satellites, and temporal systems with full scientific coupling
Documentation 
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use sciforge::hub::prelude::constants::EARTH_RADIUS;
#[derive(Debug, Clone, Copy)]
pub struct Vertex {
    pub position: [f64; 3],
    pub normal: [f64; 3],
    pub uv: [f64; 2],
    pub tangent: [f64; 4],
}
pub struct TerrainMesh {
    pub vertices: Vec<Vertex>,
    pub indices: Vec<u32>,
}
impl TerrainMesh {
    pub fn from_region(
        lat_min: f64,
        lat_max: f64,
        lon_min: f64,
        lon_max: f64,
        subdivisions: u32,
        elevation_fn: &dyn Fn(f64, f64) -> f64,
    ) -> Self {
        let mut vertices = Vec::new();
        let mut indices = Vec::new();
        let steps = subdivisions + 1;
        for j in 0..steps {
            for i in 0..steps {
                let u = i as f64 / subdivisions as f64;
                let v = j as f64 / subdivisions as f64;
                let lat = lat_min + (lat_max - lat_min) * v;
                let lon = lon_min + (lon_max - lon_min) * u;
                let lat_rad = lat.to_radians();
                let lon_rad = lon.to_radians();
                let r = EARTH_RADIUS + elevation_fn(lat, lon);
                let x = r * lat_rad.cos() * lon_rad.cos();
                let y = r * lat_rad.cos() * lon_rad.sin();
                let z = r * lat_rad.sin();
                let nx = lat_rad.cos() * lon_rad.cos();
                let ny = lat_rad.cos() * lon_rad.sin();
                let nz = lat_rad.sin();
                let tx = -lon_rad.sin();
                let ty = lon_rad.cos();
                vertices.push(Vertex {
                    position: [x, y, z],
                    normal: [nx, ny, nz],
                    uv: [u, v],
                    tangent: [tx, ty, 0.0, 1.0],
                });
            }
        }
        for j in 0..subdivisions {
            for i in 0..subdivisions {
                let a = j * steps + i;
                let b = a + 1;
                let c = a + steps;
                let d = c + 1;
                indices.extend_from_slice(&[a, c, b, b, c, d]);
            }
        }
        Self { vertices, indices }
    }
    pub fn vertex_count(&self) -> usize {
        self.vertices.len()
    }
    pub fn triangle_count(&self) -> usize {
        self.indices.len() / 3
    }
}