extern crate nalgebra as na;
extern crate tessellation;
//!
struct UnitSphere {
  bbox : tessellation::BoundingBox<f64>
}
//!
impl UnitSphere {
  fn new() -> UnitSphere {
    UnitSphere {
      bbox: tessellation::BoundingBox::new(&na::Point3::new(-1., -1., -1.),
                                           &na::Point3::new( 1.,  1.,  1.)) }
  }
}

impl tessellation::ImplicitFunction<f64> for UnitSphere {
   fn bbox(&self) -> &tessellation::BoundingBox<f64> {
     &self.bbox
   }
  fn value(&self, p: &na::Point3<f64>) -> f64 {
    return na::Vector3::new(p.x, p.y, p.z).norm() - 1.0;
  }
  fn normal(&self, p: &na::Point3<f64>) -> na::Vector3<f64> {
    return na::Vector3::new(p.x, p.y, p.z).normalize();
  }
}

let sphere = UnitSphere::new();
let mut mdc =  tessellation::ManifoldDualContouring::new(&sphere, 0.2, 0.1);
let triangles = mdc.tessellate().unwrap();