use math::Point;
use partitioning::BVT;
use bounding_volume::AABB;
use shape::Shape;

/// Trait implemented by shapes composed of multiple simpler shapes.
///
/// A composite shape is composed of several shapes. Typically, it is a convex decomposition of
/// a concave shape.
pub trait CompositeShape<P: Point, M> {
    /// Applies a function to each sub-shape of this concave shape.
    fn map_part_at(&self, usize, &mut FnMut(&M, &Shape<P, M>));
    /// Applies a transformation matrix and a function to each sub-shape of this concave
    /// shape.
    fn map_transformed_part_at(&self, usize, m: &M, &mut FnMut(&M, &Shape<P, M>));

    // FIXME: the following two methods really are not generic enough.
    /// Gets the AABB of the shape identified by the index `i`.
    fn aabb_at(&self, i: usize) -> AABB<P>;
    /// Gets the acceleration structure of the concave shape.
    fn bvt(&self) -> &BVT<usize, AABB<P>>;
}