More idiomatic rust wrappers, and optimize some poorly performing translations about meshopt-rs HOT 3 CLOSED

fn remap_vertex_buffer<T>(
    vertex_remap: &[u32],
    source_vertices: &[T],
    default_fn: fn() -> T,
) -> Vec<T>
where
    T: Clone,
{
    let mut dest_vertices: Vec<T> = vec![default_fn(); vertex_remap.len()];
    unsafe {
        meshopt::ffi::meshopt_remapVertexBuffer(
            dest_vertices.as_mut_ptr() as *mut ::std::os::raw::c_void,
            source_vertices.as_ptr() as *const ::std::os::raw::c_void,
            vertex_remap.len(),
            std::mem::size_of::<T>(),
            vertex_remap.as_ptr() as *const ::std::os::raw::c_uint,
        );
    }
    dest_vertices
}

mesh.positions = remap_vertex_buffer(&vertex_remap, &mesh.positions, || glm::vec3(0.0, 0.0, 0.0));

fn optimize_overdraw_in_place(indices: &mut [u32], vertices: &[glm::Vec3], threshold: f32) {
    let positions = vertices
        .iter()
        .map(|vertex| [vertex.x, vertex.y, vertex.z])
        .collect::<Vec<[f32; 3]>>();
    unsafe {
        meshopt::ffi::meshopt_optimizeOverdraw(
            indices.as_mut_ptr() as *mut ::std::os::raw::c_uint,
            indices.as_ptr() as *const ::std::os::raw::c_uint,
            indices.len(),
            positions.as_ptr() as *const f32,
            positions.len(),
            std::mem::size_of::<f32>() * 3,
            threshold,
        );
    }
}