xref: /libCEED/examples/rust/ex2-surface/src/transform.rs (revision 3d8e882215d238700cdceb37404f76ca7fa24eaa)
1*3d8e8822SJeremy L Thompson // Copyright (c) 2017-2022, Lawrence Livermore National Security, LLC and other CEED contributors.
2*3d8e8822SJeremy L Thompson // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3ded9b81dSJeremy L Thompson //
4*3d8e8822SJeremy L Thompson // SPDX-License-Identifier: BSD-2-Clause
5ded9b81dSJeremy L Thompson //
6*3d8e8822SJeremy L Thompson // This file is part of CEED:  http://github.com/ceed
7ded9b81dSJeremy L Thompson 
8ded9b81dSJeremy L Thompson use libceed::prelude::*;
9ded9b81dSJeremy L Thompson 
10ded9b81dSJeremy L Thompson // ----------------------------------------------------------------------------
11ded9b81dSJeremy L Thompson // Transform mesh coordinates
12ded9b81dSJeremy L Thompson // ----------------------------------------------------------------------------
134d27c890SJeremy L Thompson pub(crate) fn transform_mesh_coordinates(
144d27c890SJeremy L Thompson     dim: usize,
154d27c890SJeremy L Thompson     mesh_coords: &mut Vector,
164d27c890SJeremy L Thompson ) -> libceed::Result<Scalar> {
17ded9b81dSJeremy L Thompson     // Transform coordinates
18d3677ae8SJeremy L Thompson     for coord in mesh_coords.view_mut()?.iter_mut() {
19ded9b81dSJeremy L Thompson         // map [0,1] to [0,1] varying the mesh density
20ded9b81dSJeremy L Thompson         *coord = 0.5
2180a9ef05SNatalie Beams             + 1.0 / (3.0 as Scalar).sqrt()
2280a9ef05SNatalie Beams                 * ((2.0 / 3.0) * std::f64::consts::PI as Scalar * (*coord - 0.5)).sin()
23d3677ae8SJeremy L Thompson     }
24ded9b81dSJeremy L Thompson 
25ded9b81dSJeremy L Thompson     // Exact surface area of transformed region
26ded9b81dSJeremy L Thompson     let exact_area = match dim {
27ded9b81dSJeremy L Thompson         1 => 2.0,
28ded9b81dSJeremy L Thompson         2 => 4.0,
29ded9b81dSJeremy L Thompson         _ => 6.0,
30ded9b81dSJeremy L Thompson     };
31e78171edSJeremy L Thompson     Ok(exact_area)
32ded9b81dSJeremy L Thompson }
33ded9b81dSJeremy L Thompson 
34ded9b81dSJeremy L Thompson // ----------------------------------------------------------------------------
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