conspire 0.7.2

The Rust interface to conspire.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117

use crate::{
    geometry::{
        Coordinate, CoordinatesRef,
        bvh::BoundingVolumeHierarchy,
        mesh::{
            Fitting, Mesh,
            tessellation::{D, Tessellation},
        },
        ntree::{Balance, Balancing, CurvatureSizing, Dualization, Octree, Pairing},
    },
    math::{Scalar, Tensor},
};
use std::thread::{available_parallelism, scope};

const GRAZING_TOLERANCE: Scalar = 1.0e-4;
const TRIM_MARGIN: Scalar = 0.5;
const EDGES: [[usize; 2]; 12] = [
    [0, 1],
    [1, 2],
    [2, 3],
    [3, 0],
    [4, 5],
    [5, 6],
    [6, 7],
    [7, 4],
    [0, 4],
    [1, 5],
    [2, 6],
    [3, 7],
];
const DIRECTIONS: [Coordinate<D>; 3] = [
    Coordinate::const_from([1.0, 0.140_412_03, 0.092_153_88]),
    Coordinate::const_from([0.097_153_2, 1.0, 0.131_771_4]),
    Coordinate::const_from([0.123_456_7, 0.087_654_3, 1.0]),
];
impl Tessellation {
    pub fn dualize(
        &self,
        balancing: Balancing,
        scale: Scalar,
        curvature: CurvatureSizing,
        fitting: Fitting,
    ) -> Result<Mesh<D>, &'static str> {
        let mut octree = Octree::<u16, usize>::from_features(self, scale, curvature, 0);
        octree.equilibrate(balancing, Pairing::Regular)?;
        let mut mesh = octree.dualize();
        self.trim(&mut mesh, self.bvh())?;
        mesh.buffer(self, fitting)
    }
    fn trim(
        &self,
        mesh: &mut Mesh<D>,
        bvh: &BoundingVolumeHierarchy<D>,
    ) -> Result<(), &'static str> {
        let surface = self.mesh();
        let surface_coordinates = surface.coordinates();
        let elements: Vec<&[usize]> = surface.connectivities().iter().flatten().collect();
        let normals: CoordinatesRef<'_, D> = self.normals().iter().flatten().collect();
        let directions = DIRECTIONS.map(|direction| direction.normalized());
        let coordinates = mesh.coordinates();
        let number_of_nodes = coordinates.len();
        let mut inside = vec![false; number_of_nodes];
        let mut clearance = vec![0.0; number_of_nodes];
        let threads = available_parallelism().map_or(1, |threads| threads.get());
        let chunk_size = number_of_nodes.div_ceil(threads).max(1);
        scope(|scope| {
            let (elements, normals, directions) = (&elements, &normals, &directions);
            inside
                .chunks_mut(chunk_size)
                .zip(clearance.chunks_mut(chunk_size))
                .enumerate()
                .for_each(|(chunk, (flags, distances))| {
                    scope.spawn(move || {
                        let offset = chunk * chunk_size;
                        flags
                            .iter_mut()
                            .zip(distances.iter_mut())
                            .enumerate()
                            .for_each(|(local, (flag, distance))| {
                                let point = &coordinates[offset + local];
                                *flag = directions
                                    .iter()
                                    .find_map(|direction| {
                                        let ray = (point.clone(), direction.clone()).into();
                                        match bvh.intersect(&ray, surface_coordinates, elements) {
                                            None => Some(false),
                                            Some(hit) => {
                                                let normal = &normals[hit.index()];
                                                let cosine = (direction * normal) / normal.norm();
                                                (cosine.abs() > GRAZING_TOLERANCE)
                                                    .then_some(cosine > 0.0)
                                            }
                                        }
                                    })
                                    .unwrap_or(false);
                                if *flag
                                    && let Some((closest, _)) =
                                        bvh.closest_point(point, surface_coordinates, elements)
                                {
                                    *distance = (&closest - point).norm();
                                }
                            });
                    });
                });
        });
        mesh.keep_hexes(|_, hex, coordinates| {
            hex.iter().all(|&node| inside[node]) && {
                let margin = TRIM_MARGIN
                    * EDGES
                        .iter()
                        .map(|&[a, b]| (&coordinates[hex[a]] - &coordinates[hex[b]]).norm())
                        .fold(Scalar::INFINITY, Scalar::min);
                hex.iter().all(|&node| clearance[node] >= margin)
            }
        })
    }
}