honeycomb_kernels/grisubal/routines/
insert_new_edges.rs

1//! Step 5 implementation
2//
3//! Use the information computed at step 4 and insert all new edges into the map.
4
5use honeycomb_core::cmap::{CMap2, DartIdType};
6use honeycomb_core::geometry::CoordsFloat;
7use honeycomb_core::stm::atomically_with_err;
8
9use crate::cell_insertion::insert_vertices_on_edge;
10use crate::grisubal::model::{Boundary, MapEdge};
11
12pub(crate) fn insert_edges_in_map<T: CoordsFloat>(cmap: &mut CMap2<T>, edges: &[MapEdge<T>]) {
13    // FIXME: minimize allocs & redundant operations
14    // prealloc all darts needed
15    let n_darts_per_seg: Vec<_> = edges
16        .iter()
17        .map(|e| 2 + 2 * e.intermediates.len())
18        .collect();
19    let n_tot: usize = n_darts_per_seg.iter().sum();
20    let tmp = cmap.add_free_darts(n_tot) as usize;
21    // the prefix sum gives an offset that corresponds to the starting index of each slice, minus
22    // the location of the allocated dart block (given by `tmp`)
23    // end of the slice is deduced using these values and the number of darts the current seg needs
24    let prefix_sum: Vec<usize> = n_darts_per_seg
25        .iter()
26        .scan(0, |state, &n_d| {
27            *state += n_d;
28            Some(*state - n_d) // we want an offset, not the actual sum
29        })
30        .collect();
31    #[allow(clippy::cast_possible_truncation)]
32    let dart_slices: Vec<Vec<DartIdType>> = n_darts_per_seg
33        .iter()
34        .zip(prefix_sum.iter())
35        .map(|(n_d, start)| {
36            ((tmp + start) as DartIdType..(tmp + start + n_d) as DartIdType).collect::<Vec<_>>()
37        })
38        .collect();
39
40    // insert new edges
41    for (
42        MapEdge {
43            start,
44            intermediates,
45            end,
46        },
47        dslice,
48    ) in edges.iter().zip(dart_slices.iter())
49    {
50        // remove deprecated connectivities & save what data is necessary
51        let b1_start_old = cmap.beta::<1>(*start);
52        let b0_end_old = cmap.beta::<0>(*end);
53        cmap.force_unlink::<1>(*start).unwrap();
54        cmap.force_unlink::<1>(b0_end_old).unwrap();
55
56        let &[d_new, b2_d_new] = &dslice[0..2] else {
57            unreachable!()
58        };
59        cmap.force_link::<2>(d_new, b2_d_new).unwrap();
60
61        // rebuild - this is the final construct if there are no intermediates
62        cmap.force_link::<1>(*start, d_new).unwrap();
63        cmap.force_link::<1>(b2_d_new, b1_start_old).unwrap();
64        cmap.force_link::<1>(d_new, *end).unwrap();
65        cmap.force_link::<1>(b0_end_old, b2_d_new).unwrap();
66
67        if !intermediates.is_empty() {
68            // create the topology components
69            let edge_id = cmap.edge_id(d_new);
70            let new_darts = &dslice[2..];
71            atomically_with_err(|trans| {
72                insert_vertices_on_edge(
73                    cmap,
74                    trans,
75                    edge_id,
76                    new_darts,
77                    &vec![T::from(0.5).unwrap(); intermediates.len()],
78                )
79            })
80            .unwrap();
81            // replace placeholder vertices
82            let mut dart_id = cmap.beta::<1>(edge_id as DartIdType);
83            for v in intermediates {
84                let vid = cmap.vertex_id(dart_id);
85                let _ = cmap.force_write_vertex(vid, *v);
86                dart_id = cmap.beta::<1>(dart_id);
87            }
88        }
89
90        let mut d_boundary = cmap.beta::<1>(*start);
91        while d_boundary != *end {
92            cmap.force_write_attribute::<Boundary>(d_boundary, Boundary::Left);
93            cmap.force_write_attribute::<Boundary>(cmap.beta::<2>(d_boundary), Boundary::Right);
94            d_boundary = cmap.beta::<1>(d_boundary);
95        }
96    }
97}
honeycomb_kernels/grisubal/routines/insert_new_edges.rs

honeycomb_kernels/grisubal/routines/
insert_new_edges.rs
