Document and refactor dodeca.rs

Ralith · Feb 16, 2025 · c217285 · c217285
1 parent 4f79f6b
commit c217285
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Showing 5 changed files with 277 additions and 271 deletions.
diff --git a/common/src/cursor.rs b/common/src/cursor.rs
@@ -1,6 +1,5 @@
-use std::sync::OnceLock;
+use std::sync::LazyLock;
 
-use crate::dodeca::SIDE_COUNT;
 use crate::dodeca::{Side, Vertex};
 use crate::graph::{Graph, NodeId};
 use crate::node::ChunkId;
@@ -29,9 +28,9 @@ impl Cursor {
         // in both the dodecahedron sharing the face unique to the new vertex and that sharing the
         // face that the new vertex isn't incident to.
         let (a, b, c) = (self.a, self.b, self.c);
-        let a_prime = neighbors()[a as usize][b as usize][c as usize].unwrap();
-        let b_prime = neighbors()[b as usize][a as usize][c as usize].unwrap();
-        let c_prime = neighbors()[c as usize][b as usize][a as usize].unwrap();
+        let a_prime = NEIGHBORS[a as usize][b as usize][c as usize].unwrap();
+        let b_prime = NEIGHBORS[b as usize][a as usize][c as usize].unwrap();
+        let c_prime = NEIGHBORS[c as usize][b as usize][a as usize].unwrap();
         use Dir::*;
         let (sides, neighbor) = match dir {
             Left => ((a, b, c_prime), c),
@@ -54,7 +53,7 @@ impl Cursor {
     pub fn canonicalize(self, graph: &Graph) -> Option<ChunkId> {
         graph.canonicalize(ChunkId::new(
             self.node,
-            Vertex::from_sides(self.a, self.b, self.c).unwrap(),
+            Vertex::from_sides([self.a, self.b, self.c]).unwrap(),
         ))
     }
 }
@@ -105,10 +104,9 @@ impl std::ops::Neg for Dir {
 }
 
 /// Maps every (A, B, C) sharing a vertex to A', the side that shares edges with B and C but not A
-fn neighbors() -> &'static [[[Option<Side>; SIDE_COUNT]; SIDE_COUNT]; SIDE_COUNT] {
-    static LOCK: OnceLock<[[[Option<Side>; SIDE_COUNT]; SIDE_COUNT]; SIDE_COUNT]> = OnceLock::new();
-    LOCK.get_or_init(|| {
-        let mut result = [[[None; SIDE_COUNT]; SIDE_COUNT]; SIDE_COUNT];
+static NEIGHBORS: LazyLock<[[[Option<Side>; Side::COUNT]; Side::COUNT]; Side::COUNT]> =
+    LazyLock::new(|| {
+        let mut result = [[[None; Side::COUNT]; Side::COUNT]; Side::COUNT];
         for a in Side::iter() {
             for b in Side::iter() {
                 for c in Side::iter() {
@@ -129,8 +127,7 @@ fn neighbors() -> &'static [[[Option<Side>; SIDE_COUNT]; SIDE_COUNT]; SIDE_COUNT
             }
         }
         result
-    })
-}
+    });
 
 #[cfg(test)]
 mod tests {
@@ -142,8 +139,8 @@ mod tests {
         for v in Vertex::iter() {
             let [a, b, c] = v.canonical_sides();
             assert_eq!(
-                neighbors()[a as usize][b as usize][c as usize],
-                neighbors()[a as usize][c as usize][b as usize]
+                NEIGHBORS[a as usize][b as usize][c as usize],
+                NEIGHBORS[a as usize][c as usize][b as usize]
             );
         }
     }