perf again

src/merger.rs

@@ -1,5 +1,4 @@
 use geo::IsConvex;
-use hashbrown::HashMap;
 #[cfg(feature = "tracing")]
 use tracing::instrument;
 
@@ -53,7 +52,7 @@ impl Mesh {
                     continue;
                 }
 
-                let other_vertices = self.polygons[other_side as usize].vertices.clone();
+                let other_vertices = &self.polygons[other_side as usize].vertices;
                 let mut joined_vertices_index =
                     Vec::with_capacity(poly.vertices.len() + other_vertices.len() - 2);
                 let mut joined_vertices =
@@ -100,34 +99,36 @@ impl Mesh {
             }
         }
 
-        let mut new_indexes: HashMap<i32, i32> = HashMap::new();
+        let mut new_indexes = vec![-1; self.polygons.len()];
         let mut kept = 0;
         for i in 0..union_polygons.parent.len() {
             union_polygons.find(i as i32);
         }
         for (i, p) in union_polygons.parent.iter().enumerate() {
-            if !new_indexes.contains_key(p) {
-                new_indexes.insert(*p, kept);
+            if new_indexes[*p as usize] == -1 {
+                new_indexes[*p as usize] = kept;
                 kept += 1;
             }
 
             if i as i32 == *p {
-                let j = *new_indexes.get(p).unwrap() as usize;
+                let j = new_indexes[*p as usize] as usize;
                 if i != j {
                     self.polygons.swap(i, j);
                 }
             } else {
-                new_indexes.insert(i as i32, *new_indexes.get(p).unwrap());
+                new_indexes[i] = new_indexes[*p as usize];
             }
         }
         self.polygons.resize_with(kept as usize, || unreachable!());
 
         for vertex in self.vertices.iter_mut() {
             for p in vertex.polygons.iter_mut() {
-                *p = *new_indexes.get(&(*p as i32)).unwrap_or(&-1) as isize;
+                if *p != -1 {
+                    *p = new_indexes[*p as usize];
+                }
             }
         }
-        new_indexes.len() as i32 != kept
+        new_indexes.len() != kept as usize
     }
 }