From ded236151a4719892b8f6905db4dd2a8176e5c79 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Wed, 19 Oct 2022 14:55:38 +0200
Subject: [PATCH] Fix `GlobalVertex` duplication in sweep algorithm

---
 crates/fj-kernel/src/algorithms/sweep/mod.rs    | 12 ++++++++++--
 crates/fj-kernel/src/algorithms/sweep/vertex.rs | 14 +++++++++++---
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/sweep/mod.rs b/crates/fj-kernel/src/algorithms/sweep/mod.rs
index e0063c36f..d7ba6fc1a 100644
--- a/crates/fj-kernel/src/algorithms/sweep/mod.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/mod.rs
@@ -6,9 +6,14 @@ mod face;
 mod sketch;
 mod vertex;
 
+use std::collections::BTreeMap;
+
 use fj_math::Vector;
 
-use crate::objects::Objects;
+use crate::{
+    objects::{GlobalVertex, Objects},
+    storage::{Handle, ObjectId},
+};
 
 /// Sweep an object along a path to create another object
 pub trait Sweep: Sized {
@@ -38,4 +43,7 @@ pub trait Sweep: Sized {
 ///
 /// See [`Sweep`].
 #[derive(Default)]
-pub struct SweepCache;
+pub struct SweepCache {
+    /// Cache for global vertices
+    pub global_vertex: BTreeMap<ObjectId, Handle<GlobalVertex>>,
+}
diff --git a/crates/fj-kernel/src/algorithms/sweep/vertex.rs b/crates/fj-kernel/src/algorithms/sweep/vertex.rs
index 0dda7d114..24c35f3ca 100644
--- a/crates/fj-kernel/src/algorithms/sweep/vertex.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/vertex.rs
@@ -126,14 +126,22 @@ impl Sweep for Handle<GlobalVertex> {
     fn sweep_with_cache(
         self,
         path: impl Into<Vector<3>>,
-        _: &mut SweepCache,
+        cache: &mut SweepCache,
         objects: &Objects,
     ) -> Self::Swept {
         let curve = GlobalCurve::new(objects);
 
         let a = self.clone();
-        let b =
-            GlobalVertex::from_position(self.position() + path.into(), objects);
+        let b = cache
+            .global_vertex
+            .entry(self.id())
+            .or_insert_with(|| {
+                GlobalVertex::from_position(
+                    self.position() + path.into(),
+                    objects,
+                )
+            })
+            .clone();
 
         let vertices = [a, b];
         let global_edge = GlobalEdge::new(curve, vertices.clone());