From 1a6ca8f751c4c6bc1f5de4edb77eb2a405f656e0 Mon Sep 17 00:00:00 2001
From: A-Walrus <ofek.r.guy@gmail.com>
Date: Mon, 20 Mar 2023 16:24:10 +0200
Subject: [PATCH] Fix Sweep edge duplication

Fixed cycle builder like you commented, global_edge order, and added
an edge cache.
PS: We might want to make the `SweepCache` more general
---
 crates/fj-kernel/src/algorithms/sweep/edge.rs   | 2 +-
 crates/fj-kernel/src/algorithms/sweep/mod.rs    | 4 +++-
 crates/fj-kernel/src/algorithms/sweep/vertex.rs | 6 +++++-
 crates/fj-kernel/src/builder/cycle.rs           | 3 ++-
 4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/crates/fj-kernel/src/algorithms/sweep/edge.rs b/crates/fj-kernel/src/algorithms/sweep/edge.rs
index dfe033f8dc..e52bd5db5f 100644
--- a/crates/fj-kernel/src/algorithms/sweep/edge.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/edge.rs
@@ -37,8 +37,8 @@ impl Sweep for (&HalfEdge, &Handle<Vertex>, &Surface, Option<Color>) {
                 [
                     Some(edge.global_form().clone()),
                     Some(edge_up),
-                    Some(edge_down),
                     None,
+                    Some(edge_down),
                 ],
             )
         };
diff --git a/crates/fj-kernel/src/algorithms/sweep/mod.rs b/crates/fj-kernel/src/algorithms/sweep/mod.rs
index e2e98704ab..6cdc144308 100644
--- a/crates/fj-kernel/src/algorithms/sweep/mod.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/mod.rs
@@ -11,7 +11,7 @@ use std::collections::BTreeMap;
 use fj_math::Vector;
 
 use crate::{
-    objects::{Objects, Vertex},
+    objects::{GlobalEdge, Objects, Vertex},
     services::Service,
     storage::{Handle, ObjectId},
 };
@@ -47,4 +47,6 @@ pub trait Sweep: Sized {
 pub struct SweepCache {
     /// Cache for global vertices
     pub global_vertex: BTreeMap<ObjectId, Handle<Vertex>>,
+    /// Cache for global edges
+    pub global_edge: BTreeMap<ObjectId, Handle<GlobalEdge>>,
 }
diff --git a/crates/fj-kernel/src/algorithms/sweep/vertex.rs b/crates/fj-kernel/src/algorithms/sweep/vertex.rs
index 868f8e9ef7..d2f86193c2 100644
--- a/crates/fj-kernel/src/algorithms/sweep/vertex.rs
+++ b/crates/fj-kernel/src/algorithms/sweep/vertex.rs
@@ -26,7 +26,11 @@ impl Sweep for Handle<Vertex> {
             .clone();
 
         let vertices = [a, b];
-        let global_edge = GlobalEdge::new().insert(objects);
+        let global_edge = cache
+            .global_edge
+            .entry(self.id())
+            .or_insert_with(|| GlobalEdge::new().insert(objects))
+            .clone();
 
         // The vertices of the returned `GlobalEdge` are in normalized order,
         // which means the order can't be relied upon by the caller. Return the
diff --git a/crates/fj-kernel/src/builder/cycle.rs b/crates/fj-kernel/src/builder/cycle.rs
index 2f5a8cbb17..92fc63cd89 100644
--- a/crates/fj-kernel/src/builder/cycle.rs
+++ b/crates/fj-kernel/src/builder/cycle.rs
@@ -44,9 +44,10 @@ impl CycleBuilder {
         let half_edges = edges
             .into_iter()
             .circular_tuple_windows()
-            .map(|((prev, _, _), (_, curve, boundary))| {
+            .map(|((prev, _, _), (half_edge, curve, boundary))| {
                 HalfEdgeBuilder::new(curve, boundary)
                     .with_start_vertex(prev.start_vertex().clone())
+                    .with_global_form(half_edge.global_form().clone())
             })
             .collect();