From c3323d6d4e14a39d382f4012f7b95dc5d14a2541 Mon Sep 17 00:00:00 2001
From: Ernest Micklei <ernest.micklei@gmail.com>
Date: Fri, 11 Oct 2024 09:14:29 +0200
Subject: [PATCH 1/3] add ReindexShape

---
 space.go | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/space.go b/space.go
index afcee9f..878c72f 100644
--- a/space.go
+++ b/space.go
@@ -1129,3 +1129,15 @@ func (space *Space) ShapeQuery(shape *Shape, callback func(shape *Shape, points
 
 	return anyCollision
 }
+
+// ReindexShape re-computes the hash of the shape in both the dynamic and static list.
+func (space *Space) ReindexShape(shape *Shape) {
+
+	assert(space.locked > 0, "You cannot manually reindex objects while the space is locked. Wait until the current query or step is complete.")
+
+	shape.CacheBB()
+
+	// attempt to rehash the shape in both hashes
+	space.dynamicShapes.class.ReindexObject(shape, shape.hashid)
+	space.staticShapes.class.ReindexObject(shape, shape.hashid)
+}

From 480fa9ae499ecb44d0486713003f0e1d55c5b200 Mon Sep 17 00:00:00 2001
From: Ernest Micklei <ernest.micklei@gmail.com>
Date: Fri, 11 Oct 2024 13:18:44 +0200
Subject: [PATCH 2/3] add test, add BBTree>ReindexObject

---
 bbtree.go     | 8 +++++++-
 space.go      | 2 +-
 space_test.go | 8 ++++++++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/bbtree.go b/bbtree.go
index 26fd6e6..e2c20e6 100644
--- a/bbtree.go
+++ b/bbtree.go
@@ -320,7 +320,13 @@ func (tree *BBTree) Reindex() {
 }
 
 func (tree *BBTree) ReindexObject(obj *Shape, hashId HashValue) {
-	panic("implement me")
+	leaf := tree.leaves.Find(hashId, obj)
+	if leaf != nil {
+		if tree.LeafUpdate(leaf) {
+			tree.LeafAddPairs(leaf)
+		}
+		tree.IncrementStamp()
+	}
 }
 
 func (tree *BBTree) ReindexQuery(f SpatialIndexQuery, data interface{}) {
diff --git a/space.go b/space.go
index 878c72f..a3a1bfe 100644
--- a/space.go
+++ b/space.go
@@ -1133,7 +1133,7 @@ func (space *Space) ShapeQuery(shape *Shape, callback func(shape *Shape, points
 // ReindexShape re-computes the hash of the shape in both the dynamic and static list.
 func (space *Space) ReindexShape(shape *Shape) {
 
-	assert(space.locked > 0, "You cannot manually reindex objects while the space is locked. Wait until the current query or step is complete.")
+	assert(space.locked == 0, "You cannot manually reindex objects while the space is locked. Wait until the current query or step is complete.")
 
 	shape.CacheBB()
 
diff --git a/space_test.go b/space_test.go
index a8dec9e..d0ec7c4 100644
--- a/space_test.go
+++ b/space_test.go
@@ -23,3 +23,11 @@ func TestSpace_ShapeQuery(t *testing.T) {
 		t.Error("Box should be just out of range")
 	})
 }
+
+func TestSpace_ReindexShape(t *testing.T) {
+	space := NewSpace()
+	circle := space.AddShape(NewCircle(space.StaticBody, 1, Vector{}))
+	space.ReindexShape(circle)
+	circle.body.SetPosition(Vector{X: 12.0, Y: 34.0})
+	space.ReindexShape(circle)
+}

From 2e1201b8768b978dcadbc04850d9c7e4e5b2e919 Mon Sep 17 00:00:00 2001
From: Ernest Micklei <ernest.micklei@gmail.com>
Date: Fri, 11 Oct 2024 13:27:01 +0200
Subject: [PATCH 3/3] add bb test

---
 space_test.go | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/space_test.go b/space_test.go
index d0ec7c4..7c668e8 100644
--- a/space_test.go
+++ b/space_test.go
@@ -27,7 +27,18 @@ func TestSpace_ShapeQuery(t *testing.T) {
 func TestSpace_ReindexShape(t *testing.T) {
 	space := NewSpace()
 	circle := space.AddShape(NewCircle(space.StaticBody, 1, Vector{}))
+	bb1 := circle.bb
 	space.ReindexShape(circle)
+	bb2 := circle.bb
+	// check unchanged
+	if got, want := bb1.String(), bb2.String(); got != want {
+		t.Errorf("got [%[1]v:%[1]T] want [%[2]v:%[2]T]", got, want)
+	}
 	circle.body.SetPosition(Vector{X: 12.0, Y: 34.0})
 	space.ReindexShape(circle)
+	bb3 := circle.bb
+	// check changed
+	if got, want := bb2.String(), bb3.String(); got == want {
+		t.Errorf("got [%[1]v:%[1]T] want [%[2]v:%[2]T]", got, want)
+	}
 }