From 8476d83e57d83f5db55f9113e09ceb5716b8b378 Mon Sep 17 00:00:00 2001
From: Christoph Bornkessel <christoph.bornkessel@wrs-leipzig.de>
Date: Thu, 1 Sep 2022 19:33:18 +0200
Subject: [PATCH 1/4] create function to get the zoom level where a point gets
 unclustered

---
 README.md |  4 ++++
 index.js  | 21 +++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/README.md b/README.md
index df5dbb65..ab16c78e 100644
--- a/README.md
+++ b/README.md
@@ -65,6 +65,10 @@ and `offset` is the amount of points to skip (for pagination).
 
 Returns the zoom on which the cluster expands into several children (useful for "click to zoom" feature) given the cluster's `cluster_id`.
 
+#### `getPointUnclusterZoom(point)`
+
+Returns the zoom on which a point appears unclustered. The point must be provided as array with `[Lng, Lat]`.
+
 ## Options
 
 | Option     | Default | Description                                                       |
diff --git a/index.js b/index.js
index dc2601ba..24f75997 100644
--- a/index.js
+++ b/index.js
@@ -167,6 +167,27 @@ export default class Supercluster {
         return expansionZoom;
     }
 
+    getPointUnclusterZoom(point) {
+        const [lng, lat] = point;
+        const pointX = fround(lngX(lng));
+        const pointY = fround(latY(lat));
+
+        let expansionZoom = 0;
+        while (expansionZoom <= this.options.maxZoom) {
+            const tree = this.trees[expansionZoom];
+
+            const unclustered = tree.points.some(
+                treePoint => !treePoint.id && treePoint.x === pointX && treePoint.y === pointY
+            );
+
+            if (unclustered) return expansionZoom;
+
+            expansionZoom++;
+        }
+
+        return expansionZoom;
+    }
+
     _appendLeaves(result, clusterId, limit, offset, skipped) {
         const children = this.getChildren(clusterId);
 

From b825ae1c4caad2a302e34e9a29b8ea1b77406cd7 Mon Sep 17 00:00:00 2001
From: Christoph Bornkessel <christoph.bornkessel@wrs-leipzig.de>
Date: Mon, 5 Sep 2022 16:55:17 +0200
Subject: [PATCH 2/4] improved logic of getPointUnclusterZoom function

---
 index.js | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/index.js b/index.js
index 24f75997..6e762730 100644
--- a/index.js
+++ b/index.js
@@ -172,14 +172,15 @@ export default class Supercluster {
         const pointX = fround(lngX(lng));
         const pointY = fround(latY(lat));
 
-        let expansionZoom = 0;
+        let expansionZoom = this.options.minZoom;
         while (expansionZoom <= this.options.maxZoom) {
             const tree = this.trees[expansionZoom];
 
-            const unclustered = tree.points.some(
-                treePoint => !treePoint.id && treePoint.x === pointX && treePoint.y === pointY
-            );
+            const pointIdxs = tree.within(pointX, pointY, 0);
 
+            const unclustered = pointIdxs.some(
+                idx => tree.points[idx].parentId !== -1
+            );
             if (unclustered) return expansionZoom;
 
             expansionZoom++;

From 033a66ca49033496a9e25f55446f12a58e9cdec3 Mon Sep 17 00:00:00 2001
From: Christoph Bornkessel <christoph.bornkessel@wrs-leipzig.de>
Date: Fri, 16 Sep 2022 10:50:05 +0200
Subject: [PATCH 3/4] minor bug fix to prevent exceeding the max zoom level

---
 index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.js b/index.js
index 6e762730..a151c9d2 100644
--- a/index.js
+++ b/index.js
@@ -173,7 +173,7 @@ export default class Supercluster {
         const pointY = fround(latY(lat));
 
         let expansionZoom = this.options.minZoom;
-        while (expansionZoom <= this.options.maxZoom) {
+        while (expansionZoom < this.options.maxZoom) {
             const tree = this.trees[expansionZoom];
 
             const pointIdxs = tree.within(pointX, pointY, 0);

From 94ed77d44537c38bac69ae01106235c00069ec21 Mon Sep 17 00:00:00 2001
From: Christoph Bornkessel <christoph.bornkessel@propdeck.de>
Date: Wed, 26 Apr 2023 22:22:58 +0200
Subject: [PATCH 4/4] updates getPointUnclusterZoom function to latest
 supercluster version

adds unit test for point uncluster function
---
 index.js     |  2 +-
 test/test.js | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/index.js b/index.js
index c06614af..b86c58a9 100644
--- a/index.js
+++ b/index.js
@@ -203,7 +203,7 @@ export default class Supercluster {
             const pointIdxs = tree.within(pointX, pointY, 0);
 
             const unclustered = pointIdxs.some(
-                idx => tree.points[idx].parentId !== -1
+                idx => tree.data[idx].parentId !== -1
             );
             if (unclustered) return expansionZoom;
 
diff --git a/test/test.js b/test/test.js
index 74671ff0..59525495 100644
--- a/test/test.js
+++ b/test/test.js
@@ -172,3 +172,17 @@ test('makes sure unclustered point coords are not rounded', () => {
 
     assert.deepEqual(index.getTile(20, 1028744, 656754).features[0].geometry[0], [421, 281]);
 });
+
+test('returns point uncluster zoom level', () => {
+    const points = [
+        {type: 'Feature', geometry: {type: 'Point', coordinates: [173, 53]}},
+        {type: 'Feature', geometry: {type: 'Point', coordinates: [174, 54]}}
+    ];
+    const index = new Supercluster({maxZoom: 19}).load(points);
+    const cluster = index.getClusters([172, 52, 175, 55], 1)[0];
+
+    const clusterExpansionZoom = index.getClusterExpansionZoom(cluster.id);
+    const pointUnclusterZoom = index.getPointUnclusterZoom(points[0].geometry.coordinates);
+
+    assert.deepEqual(clusterExpansionZoom, pointUnclusterZoom);
+});