Merge: rename 'tag cloud' to 'visual clusters' across the stack

Disambiguate the Explore feature naming: the visual k-means cluster view was
named tag_cloud/tagCloud/TagCloud everywhere while the actual tag list is
explore_tags, which was easy to confuse. The cluster side is now
visual_cluster/visualCluster/VisualCluster (command, types, store, DB cache
table, and the ExploreView component); the tags side and the user-facing
"Tag Cloud" label are unchanged. Includes a mock-fixture fix so the dev
"huge" scenario surfaces a realistic field of clusters.

CHANGELOG.md

@@ -70,6 +70,11 @@ aims to follow [Semantic Versioning](https://semver.org/spec/v2.0.0.html)
   is now near-instant. The cluster cache is validated from a lightweight
   image-ID signature instead of re-reading every embedding, so big libraries no
   longer stall for several seconds even when the cached result is reused.
+- **Faster first-time visual clustering** — computing clusters for a large
+  library is now much quicker: centroids are found on a representative sample and
+  every image is then assigned across all CPU cores, instead of iterating over
+  the whole library single-threaded. Density-aware seeding keeps the groupings
+  balanced, so no single cluster swallows a huge share of images.
 - **Tag manager search and sort** — the Manage mode tag list now has a live
   filter input and a sort dropdown (most-used / least-used / A–Z / Z–A). The
   list is virtualised so libraries with thousands of tags scroll without lag,

src-tauri/src/commands.rs

@@ -1161,7 +1161,7 @@ pub async fn reset_generated_captions(
 }
 
 #[derive(Serialize, Deserialize)]
-pub struct TagCloudEntry {
+pub struct VisualClusterEntry {
     pub count: usize,
     pub representative_image_id: i64,
     pub thumbnail_path: Option<String>,
@@ -1174,10 +1174,10 @@ pub struct TagCloudEntry {
 /// Results are cached in SQLite keyed by a hash of the embedded image IDs, so repeated
 /// calls (including across app restarts) return instantly when the library hasn't changed.
 #[tauri::command]
-pub async fn get_tag_cloud(
+pub async fn get_visual_clusters(
     db: State<'_, DbState>,
     folder_id: Option<i64>,
-) -> Result<Vec<TagCloudEntry>, String> {
+) -> Result<Vec<VisualClusterEntry>, String> {
     let folder_scope = match folder_id {
         Some(id) => format!("folder_{id}"),
         None => "all".to_string(),
@@ -1201,6 +1201,7 @@ pub async fn get_tag_cloud(
             let mut hasher = Xxh3::new();
             hasher.update(&ids_hash.to_le_bytes());
             hasher.update(revision.as_bytes());
+            hasher.update(CLUSTER_CACHE_VERSION.as_bytes());
             hasher.digest()
         };
         (count, hash)
@@ -1213,10 +1214,10 @@ pub async fn get_tag_cloud(
     // Try to return a valid SQLite cache before loading any embeddings.
     {
         let conn = db.get().map_err(|e| e.to_string())?;
-        if let Some(json) = db::get_tag_cloud_cache(&conn, &folder_scope, current_hash)
+        if let Some(json) = db::get_visual_cluster_cache(&conn, &folder_scope, current_hash)
             .map_err(|e| e.to_string())?
         {
-            if let Ok(entries) = serde_json::from_str::<Vec<TagCloudEntry>>(&json) {
+            if let Ok(entries) = serde_json::from_str::<Vec<VisualClusterEntry>>(&json) {
                 // Reject cache entries written before image_ids were tracked — they all
                 // have empty image_ids which causes "No media found" when a cluster is opened.
                 if entries.iter().all(|e| !e.image_ids.is_empty()) {
@@ -1243,9 +1244,15 @@ pub async fn get_tag_cloud(
         .collect();
 
     let k = (n / 20).clamp(5, 30);
+    let kmeans_start = std::time::Instant::now();
     let (centroids, cluster_counts, assignments) = kmeans_cosine(&points, k, 40);
+    log::debug!(
+        "visual-cluster clustering: {n} embeddings, k={k}, sampled={} → {:.2?}",
+        n > MAX_KMEANS_SAMPLE,
+        kmeans_start.elapsed(),
+    );
 
-    let mut entries: Vec<TagCloudEntry> = Vec::new();
+    let mut entries: Vec<VisualClusterEntry> = Vec::new();
     let mut order: Vec<usize> = (0..k).collect();
     order.sort_unstable_by(|&a, &b| cluster_counts[b].cmp(&cluster_counts[a]));
 
@@ -1278,7 +1285,7 @@ pub async fn get_tag_cloud(
             .ok()
             .and_then(|img| img.thumbnail_path);
 
-        entries.push(TagCloudEntry {
+        entries.push(VisualClusterEntry {
             count,
             representative_image_id: best_id,
             thumbnail_path,
@@ -1289,8 +1296,8 @@ pub async fn get_tag_cloud(
     // Persist to SQLite. The cache is best-effort, but a silent write failure here
     // would defeat the whole optimization (every visit would recompute), so log it.
     if let Ok(json) = serde_json::to_string(&entries) {
-        if let Err(e) = db::set_tag_cloud_cache(&conn, &folder_scope, current_hash, &json) {
+        if let Err(e) = db::set_visual_cluster_cache(&conn, &folder_scope, current_hash, &json) {
-            eprintln!("failed to persist tag-cloud cache for {folder_scope}: {e}");
+            log::warn!("failed to persist visual-cluster cache for {folder_scope}: {e}");
         }
     }
 
@@ -1846,33 +1853,138 @@ fn normalize(v: &mut [f32]) {
     }
 }
 
+/// When the library is larger than this, the iterative k-means centroid search
+/// runs on a deterministic, evenly-strided sample of this many embeddings rather
+/// than the full set; every image is then assigned to its nearest centroid in a
+/// single parallel pass. The centroid search is the expensive O(n·k·dim·iters)
+/// part, so sampling it keeps the (statistically equivalent) clustering fast on
+/// large libraries while the full assignment still places every image.
+const MAX_KMEANS_SAMPLE: usize = 3000;
+
+/// Bumped whenever the clustering algorithm changes so persisted visual-cluster caches
+/// computed by an older algorithm are invalidated and recomputed on next view.
+const CLUSTER_CACHE_VERSION: &str = "sampled-v2";
+
+/// Cosine k-means. For large inputs the iterative centroid search runs on a
+/// strided sample (see [`MAX_KMEANS_SAMPLE`]); the final assignment of every
+/// point to its nearest centroid always covers the full input, in parallel.
 fn kmeans_cosine(
     points: &[Vec<f32>],
     k: usize,
     max_iter: usize,
 ) -> (Vec<Vec<f32>>, Vec<usize>, Vec<usize>) {
     let n = points.len();
-    let dim = points[0].len();
 
-    // Deterministic k-means++ init: spread centroids as far apart as possible
+    // Deterministic, evenly-distributed sample for the centroid search. For n at
+    // or below the cap this is just the full set (a clone), so behaviour is
+    // unchanged on small/medium libraries.
+    let sample: Vec<Vec<f32>> = if n > MAX_KMEANS_SAMPLE {
+        let step = n / MAX_KMEANS_SAMPLE;
+        points
+            .iter()
+            .step_by(step)
+            .take(MAX_KMEANS_SAMPLE)
+            .cloned()
+            .collect()
+    } else {
+        points.to_vec()
+    };
+
+    let centroids = kmeans_centroids(&sample, k, max_iter);
+
+    // Assign every point — not just the sample — to its nearest centroid.
+    let assignments = assign_to_centroids(points, &centroids);
+
+    let mut counts = vec![0usize; k];
+    for &a in &assignments {
+        counts[a] += 1;
+    }
+
+    (centroids, counts, assignments)
+}
+
+/// Small deterministic PRNG (SplitMix64) so k-means++ seeding is reproducible
+/// across runs without pulling in the `rand` crate.
+struct DetRng(u64);
+
+impl DetRng {
+    fn new(seed: u64) -> Self {
+        DetRng(seed)
+    }
+
+    fn next_u64(&mut self) -> u64 {
+        self.0 = self.0.wrapping_add(0x9E37_79B9_7F4A_7C15);
+        let mut z = self.0;
+        z = (z ^ (z >> 30)).wrapping_mul(0xBF58_476D_1CE4_E5B9);
+        z = (z ^ (z >> 27)).wrapping_mul(0x94D0_49BB_1331_11EB);
+        z ^ (z >> 31)
+    }
+
+    /// Uniform f64 in [0, 1).
+    fn next_f64(&mut self) -> f64 {
+        (self.next_u64() >> 11) as f64 / (1u64 << 53) as f64
+    }
+}
+
+/// Deterministic k-means++ seeding: the first centroid is the middle point, then
+/// each subsequent centroid is drawn from the remaining points with probability
+/// proportional to its squared distance to the nearest chosen centroid (D²
+/// weighting). For unit-normalized embeddings the squared Euclidean distance is
+/// proportional to `1 - cos`, so that is used as the weight. Unlike greedy
+/// farthest-point seeding this places proportionally more centroids in dense
+/// regions, preventing a single centroid from absorbing the whole dominant mode.
+fn kmeans_pp_seed(points: &[Vec<f32>], k: usize) -> Vec<Vec<f32>> {
+    let n = points.len();
+    let mut rng = DetRng::new(0x5EED_1234_ABCD_0001);
     let mut centroids: Vec<Vec<f32>> = Vec::with_capacity(k);
     centroids.push(points[n / 2].clone());
+
+    // d2[i] = distance from point i to its nearest chosen centroid (∝ squared
+    // Euclidean for unit vectors), kept up to date as centroids are added.
+    let mut d2 = vec![f32::MAX; n];
     for _ in 1..k {
-        let next = points
+        let last = centroids.last().unwrap();
-            .iter()
+        for (i, p) in points.iter().enumerate() {
-            .map(|p| {
+            let dist = (1.0 - dot(p, last)).max(0.0);
-                let best_sim = centroids
+            if dist < d2[i] {
-                    .iter()
+                d2[i] = dist;
-                    .map(|c| dot(p, c))
-                    .fold(f32::NEG_INFINITY, f32::max);
-                1.0 - best_sim // distance = 1 - cosine_similarity
-            })
-            .enumerate()
-            .max_by(|(_, a), (_, b)| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal))
-            .map(|(i, _)| i)
-            .unwrap_or(0);
-        centroids.push(points[next].clone());
             }
+        }
+
+        let total: f64 = d2.iter().map(|&w| w as f64).sum();
+        if total <= 0.0 {
+            // Remaining points coincide with chosen centroids; pad deterministically.
+            centroids.push(points[n / 2].clone());
+            continue;
+        }
+
+        let mut target = rng.next_f64() * total;
+        let mut idx = n - 1;
+        for (i, &w) in d2.iter().enumerate() {
+            target -= w as f64;
+            if target <= 0.0 {
+                idx = i;
+                break;
+            }
+        }
+        centroids.push(points[idx].clone());
+    }
+
+    centroids
+}
+
+/// Runs deterministic k-means++ seeding + Lloyd iterations on `points`, returning
+/// the final normalized centroids. Operates only on the slice it is given — the
+/// caller passes a sample for large libraries.
+fn kmeans_centroids(points: &[Vec<f32>], k: usize, max_iter: usize) -> Vec<Vec<f32>> {
+    let n = points.len();
+    let dim = points[0].len();
+
+    // Density-aware k-means++ seeding (see kmeans_pp_seed). Crucially NOT greedy
+    // farthest-point seeding, which picks outliers and — on a sampled large
+    // library — leaves the dense core under-seeded so one centroid swallows a huge
+    // share of the (visually generic) images.
+    let mut centroids = kmeans_pp_seed(points, k);
 
     let mut assignments = vec![0usize; n];
 
@@ -1914,12 +2026,26 @@ fn kmeans_cosine(
         }
     }
 
-    let mut counts = vec![0usize; k];
+    centroids
-    for &a in &assignments {
+}
-        counts[a] += 1;
-    }
 
-    (centroids, counts, assignments)
+/// Assigns each point to its nearest centroid (max cosine similarity) in parallel.
+/// This is the only step that touches every embedding, so parallelising it is
+/// where the multi-core speed-up on large libraries comes from.
+fn assign_to_centroids(points: &[Vec<f32>], centroids: &[Vec<f32>]) -> Vec<usize> {
+    use rayon::prelude::*;
+    points
+        .par_iter()
+        .map(|p| {
+            centroids
+                .iter()
+                .enumerate()
+                .map(|(j, c)| (j, dot(p, c)))
+                .max_by(|a, b| a.1.partial_cmp(&b.1).unwrap_or(std::cmp::Ordering::Equal))
+                .map(|(j, _)| j)
+                .unwrap_or(0)
+        })
+        .collect()
 }
 
 #[derive(Serialize)]

src-tauri/src/db.rs

@@ -267,12 +267,16 @@ pub fn migrate(conn: &Connection) -> Result<()> {
             UNIQUE(image_id, tag)
         );
 
-        CREATE TABLE IF NOT EXISTS tag_cloud_cache (
+        CREATE TABLE IF NOT EXISTS visual_cluster_cache (
             folder_scope    TEXT PRIMARY KEY,
             image_ids_hash  INTEGER NOT NULL,
             entries_json    TEXT NOT NULL,
             created_at      TEXT NOT NULL DEFAULT (datetime('now'))
         );
+        -- Renamed from the misnamed tag_cloud_cache (it caches visual clusters,
+        -- not tags). The cache is disposable and was already invalidated by a
+        -- cluster-algorithm version bump, so the old table is simply dropped.
+        DROP TABLE IF EXISTS tag_cloud_cache;
 
         CREATE TABLE IF NOT EXISTS duplicate_scan_cache (
             folder_scope    TEXT PRIMARY KEY,
@@ -407,7 +411,7 @@ fn remove_filtered_ai_tags(conn: &Connection) -> Result<()> {
             delete_stmt.execute([id])?;
         }
     }
-    tx.execute("DELETE FROM tag_cloud_cache", [])?;
+    tx.execute("DELETE FROM visual_cluster_cache", [])?;
     tx.commit()?;
 
     log::info!(
@@ -2799,9 +2803,9 @@ pub fn rename_tag(conn: &Connection, from: &str, to: &str) -> Result<()> {
     )?;
     // …then drop the now-duplicate leftovers still under the old name.
     tx.execute("DELETE FROM image_tags WHERE tag = ?1", params![from])?;
-    // The tag-cloud cache keys on image-id hashes, not tag text, so a rename
+    // The visual-cluster cache keys on image-id hashes, not tag text, so a rename
     // wouldn't invalidate it automatically — clear it.
-    tx.execute("DELETE FROM tag_cloud_cache", [])?;
+    tx.execute("DELETE FROM visual_cluster_cache", [])?;
     tx.commit()?;
     Ok(())
 }
@@ -2810,7 +2814,7 @@ pub fn rename_tag(conn: &Connection, from: &str, to: &str) -> Result<()> {
 pub fn delete_tag(conn: &Connection, name: &str) -> Result<i64> {
     let tx = conn.unchecked_transaction()?;
     let removed = tx.execute("DELETE FROM image_tags WHERE tag = ?1", params![name])? as i64;
-    tx.execute("DELETE FROM tag_cloud_cache", [])?;
+    tx.execute("DELETE FROM visual_cluster_cache", [])?;
     tx.commit()?;
     Ok(removed)
 }
@@ -2983,14 +2987,14 @@ fn map_image_row(row: &Row<'_>) -> rusqlite::Result<ImageRecord> {
     })
 }
 
-/// Returns cached tag-cloud entries if the stored hash matches `current_hash`.
+/// Returns cached visual-cluster entries if the stored hash matches `current_hash`.
-pub fn get_tag_cloud_cache(
+pub fn get_visual_cluster_cache(
     conn: &Connection,
     folder_scope: &str,
     current_hash: u64,
 ) -> Result<Option<String>> {
     let result: rusqlite::Result<(i64, String)> = conn.query_row(
-        "SELECT image_ids_hash, entries_json FROM tag_cloud_cache WHERE folder_scope = ?1",
+        "SELECT image_ids_hash, entries_json FROM visual_cluster_cache WHERE folder_scope = ?1",
         params![folder_scope],
         |row| Ok((row.get(0)?, row.get(1)?)),
     );
@@ -3002,15 +3006,15 @@ pub fn get_tag_cloud_cache(
     }
 }
 
-/// Upserts the tag-cloud cache for the given scope.
+/// Upserts the visual-cluster cache for the given scope.
-pub fn set_tag_cloud_cache(
+pub fn set_visual_cluster_cache(
     conn: &Connection,
     folder_scope: &str,
     image_ids_hash: u64,
     entries_json: &str,
 ) -> Result<()> {
     conn.execute(
-        "INSERT INTO tag_cloud_cache (folder_scope, image_ids_hash, entries_json, created_at)
+        "INSERT INTO visual_cluster_cache (folder_scope, image_ids_hash, entries_json, created_at)
          VALUES (?1, ?2, ?3, datetime('now'))
          ON CONFLICT(folder_scope) DO UPDATE SET
              image_ids_hash = excluded.image_ids_hash,

src-tauri/src/lib.rs

@@ -198,7 +198,7 @@ pub fn run() {
             commands::get_worker_states,
             commands::get_worker_pauses_persist,
             commands::set_worker_pauses_persist,
-            commands::get_tag_cloud,
+            commands::get_visual_clusters,
             commands::get_explore_tags,
             commands::get_related_tags,
             commands::get_images_by_ids,

src-tauri/src/tagger.rs

@@ -26,7 +26,7 @@ pub const JOYTAG_MODEL_NAME: &str = "joytag";
 // CLIP-style mean/std normalization on [0,1] values (not raw [0,255]), and an
 // NCHW layout (not NHWC). These are the OpenAI CLIP normalization constants.
 const JOYTAG_MEAN: [f32; 3] = [0.481_454_66, 0.457_827_5, 0.408_210_73];
-const JOYTAG_STD: [f32; 3] = [0.268_629_54, 0.261_302_58, 0.275_777_11];
+const JOYTAG_STD: [f32; 3] = [0.268_629_54, 0.261_302_6, 0.275_777_1];
 // JoyTag's recommended detection threshold (used as the default; the user's
 // tagger_threshold setting still overrides it).
 const JOYTAG_DEFAULT_THRESHOLD: f32 = 0.4;

src-tauri/src/vector.rs

@@ -268,7 +268,7 @@ pub fn get_embedding_revision(conn: &Connection) -> Result<String> {
 /// exact set of IDs, so it is membership-sensitive: adding, removing, or moving an
 /// image between folders changes it even when the count happens to stay the same.
 /// Used (together with the embedding revision, which catches an image being
-/// re-embedded in place) as the cheap tag-cloud cache key so a cache hit doesn't
+/// re-embedded in place) as the cheap visual-cluster cache key so a cache hit doesn't
 /// have to read and unpack hundreds of MB of embeddings just to validate freshness.
 pub fn embedding_ids_signature(conn: &Connection, folder_id: Option<i64>) -> Result<(i64, u64)> {
     use xxhash_rust::xxh3::Xxh3;

src/App.tsx

@@ -5,7 +5,7 @@ import { BackgroundTasks } from "./components/BackgroundTasks";
 import { Toolbar } from "./components/Toolbar";
 import { Gallery } from "./components/Gallery";
 import { Lightbox } from "./components/Lightbox";
-import { TagCloud } from "./components/TagCloud";
+import { ExploreView } from "./components/ExploreView";
 import { DuplicateFinder } from "./components/DuplicateFinder";
 import { Timeline } from "./components/Timeline";
 import { TitleBar } from "./components/TitleBar";
@@ -88,7 +88,7 @@ export default function App() {
           ) : activeView === "explore" ? (
             <>
               <BackgroundTasks />
-              <TagCloud />
+              <ExploreView />
             </>
           ) : activeView === "duplicates" ? (
             <>

src/components/ExploreView.tsx

@@ -1,7 +1,7 @@
 import { useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState } from "react";
 import { motion, useReducedMotion } from "framer-motion";
 import { useVirtualizer } from "@tanstack/react-virtual";
-import { ExploreMode, ExploreTagEntry, RelatedTagEntry, TagCloudEntry, useGalleryStore } from "../store";
+import { ExploreMode, ExploreTagEntry, RelatedTagEntry, VisualClusterEntry, useGalleryStore } from "../store";
 import { FolderScopeDropdown } from "./FolderScopeDropdown";
 import { ThemedDropdown } from "./ThemedDropdown";
 import { Tooltip } from "./Tooltip";
@@ -43,7 +43,7 @@ function seeded(n: number): number {
 }
 
 interface PlacedNode {
-  entry: TagCloudEntry;
+  entry: VisualClusterEntry;
   index: number;
   x: number;
   y: number;
@@ -57,7 +57,7 @@ interface PlacedNode {
   rotateSeed: number;
 }
 
-function buildCloud(entries: TagCloudEntry[], containerW: number, containerH: number): PlacedNode[] {
+function buildCloud(entries: VisualClusterEntry[], containerW: number, containerH: number): PlacedNode[] {
   if (!entries.length || containerW <= 0 || containerH <= 0) return [];
 
   const maxCount = Math.max(...entries.map((e) => e.count));
@@ -622,13 +622,13 @@ function ExploreLoadingPanel({ mode }: { mode: ExploreMode }) {
 }
 
 // Separate component so its useLayoutEffect fires when the canvas is actually
-// mounted — not at TagCloud mount time when the container may still be hidden
+// mounted — not at ExploreView mount time when the container may still be hidden
 // behind a loading state.
 function ClusterCloud({
   entries,
   onOpen,
 }: {
-  entries: TagCloudEntry[];
+  entries: VisualClusterEntry[];
   onOpen: (imageIds: number[]) => void;
 }) {
   const reducedMotion = useReducedMotion();
@@ -968,12 +968,12 @@ function TagManageList({
   );
 }
 
-export function TagCloud() {
+export function ExploreView() {
   const exploreMode = useGalleryStore((state) => state.exploreMode);
   const setExploreMode = useGalleryStore((state) => state.setExploreMode);
-  const tagCloudEntries = useGalleryStore((state) => state.tagCloudEntries);
+  const visualClusterEntries = useGalleryStore((state) => state.visualClusterEntries);
-  const tagCloudLoading = useGalleryStore((state) => state.tagCloudLoading);
+  const visualClusterLoading = useGalleryStore((state) => state.visualClusterLoading);
-  const loadTagCloud = useGalleryStore((state) => state.loadTagCloud);
+  const loadVisualClusters = useGalleryStore((state) => state.loadVisualClusters);
   const exploreTagEntries = useGalleryStore((state) => state.exploreTagEntries);
   const exploreTagLoading = useGalleryStore((state) => state.exploreTagLoading);
   const loadExploreTags = useGalleryStore((state) => state.loadExploreTags);
@@ -989,13 +989,13 @@ export function TagCloud() {
   const handleDeleteTag = async (tag: string) => { await deleteTag(tag); };
 
   useEffect(() => {
-    if (exploreMode === "visual") void loadTagCloud();
+    if (exploreMode === "visual") void loadVisualClusters();
     else void loadExploreTags();
-  }, [exploreMode, selectedFolderId, loadTagCloud, loadExploreTags]);
+  }, [exploreMode, selectedFolderId, loadVisualClusters, loadExploreTags]);
 
-  const loading = exploreMode === "visual" ? tagCloudLoading : exploreTagLoading;
+  const loading = exploreMode === "visual" ? visualClusterLoading : exploreTagLoading;
-  const hasEntries = exploreMode === "visual" ? tagCloudEntries.length > 0 : exploreTagEntries.length > 0;
+  const hasEntries = exploreMode === "visual" ? visualClusterEntries.length > 0 : exploreTagEntries.length > 0;
-  const entryCount = exploreMode === "visual" ? tagCloudEntries.length : exploreTagEntries.length;
+  const entryCount = exploreMode === "visual" ? visualClusterEntries.length : exploreTagEntries.length;
   const visibleTagCount = Math.min(exploreTagEntries.length, TAG_ATLAS_MAX_VISIBLE);
 
   return (
@@ -1070,7 +1070,7 @@ export function TagCloud() {
         </div>
       ) : exploreMode === "visual" ? (
         <div className="relative flex min-h-0 flex-1 flex-col">
-          <ClusterCloud entries={tagCloudEntries} onOpen={showVisualCluster} />
+          <ClusterCloud entries={visualClusterEntries} onOpen={showVisualCluster} />
         </div>
       ) : manageTags ? (
         <div className="relative flex min-h-0 flex-1 flex-col overflow-hidden">

src/dev/mockBackend.ts

@@ -250,8 +250,8 @@ export async function handleMockCommand(cmd: string, payload?: unknown): Promise
     case "find_similar_images":
     case "find_similar_by_region":
       return similarImages(payload);
-    case "get_tag_cloud":
+    case "get_visual_clusters":
-      return db.scenario === "empty" ? [] : db.tagCloud;
+      return db.scenario === "empty" ? [] : db.visualClusters;
     case "get_explore_tags":
       return db.scenario === "empty" ? [] : db.exploreTags.slice(0, Number(p.limit ?? 180));
     case "get_related_tags": {

src/dev/mockFixtures.ts

@@ -9,7 +9,7 @@ import type {
   ImageRecord,
   ImageTag,
   SortOrder,
-  TagCloudEntry,
+  VisualClusterEntry,
 } from "../store";
 import type { MockScenario } from "./mockScenarios";
 import { fixtureMediaPath } from "./mockMedia";
@@ -21,7 +21,7 @@ export interface MockDb {
   albums: Album[];
   albumImageIds: Record<number, number[]>;
   tagsByImageId: Record<number, ImageTag[]>;
-  tagCloud: TagCloudEntry[];
+  visualClusters: VisualClusterEntry[];
   exploreTags: ExploreTagEntry[];
   backgroundJobs: FolderJobProgress[];
   duplicateGroups: DuplicateGroup[];
@@ -252,12 +252,22 @@ function makeProgress(folders: Folder[], scenario: MockScenario): FolderJobProgr
   }));
 }
 
-function makeTagCloud(images: ImageRecord[]): TagCloudEntry[] {
+function makeVisualClusters(images: ImageRecord[], scenario: MockScenario): VisualClusterEntry[] {
-  return tags.slice(0, 10).map((_, index) => {
+  if (images.length < 5) return [];
+  // Mirror the backend's k = (n / 20).clamp(5, 30). Force the full spread for the
+  // "huge" scenario so Explore shows a realistic field of clusters rather than a
+  // fixed handful, and size the counts off a large virtual library so the badges
+  // read like a big collection.
+  const clusterCount = scenario === "huge" ? 30 : Math.min(30, Math.max(5, Math.round(images.length / 20)));
+  const virtualTotal = scenario === "huge" ? 12_000 : images.length;
+  // Long-tailed sizes (a few large clusters, many smaller), like real k-means output.
+  const weights = Array.from({ length: clusterCount }, (_, i) => 1 / (i + 1.5));
+  const weightSum = weights.reduce((sum, weight) => sum + weight, 0);
+  return weights.map((weight, index) => {
     const group = images.filter((image) => image.id % (index + 2) === 0).slice(0, 28);
-    const representative = group[0] ?? images[index];
+    const representative = group[0] ?? images[index % images.length];
     return {
-      count: Math.max(group.length, 1),
+      count: Math.max(1, Math.round((virtualTotal * weight) / weightSum)),
       representative_image_id: representative?.id ?? index + 1,
       thumbnail_path: representative?.thumbnail_path ?? null,
       image_ids: group.length ? group.map((image) => image.id) : [representative?.id ?? 1],
@@ -305,7 +315,7 @@ export function createMockDb(scenario: MockScenario): MockDb {
     albums,
     albumImageIds,
     tagsByImageId: makeTags(images, scenario),
-    tagCloud: makeTagCloud(images),
+    visualClusters: makeVisualClusters(images, scenario),
     exploreTags: makeExploreTags(images, scenario),
     backgroundJobs: makeProgress(folders, scenario),
     duplicateGroups: makeDuplicateGroups(images, scenario),

src/store.ts

@@ -203,7 +203,7 @@ export interface ImageExif {
   gps_lon: number | null;
 }
 
-export interface TagCloudEntry {
+export interface VisualClusterEntry {
   count: number;
   representative_image_id: number;
   thumbnail_path: string | null;
@@ -376,9 +376,9 @@ interface GalleryState {
   activeView: ActiveView;
   exploreMode: ExploreMode;
   tagManagerOpen: boolean;
-  tagCloudEntries: TagCloudEntry[];
+  visualClusterEntries: VisualClusterEntry[];
-  tagCloudLoading: boolean;
+  visualClusterLoading: boolean;
-  tagCloudFolderId: number | null | undefined; // undefined = never loaded
+  visualClusterFolderId: number | null | undefined; // undefined = never loaded
   exploreTagEntries: ExploreTagEntry[];
   exploreTagLoading: boolean;
   // Cache-freshness key: the folder the loaded tags belong to. Set to undefined
@@ -497,7 +497,7 @@ interface GalleryState {
   setExploreMode: (mode: ExploreMode) => void;
   setTagManagerOpen: (open: boolean) => void;
   openTagManager: () => void;
-  loadTagCloud: (options?: { force?: boolean }) => Promise<void>;
+  loadVisualClusters: (options?: { force?: boolean }) => Promise<void>;
   loadExploreTags: (options?: { force?: boolean }) => Promise<void>;
   loadRelatedTags: (tag: string) => Promise<RelatedTagEntry[]>;
   showVisualCluster: (imageIds: number[]) => Promise<void>;
@@ -633,7 +633,7 @@ const SIMILAR_DISTANCE_THRESHOLD = 0.24;
 // similarity, region search). Any new request increments it so a stale response
 // from a previous collection type cannot overwrite newer results.
 let galleryRequestToken = 0;
-let tagCloudRequestToken = 0;
+let visualClusterRequestToken = 0;
 let exploreTagRequestToken = 0;
 let exploreTagRefreshTimer: ReturnType<typeof setTimeout> | null = null;
 
@@ -878,9 +878,9 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
   activeView: "gallery",
   exploreMode: "visual",
   tagManagerOpen: false,
-  tagCloudEntries: [],
+  visualClusterEntries: [],
-  tagCloudLoading: false,
+  visualClusterLoading: false,
-  tagCloudFolderId: undefined,
+  visualClusterFolderId: undefined,
   exploreTagEntries: [],
   exploreTagLoading: false,
   exploreTagsFolderId: undefined,
@@ -1010,7 +1010,7 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
     await loadFolders();
     await loadBackgroundJobProgress();
     // Invalidate tag cloud and explore-tags cache since library content changed.
-    set({ tagCloudFolderId: undefined, tagCloudEntries: [], exploreTagsFolderId: undefined });
+    set({ visualClusterFolderId: undefined, visualClusterEntries: [], exploreTagsFolderId: undefined });
     // Always refresh the gallery: the removed folder's images may be on screen
     // (e.g. in All Media), not only when that folder was the active selection.
     await loadImages(true);
@@ -1021,7 +1021,7 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
     await invoke("reindex_folder", { folderId });
     await loadFolders();
     // Invalidate tag cloud cache since embeddings will be regenerated
-    set({ tagCloudFolderId: undefined, tagCloudEntries: [] });
+    set({ visualClusterFolderId: undefined, visualClusterEntries: [] });
     await loadBackgroundJobProgress();
   },
 
@@ -1085,7 +1085,7 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
       return;
     }
 
-    // Explore reloads itself via TagCloud's useEffect on selectedFolderId.
+    // Explore reloads itself via ExploreView's useEffect on selectedFolderId.
     if (activeView === "explore") return;
 
     void get().loadImages(true);
@@ -1425,33 +1425,33 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
     set({ exploreMode: "tags", tagManagerOpen: true, settingsOpen: false });
   },
 
-  loadTagCloud: async (options) => {
+  loadVisualClusters: async (options) => {
-    const { selectedFolderId, tagCloudFolderId, tagCloudLoading } = get();
+    const { selectedFolderId, visualClusterFolderId, visualClusterLoading } = get();
     const force = options?.force ?? false;
     // Skip if already loaded for this folder and not currently loading
-    if (!force && !tagCloudLoading && tagCloudFolderId !== undefined && tagCloudFolderId === selectedFolderId) {
+    if (!force && !visualClusterLoading && visualClusterFolderId !== undefined && visualClusterFolderId === selectedFolderId) {
       return;
     }
-    const requestToken = ++tagCloudRequestToken;
+    const requestToken = ++visualClusterRequestToken;
     // On a real folder switch, drop the previous folder's clusters so the loading
     // panel shows instead of lingering stale results. A same-folder refresh keeps
     // them to avoid a flicker when the cache returns instantly.
-    const isFolderSwitch = tagCloudFolderId !== selectedFolderId;
+    const isFolderSwitch = visualClusterFolderId !== selectedFolderId;
     set({
-      tagCloudLoading: true,
+      visualClusterLoading: true,
-      tagCloudFolderId: selectedFolderId,
+      visualClusterFolderId: selectedFolderId,
-      ...(isFolderSwitch ? { tagCloudEntries: [] } : {}),
+      ...(isFolderSwitch ? { visualClusterEntries: [] } : {}),
     });
     try {
-      const entries = await invoke<TagCloudEntry[]>("get_tag_cloud", {
+      const entries = await invoke<VisualClusterEntry[]>("get_visual_clusters", {
         folderId: selectedFolderId,
       });
-      if (requestToken !== tagCloudRequestToken) return;
+      if (requestToken !== visualClusterRequestToken) return;
-      set({ tagCloudEntries: entries, tagCloudLoading: false });
+      set({ visualClusterEntries: entries, visualClusterLoading: false });
     } catch (error) {
-      if (requestToken !== tagCloudRequestToken) return;
+      if (requestToken !== visualClusterRequestToken) return;
       console.error("Failed to load tag cloud:", error);
-      set({ tagCloudLoading: false });
+      set({ visualClusterLoading: false });
     }
   },
 
@@ -2411,13 +2411,13 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
 
   renameTag: async (from, to) => {
     await invoke("rename_tag", { params: { from, to } });
-    // Tag content changed — invalidate the explore-tags and tag-cloud caches.
+    // Tag content changed — invalidate the explore-tags and visual-cluster caches.
     // Keep the current tag list visible while the refresh runs so manager UI
     // state such as filtering and sorting is not lost to a loading remount.
     set({
       exploreTagsFolderId: undefined,
-      tagCloudFolderId: undefined,
+      visualClusterFolderId: undefined,
-      tagCloudEntries: [],
+      visualClusterEntries: [],
     });
     const parsed = parseSearchValue(get().search);
     if (parsed.mode === "tag" && parsed.query === from) {
@@ -2435,8 +2435,8 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
     // state such as filtering and sorting is not lost to a loading remount.
     set({
       exploreTagsFolderId: undefined,
-      tagCloudFolderId: undefined,
+      visualClusterFolderId: undefined,
-      tagCloudEntries: [],
+      visualClusterEntries: [],
     });
     const parsed = parseSearchValue(get().search);
     if (parsed.mode === "tag" && parsed.query === tag) {
@@ -2507,14 +2507,14 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
     if (ids.length === 0 || cleaned.length === 0) return;
     await invoke<void>("bulk_add_tags", { params: { image_ids: ids, tags: cleaned } });
     // New tags landed — invalidate Explore tag caches.
-    set({ exploreTagsFolderId: undefined, tagCloudFolderId: undefined, tagCloudEntries: [] });
+    set({ exploreTagsFolderId: undefined, visualClusterFolderId: undefined, visualClusterEntries: [] });
   },
 
   bulkRemoveTag: async (tag) => {
     const ids = Array.from(get().gallerySelectedIds);
     if (ids.length === 0 || !tag.trim()) return;
     await invoke<void>("bulk_remove_tag", { params: { image_ids: ids, tag: tag.trim() } });
-    set({ exploreTagsFolderId: undefined, tagCloudFolderId: undefined, tagCloudEntries: [] });
+    set({ exploreTagsFolderId: undefined, visualClusterFolderId: undefined, visualClusterEntries: [] });
   },
 
   bulkDeleteSelected: async () => {
@@ -2532,8 +2532,8 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
       totalImages: Math.max(0, state.totalImages - succeededIds.length),
       gallerySelectedIds: new Set([...state.gallerySelectedIds].filter((id) => !succeededSet.has(id))),
       // Deletion changes tag/duplicate/album aggregates.
-      tagCloudFolderId: undefined,
+      visualClusterFolderId: undefined,
-      tagCloudEntries: [],
+      visualClusterEntries: [],
       exploreTagsFolderId: undefined,
     }));
     // The DB cascade already removed these from album_images; refresh counts/covers.