Speed up timeline load with portrait thumbs, bootstrap API, and caching.

Add catalog bootstrap endpoint, portrait thumbnail pipeline, lazy queued timeline images, gzip compression, and 3D texture throttling with code-split VirtualGallery.

Documentation/API.md

@@ -86,6 +86,48 @@ Curator mutations are recorded in `curator_audit_log` (see [DB_structure.md](DB_
 
 ---
 
+## `GET /api/catalog/bootstrap`
+
+**Preferred for timeline first paint.** Returns bounds, eras, movements, and slim artist rows in a single response (replaces the separate `bounds` + `timeline` + `artists?timeline=1` waterfall).
+
+**Query**
+
+| Param | Type | Default | Description |
+|-------|------|---------|-------------|
+| `start` | int | bounds `min_year` | Window start year |
+| `end` | int | bounds `max_year` | Window end year |
+
+**Response**
+
+```json
+{
+  "bounds": { "min_year": -800, "max_year": 2100 },
+  "eras": [ … ],
+  "movements": [ … ],
+  "artists": [
+    {
+      "id": 1,
+      "name": "Claude Monet",
+      "birth_year": 1840,
+      "death_year": 1926,
+      "movement_id": 12,
+      "portrait_path": "portraits/Claude_Monet.jpg",
+      "portrait_thumb_path": "portraits/thumbs/Claude_Monet_thumb.jpg",
+      "wikipedia_title": "Claude Monet",
+      "century": 19,
+      "movement_name": "Impressionism",
+      "movement_color": "#6B8E9F"
+    }
+  ]
+}
+```
+
+**Caching:** `Cache-Control: public, max-age=300` with `ETag` (304 when catalog row counts unchanged).
+
+The React home page loads this endpoint **once** on mount. Pan and zoom filter movements and portraits **client-side** — no refetch per view change.
+
+---
+
 ## `GET /api/bounds`
 
 Returns the overall timeline year range used to initialise the zoomable timeline.
@@ -138,11 +180,11 @@ Artists for timeline portraits and the movement flow diagram.
 | `start` | int | Only artists alive after this year |
 | `end` | int | Only artists born before this year |
 | `movement_id` | int | Filter by movement |
-| `timeline` | bool | When `1` or `true`, return a lightweight row set for the home-page timeline (omits `bio_full` and other heavy fields) |
+| `timeline` | bool | When `1` or `true`, return a lightweight row set for the home-page timeline (omits `bio_short`, `bio_full`; includes `portrait_thumb_path`) |
 
 **Response** — array of artist objects with joined `movement_name` and `movement_color`.
 
-The React home page loads the timeline catalog **once** on mount via `GET /api/bounds`, `GET /api/timeline?start=…&end=…` (full range), and `GET /api/artists?timeline=1`. Pan and zoom filter movements and portraits **client-side** — no refetch per view change. Rapid pan/zoom is batched with `createViewChangeScheduler()` (one React update per animation frame).
+The React home page loads the timeline catalog **once** on mount via `GET /api/catalog/bootstrap` (or legacy: `GET /api/bounds` + `GET /api/timeline` + `GET /api/artists?timeline=1`). Pan and zoom filter movements and portraits **client-side** — no refetch per view change. Rapid pan/zoom is batched with `createViewChangeScheduler()` (one React update per animation frame).
 
 ---
 

Documentation/data-and-images.md

@@ -12,8 +12,10 @@ How catalog content, biographies, and artwork files enter the system.
 
 ```text
 data/images/
-├── portraits/           # Artist headshots
-│   └── Claude_Monet.jpg
+├── portraits/           # Artist headshots (display ~900px wide)
+│   ├── Claude_Monet.jpg
+│   └── thumbs/          # Timeline thumbnails (~256px)
+│       └── Claude_Monet_thumb.jpg
 └── paintings/
     ├── Claude_Monet_Water_Lilies.jpg
     └── thumbs/
@@ -47,7 +49,8 @@ Promote dev → prod files: `npm run images:sync-to-prod` (after `net use \\192.
 | `fetch-missing-images.js` | `npm run fetch-images` | Downloads files for paintings missing on disk |
 | `image-fetcher.js` | *(library)* | Wikimedia / museum resolution used by fetch scripts and API |
 | `sync-images-to-prod.ps1` / `sync-images-from-prod.ps1` | `npm run images:sync-*` | Robocopy via SMB `\\192.168.10.122\Gallery` |
-| `regenerate-thumbnails.js` | `npm run regenerate-thumbnails` | Rebuild thumbs from full images via `sharp` |
+| `regenerate-thumbnails.js` | `npm run regenerate-thumbnails` | Rebuild painting thumbs from full images via `sharp` |
+| `regenerate-portrait-thumbs.js` | `npm run regenerate-portrait-thumbs` | Rebuild timeline portrait thumbs (~256px) and set `portrait_thumb_path` |
 | `audit-painting-images.js` | `npm run audit-painting-images` | Detect thumb/full aspect-ratio mismatches |
 | `find-duplicate-paintings.js` | `npm run find-duplicates` | Report exact and near-duplicate catalog rows |
 | `migrate-checkup-flags.js` | `npm run migrate:checkup-flags` | Add `checkup_checked` / `checkup_fixed` columns |
@@ -154,6 +157,8 @@ Typical result on a full clone: ~1,000+ paintings linked from ~1,000 on-disk fil
 
 ## Artist portraits
 
+Timeline movement flow loads **`portrait_thumb_path`** (~256px JPEG under `portraits/thumbs/{Artist}_thumb.jpg`) when available; biography and 3D exit navigation use full `portrait_path`. After adding portraits, run `npm run regenerate-portrait-thumbs` to backfill thumbs on dev.
+
 `npm run fetch-artist-images` runs `scripts/fetch-artist-images.js`:
 
 1. For each artist, checks `data/images/portraits/{Artist}.jpg` (or other extensions) and sets `portrait_path` when a local file exists.

client/src/api/client.ts

@@ -1,5 +1,6 @@
 import type {
   TimelineData,
+  CatalogBootstrap,
   YearBounds,
   Artist,
   ArtistDetail,
@@ -62,13 +63,25 @@ export function portraitUrl(path: string | null | undefined, revision?: number):
   return `${base}${base.includes('?') ? '&' : '?'}v=${revision}`;
 }
 
-/** Image for 3D gallery — local cached files only (API fetch is too slow for realtime 3D) */
+/** Small portrait for timeline / movement flow (~256px). Falls back to full portrait. */
+export function portraitThumbUrl(
+  artist: {
+    portrait_thumb_path?: string | null;
+    portrait_path?: string | null;
+  },
+  revision?: number
+): string {
+  const path = artist.portrait_thumb_path || artist.portrait_path;
+  return portraitUrl(path, revision);
+}
+
+/** Image for 3D gallery — prefer thumbnail for faster texture loads */
 export function galleryImageUrl(painting: {
   thumbnail_path?: string | null;
   image_path?: string | null;
 }): string | null {
-  if (painting.image_path) return `/images/${painting.image_path}`;
   if (painting.thumbnail_path) return `/images/${painting.thumbnail_path}`;
+  if (painting.image_path) return `/images/${painting.image_path}`;
   return null;
 }
 
@@ -202,6 +215,14 @@ export interface PaintingCheckupData {
 export const api = {
   getBounds: () => fetchJson<YearBounds>(`${API}/bounds`),
 
+  getCatalogBootstrap: (start?: number, end?: number) => {
+    const params = new URLSearchParams();
+    if (start != null) params.set('start', String(start));
+    if (end != null) params.set('end', String(end));
+    const qs = params.toString();
+    return fetchJson<CatalogBootstrap>(`${API}/catalog/bootstrap${qs ? `?${qs}` : ''}`);
+  },
+
   getTimeline: (start: number, end: number) =>
     fetchJson<TimelineData>(`${API}/timeline?start=${start}&end=${end}`),
 
@@ -345,6 +366,8 @@ export const api = {
       }
       return res.json() as Promise<{ checked: boolean; fixed: boolean }>;
     }),
+
+  preloadArtistImages,
 };
 
 export function debugImageProxyUrl(

client/src/components/MovementBands.tsx

@@ -1,6 +1,7 @@
-import { useMemo, useRef, useCallback, useEffect, useLayoutEffect, useState } from 'react';
+import { useMemo, useRef, useCallback, useEffect, useLayoutEffect, useState, memo } from 'react';
 import type { ArtMovement, Artist } from '../types';
-import { portraitUrl } from '../api/client';
+import { portraitThumbUrl } from '../api/client';
+import { useQueuedImageSrc } from '../hooks/useQueuedImageSrc';
 import { MOVEMENT_LINEAGE } from '../data/movement-lineage';
 import { panTimelineView, zoomTimelineView } from '../utils/timelineView';
 import './MovementBands.css';
@@ -639,6 +640,108 @@ function branchTargetOnChild(layout: MovementLayout): { x: number; y: number } {
   return { x, y: yOnStream(layout, x) };
 }
 
+const MovementArtistPortrait = memo(function MovementArtistPortrait({
+  artist,
+  portraitRevision,
+  lineLeft,
+  lineWidth,
+  portraitX,
+  y,
+  layoutHeight,
+  color,
+  colorIndex,
+  isHovered,
+  birthLabel,
+  deathLabel,
+  movementName,
+  viewStart,
+  viewEnd,
+  onArtistClick,
+  onArtistHover,
+  onHoverStart,
+  onHoverEnd,
+}: {
+  artist: Artist;
+  portraitRevision?: number;
+  lineLeft: number;
+  lineWidth: number;
+  portraitX: number;
+  y: number;
+  layoutHeight: number;
+  color: string;
+  colorIndex: number;
+  isHovered: boolean;
+  birthLabel: string | number;
+  deathLabel: string | number;
+  movementName: string;
+  viewStart: number;
+  viewEnd: number;
+  onArtistClick: (id: number) => void;
+  onArtistHover?: (lifespan: { birthYear: number; deathYear: number; color: string } | null) => void;
+  onHoverStart: () => void;
+  onHoverEnd: () => void;
+}) {
+  const thumbSrc = portraitThumbUrl(artist, portraitRevision);
+  const queuedSrc = useQueuedImageSrc(thumbSrc);
+
+  return (
+    <div className={`artist-on-band${isHovered ? ' artist-on-band-active' : ''}`}>
+      <div
+        className={`artist-lifespan${isHovered ? ' artist-lifespan-active' : ''}`}
+        style={{
+          left: `${lineLeft}%`,
+          width: `${lineWidth}%`,
+          top: `${(y / layoutHeight) * 100}%`,
+          zIndex: isHovered ? 12 : 4 + colorIndex,
+          ['--lifespan-color' as string]: color,
+        }}
+      >
+        {isHovered && <span className="artist-lifespan-line" aria-hidden />}
+      </div>
+      <button
+        type="button"
+        className="artist-portrait"
+        style={{
+          left: `${portraitX}%`,
+          top: `${(y / layoutHeight) * 100}%`,
+          borderColor: color,
+          zIndex: isHovered ? 13 : 5 + colorIndex,
+        }}
+        onClick={() => onArtistClick(artist.id)}
+        onMouseEnter={() => {
+          onHoverStart();
+          onArtistHover?.({
+            birthYear: artist.birth_year ?? viewStart,
+            deathYear: artist.death_year ?? viewEnd,
+            color,
+          });
+        }}
+        onMouseLeave={() => {
+          onHoverEnd();
+          onArtistHover?.(null);
+        }}
+        onMouseDown={(e) => e.stopPropagation()}
+        title={`${artist.name} (${birthLabel}–${deathLabel}) · ${movementName}`}
+      >
+        {queuedSrc ? (
+          <img
+            src={queuedSrc}
+            alt={artist.name}
+            loading="lazy"
+            decoding="async"
+            onError={(e) => {
+              (e.target as HTMLImageElement).src = '/placeholder-portrait.svg';
+            }}
+          />
+        ) : (
+          <img src="/placeholder-portrait.svg" alt="" aria-hidden />
+        )}
+        <span className="artist-name">{artist.name}</span>
+      </button>
+    </div>
+  );
+});
+
 export default function MovementBands({
   movements,
   artists,
@@ -674,7 +777,7 @@ export default function MovementBands({
     interactionTimer.current = window.setTimeout(() => {
       interactionTimer.current = null;
       setInteracting(false);
-    }, 120);
+    }, 200);
   }, []);
 
   useEffect(() => () => {
@@ -1216,60 +1319,30 @@ export default function MovementBands({
             const birthLabel = artist.birth_year != null ? artist.birth_year : '?';
             const deathLabel = artist.death_year != null ? artist.death_year : '?';
             const artistKey = `${layout.movement.id}-${artist.id}`;
-            const isHovered = hoveredArtistKey === artistKey;
 
             return (
-              <div
+              <MovementArtistPortrait
                 key={artistKey}
-                className={`artist-on-band${isHovered ? ' artist-on-band-active' : ''}`}
-              >
-                <div
-                  className={`artist-lifespan${isHovered ? ' artist-lifespan-active' : ''}`}
-                  style={{
-                    left: `${lineLeft}%`,
-                    width: `${lineWidth}%`,
-                    top: `${(y / layoutHeight) * 100}%`,
-                    zIndex: isHovered ? 12 : 4 + colorIndex,
-                    ['--lifespan-color' as string]: color,
-                  }}
-                >
-                  {isHovered && <span className="artist-lifespan-line" aria-hidden />}
-                </div>
-                <button
-                  type="button"
-                  className="artist-portrait"
-                  style={{
-                    left: `${portraitX}%`,
-                    top: `${(y / layoutHeight) * 100}%`,
-                    borderColor: color,
-                    zIndex: isHovered ? 13 : 5 + colorIndex,
-                  }}
-                  onClick={() => onArtistClick(artist.id)}
-                  onMouseEnter={() => {
-                    setHoveredArtistKey(artistKey);
-                    onArtistHover?.({
-                      birthYear: artist.birth_year ?? viewStart,
-                      deathYear: artist.death_year ?? viewEnd,
-                      color,
-                    });
-                  }}
-                  onMouseLeave={() => {
-                    setHoveredArtistKey(null);
-                    onArtistHover?.(null);
-                  }}
-                  onMouseDown={(e) => e.stopPropagation()}
-                  title={`${artist.name} (${birthLabel}–${deathLabel}) · ${layout.movement.name}`}
-                >
-                  <img
-                    src={portraitUrl(artist.portrait_path, portraitRevisions?.[artist.id])}
-                    alt={artist.name}
-                    onError={(e) => {
-                      (e.target as HTMLImageElement).src = '/placeholder-portrait.svg';
-                    }}
-                  />
-                  <span className="artist-name">{artist.name}</span>
-                </button>
-              </div>
+                artist={artist}
+                portraitRevision={portraitRevisions?.[artist.id]}
+                lineLeft={lineLeft}
+                lineWidth={lineWidth}
+                portraitX={portraitX}
+                y={y}
+                layoutHeight={layoutHeight}
+                color={color}
+                colorIndex={colorIndex}
+                isHovered={hoveredArtistKey === artistKey}
+                birthLabel={birthLabel}
+                deathLabel={deathLabel}
+                movementName={layout.movement.name}
+                viewStart={viewStart}
+                viewEnd={viewEnd}
+                onArtistClick={onArtistClick}
+                onArtistHover={onArtistHover}
+                onHoverStart={() => setHoveredArtistKey(artistKey)}
+                onHoverEnd={() => setHoveredArtistKey(null)}
+              />
             );
           })}
         </div>

client/src/components/PaintingDetail.tsx

@@ -130,6 +130,8 @@ function InfluenceCard({
           <img
             src={imageUrl(inf.artist_portrait)}
             alt={artistName}
+            loading="lazy"
+            decoding="async"
             onError={(e) => {
               (e.target as HTMLImageElement).src = '/placeholder-portrait.svg';
             }}
@@ -164,6 +166,8 @@ function InfluenceCard({
         <img
           src={paintingImageUrl({ id: inf.id, image_path: inf.image_path }) ?? '/placeholder-art.svg'}
           alt={inf.title || 'Painting'}
+          loading="lazy"
+          decoding="async"
           onError={(e) => {
             (e.target as HTMLImageElement).src = '/placeholder-art.svg';
           }}

client/src/components/VirtualGallery.tsx

@@ -10,7 +10,8 @@ import type {
   ArtistNavigation,
   MovementArtistGroup,
 } from '../types';
-import { galleryImageUrlWithRevision, imageUrl, api, preloadArtistImages } from '../api/client';
+import { galleryImageUrlWithRevision, imageUrl, api } from '../api/client';
+import { loadTextureQueued } from '../utils/textureLoadQueue';
 import { comparePaintingsChronological, paintingHasInfluenceLinks, paintingWallCaption } from '../utils/paintingUtils';
 import { cloneSurfaceTexture, getSurfaceTexture } from '../utils/galleryProceduralTextures';
 import { resolveMovementInteriorStyle, type MovementInteriorStyle, type GalleryWindowSpec } from '../data/movement-interior-styles';
@@ -561,11 +562,9 @@ function usePaintingTexture(url: string | null) {
     setFailed(false);
     let disposed = false;
     let loaded: THREE.Texture | null = null;
-    const loader = new THREE.TextureLoader();
-    loader.setCrossOrigin('anonymous');
-    loader.load(
-      url,
-      (tex) => {
+
+    loadTextureQueued(url)
+      .then((tex) => {
         if (disposed) {
           tex.dispose();
           return;
@@ -580,12 +579,10 @@ function usePaintingTexture(url: string | null) {
         tex.colorSpace = THREE.SRGBColorSpace;
         tex.anisotropy = 4;
         setTexture(tex);
-      },
-      undefined,
-      () => {
+      })
+      .catch(() => {
         if (!disposed) setFailed(true);
-      }
-    );
+      });
 
     return () => {
       disposed = true;
@@ -1675,32 +1672,13 @@ export default function VirtualGallery(props: Props) {
       return;
     }
 
-    let cancelled = false;
-    const artistId = props.data.artist.id;
-    (async () => {
-      try {
-        setSyncStatus('Syncing images…');
-        const timeout = new Promise<void>((resolve) => setTimeout(resolve, 2000));
-        await Promise.race([preloadArtistImages(artistId), timeout]);
-        const fresh = await api.getArtist(artistId);
-        if (!cancelled) {
-          setPaintings(fresh.paintings);
-          setPeriods(fresh.periods);
-          const withImg = fresh.paintings.filter((p) => p.image_path || p.thumbnail_path).length;
-          setSyncStatus(
-            withImg < fresh.paintings.length
-              ? `${withImg} of ${fresh.paintings.length} works have images`
-              : ''
-          );
-        }
-      } catch {
-        if (!cancelled) setSyncStatus('');
-      }
-    })();
-    return () => {
-      cancelled = true;
-    };
-  }, [hallKey, props.mode, initialPaintings.length, props.mode === 'artist' ? props.data.artist.id : null]);
+    const withImg = initialPaintings.filter((p) => p.image_path || p.thumbnail_path).length;
+    setSyncStatus(
+      withImg < initialPaintings.length
+        ? `${withImg} of ${initialPaintings.length} works have images`
+        : ''
+    );
+  }, [hallKey, props.mode, initialPaintings]);
 
   const interiorStyle = useMemo(
     () => (isMovement ? resolveMovementInteriorStyle(props.data.movement) : undefined),
@@ -2017,7 +1995,7 @@ export default function VirtualGallery(props: Props) {
             intensity={interiorStyle ? 0.85 : 0.65}
             color={interiorStyle?.sunLight ?? '#fff8f0'}
             castShadow
-            shadow-mapSize={[2048, 2048]}
+            shadow-mapSize={[1024, 1024]}
           />
           <Suspense fallback={null}>
             <Environment

client/src/hooks/useQueuedImageSrc.ts

@@ -0,0 +1,54 @@
+import { useEffect, useState } from 'react';
+
+const MAX_CONCURRENT = 6;
+const queue: Array<() => void> = [];
+let inFlight = 0;
+
+function pumpQueue() {
+  while (inFlight < MAX_CONCURRENT && queue.length > 0) {
+    const next = queue.shift();
+    if (next) next();
+  }
+}
+
+function enqueueLoad(run: () => void) {
+  return new Promise<void>((resolve) => {
+    const task = () => {
+      inFlight++;
+      run();
+      resolve();
+      inFlight--;
+      pumpQueue();
+    };
+    queue.push(task);
+    pumpQueue();
+  });
+}
+
+/**
+ * Limits parallel image URL activation so hundreds of timeline portraits
+ * do not saturate the browser connection pool at once.
+ */
+export function useQueuedImageSrc(src: string | null | undefined): string | undefined {
+  const [activeSrc, setActiveSrc] = useState<string | undefined>(undefined);
+
+  useEffect(() => {
+    if (!src) {
+      setActiveSrc(undefined);
+      return;
+    }
+
+    let cancelled = false;
+    setActiveSrc(undefined);
+
+    enqueueLoad(() => {
+      if (!cancelled) setActiveSrc(src);
+    });
+
+    return () => {
+      cancelled = true;
+    };
+  }, [src]);
+
+  return activeSrc;
+}

client/src/pages/HomePage.tsx

@@ -1,8 +1,8 @@
-import { useState, useEffect, useCallback, useMemo, useRef } from 'react';
+import { useState, useEffect, useCallback, useMemo, useRef, lazy, Suspense } from 'react';
 import Timeline from '../components/Timeline';
 import TimelineEventGuides from '../components/TimelineEventGuides';
 import MovementBands from '../components/MovementBands';
-import VirtualGallery from '../components/VirtualGallery';
+const VirtualGallery = lazy(() => import('../components/VirtualGallery'));
 import PaintingDetailView from '../components/PaintingDetail';
 import ArtistBio from '../components/ArtistBio';
 import CheckupPage from '../pages/CheckupPage';
@@ -144,23 +144,16 @@ export default function HomePage() {
     (async () => {
       try {
         setLoading(true);
-        const b = await api.getBounds();
-        const min = b.min_year ?? -800;
-        const max = b.max_year ?? 2025;
+        const catalog = await api.getCatalogBootstrap();
         if (cancelled) return;
 
+        const min = catalog.bounds.min_year ?? -800;
+        const max = catalog.bounds.max_year ?? 2025;
         setBounds({ min, max });
         setViewStart(min);
         setViewEnd(max);
-
-        const [timeline, artistList] = await Promise.all([
-          api.getTimeline(min, max),
-          api.getTimelineArtists(),
-        ]);
-        if (cancelled) return;
-
-        setTimelineData(timeline);
-        setArtists(artistList);
+        setTimelineData({ eras: catalog.eras, movements: catalog.movements });
+        setArtists(catalog.artists);
         setError(null);
       } catch {
         if (!cancelled) setError('Could not load gallery data. Is the server running?');
@@ -407,6 +400,7 @@ export default function HomePage() {
 
   const handleArtistClick = async (artistId: number) => {
     try {
+      await api.preloadArtistImages(artistId).catch(() => undefined);
       const data = await api.getArtist(artistId);
       openArtistGallery(artistId, data);
     } catch {
@@ -605,6 +599,7 @@ export default function HomePage() {
           aria-hidden={!galleryActive}
         >
           {displayGallery.kind === 'artist' ? (
+            <Suspense fallback={null}>
             <VirtualGallery
               key={`artist-${displayGallery.artistId}-${galleryRevision}-${galleryActive ? 'live' : 'parked'}`}
               mode="artist"
@@ -622,7 +617,9 @@ export default function HomePage() {
                 })
               }
             />
+            </Suspense>
           ) : (
+            <Suspense fallback={null}>
             <VirtualGallery
               key={`movement-${displayGallery.movementId}-${galleryRevision}-${galleryActive ? 'live' : 'parked'}`}
               mode="movement"
@@ -632,6 +629,7 @@ export default function HomePage() {
               onPaintingClick={handlePaintingClick}
               onBack={() => setView({ type: 'timeline' })}
             />
+            </Suspense>
           )}
         </div>
       )}

client/src/types/index.ts

@@ -31,8 +31,9 @@ export interface Artist {
   movement_name?: string;
   movement_color?: string;
   portrait_path: string | null;
-  bio_short: string;
-  bio_full: string;
+  portrait_thumb_path?: string | null;
+  bio_short?: string;
+  bio_full?: string;
   wikipedia_title: string;
   century: number;
   checkup_checked?: boolean;
@@ -133,6 +134,11 @@ export interface TimelineData {
   movements: ArtMovement[];
 }
 
+export interface CatalogBootstrap extends TimelineData {
+  bounds: YearBounds;
+  artists: Artist[];
+}
+
 export interface YearBounds {
   min_year: number;
   max_year: number;

client/src/utils/textureLoadQueue.ts

@@ -0,0 +1,39 @@
+import * as THREE from 'three';
+
+const MAX_CONCURRENT = 8;
+const queue: Array<() => void> = [];
+let inFlight = 0;
+
+function pumpQueue() {
+  while (inFlight < MAX_CONCURRENT && queue.length > 0) {
+    const next = queue.shift();
+    if (next) next();
+  }
+}
+
+const loader = new THREE.TextureLoader();
+loader.setCrossOrigin('anonymous');
+
+export function loadTextureQueued(url: string): Promise<THREE.Texture> {
+  return new Promise((resolve, reject) => {
+    const task = () => {
+      inFlight++;
+      loader.load(
+        url,
+        (tex) => {
+          inFlight--;
+          pumpQueue();
+          resolve(tex);
+        },
+        undefined,
+        (err) => {
+          inFlight--;
+          pumpQueue();
+          reject(err);
+        }
+      );
+    };
+    queue.push(task);
+    pumpQueue();
+  });
+}