Polish early battle onboarding

src/game/data/unitAssets.ts

@@ -47,6 +47,7 @@ const unitSheets = Object.entries(unitSheetUrls)
   .sort((left, right) => left.key.localeCompare(right.key));
 
 const unitSheetAssetsByKey = new Map(unitSheets.map((sheet) => [sheet.key, sheet]));
+const pendingUnitTextureKeys = new Set<string>();
 
 export function unitTextureVariantKeys(baseKey: string) {
   const prefix = `${baseKey}-`;
@@ -64,33 +65,65 @@ export function hasUnitSheetAsset(key: string) {
 
 export function loadUnitSheets(scene: Phaser.Scene, keys: Iterable<string>, onReady: () => void) {
   const uniqueKeys = Array.from(new Set(keys));
-  const missingSheets = uniqueKeys
-    .filter((key) => !scene.textures.exists(key) || !scene.textures.exists(`${key}-actions`))
-    .map((key) => unitSheetAssetsByKey.get(key) ?? missingUnitSheet(key));
-
-  if (missingSheets.length <= 0) {
+  if (unitSheetsReady(scene, uniqueKeys)) {
     onReady();
     return;
   }
 
-  scene.load.once('complete', onReady);
-  missingSheets.forEach(({ key, url, actionKey, actionUrl }) => {
-    if (!scene.textures.exists(key)) {
-      scene.load.spritesheet(key, url, {
-        frameWidth: unitSheetFrameSize,
-        frameHeight: unitSheetFrameSize
-      });
+  const pendingLoads: Array<{ key: string; url: string }> = [];
+  uniqueKeys.forEach((key) => {
+    const sheet = unitSheetAssetsByKey.get(key) ?? missingUnitSheet(key);
+    if (!scene.textures.exists(sheet.key) && !pendingUnitTextureKeys.has(sheet.key)) {
+      pendingUnitTextureKeys.add(sheet.key);
+      pendingLoads.push({ key: sheet.key, url: sheet.url });
     }
-    if (!scene.textures.exists(actionKey)) {
-      scene.load.spritesheet(actionKey, actionUrl, {
-        frameWidth: unitSheetFrameSize,
-        frameHeight: unitSheetFrameSize
-      });
+    if (!scene.textures.exists(sheet.actionKey) && !pendingUnitTextureKeys.has(sheet.actionKey)) {
+      pendingUnitTextureKeys.add(sheet.actionKey);
+      pendingLoads.push({ key: sheet.actionKey, url: sheet.actionUrl });
     }
   });
+
+  if (pendingLoads.length <= 0) {
+    waitForUnitSheets(scene, uniqueKeys, onReady);
+    return;
+  }
+
+  const clearPendingLoads = () => {
+    pendingLoads.forEach(({ key }) => pendingUnitTextureKeys.delete(key));
+  };
+
+  scene.load.once('complete', () => {
+    clearPendingLoads();
+    waitForUnitSheets(scene, uniqueKeys, onReady);
+  });
+  scene.load.once('loaderror', clearPendingLoads);
+  pendingLoads.forEach(({ key, url }) => {
+    scene.load.spritesheet(key, url, {
+      frameWidth: unitSheetFrameSize,
+      frameHeight: unitSheetFrameSize
+    });
+  });
   scene.load.start();
 }
 
+function unitSheetsReady(scene: Phaser.Scene, keys: Iterable<string>) {
+  return Array.from(keys).every((key) => scene.textures.exists(key) && scene.textures.exists(`${key}-actions`));
+}
+
+function waitForUnitSheets(scene: Phaser.Scene, keys: string[], onReady: () => void, attempts = 0) {
+  if (unitSheetsReady(scene, keys)) {
+    onReady();
+    return;
+  }
+
+  if (attempts > 200) {
+    const missing = keys.filter((key) => !scene.textures.exists(key) || !scene.textures.exists(`${key}-actions`));
+    throw new Error(`Timed out waiting for unit sheet textures: ${missing.join(', ')}`);
+  }
+
+  scene.time.delayedCall(50, () => waitForUnitSheets(scene, keys, onReady, attempts + 1));
+}
+
 export function ensureUnitAnimations(scene: Phaser.Scene, keys: Iterable<string>) {
   Array.from(new Set(keys)).forEach((key) => {
     if (!scene.textures.exists(key)) {