Add fourth sequential asset expansion batch

src/game/data/portraitAssets.ts

@@ -65,6 +65,16 @@ export function portraitTextureKey(key: string) {
   return portraitAssets[slug] ? `portrait-${slug}` : undefined;
 }
 
+export function portraitTextureKeysForKey(key: string) {
+  const slug = portraitSlugForKey(key);
+  const prefix = `${slug}-`;
+  const slugs = Object.keys(portraitAssets)
+    .filter((candidate) => candidate === slug || candidate.startsWith(prefix))
+    .sort();
+
+  return Array.from(new Set(slugs.map((candidate) => `portrait-${candidate}`)));
+}
+
 export function portraitKeyForSpeaker(speaker?: string) {
   return speaker ? speakerPortraitKeys[speaker] : undefined;
 }

src/game/scenes/StoryScene.ts

@@ -1,6 +1,6 @@
 import Phaser from 'phaser';
 import { soundDirector } from '../audio/SoundDirector';
-import { portraitKeyForSpeaker, portraitTextureKey } from '../data/portraitAssets';
+import { portraitKeyForSpeaker, portraitTextureKeysForKey } from '../data/portraitAssets';
 import { storyBackgroundAssets, storyBackgroundKeysFor } from '../data/storyAssets';
 import { prologuePages, type PortraitKey, type StoryPage } from '../data/scenario';
 import { palette } from '../ui/palette';
@@ -238,8 +238,7 @@ export class StoryScene extends Phaser.Scene {
     this.applyBackground(page);
     this.chapterText?.setText(page.chapter);
 
-    const portraitKey = this.pagePortraitKey(page);
-    const textureKey = portraitKey ? portraitTextureKey(portraitKey) : undefined;
+    const textureKey = this.pagePortraitTextureKey(page);
 
     if (textureKey && this.textures.exists(textureKey)) {
       this.portraitFrame?.setVisible(true);
@@ -268,6 +267,20 @@ export class StoryScene extends Phaser.Scene {
     return page.portrait ?? portraitKeyForSpeaker(page.speaker);
   }
 
+  private pagePortraitTextureKey(page: StoryPage) {
+    const portraitKey = this.pagePortraitKey(page);
+    if (!portraitKey) {
+      return undefined;
+    }
+
+    const keys = portraitTextureKeysForKey(portraitKey).filter((key) => this.textures.exists(key));
+    if (keys.length <= 1) {
+      return keys[0];
+    }
+
+    return keys[this.hashString(page.id) % keys.length];
+  }
+
   private pageBackgroundKey(page: StoryPage) {
     const keys = storyBackgroundKeysFor(page.background).filter((key) => this.textures.exists(key));
     if (keys.length <= 1) {