1 files changed, 151 insertions, 0 deletions
diff --git a/webAO/viewport/utils/preloadMessageAssets.ts b/webAO/viewport/utils/preloadMessageAssets.ts
new file mode 100644
index 0000000..0a24e84
--- /dev/null
+++ b/webAO/viewport/utils/preloadMessageAssets.ts
@@ -0,0 +1,151 @@
+import { ChatMsg } from "../interfaces/ChatMsg";
+import { PreloadedAssets } from "../interfaces/PreloadedAssets";
+import {
+  resolveAndPreloadImage,
+  resolveAndPreloadAudio,
+  getAnimDuration,
+} from "../../utils/assetCache";
+import transparentPng from "../../constants/transparentPng";
+
+const GLOBAL_TIMEOUT_MS = 8000;
+
+/**
+ * Builds the list of candidate URLs for a character emote across all extensions.
+ * Replicates the URL construction logic from setEmote.ts.
+ */
+function buildEmoteUrls(
+  AO_HOST: string,
+  extensions: string[],
+  charactername: string,
+  emotename: string,
+  prefix: string,
+): string[] {
+  const characterFolder = `${AO_HOST}characters/`;
+  const urls: string[] = [];
+
+  for (const extension of extensions) {
+    let url: string;
+    if (extension === ".png") {
+      url = `${characterFolder}${encodeURI(charactername)}/${encodeURI(emotename)}${extension}`;
+    } else if (extension === ".webp.static") {
+      url = `${characterFolder}${encodeURI(charactername)}/${encodeURI(emotename)}.webp`;
+    } else {
+      url = `${characterFolder}${encodeURI(charactername)}/${encodeURI(prefix)}${encodeURI(emotename)}${extension}`;
+    }
+    urls.push(url);
+  }
+
+  return urls;
+}
+
+const DEFAULT_ASSETS: PreloadedAssets = {
+  idleUrl: transparentPng,
+  talkingUrl: transparentPng,
+  preanimUrl: transparentPng,
+  preanimDuration: 0,
+  pairIdleUrl: transparentPng,
+  shoutSfxUrl: null,
+  emoteSfxUrl: null,
+  realizationSfxUrl: null,
+  stabSfxUrl: null,
+};
+
+/**
+ * Preloads all assets referenced in an IC message before the animation timeline starts.
+ * Resolves all file extensions in parallel and primes the browser cache.
+ * All resolution and preloading is cached via assetCache, so repeated messages
+ * from the same character with the same emotes resolve near-instantly.
+ */
+export default async function preloadMessageAssets(
+  chatmsg: ChatMsg,
+  AO_HOST: string,
+  emoteExtensions: string[],
+): Promise<PreloadedAssets> {
+  const charName = chatmsg.name!.toLowerCase();
+  const charEmote = chatmsg.sprite!.toLowerCase();
+
+  const doPreload = async (): Promise<PreloadedAssets> => {
+    // Build candidate URL lists for each emote
+    const idleUrls = buildEmoteUrls(AO_HOST, emoteExtensions, charName, charEmote, "(a)");
+    const talkingUrls = buildEmoteUrls(AO_HOST, emoteExtensions, charName, charEmote, "(b)");
+
+    const hasPreanim =
+      chatmsg.type === 1 &&
+      chatmsg.preanim &&
+      chatmsg.preanim !== "-" &&
+      chatmsg.preanim !== "";
+
+    const preanimUrls = hasPreanim
+      ? buildEmoteUrls(AO_HOST, emoteExtensions, charName, chatmsg.preanim!.toLowerCase(), "")
+      : null;
+
+    const hasPair = !!chatmsg.other_name;
+    const pairIdleUrls = hasPair
+      ? buildEmoteUrls(AO_HOST, emoteExtensions, chatmsg.other_name!.toLowerCase(), chatmsg.other_emote!.toLowerCase(), "(a)")
+      : null;
+
+    // Shout SFX per-character path
+    const shoutNames = [undefined, "holdit", "objection", "takethat", "custom"];
+    const shoutName = shoutNames[chatmsg.objection];
+    const shoutSfxPath = (chatmsg.objection > 0 && chatmsg.objection < 4 && shoutName)
+      ? `${AO_HOST}characters/${encodeURI(charName)}/${shoutName}.opus`
+      : null;
+
+    // Emote SFX
+    const invalidSounds = ["0", "1", "", undefined];
+    const emoteSfxPath = (
+      !invalidSounds.includes(chatmsg.sound) &&
+      (chatmsg.type == 1 || chatmsg.type == 2 || chatmsg.type == 6)
+    ) ? `${AO_HOST}sounds/general/${encodeURI(chatmsg.sound.toLowerCase())}.opus`
+      : null;
+
+    // Realization and stab SFX (always preloaded - used by \f and \s text commands)
+    const realizationPath = `${AO_HOST}sounds/general/sfx-realization.opus`;
+    const stabPath = `${AO_HOST}sounds/general/sfx-stab.opus`;
+
+    // Launch everything in parallel - assetCache handles per-URL dedup and caching
+    const [
+      idleUrl, talkingUrl, preanimUrl, preanimDuration, pairIdleUrl,
+      shoutSfxUrl, emoteSfxUrl, realizationSfxUrl, stabSfxUrl,
+    ] = await Promise.all([
+      resolveAndPreloadImage(idleUrls),
+      resolveAndPreloadImage(talkingUrls),
+      preanimUrls ? resolveAndPreloadImage(preanimUrls) : Promise.resolve(transparentPng),
+      hasPreanim
+        ? getAnimDuration(`${AO_HOST}characters/${encodeURI(charName)}/${encodeURI(chatmsg.preanim!.toLowerCase())}`)
+        : Promise.resolve(0),
+      pairIdleUrls ? resolveAndPreloadImage(pairIdleUrls) : Promise.resolve(transparentPng),
+      shoutSfxPath ? resolveAndPreloadAudio(shoutSfxPath) : Promise.resolve(null),
+      emoteSfxPath ? resolveAndPreloadAudio(emoteSfxPath) : Promise.resolve(null),
+      resolveAndPreloadAudio(realizationPath),
+      resolveAndPreloadAudio(stabPath),
+    ]);
+
+    return {
+      idleUrl,
+      talkingUrl,
+      preanimUrl,
+      preanimDuration,
+      pairIdleUrl,
+      shoutSfxUrl,
+      emoteSfxUrl,
+      realizationSfxUrl,
+      stabSfxUrl,
+    };
+  };
+
+  // Race against global timeout for graceful degradation
+  const timeoutPromise = new Promise<PreloadedAssets>((resolve) => {
+    setTimeout(() => {
+      console.warn("Asset preloading timed out, using defaults");
+      resolve({ ...DEFAULT_ASSETS });
+    }, GLOBAL_TIMEOUT_MS);
+  });
+
+  try {
+    return await Promise.race([doPreload(), timeoutPromise]);
+  } catch (error) {
+    console.error("Asset preloading failed:", error);
+    return { ...DEFAULT_ASSETS };
+  }
+}