perf(launcher): reduce background resource usage

Make the custom cursor event-driven, pause CSS, theme video, and Lottie work
while the launcher is hidden or unfocused, and reduce presence polling while
osu is running.

src/app.css

@@ -174,6 +174,13 @@
   }
 }
 
+/* Pause continuous visual work while the launcher is hidden or in the background. */
+main.app-inactive *,
+main.app-inactive *::before,
+main.app-inactive *::after {
+  animation-play-state: paused !important;
+}
+
 /* Suppress browser and WebKit native media controls and overlay play buttons on theme videos */
 video::-webkit-media-controls,
 video::-webkit-media-controls-enclosure,

src/lib/components/theme/ThemeLottieLayer.svelte

@@ -17,12 +17,38 @@
   let container = $state<HTMLDivElement | undefined>(undefined);
   let animation: AnimationItem | undefined;
   let reducedMotion = false;
+  let windowActive = true;
+
+  function syncPlayback() {
+    if (!animation) return;
+    animation.loop = loop;
+    animation.setSpeed(speed);
+    if (autoplay && !reducedMotion && windowActive && document.visibilityState === 'visible') {
+      animation.play();
+    } else {
+      animation.pause();
+    }
+  }
 
   onMount(() => {
     if (!container || !src) return;
     reducedMotion = window.matchMedia?.('(prefers-reduced-motion: reduce)').matches ?? false;
     let cancelled = false;
 
+    const onBlur = () => {
+      windowActive = false;
+      syncPlayback();
+    };
+    const onFocus = () => {
+      windowActive = true;
+      syncPlayback();
+    };
+    const onVisibilityChange = () => syncPlayback();
+
+    window.addEventListener('blur', onBlur);
+    window.addEventListener('focus', onFocus);
+    document.addEventListener('visibilitychange', onVisibilityChange);
+
     const start = (animationData?: unknown) => {
       if (cancelled || !container) return;
       try {
@@ -30,7 +56,8 @@
           container,
           renderer: 'svg',
           loop,
-          autoplay: autoplay && !reducedMotion,
+          autoplay:
+            autoplay && !reducedMotion && windowActive && document.visibilityState === 'visible',
           ...(animationData ? { animationData } : { path: src }),
           rendererSettings: { preserveAspectRatio: 'xMidYMid meet' },
         });
@@ -52,15 +79,14 @@
 
     return () => {
       cancelled = true;
+      window.removeEventListener('blur', onBlur);
+      window.removeEventListener('focus', onFocus);
+      document.removeEventListener('visibilitychange', onVisibilityChange);
     };
   });
 
   $effect(() => {
-    if (!animation) return;
-    animation.loop = loop;
-    animation.setSpeed(speed);
-    if (autoplay && !reducedMotion) animation.play();
-    else animation.pause();
+    syncPlayback();
   });
 
   onDestroy(() => {

src/lib/components/ui/animated-bg/AnimatedBg.svelte

@@ -48,6 +48,7 @@
         opacity:{$reduceAnimations ? 0 : s.opacity};
         animation-duration:{s.duration}s;
         animation-delay:-{s.delay}s;
+        animation-play-state:{$reduceAnimations ? 'paused' : 'running'};
       "
     ></div>
   {/each}

src/lib/components/ui/osu-cursor/OsuCursor.svelte

@@ -34,6 +34,7 @@
   let velocityAccumX = 0;
   let velocityAccumY = 0;
   let rotateSpringAnim: ReturnType<typeof animate> | null = null;
+  let scheduleCursorFrame = () => {};
 
   let cursor: HTMLElement;
   let cursorRotateWrapper: HTMLDivElement;
@@ -41,20 +42,15 @@
   let cursorAdditive: HTMLImageElement;
 
   function isInteractive(el: Element | null): boolean {
-    while (el) {
-      const tag = el.tagName.toLowerCase();
-      const role = el.getAttribute('role');
-      const computed = getComputedStyle(el);
-      if (
-        ['button', 'a', 'input', 'select', 'textarea', 'label', 'option'].includes(tag) ||
-        (role && ['button', 'link', 'checkbox', 'combobox', 'menuitem', 'option'].includes(role)) ||
-        computed.cursor === 'pointer'
-      ) {
-        return true;
-      }
-      el = el.parentElement;
+    if (!el) return false;
+    if (
+      el.closest(
+        'button, a, input, select, textarea, label, option, [role="button"], [role="link"], [role="checkbox"], [role="combobox"], [role="menuitem"], [role="option"]'
+      )
+    ) {
+      return true;
     }
-    return false;
+    return getComputedStyle(el).cursor === 'pointer';
   }
 
   function dampContinuously(current: number, target: number, halfLife: number, dt: number): number {
@@ -133,6 +129,7 @@
       }
     }
 
+    scheduleCursorFrame();
     lastMouseX = targetX;
     lastMouseY = targetY;
   };
@@ -147,6 +144,7 @@
     lastVelocityTime = performance.now();
 
     isMouseDown = true;
+    scheduleCursorFrame();
 
     if (rotateSpringAnim) {
       rotateSpringAnim.pause();
@@ -213,12 +211,17 @@
     document.addEventListener('mouseleave', handleMouseLeave);
     document.addEventListener('mouseenter', handleMouseEnter);
 
-    let animationFrameId: number;
+    let animationFrameId: number | undefined;
     let lastFrameTime = performance.now();
+    let paused = false;
 
     const tick = (now: number) => {
+      animationFrameId = undefined;
+      if (paused) return;
+
       const dt = Math.min(Math.max(now - lastFrameTime, 0), 64);
       lastFrameTime = now;
+      let needsAnotherFrame = false;
 
       if (hasMoved && cursor) {
         if (!smoothCursor) {
@@ -229,6 +232,8 @@
           const halfLife = $cursorSmoothness > 50 ? 14 : Math.max(1, $cursorSmoothness || 14);
           currentX = dampContinuously(currentX, targetX, halfLife, dt);
           currentY = dampContinuously(currentY, targetY, halfLife, dt);
+          needsAnotherFrame =
+            Math.abs(targetX - currentX) >= 0.05 || Math.abs(targetY - currentY) >= 0.05;
         }
 
         if (Math.abs(targetX - currentX) < 0.05) currentX = targetX;
@@ -244,19 +249,62 @@
           const rotFactor = 1 - Math.pow(0.5, dt / 25);
           currentDegrees += (targetDegrees - currentDegrees) * rotFactor;
           cursorRotateWrapper.style.transform = `rotate(${currentDegrees}deg)`;
+          needsAnotherFrame = true;
         }
       }
 
+      if (needsAnotherFrame) {
+        animationFrameId = requestAnimationFrame(tick);
+      }
+    };
+
+    scheduleCursorFrame = () => {
+      if (paused || animationFrameId !== undefined) return;
+      lastFrameTime = performance.now();
       animationFrameId = requestAnimationFrame(tick);
     };
 
-    animationFrameId = requestAnimationFrame(tick);
+    const suspendCursor = () => {
+      paused = true;
+      if (animationFrameId !== undefined) {
+        cancelAnimationFrame(animationFrameId);
+        animationFrameId = undefined;
+      }
+      if (cursor) cursor.style.opacity = '0';
+    };
+
+    const resumeCursor = () => {
+      if (!paused) return;
+      paused = false;
+      lastFrameTime = performance.now();
+      if (!hasMoved) return;
+      if (cursor) cursor.style.opacity = '1';
+      scheduleCursorFrame();
+    };
+
+    const onVisibilityChange = () => {
+      if (document.visibilityState === 'hidden') suspendCursor();
+      else if (document.hasFocus()) resumeCursor();
+    };
+    const onWindowBlur = () => suspendCursor();
+    const onWindowFocus = () => {
+      if (document.visibilityState !== 'hidden') resumeCursor();
+    };
+
+    document.addEventListener('visibilitychange', onVisibilityChange);
+    window.addEventListener('blur', onWindowBlur);
+    window.addEventListener('focus', onWindowFocus);
+    onVisibilityChange();
 
     return () => {
       document.documentElement.classList.remove('hiddenCursor');
       document.removeEventListener('mouseleave', handleMouseLeave);
       document.removeEventListener('mouseenter', handleMouseEnter);
-      cancelAnimationFrame(animationFrameId);
+      document.removeEventListener('visibilitychange', onVisibilityChange);
+      window.removeEventListener('blur', onWindowBlur);
+      window.removeEventListener('focus', onWindowFocus);
+      scheduleCursorFrame = () => {};
+      suspendCursor();
       if (rotateSpringAnim) {
         rotateSpringAnim.pause();
       }

src/lib/theme/themeMedia.ts

@@ -532,12 +532,13 @@ export function themeMediaSuspension(node: HTMLElement) {
 
 /**
  * Manage background video playback across document visibility changes.
- * Videos continue playing when the launcher window loses focus. Muted background
- * videos pause only when the document is hidden/minimized to save GPU decoding
- * cycles without interrupting theme music or audio.
+ * Muted background videos pause when the document is hidden/minimized or the
+ * launcher loses focus, which saves GPU decoding cycles behind a running game
+ * without interrupting unmuted theme music or audio.
  */
 export function themeVideoLifecycle(node: HTMLVideoElement) {
   let pausedByLifecycle = false;
+  let focused = true;
 
   const pause = () => {
     if (node.paused) return;
@@ -551,12 +552,22 @@ export function themeVideoLifecycle(node: HTMLVideoElement) {
     playThemeMedia(node);
   };
 
+  const onBlur = () => {
+    focused = false;
+    sync();
+  };
+  const onFocus = () => {
+    focused = true;
+    sync();
+  };
   const sync = () => {
     if (!node.isConnected) {
       document.removeEventListener('visibilitychange', sync);
+      window.removeEventListener('blur', onBlur);
+      window.removeEventListener('focus', onFocus);
       return;
     }
-    if (document.visibilityState === 'visible') {
+    if (document.visibilityState === 'visible' && focused) {
       resume();
     } else if (node.muted || node.volume === 0) {
       pause();
@@ -564,11 +575,15 @@ export function themeVideoLifecycle(node: HTMLVideoElement) {
   };
 
   document.addEventListener('visibilitychange', sync);
+  window.addEventListener('blur', onBlur);
+  window.addEventListener('focus', onFocus);
   sync();
 
   return {
     destroy() {
       document.removeEventListener('visibilitychange', sync);
+      window.removeEventListener('blur', onBlur);
+      window.removeEventListener('focus', onFocus);
     },
   };
 }

src/lib/utils.ts

@@ -133,7 +133,7 @@ export const urlIsValidImage = async (url: string) => {
     const request = await fetch(url);
     if (!request.ok) return false;
     const contentType = request.headers.get('content-type');
-    return contentType?.startsWith('image/');
+    return contentType?.startsWith('image/') === true;
   } catch {
     return false;
   }

src/routes/+layout.svelte

@@ -71,6 +71,37 @@
 
   let { children } = $props();
 
+  function appActivity(node: HTMLElement) {
+    let focused = true;
+
+    const sync = () => {
+      node.classList.toggle('app-inactive', document.hidden || !focused);
+    };
+    const onBlur = () => {
+      focused = false;
+      sync();
+    };
+    const onFocus = () => {
+      focused = true;
+      sync();
+    };
+    const onVisibilityChange = () => sync();
+
+    window.addEventListener('blur', onBlur);
+    window.addEventListener('focus', onFocus);
+    document.addEventListener('visibilitychange', onVisibilityChange);
+    sync();
+
+    return {
+      destroy() {
+        window.removeEventListener('blur', onBlur);
+        window.removeEventListener('focus', onFocus);
+        document.removeEventListener('visibilitychange', onVisibilityChange);
+        node.classList.remove('app-inactive');
+      },
+    };
+  }
+
   let unlistenEditorState: (() => void) | undefined;
   let unlistenRequestEditorData: (() => void) | undefined;
   let unlistenPresenceEditorState: (() => void) | undefined;
@@ -552,6 +583,7 @@
   </AlertDialog.Root>
 
   <main
+    use:appActivity
     use:themeMediaSuspension
     use:themeParallax={{
       enabled: $active_custom_theme?.definition?.parallax?.enabled === true,

src/screens/Launch.svelte

@@ -1580,6 +1580,7 @@
       await getCurrentWindow().hide();
 
       let presenceUpdater: number | undefined = undefined;
+      const beatmapCoverValidity = new SvelteMap<string, boolean>();
 
       const isPresenceConnected = await presence.isConnected();
 
@@ -1592,8 +1593,10 @@
             return;
           }
           if ($currentUser) {
-            const userStats = await ezppfarm.getUserInfo($currentUser.id, 'stats');
-            const userStatus = await ezppfarm.getUserStatus($currentUser.id);
+            const [userStats, userStatus] = await Promise.all([
+              ezppfarm.getUserInfo($currentUser.id, 'stats'),
+              ezppfarm.getUserStatus($currentUser.id),
+            ]);
             if (userStatus?.player_status.online) {
               let actionName = 'Idle...';
               const gamemode = getModeAndTypeFromGamemode(userStatus.player_status.status.mode);
@@ -1648,7 +1651,15 @@
               if (beatmap !== null) {
                 beatmapString = `${beatmap.artist} - ${beatmap.title} [${beatmap.version}]`;
                 const coverCandidate = `https://assets.ppy.sh/beatmaps/${beatmap.set_id}/covers/[email protected]`;
-                const isValidImage = await urlIsValidImage(coverCandidate);
+                const cachedCoverValidity = beatmapCoverValidity.get(coverCandidate);
+                let isValidImage: boolean;
+                if (cachedCoverValidity === undefined) {
+                  isValidImage = await urlIsValidImage(coverCandidate);
+                  if (beatmapCoverValidity.size >= 32) beatmapCoverValidity.clear();
+                  beatmapCoverValidity.set(coverCandidate, isValidImage);
+                } else {
+                  isValidImage = cachedCoverValidity;
+                }
                 if (isValidImage) beatmapCoverImage = coverCandidate;
               }
 
@@ -1678,7 +1689,7 @@
               }
             }
           }
-        }, 1000 * 2);
+        }, 5000);
       }
 
       await runOsu(osuPath, $patch, $gameOptimization);