Extract beforeUpdate steps

src/main.js

@@ -636,6 +636,83 @@
     rebuildSceneBodies();
   };
 
+  const runSceneBeforeUpdateHook = () => {
+    if (
+      state.levelWon ||
+      typeof currentScene?.config?.onBeforeUpdate !== "function"
+    ) {
+      return;
+    }
+    currentScene.config.onBeforeUpdate({
+      engine,
+      width: state.width,
+      height: state.height,
+    });
+  };
+
+  const stepRopeConstraints = () => {
+    chain.constraints.forEach((c) => {
+      if (!c.plugin || !c.plugin.rope) return;
+      const current = Vector.magnitude(
+        Vector.sub(c.bodyA.position, c.bodyB.position),
+      );
+      const maxLen = c.plugin.maxLength ?? c.length;
+      if (current <= maxLen) {
+        c.length = current;
+        c.stiffness = 0;
+      } else {
+        c.length = maxLen;
+        c.stiffness = c.plugin.baseStiffness ?? c.stiffness;
+      }
+    });
+  };
+
+  const stepRotators = (dt, timeScale) => {
+    state.rotators.forEach((b) => {
+      const speed = b.plugin.rotSpeed || 0;
+      if (speed !== 0) {
+        Body.rotate(b, speed * ((dt * timeScale) / 1000));
+      }
+    });
+  };
+
+  const stepOscillators = () => {
+    state.oscillators.forEach((b) => {
+      const osc = b.plugin.oscillate;
+      if (!osc) return;
+      if (!osc.base) {
+        osc.base = { x: b.position.x, y: b.position.y };
+      }
+      const now = (engine.timing.timestamp || 0) / 1000;
+      const amplitude = osc.amplitude ?? 0;
+      const speed = osc.speed ?? 1;
+      const phase = osc.phase ?? 0;
+      const offset = Math.sin(now * speed + phase) * amplitude;
+      const target =
+        osc.axis === "x"
+          ? { x: osc.base.x + offset, y: osc.base.y }
+          : { x: osc.base.x, y: osc.base.y + offset };
+      Body.setPosition(b, target);
+      Body.setVelocity(b, { x: 0, y: 0 });
+    });
+  };
+
+  const stepTimer = () => {
+    if (!state.timerEndMs) return;
+    const winCond = currentScene?.config?.winCondition;
+    const duration = winCond?.durationSec ?? 120;
+    const now = Date.now();
+    const remainingMs = Math.max(0, state.timerEndMs - now);
+    const remainingSec = Math.ceil(remainingMs / 1000);
+    if (state.lastTimerDisplay !== remainingSec) {
+      state.lastTimerDisplay = remainingSec;
+      updateHud();
+    }
+    if (remainingMs <= 0 && !state.levelWon) {
+      checkWinCondition();
+    }
+  };
+
   Events.on(engine, "afterUpdate", () => {
     // Keep stray balls within the play area horizontally.
     state.balls.forEach((ball) => {
@@ -674,72 +751,15 @@
 
   Events.on(engine, "beforeUpdate", () => {
     // Rope-like constraint handling: allow shortening without push-back, tension when stretched.
-    if (
-      !state.levelWon &&
-      typeof currentScene?.config?.onBeforeUpdate === "function"
-    ) {
-      currentScene.config.onBeforeUpdate({
-        engine,
-        width: state.width,
-        height: state.height,
-      });
-    }
-    chain.constraints.forEach((c) => {
-      if (!c.plugin || !c.plugin.rope) return;
-      const current = Vector.magnitude(
-        Vector.sub(c.bodyA.position, c.bodyB.position),
-      );
-      const maxLen = c.plugin.maxLength ?? c.length;
-      if (current <= maxLen) {
-        c.length = current;
-        c.stiffness = 0;
-      } else {
-        c.length = maxLen;
-        c.stiffness = c.plugin.baseStiffness ?? c.stiffness;
-      }
-    });
-    // Rotate any scene rotators slowly.
+    runSceneBeforeUpdateHook();
+    stepRopeConstraints();
     const dt = (engine.timing && engine.timing.delta) || 16;
     const timeScale = engine.timing?.timeScale ?? 1;
     if (state.paused || state.gameOver || timeScale === 0) return;
-    state.rotators.forEach((b) => {
-      const speed = b.plugin.rotSpeed || 0;
-      if (speed !== 0) {
-        Body.rotate(b, speed * ((dt * timeScale) / 1000));
-      }
-    });
-    state.oscillators.forEach((b) => {
-      const osc = b.plugin.oscillate;
-      if (!osc) return;
-      if (!osc.base) {
-        osc.base = { x: b.position.x, y: b.position.y };
-      }
-      const now = (engine.timing.timestamp || 0) / 1000;
-      const amplitude = osc.amplitude ?? 0;
-      const speed = osc.speed ?? 1;
-      const phase = osc.phase ?? 0;
-      const offset = Math.sin(now * speed + phase) * amplitude;
-      const target =
-        osc.axis === "x"
-          ? { x: osc.base.x + offset, y: osc.base.y }
-          : { x: osc.base.x, y: osc.base.y + offset };
-      Body.setPosition(b, target);
-      Body.setVelocity(b, { x: 0, y: 0 });
-    });
-    if (state.timerEndMs) {
-      const winCond = currentScene?.config?.winCondition;
-      const duration = winCond?.durationSec ?? 120;
-      const now = Date.now();
-      const remainingMs = Math.max(0, state.timerEndMs - now);
-      const remainingSec = Math.ceil(remainingMs / 1000);
-      if (state.lastTimerDisplay !== remainingSec) {
-        state.lastTimerDisplay = remainingSec;
-        updateHud();
-      }
-      if (remainingMs <= 0 && !state.levelWon) {
-        checkWinCondition();
-      }
-    }
+    // Rotate any scene rotators slowly.
+    stepRotators(dt, timeScale);
+    stepOscillators();
+    stepTimer();
   });
 
   Events.on(render, "afterRender", () => {