From 6e982ff7723e3f2248113e2321678b5ee976b54f Mon Sep 17 00:00:00 2001
From: alexpaynex <55271826-alexpaynex@users.noreply.replit.com>
Date: Thu, 19 Mar 2026 03:18:20 +0000
Subject: [PATCH] Improve mouth geometry performance by precomputing all shapes

Optimize mouth geometry generation by precomputing a cache of shapes, eliminating runtime allocations and reducing garbage collection pressure during animations.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 418bf6f8-212b-4bb0-a7a5-8231a061da4e
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Event-Id: 92d6d2fb-91ca-4dea-98b6-ff5053cb5ac7
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/9f85e954-647c-46a5-90a7-396e495a805a/418bf6f8-212b-4bb0-a7a5-8231a061da4e/Q83Uqvu
Replit-Helium-Checkpoint-Created: true
---
 the-matrix/js/agents.js | 40 ++++++++++++++++++++++++++--------------
 1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/the-matrix/js/agents.js b/the-matrix/js/agents.js
index 5c990a3..058740d 100644
--- a/the-matrix/js/agents.js
+++ b/the-matrix/js/agents.js
@@ -38,11 +38,16 @@ const MOOD_ALIASES = {
   working:       'working',
 };
 
-// ── Mouth arc geometry helpers ────────────────────────────────────────────────
+// ── Mouth arc geometry — precomputed cache (no runtime allocation) ────────────
+// 21 steps from smileAmount -1.0 → +1.0 (step 0.1). All geometries built once
+// at module init; updateAgents() just swaps references → zero GC pressure.
+
+const _MOUTH_GEO_STEPS = 21;
+const _MOUTH_GEO_MIN   = -1.0;
+const _MOUTH_GEO_MAX   =  1.0;
 
 function _buildMouthGeo(smileAmount) {
-  // smileAmount: +1 = smile (arc bows down), 0 = flat, -1 = frown (arc bows up)
-  const ctrlY = -smileAmount * 0.065; // control point moves down for smile
+  const ctrlY = -smileAmount * 0.065; // control point: down for smile, up for frown
   const curve = new THREE.QuadraticBezierCurve3(
     new THREE.Vector3(-0.115,  0.000, 0.000),
     new THREE.Vector3( 0.000, ctrlY,  0.020),
@@ -51,6 +56,17 @@ function _buildMouthGeo(smileAmount) {
   return new THREE.TubeGeometry(curve, 12, 0.013, 5, false);
 }
 
+const _MOUTH_GEO_CACHE = Array.from({ length: _MOUTH_GEO_STEPS }, (_, i) => {
+  const t = i / (_MOUTH_GEO_STEPS - 1);
+  return _buildMouthGeo(_MOUTH_GEO_MIN + t * (_MOUTH_GEO_MAX - _MOUTH_GEO_MIN));
+});
+
+function _pickMouthGeo(smileAmount) {
+  const clamped = Math.max(_MOUTH_GEO_MIN, Math.min(_MOUTH_GEO_MAX, smileAmount));
+  const idx = Math.round((clamped - _MOUTH_GEO_MIN) / (_MOUTH_GEO_MAX - _MOUTH_GEO_MIN) * (_MOUTH_GEO_STEPS - 1));
+  return _MOUTH_GEO_CACHE[idx];
+}
+
 // ── Build Timmy ───────────────────────────────────────────────────────────────
 
 export function initAgents(sceneRef) {
@@ -115,8 +131,7 @@ function buildTimmy(sc) {
     roughness: 0.7,
     metalness: 0.0,
   });
-  const mouthInitialGeo = _buildMouthGeo(0.08); // start at idle smile
-  const mouth = new THREE.Mesh(mouthInitialGeo, mouthMat);
+  const mouth = new THREE.Mesh(_pickMouthGeo(0.08), mouthMat); // start at idle smile
   // Position in head-local space: lower face (y=-0.18), on the face surface (z≈0.30)
   mouth.position.set(0, -0.18, 0.30);
   head.add(mouth);
@@ -218,8 +233,6 @@ function buildTimmy(sc) {
     faceTarget:   { lidScale: 0.44, pupilScale: 0.90, smileAmount: 0.08 },
     // External override: when non-null, setFaceEmotion() takes precedence over derived state
     _overrideMood: null,
-    // Track last geometry rebuild to throttle TubeGeometry updates
-    _lastMouthSmile: 0.08,
   };
 }
 
@@ -322,12 +335,10 @@ export function updateAgents(time) {
   timmy.pupilL.scale.setScalar(ps);
   timmy.pupilR.scale.setScalar(ps);
 
-  // Rebuild TubeGeometry mouth arc when smile value changes enough
-  const smileDelta = Math.abs(timmy.faceParams.smileAmount - timmy._lastMouthSmile);
-  if (smileDelta > 0.016) {
-    timmy.mouth.geometry.dispose();
-    timmy.mouth.geometry = _buildMouthGeo(timmy.faceParams.smileAmount);
-    timmy._lastMouthSmile = timmy.faceParams.smileAmount;
+  // Swap precomputed mouth geometry when cached index changes (zero runtime allocation)
+  const nextMouthGeo = _pickMouthGeo(timmy.faceParams.smileAmount);
+  if (timmy.mouth.geometry !== nextMouthGeo) {
+    timmy.mouth.geometry = nextMouthGeo;
   }
 }
 
@@ -425,7 +436,8 @@ export function disposeAgents() {
   [timmy.eyeL, timmy.eyeR].forEach(m => {
     if (m) { m.geometry?.dispose(); m.material?.dispose(); }
   });
-  timmy.mouth?.geometry?.dispose();
+  // Cached mouth geometries are shared; dispose the cache here
+  _MOUTH_GEO_CACHE.forEach(g => g.dispose());
   timmy.mouth?.material?.dispose();
   timmy.bubbleTex?.dispose();
   timmy.bubbleMat?.dispose();