minor fixing, adapting for mobile web

src/Character.cpp

@@ -205,7 +205,23 @@ void Character::update(int64_t deltaMs) {
                     cb();
             }
 
-            targetFacingAngle = facingAngle;
+            // While standing, optionally orient toward another character (e.g. the
+            // player when this NPC is being talked to). The smoothed rotation block
+            // below converges facingAngle to targetFacingAngle.
+            if (faceTarget) {
+                Eigen::Vector3f toFace = faceTarget->position - position;
+                toFace.y() = 0.f;
+                float d = toFace.norm();
+                if (d > 1e-3f) {
+                    targetFacingAngle = atan2(toFace.x() / d, -toFace.z() / d);
+                }
+                else {
+                    targetFacingAngle = facingAngle;
+                }
+            }
+            else {
+                targetFacingAngle = facingAngle;
+            }
         }
     }
 
@@ -267,6 +283,10 @@ void Character::update(int64_t deltaMs) {
     float rotStep = rotationSpeed * static_cast<float>(deltaMs) / 1000.f;
     if (std::fabs(angleDiff) <= rotStep) {
         facingAngle = targetFacingAngle;
+        // One-shot face-target: once aligned, stop tracking. Otherwise the NPC
+        // would keep snapping to the player every tick after the conversation
+        // started, even as the player moved away.
+        faceTarget = nullptr;
     } else {
         facingAngle += (angleDiff > 0.f ? rotStep : -rotStep);
     }