From 955f408f6317bd4192119c461baf5ad3ba8f2c9e Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Wed, 14 Jan 2026 21:46:54 +0000
Subject: [PATCH] Optimize EntityManager::getTransforms to reuse memory

- Added `mutable std::vector<Transform> cachedTransforms` to EntityManager.
- Updated `getTransforms` to return `const std::vector<Transform>&`.
- Reused `cachedTransforms` to avoid per-frame allocation.
- Updated `main.cpp` to use the returned reference.
---
 src/EntityManager.h | 11 ++++++-----
 src/main.cpp        |  2 +-
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/EntityManager.h b/src/EntityManager.h
index 3720a3f..e65603e 100644
--- a/src/EntityManager.h
+++ b/src/EntityManager.h
@@ -9,6 +9,7 @@ class EntityManager {
 private:
     std::vector<std::unique_ptr<Entity>> entities;
     std::unordered_map<std::string, Entity*> entityMap;
+    mutable std::vector<Transform> cachedTransforms;
 
 public:
     // Add entity to the scene
@@ -38,13 +39,13 @@ class EntityManager {
     }
 
     // Get all transforms for acceleration structure
-    std::vector<Transform> getTransforms() const {
-        std::vector<Transform> transforms;
-        transforms.reserve(entities.size());
+    const std::vector<Transform>& getTransforms() const {
+        cachedTransforms.clear();
+        cachedTransforms.reserve(entities.size());
         for (const auto& entity : entities) {
-            transforms.push_back(entity->transform);
+            cachedTransforms.push_back(entity->transform);
         }
-        return transforms;
+        return cachedTransforms;
     }
 
     // Get entity by name
diff --git a/src/main.cpp b/src/main.cpp
index 4d62011..72b5d54 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -834,7 +834,7 @@ class RacingEngine {
 
             // Prepare TLAS instance data (CPU-side, before command buffer recording)
             if (entityManager.countDynamic() > 0) {
-                auto transforms = entityManager.getTransforms();
+                const auto& transforms = entityManager.getTransforms();
                 acceleration.prepareInstanceData(device, transforms);
             }