From f56d6a7fc8dc7aae290fd28ae995c9e40016373b Mon Sep 17 00:00:00 2001
From: Syntriax <Syntriax@gmail.com>
Date: Mon, 9 Jun 2025 20:27:29 +0300
Subject: [PATCH] chore: standalone physics engine not having pooled lists
 fixed

---
 Engine.Physics2D/PhysicsEngine2DStandalone.cs | 22 ++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/Engine.Physics2D/PhysicsEngine2DStandalone.cs b/Engine.Physics2D/PhysicsEngine2DStandalone.cs
index dc16d4c..5998f04 100644
--- a/Engine.Physics2D/PhysicsEngine2DStandalone.cs
+++ b/Engine.Physics2D/PhysicsEngine2DStandalone.cs
@@ -21,6 +21,12 @@ public class PhysicsEngine2DStandalone : IPhysicsEngine2D
     private readonly ICollisionResolver2D collisionResolver = null!;
     private readonly IRaycastResolver2D raycastResolver = null!;
 
+    private readonly ListPool<ICollider2D> colliderPool = new(() => new(32));
+    private readonly ListPool<IPrePhysicsUpdate> prePhysicsUpdatePool = new(() => new(32));
+    private readonly ListPool<IPhysicsUpdate> physicsUpdatePool = new(() => new(32));
+    private readonly ListPool<IPhysicsIteration> physicsIterationPool = new(() => new(32));
+    private readonly ListPool<IPostPhysicsUpdate> postPhysicsUpdatePool = new(() => new(32));
+
     public int IterationPerStep { get => _iterationCount; set => _iterationCount = value < 1 ? 1 : value; }
 
     public void AddRigidBody(IRigidBody2D rigidBody)
@@ -112,11 +118,11 @@ public class PhysicsEngine2DStandalone : IPhysicsEngine2D
     {
         float intervalDeltaTime = deltaTime / IterationPerStep;
 
-        List<ICollider2D> childColliders = [];
-        List<IPrePhysicsUpdate> physicsPreUpdates = [];
-        List<IPhysicsUpdate> physicsUpdates = [];
-        List<IPhysicsIteration> physicsIterations = [];
-        List<IPostPhysicsUpdate> physicsPostUpdates = [];
+        List<ICollider2D> childColliders = colliderPool.Get();
+        List<IPrePhysicsUpdate> physicsPreUpdates = prePhysicsUpdatePool.Get();
+        List<IPhysicsUpdate> physicsUpdates = physicsUpdatePool.Get();
+        List<IPhysicsIteration> physicsIterations = physicsIterationPool.Get();
+        List<IPostPhysicsUpdate> physicsPostUpdates = postPhysicsUpdatePool.Get();
 
         rigidBody.BehaviourController.GetBehavioursInChildren(childColliders);
         rigidBody.BehaviourController.GetBehavioursInChildren(physicsPreUpdates);
@@ -160,6 +166,12 @@ public class PhysicsEngine2DStandalone : IPhysicsEngine2D
 
         for (int i = physicsPostUpdates.Count - 1; i >= 0; i--)
             physicsPostUpdates[i].PostPhysicsUpdate(deltaTime);
+
+        colliderPool.Return(childColliders);
+        prePhysicsUpdatePool.Return(physicsPreUpdates);
+        physicsUpdatePool.Return(physicsUpdates);
+        physicsIterationPool.Return(physicsIterations);
+        postPhysicsUpdatePool.Return(physicsPostUpdates);
     }
 
     private void ResolveColliders(ICollider2D colliderX, ICollider2D colliderY)