From 508881091a4ed05ce651c87bf5ecbda5292d2b0f Mon Sep 17 00:00:00 2001
From: Antoine Pilote <antoinepilote1@hotmail.com>
Date: Thu, 25 Apr 2024 21:43:48 -0400
Subject: [PATCH] Physics now calculates proper local transform if body has
 parent

---
 Nuake/src/Physics/DynamicWorld.cpp | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/Nuake/src/Physics/DynamicWorld.cpp b/Nuake/src/Physics/DynamicWorld.cpp
index a4e00f66..d8f8f145 100644
--- a/Nuake/src/Physics/DynamicWorld.cpp
+++ b/Nuake/src/Physics/DynamicWorld.cpp
@@ -33,6 +33,7 @@
 #include <Jolt/Core/TempAllocator.h>
 
 #include <dependencies/JoltPhysics/Jolt/Physics/Collision/CollisionCollectorImpl.h>
+#include <src/Scene/Components/ParentComponent.h>
 
 namespace Nuake
 {
@@ -529,14 +530,23 @@ namespace Nuake
 						joltTransform(0, 3), joltTransform(1, 3), joltTransform(2, 3), joltTransform(3, 3)
 					);
 
+					Entity entity = { (entt::entity)entId, Engine::GetCurrentScene().get() };
+					if (entity.GetComponent<ParentComponent>().HasParent)
+					{
+						auto& parent = entity.GetComponent<ParentComponent>().Parent;
+						auto& parentTransformComponent = parent.GetComponent<TransformComponent>();
+						const Matrix4& parentTransform = parentTransformComponent.GetGlobalTransform();
+
+						transform = glm::inverse(parentTransform) * transform;
+					}
+
 					Vector3 scale = Vector3();
 					Quat rotation = Quat();
 					Vector3 pos = Vector3();
 					Vector3 skew = Vector3();
 					Vector4 pesp = Vector4();
 					glm::decompose(transform, scale, rotation, pos, skew, pesp);
-
-					Entity entity = { (entt::entity)entId, Engine::GetCurrentScene().get() };
+					
 					auto& transformComponent = entity.GetComponent<TransformComponent>();
 					transformComponent.SetLocalPosition(pos);
 					transformComponent.SetLocalRotation(Quat(bodyRotation.GetW(), bodyRotation.GetX(), bodyRotation.GetY(), bodyRotation.GetZ()));
@@ -563,6 +573,15 @@ namespace Nuake
 					joltTransform(0, 3), joltTransform(1, 3), joltTransform(2, 3), joltTransform(3, 3)
 				);
 
+				if(entity.GetComponent<ParentComponent>().HasParent)
+				{
+					auto& parent = entity.GetComponent<ParentComponent>().Parent;
+					auto& parentTransformComponent = parent.GetComponent<TransformComponent>();
+					const Matrix4& parentTransform = parentTransformComponent.GetGlobalTransform();
+
+					transform = glm::inverse(parentTransform) * transform;
+				}
+
 				Vector3 scale = Vector3();
 				Quat rotation = Quat();
 				Vector3 pos = Vector3();