Reworked SceneGraph Interface

Assets/Scenes/M2Scene.shade

@@ -124,48 +124,6 @@
       Mesh: 144838771
       Material: 123745521
   Scripts: ~
-- EID: 5
-  Name: item
-  IsActive: true
-  NumberOfChildren: 0
-  Components:
-    Transform Component:
-      Translate: {x: 0, y: -2, z: -5}
-      Rotate: {x: 0, y: 0, z: 0}
-      Scale: {x: 2, y: 2, z: 2}
-    Renderable Component:
-      Mesh: 144838771
-      Material: 123745521
-    RigidBody Component:
-      Type: Dynamic
-      Mass: 1
-      Drag: 0
-      Angular Drag: 0
-      Use Gravity: true
-      Interpolate: false
-      Freeze Position X: false
-      Freeze Position Y: false
-      Freeze Position Z: false
-      Freeze Rotation X: true
-      Freeze Rotation Y: true
-      Freeze Rotation Z: true
-    Collider Component:
-      Colliders:
-        - Is Trigger: false
-          Type: Box
-          Half Extents: {x: 1, y: 1, z: 1}
-          Friction: 0.400000006
-          Bounciness: 0
-          Density: 1
-          Position Offset: {x: 0, y: 0.5, z: 0}
-        - Is Trigger: true
-          Type: Box
-          Half Extents: {x: 2, y: 2, z: 2}
-          Friction: 0.400000006
-          Bounciness: 0
-          Density: 1
-          Position Offset: {x: 0, y: 0.5, z: 0}
-  Scripts: ~
 - EID: 6
   Name: AI
   IsActive: true
@@ -226,4 +184,46 @@
       Color: {x: 1, y: 1, z: 1, w: 1}
       Layer: 4294967295
       Strength: 0.25
+  Scripts: ~
+- EID: 5
+  Name: item
+  IsActive: true
+  NumberOfChildren: 0
+  Components:
+    Transform Component:
+      Translate: {x: 0, y: -2, z: -5}
+      Rotate: {x: 0, y: 0, z: 0}
+      Scale: {x: 2, y: 2, z: 2}
+    Renderable Component:
+      Mesh: 144838771
+      Material: 123745521
+    RigidBody Component:
+      Type: Dynamic
+      Mass: 1
+      Drag: 0
+      Angular Drag: 0
+      Use Gravity: true
+      Interpolate: false
+      Freeze Position X: false
+      Freeze Position Y: false
+      Freeze Position Z: false
+      Freeze Rotation X: true
+      Freeze Rotation Y: true
+      Freeze Rotation Z: true
+    Collider Component:
+      Colliders:
+        - Is Trigger: false
+          Type: Box
+          Half Extents: {x: 1, y: 1, z: 1}
+          Friction: 0.400000006
+          Bounciness: 0
+          Density: 1
+          Position Offset: {x: 0, y: 0.5, z: 0}
+        - Is Trigger: true
+          Type: Box
+          Half Extents: {x: 2, y: 2, z: 2}
+          Friction: 0.400000006
+          Bounciness: 0
+          Density: 1
+          Position Offset: {x: 0, y: 0.5, z: 0}
   Scripts: ~

SHADE_Engine/src/Editor/EditorWindow/HierarchyPanel/SHHierarchyPanel.cpp

@@ -419,7 +419,7 @@ namespace SHADE
 
   void SHEntityParentCommand::Execute()
   {
-    auto const& sceneGraph = SHSceneManager::GetCurrentSceneGraph();
+    auto& sceneGraph = SHSceneManager::GetCurrentSceneGraph();
     for (auto const& eid : entities)
     {
       if (entityParentData[eid].newParentEID == MAX_EID)
@@ -431,7 +431,7 @@ namespace SHADE
 
   void SHEntityParentCommand::Undo()
   {
-    auto const& sceneGraph = SHSceneManager::GetCurrentSceneGraph();
+    auto& sceneGraph = SHSceneManager::GetCurrentSceneGraph();
     for (auto const& eid : entities)
     {
       if (entityParentData[eid].oldParentEID == MAX_EID)

SHADE_Engine/src/Scene/SHSceneGraph.cpp

@@ -16,8 +16,6 @@
 // Project Headers
 #include "ECS_Base/Managers/SHEntityManager.h"
 #include "Events/SHEventManager.hpp"
-#include "Tools/SHLogger.h"
-#include "Tools/SHException.h"
 
 namespace SHADE
 {
@@ -25,56 +23,6 @@ namespace SHADE
   /* Constructors & Destructor Definitions                                             */
   /*-----------------------------------------------------------------------------------*/
 
-  SHSceneNode::SHSceneNode(EntityID eid, SHSceneNode* parent) noexcept
-  : active  { true }
-  , entityID  { eid }
-  , parent    { parent }
-  {}
-
-
-  SHSceneNode::SHSceneNode(const SHSceneNode& rhs) noexcept
-  : active    { rhs.active }
-  , entityID  { rhs.entityID }
-  , parent    { rhs.parent }
-  {
-    std::ranges::copy(rhs.children.begin(), rhs.children.end(), std::back_inserter(children));
-  }
-
-  SHSceneNode::SHSceneNode(SHSceneNode&& rhs) noexcept
-  : active    { rhs.active }
-  , entityID  { rhs.entityID }
-  , parent    { rhs.parent }
-  {
-    std::ranges::copy(rhs.children.begin(), rhs.children.end(), std::back_inserter(children));
-  }
-
-  SHSceneNode& SHSceneNode::operator=(const SHSceneNode& rhs) noexcept
-  {
-    if (this == &rhs)
-      return *this;
-
-    active    = rhs.active;
-    entityID  = rhs.entityID;
-    parent    = rhs.parent;
-
-    children.clear();
-    std::ranges::copy(rhs.children.begin(), rhs.children.end(), std::back_inserter(children));
-
-    return *this;
-  }
-
-  SHSceneNode& SHSceneNode::operator=(SHSceneNode&& rhs) noexcept
-  {
-    active    = rhs.active;
-    entityID  = rhs.entityID;
-    parent    = rhs.parent;
-
-    children.clear();
-    std::ranges::copy(rhs.children.begin(), rhs.children.end(), std::back_inserter(children));
-
-    return *this;
-  }
-
   SHSceneGraph::SHSceneGraph() noexcept
   : root { nullptr }
   {
@@ -110,56 +58,6 @@ namespace SHADE
   /* Getter Function Definitions                                                       */
   /*-----------------------------------------------------------------------------------*/
 
-  bool SHSceneNode::IsActive() const noexcept
-  {
-    return active;
-  }
-
-  EntityID SHSceneNode::GetEntityID() const noexcept
-  {
-    return entityID;
-  }
-
-  SHSceneNode* SHSceneNode::GetParent() const noexcept
-  {
-    return parent;
-  }
-
-  const std::vector<SHSceneNode*>& SHSceneNode::GetChildren() const noexcept
-  {
-    return children;
-  }
-
-  SHSceneNode* SHSceneNode::GetChild(EntityID childID) const noexcept
-  {
-    ////////////////////////////////////////
-    // Error handling
-    if (!SHEntityManager::IsValidEID(childID))
-    {
-      SHLOG_ERROR("Child Entity {} is invalid! Unable to get child from Entity {}", childID, entityID)
-      return nullptr;
-    }
-
-    if (children.empty())
-    {
-      SHLOG_WARNING("Entity {} has no children!", entityID)
-      return nullptr;
-    }
-    ////////////////////////////////////////
-
-    // Find child
-    const auto ENTITY_MATCH = [&](const SHSceneNode* node) { return node->GetEntityID() == childID; };
-
-    const auto CHILD_ITER = std::ranges::find_if(children.begin(), children.end(),ENTITY_MATCH);
-    if (CHILD_ITER == children.end())
-    {
-      SHLOG_WARNING("Entity {} is not a child of Entity {}! Unable to retrieve child node!", childID, entityID)
-      return nullptr;
-    }
-
-    return *CHILD_ITER;
-  }
-
   const SHSceneNode* SHSceneGraph::GetRoot() const noexcept
   {
     if (root != nullptr)
@@ -313,41 +211,7 @@ namespace SHADE
   /* Setter Function Definitions                                                       */
   /*-----------------------------------------------------------------------------------*/
 
-  void SHSceneNode::SetParent(SHSceneNode* parentNode) noexcept
+  void SHSceneGraph::SetParent(EntityID entityID, SHSceneNode* newParent) noexcept
-  {
-    if (parentNode == nullptr)
-    {
-      SHLOG_WARNING("Removing Entity {}'s parent", entityID)
-
-      if (parent)
-        parent->RemoveChild(this);
-
-      return;
-    }
-
-    // Handle self assignment
-    if (parent && parentNode->entityID == parent->entityID)
-      return;
-
-    if (parent)
-      parent->RemoveChild(this);
-
-    parent = parentNode;
-    // Update parent's children
-    parent->AddChild(this);
-  }
-
-  void SHSceneNode::SetActive(bool newActiveState) noexcept
-  {
-    active = newActiveState;
-
-    for (auto* child : children)
-    {
-      SetActive(newActiveState);
-    }
-  }
-
-  void SHSceneGraph::SetParent(EntityID entityID, SHSceneNode* parent) const noexcept
   {
     ////////////////////////////////////////
     // Error Handling
@@ -369,18 +233,33 @@ namespace SHADE
     {
       .node       = NODE_ITER->second
     , .oldParent  = NODE_ITER->second->GetParent()
-    , .newParent  = parent ? parent : root
+    , .newParent  = newParent ? newParent : root
     };
 
-    if (parent == nullptr)
+    if (newParent == nullptr)
-      parent = root;
+      newParent = root;
 
-    NODE_ITER->second->SetParent(parent);
+    ChangeParent(NODE_ITER->second, newParent);
 
     SHEventManager::BroadcastEvent<SHSceneGraphChangeParentEvent>(EVENT_DATA, SH_SCENEGRAPH_CHANGE_PARENT_EVENT);
   }
 
-  void SHSceneGraph::SetParent(EntityID entityID, EntityID parent) const noexcept
+  void SHSceneGraph::SetParent(SHSceneNode* node, SHSceneNode* newParent) noexcept
+  {
+    const SHSceneGraphChangeParentEvent EVENT_DATA
+    {
+      .node       = node
+    , .oldParent  = node->parent
+    , .newParent  = newParent ? newParent : root
+    };
+
+    if (newParent == nullptr)
+      newParent = root;
+
+    ChangeParent(node, newParent);
+  }
+
+  void SHSceneGraph::SetParent(EntityID entityID, EntityID newParent) noexcept
   {
     ////////////////////////////////////////
     // Error Handling
@@ -390,9 +269,9 @@ namespace SHADE
       return;
     }
 
-    if (!SHEntityManager::IsValidEID(parent))
+    if (!SHEntityManager::IsValidEID(newParent))
     {
-      SHLOG_ERROR("Parent Entity {} is invalid! Unable to set Entity {}'s parent!", parent, entityID)
+      SHLOG_ERROR("Parent Entity {} is invalid! Unable to set Entity {}'s parent!", newParent, entityID)
       return;
     }
 
@@ -403,10 +282,10 @@ namespace SHADE
       return;
     }
 
-    auto PARENT_ITER = entityNodeMap.find(parent);
+    auto PARENT_ITER = entityNodeMap.find(newParent);
     if (PARENT_ITER == entityNodeMap.end())
     {
-      SHLOG_ERROR("Entity {} cannot be found in the scene! Unable to parent to Entity {}", parent, entityID)
+      SHLOG_ERROR("Entity {} cannot be found in the scene! Unable to parent to Entity {}", newParent, entityID)
       return;
     }
     ////////////////////////////////////////
@@ -419,92 +298,46 @@ namespace SHADE
     };
 
     SHSceneNode* currentNode = NODE_ITER->second;
-    currentNode->SetParent(PARENT_ITER->second);
+    ChangeParent(currentNode, PARENT_ITER->second);
 
     SHEventManager::BroadcastEvent<SHSceneGraphChangeParentEvent>(EVENT_DATA, SH_SCENEGRAPH_CHANGE_PARENT_EVENT);
   }
 
-  /*-----------------------------------------------------------------------------------*/
+  void SHSceneGraph::SetParent(SHSceneNode* node, EntityID newParent) noexcept
-  /* Public Function Member Definitions                                                */
-  /*-----------------------------------------------------------------------------------*/
-
-  void SHSceneNode::AddChild(SHSceneNode* newChild) noexcept
   {
     ////////////////////////////////////////
     // Error Handling
-    if (newChild == nullptr)
+
+    if (!SHEntityManager::IsValidEID(newParent))
     {
-      SHLOG_WARNING("Attempting to add a non-existent child to an entity!")
+      SHLOG_ERROR("Parent Entity {} is invalid! Unable to set Entity {}'s parent!", newParent, node->entityID)
+      return;
+    }
+
+    auto PARENT_ITER = entityNodeMap.find(newParent);
+    if (PARENT_ITER == entityNodeMap.end())
+    {
+      SHLOG_ERROR("Entity {} cannot be found in the scene! Unable to parent to Entity {}", newParent, node->entityID)
       return;
     }
     ////////////////////////////////////////
 
-    if (newChild->parent)
+    const SHSceneGraphChangeParentEvent EVENT_DATA
-      newChild->parent->RemoveChild(newChild);
+    {
-    
+      .node       = node
-    newChild->parent = this;
+    , .oldParent  = node->parent
-    children.emplace_back(newChild);
+    , .newParent  = PARENT_ITER->second
+    };
+
+    ChangeParent(node, PARENT_ITER->second);
+
+    SHEventManager::BroadcastEvent<SHSceneGraphChangeParentEvent>(EVENT_DATA, SH_SCENEGRAPH_CHANGE_PARENT_EVENT);
   }
 
-  bool SHSceneNode::RemoveChild(EntityID childID) noexcept
-  {
-    ////////////////////////////////////////
-    // Error Handling
-    if (!SHEntityManager::IsValidEID(childID))
-    {
-      SHLOG_ERROR("Entity {} is invalid!", childID)
-      return false;
-    }
-    ////////////////////////////////////////
 
-    auto childIter = std::find_if(children.begin(), children.end(), [&](SHSceneNode* node)
+  /*-----------------------------------------------------------------------------------*/
-    {
+  /* Public Function Member Definitions                                                */
-      return node->GetEntityID() == childID;
+  /*-----------------------------------------------------------------------------------*/
-    });
-
-    if (childIter == children.end())
-    {
-      SHLOG_WARNING("Unable to remove Entity {} from Entity {} since it is not it's child!", childID, entityID)
-      return false;
-    }
-
-    (*childIter)->parent = nullptr;
-    childIter = children.erase(childIter);
-
-    return true;
-  }
-
-  bool SHSceneNode::RemoveChild(SHSceneNode* childToRemove) noexcept
-  {
-    ////////////////////////////////////////
-    // Error Handling
-    if (childToRemove == nullptr)
-    {
-      SHLOG_WARNING("Attempting to remove non-existent child from Entity {}", entityID)
-      return false;
-    }
-    ////////////////////////////////////////
-
-    auto childIter = std::find(children.begin(), children.end(), childToRemove);
-    if (childIter == children.end())
-    {
-      SHLOG_WARNING("Unable to remove Entity {} from Entity {} since it is not it's child!", childToRemove->entityID, entityID)
-      return false;
-    }
-
-    childIter = children.erase(childIter);
-    childToRemove->parent = nullptr;
-
-    return true;
-  }
-
-  void SHSceneNode::RemoveAllChildren() noexcept
-  {
-    for (const auto child : children)
-      child->parent = nullptr;
-
-    children.clear();
-  }
 
   SHSceneNode* SHSceneGraph::AddNode(EntityID entityID, SHSceneNode* parent)
   {
@@ -528,13 +361,12 @@ namespace SHADE
     if (parent == nullptr)
     {
       // Specific handling for root to avoid a warning when removing a non-existent child
-      parent = root;
       newNode->parent = root;
       root->children.emplace_back(newNode);
     }
     else
     {
-      newNode->SetParent(parent);
+      ChangeParent(newNode, parent);
     }
 
     return newNode;
@@ -557,9 +389,8 @@ namespace SHADE
 
     // Remove reference of current node from parent
     SHSceneNode* currentNode = NODE_ITER->second;
-    SHSceneNode* parent = currentNode->GetParent();
+    if (currentNode->parent != nullptr)
-    if (parent != nullptr)
+      RemoveChild(currentNode->parent, currentNode);
-      parent->RemoveChild(currentNode);
 
     ReleaseNode(currentNode);
     return true;
@@ -568,9 +399,8 @@ namespace SHADE
   bool SHSceneGraph::RemoveNode(SHSceneNode* nodeToRemove) noexcept
   {
     // Remove reference of current node from parent
-    SHSceneNode* parent = nodeToRemove->GetParent();
+    if (nodeToRemove->parent != nullptr)
-    if (parent != nullptr)
+      RemoveChild(nodeToRemove->parent, nodeToRemove);
-      parent->RemoveChild(nodeToRemove);
 
     ReleaseNode(nodeToRemove);
     return true;
@@ -594,11 +424,6 @@ namespace SHADE
   SHSceneNode* SHSceneGraph::AllocateNode(EntityID entityID)
   {
     SHSceneNode* newNode = new SHSceneNode{entityID};
-
-    //#ifdef _DEBUG
-    //  SHLOG_INFO("Allocated a new Scene Node for Entity {}!", entityID)
-    //#endif
-
     entityNodeMap.emplace(entityID, newNode);
     return newNode;
   }
@@ -608,19 +433,65 @@ namespace SHADE
     SHASSERT(node != nullptr, "Attempting to release Invalid Node!")
 
     // Remove parent's reference to this node if there is a parent
-    if (node->GetParent() != nullptr)
+    if (node->parent != nullptr)
-      node->GetParent()->RemoveChild(node);
+      RemoveChild(node->parent, node);
 
     // Remove child's references to this node. Children end up as floating nodes.
     for (auto* child : node->GetChildren())
     {
-      child->SetParent(nullptr);
+      ChangeParent(child, nullptr);
     }
 
     entityNodeMap.erase(node->GetEntityID());
     delete node;
   }
 
+  void SHSceneGraph::ChangeParent(SHSceneNode* node, SHSceneNode* newParent)
+  {
+    // Handle self assignment
+    if (node->parent != nullptr && newParent != nullptr && node->parent->entityID == newParent->entityID)
+      return;
+
+    // Remove child
+    if (node->parent)
+      RemoveChild(node->parent, node);
+
+    if (newParent == nullptr)
+    {
+      SHLOG_WARNING("Removing Entity {}'s parent", node->entityID)
+      return;
+    }
+
+    node->parent = newParent;
+    // Update parent's children
+    AddChild(newParent, node);
+  }
+
+  void SHSceneGraph::AddChild(SHSceneNode* node, SHSceneNode* newChild)
+  {
+    SHASSERT(node != nullptr, "Attempting to modify a non-existent scene node!")
+    SHASSERT(newChild != nullptr, "Attempting to add a non-existent child to a SceneNode!")
+
+    if (newChild->parent)
+      RemoveChild(newChild->parent, newChild);
+    
+    newChild->parent = node;
+    node->children.emplace_back(newChild);
+  }
+
+  void SHSceneGraph::RemoveChild(SHSceneNode* node, SHSceneNode* childToRemove)
+  {
+    SHASSERT(node != nullptr, "Attempting to modify a non-existent scene node!")
+    SHASSERT(childToRemove != nullptr, "Attempting to remove a non-existent child from a SceneNode!")
+
+    auto childIter = std::find(node->children.begin(), node->children.end(), childToRemove);
+    if (childIter == node->children.end())
+      return;
+
+    childIter = node->children.erase(childIter);
+    childToRemove->parent = nullptr;
+  }
+
   void SHSceneGraph::TraverseAndInvokeFunction(const SHSceneNode* node, const UnaryFunction& function)
   {
     for (auto* child : node->children)

SHADE_Engine/src/Scene/SHSceneGraph.h

@@ -1,7 +1,7 @@
 /****************************************************************************************
  * \file      SHSceneGraph.h
  * \author    Diren D Bharwani, diren.dbharwani, 390002520
- * \brief     Interface for a Scene Graph & Scene Nodes.
+ * \brief     Interface for a Scene Graph.
  *
  * \copyright Copyright (C) 2022 DigiPen Institute of Technology. Reproduction or
  *            disclosure of this file or its contents without the prior written consent
@@ -15,81 +15,14 @@
 // Project Headers
 #include "ECS_Base/Entity/SHEntity.h"
 #include "SH_API.h"
+#include "SHSceneNode.h"
 
 namespace SHADE
 {
-  /*-----------------------------------------------------------------------------------*/
-  /* Forward Declarations                                                              */
-  /*-----------------------------------------------------------------------------------*/
-
-  class SHSceneGraph;
-
   /*-----------------------------------------------------------------------------------*/
   /* Type Definitions                                                                  */
   /*-----------------------------------------------------------------------------------*/
 
-  class SH_API SHSceneNode
-  {
-  private:
-    /*---------------------------------------------------------------------------------*/
-    /* Friends                                                                         */
-    /*---------------------------------------------------------------------------------*/
-
-    friend class SHSceneGraph;
-
-  public:
-    /*---------------------------------------------------------------------------------*/
-    /* Constructors & Destructor                                                       */
-    /*---------------------------------------------------------------------------------*/
-
-    ~SHSceneNode            () = default;
-
-    SHSceneNode             (EntityID eid, SHSceneNode* parent = nullptr) noexcept;
-    SHSceneNode             (const SHSceneNode& rhs)                      noexcept;
-    SHSceneNode             (SHSceneNode&& rhs)                           noexcept;
-    SHSceneNode&  operator= (const SHSceneNode& rhs)                      noexcept;
-    SHSceneNode&  operator= (SHSceneNode&& rhs)                           noexcept;
-
-    /*---------------------------------------------------------------------------------*/
-    /* Getter Functions                                                                */
-    /*---------------------------------------------------------------------------------*/
-
-    [[nodiscard]] bool                              IsActive          ()                  const noexcept;
-    [[nodiscard]] EntityID                          GetEntityID       ()                  const noexcept;
-    [[nodiscard]] SHSceneNode*                      GetParent         ()                  const noexcept;
-    [[nodiscard]] const std::vector<SHSceneNode*>&  GetChildren       ()                  const noexcept;
-
-    [[nodiscard]] SHSceneNode*                      GetChild          (EntityID childID)  const noexcept;
-
-    /*---------------------------------------------------------------------------------*/
-    /* Setter Functions                                                                */
-    /*---------------------------------------------------------------------------------*/
-
-    void SetParent (SHSceneNode* parentNode)  noexcept;
-    void SetActive (bool newActiveState)      noexcept;
-
-    /*---------------------------------------------------------------------------------*/
-    /* Function Members                                                                */
-    /*---------------------------------------------------------------------------------*/
-
-    void  AddChild          (SHSceneNode* newChild)       noexcept;
-
-    bool  RemoveChild       (EntityID childID)            noexcept;
-    bool  RemoveChild       (SHSceneNode* childToRemove)  noexcept;
-
-    void  RemoveAllChildren ()                            noexcept;
-
-  private:
-    /*---------------------------------------------------------------------------------*/
-    /* Data Members                                                                    */
-    /*---------------------------------------------------------------------------------*/
-
-    bool                      active;
-    EntityID                  entityID;
-    SHSceneNode*              parent;
-    std::vector<SHSceneNode*> children;
-  };
-
   class SH_API SHSceneGraph
   {
   public:
@@ -130,19 +63,22 @@ namespace SHADE
     /* Setter Functions                                                                */
     /*---------------------------------------------------------------------------------*/
 
-    void SetParent (EntityID entityID, SHSceneNode* parent) const noexcept;
+    void SetParent  (EntityID entityID, SHSceneNode* newParent) noexcept;
-    void SetParent (EntityID entityID, EntityID parent)     const noexcept;
+    void SetParent  (SHSceneNode* node, SHSceneNode* newParent) noexcept;
+    
+    void SetParent  (EntityID entityID, EntityID newParent)     noexcept;
+    void SetParent  (SHSceneNode* node, EntityID newParent)     noexcept;
 
     /*---------------------------------------------------------------------------------*/
     /* Function Members                                                                */
     /*---------------------------------------------------------------------------------*/
 
     SHSceneNode*  AddNode     (EntityID entityID, SHSceneNode* parent = nullptr);
-    bool          RemoveNode  (EntityID entityID)                                 noexcept;
+    bool          RemoveNode  (EntityID entityID)         noexcept;
-    bool          RemoveNode  (SHSceneNode* nodeToRemove)                         noexcept;
+    bool          RemoveNode  (SHSceneNode* nodeToRemove) noexcept;
-    void          Reset       ()                                                  noexcept;
+    void          Reset       ()                          noexcept;
 
-    void          Traverse    (const UnaryFunction& function)                     const;
+    void          Traverse    (const UnaryFunction& function) const;
 
   private:
     /*---------------------------------------------------------------------------------*/
@@ -156,9 +92,14 @@ namespace SHADE
     /* Function Members                                                                */
     /*---------------------------------------------------------------------------------*/
 
-    SHSceneNode*  AllocateNode                (EntityID entityID);
+    SHSceneNode*  AllocateNode              (EntityID entityID);
-    void          ReleaseNode                 (SHSceneNode* node) noexcept;
+    void          ReleaseNode               (SHSceneNode* node) noexcept;
-    static void   TraverseAndInvokeFunction  (const SHSceneNode* node, const UnaryFunction& function);
+
+    void          ChangeParent              (SHSceneNode* node, SHSceneNode* newParent);
+    void          AddChild                  (SHSceneNode* node, SHSceneNode* newChild);
+    void          RemoveChild               (SHSceneNode* node, SHSceneNode* childToRemove);
+
+    static void   TraverseAndInvokeFunction (const SHSceneNode* node, const UnaryFunction& function);
   };
 
   /*-----------------------------------------------------------------------------------*/
@@ -172,4 +113,16 @@ namespace SHADE
     SHSceneNode* newParent;
   };
 
+  struct SHSceneGraphAddChildEvent
+  {
+    SHSceneNode* parent;
+    SHSceneNode* addedChild;
+  };
+
+  struct SHSceneGraphRemoveChildEvent
+  {
+    SHSceneNode* parent;
+    SHSceneNode* removedChild;
+  };
+
 } // namespace SHADE

SHADE_Engine/src/Scene/SHSceneNode.cpp

@@ -0,0 +1,143 @@
+/****************************************************************************************
+ * \file      SHSceneNode.c[[
+ * \author    Diren D Bharwani, diren.dbharwani, 390002520
+ * \brief     Implementation for a Scene Node.
+ *
+ * \copyright Copyright (C) 2022 DigiPen Institute of Technology. Reproduction or
+ *            disclosure of this file or its contents without the prior written consent
+ *            of DigiPen Institute of Technology is prohibited.
+****************************************************************************************/
+
+#include <SHpch.h>
+
+// Primary Header
+#include "SHSceneNode.h"
+
+// Project Headers
+#include "ECS_Base/Managers/SHEntityManager.h"
+
+namespace SHADE
+{
+  /*-----------------------------------------------------------------------------------*/
+  /* Constructors & Destructor Definitions                                             */
+  /*-----------------------------------------------------------------------------------*/
+
+  SHSceneNode::SHSceneNode(EntityID eid, SHSceneNode* parent) noexcept
+  : active  { true }
+  , entityID  { eid }
+  , parent    { parent }
+  {}
+
+
+  SHSceneNode::SHSceneNode(const SHSceneNode& rhs) noexcept
+  : active    { rhs.active }
+  , entityID  { rhs.entityID }
+  , parent    { rhs.parent }
+  {
+    std::ranges::copy(rhs.children.begin(), rhs.children.end(), std::back_inserter(children));
+  }
+
+  SHSceneNode::SHSceneNode(SHSceneNode&& rhs) noexcept
+  : active    { rhs.active }
+  , entityID  { rhs.entityID }
+  , parent    { rhs.parent }
+  {
+    std::ranges::copy(rhs.children.begin(), rhs.children.end(), std::back_inserter(children));
+  }
+
+  SHSceneNode& SHSceneNode::operator=(const SHSceneNode& rhs) noexcept
+  {
+    if (this == &rhs)
+      return *this;
+
+    active    = rhs.active;
+    entityID  = rhs.entityID;
+    parent    = rhs.parent;
+
+    children.clear();
+    std::ranges::copy(rhs.children.begin(), rhs.children.end(), std::back_inserter(children));
+
+    return *this;
+  }
+
+  SHSceneNode& SHSceneNode::operator=(SHSceneNode&& rhs) noexcept
+  {
+    active    = rhs.active;
+    entityID  = rhs.entityID;
+    parent    = rhs.parent;
+
+    children.clear();
+    std::ranges::copy(rhs.children.begin(), rhs.children.end(), std::back_inserter(children));
+
+    return *this;
+  }
+
+  /*-----------------------------------------------------------------------------------*/
+  /* Getter Function Definitions                                                       */
+  /*-----------------------------------------------------------------------------------*/
+
+  bool SHSceneNode::IsActive() const noexcept
+  {
+    return active;
+  }
+
+  EntityID SHSceneNode::GetEntityID() const noexcept
+  {
+    return entityID;
+  }
+
+  SHSceneNode* SHSceneNode::GetParent() const noexcept
+  {
+    return parent;
+  }
+
+  const std::vector<SHSceneNode*>& SHSceneNode::GetChildren() const noexcept
+  {
+    return children;
+  }
+
+  SHSceneNode* SHSceneNode::GetChild(EntityID childID) const noexcept
+  {
+    ////////////////////////////////////////
+    // Error handling
+    if (!SHEntityManager::IsValidEID(childID))
+    {
+      SHLOG_ERROR("Child Entity {} is invalid! Unable to get child from Entity {}", childID, entityID)
+      return nullptr;
+    }
+
+    if (children.empty())
+    {
+      SHLOG_WARNING("Entity {} has no children!", entityID)
+      return nullptr;
+    }
+    ////////////////////////////////////////
+
+    // Find child
+    const auto ENTITY_MATCH = [&](const SHSceneNode* node) { return node->GetEntityID() == childID; };
+
+    const auto CHILD_ITER = std::ranges::find_if(children.begin(), children.end(),ENTITY_MATCH);
+    if (CHILD_ITER == children.end())
+    {
+      SHLOG_WARNING("Entity {} is not a child of Entity {}! Unable to retrieve child node!", childID, entityID)
+      return nullptr;
+    }
+
+    return *CHILD_ITER;
+  }
+
+  /*-----------------------------------------------------------------------------------*/
+  /* Setter Function Definitions                                                       */
+  /*-----------------------------------------------------------------------------------*/
+
+  void SHSceneNode::SetActive(bool newActiveState) noexcept
+  {
+    active = newActiveState;
+
+    for (auto* child : children)
+    {
+      SetActive(newActiveState);
+    }
+  }
+
+} // namespace SHADE

SHADE_Engine/src/Scene/SHSceneNode.h

@@ -0,0 +1,82 @@
+/****************************************************************************************
+ * \file      SHSceneNode.h
+ * \author    Diren D Bharwani, diren.dbharwani, 390002520
+ * \brief     Interface for a Scene Node.
+ *
+ * \copyright Copyright (C) 2022 DigiPen Institute of Technology. Reproduction or
+ *            disclosure of this file or its contents without the prior written consent
+ *            of DigiPen Institute of Technology is prohibited.
+****************************************************************************************/
+
+#pragma once
+
+#include <vector>
+
+// Project Headers
+#include "ECS_Base/Entity/SHEntity.h"
+#include "SH_API.h"
+#include "SHSceneGraph.h"
+
+namespace SHADE
+{
+  /*-----------------------------------------------------------------------------------*/
+  /* Forward Declarations                                                              */
+  /*-----------------------------------------------------------------------------------*/
+
+  class SHSceneGraph;
+
+  /*-----------------------------------------------------------------------------------*/
+  /* Type Definitions                                                                  */
+  /*-----------------------------------------------------------------------------------*/
+
+  class SH_API SHSceneNode
+  {
+  private:
+    /*---------------------------------------------------------------------------------*/
+    /* Friends                                                                         */
+    /*---------------------------------------------------------------------------------*/
+
+    friend class SHSceneGraph;
+
+  public:
+    /*---------------------------------------------------------------------------------*/
+    /* Constructors & Destructor                                                       */
+    /*---------------------------------------------------------------------------------*/
+
+    ~SHSceneNode            () = default;
+
+    SHSceneNode             (EntityID eid, SHSceneNode* parent = nullptr) noexcept;
+    SHSceneNode             (const SHSceneNode& rhs)                      noexcept;
+    SHSceneNode             (SHSceneNode&& rhs)                           noexcept;
+    SHSceneNode&  operator= (const SHSceneNode& rhs)                      noexcept;
+    SHSceneNode&  operator= (SHSceneNode&& rhs)                           noexcept;
+
+    /*---------------------------------------------------------------------------------*/
+    /* Getter Functions                                                                */
+    /*---------------------------------------------------------------------------------*/
+
+    [[nodiscard]] bool                              IsActive          ()                  const noexcept;
+    [[nodiscard]] EntityID                          GetEntityID       ()                  const noexcept;
+    [[nodiscard]] SHSceneNode*                      GetParent         ()                  const noexcept;
+    [[nodiscard]] const std::vector<SHSceneNode*>&  GetChildren       ()                  const noexcept;
+
+    [[nodiscard]] SHSceneNode*                      GetChild          (EntityID childID)  const noexcept;
+
+    /*---------------------------------------------------------------------------------*/
+    /* Setter Functions                                                                */
+    /*---------------------------------------------------------------------------------*/
+
+    void SetActive (bool newActiveState)      noexcept;
+
+  private:
+    /*---------------------------------------------------------------------------------*/
+    /* Data Members                                                                    */
+    /*---------------------------------------------------------------------------------*/
+
+    bool                      active;
+    EntityID                  entityID;
+    SHSceneNode*              parent;
+    std::vector<SHSceneNode*> children;
+  };
+} // namespace SHADE
+

SHADE_Managed/src/Engine/GameObject.cxx

@@ -105,7 +105,7 @@ namespace SHADE
     {
         if (!valid)
             throw gcnew System::NullReferenceException();
-        const auto& SCENE_GRAPH = SHSceneManager::GetCurrentSceneGraph();
+        auto& SCENE_GRAPH = SHSceneManager::GetCurrentSceneGraph();
 
         if (newParent == nullptr)
             SCENE_GRAPH.SetParent(entity, nullptr);