can refactor recursive tree show to only need 1 ref now

hw3d/Mesh.cpp

@@ -98,11 +98,13 @@ void Node::AddChild( std::unique_ptr<Node> pChild ) noxnd
 	childPtrs.push_back( std::move( pChild ) );
 }
 
-void Node::ShowTree( std::optional<int>& selectedIndex,Node*& pSelectedNode ) const noexcept
+void Node::ShowTree( Node*& pSelectedNode ) const noexcept
 {
+	// if there is no selected node, set selectedId to an impossible value
+	const int selectedId = (pSelectedNode == nullptr) ? -1 : pSelectedNode->GetId();
 	// build up flags for current node
 	const auto node_flags = ImGuiTreeNodeFlags_OpenOnArrow
-		| ((GetId() == selectedIndex.value_or( -1 )) ? ImGuiTreeNodeFlags_Selected : 0)
+		| ((GetId() == selectedId) ? ImGuiTreeNodeFlags_Selected : 0)
 		| ((childPtrs.size() == 0) ? ImGuiTreeNodeFlags_Leaf : 0);
 	// render this node
 	const auto expanded = ImGui::TreeNodeEx( 
@@ -111,7 +113,6 @@ void Node::ShowTree( std::optional<int>& selectedIndex,Node*& pSelectedNode ) co
 	// processing for selecting node
 	if( ImGui::IsItemClicked() )
 	{
-		selectedIndex = GetId();
 		pSelectedNode = const_cast<Node*>(this);
 	}
 	// recursive rendering of open node's children
@@ -119,7 +120,7 @@ void Node::ShowTree( std::optional<int>& selectedIndex,Node*& pSelectedNode ) co
 	{
 		for( const auto& pChild : childPtrs )
 		{
-			pChild->ShowTree( selectedIndex,pSelectedNode );
+			pChild->ShowTree( pSelectedNode );
 		}
 		ImGui::TreePop();
 	}
@@ -149,12 +150,12 @@ public:
 		if( ImGui::Begin( windowName ) )
 		{
 			ImGui::Columns( 2,nullptr,true );
-			root.ShowTree( selectedIndex,pSelectedNode );
+			root.ShowTree( pSelectedNode );
 
 			ImGui::NextColumn();
 			if( pSelectedNode != nullptr )
 			{
-				auto& transform = transforms[*selectedIndex];
+				auto& transform = transforms[pSelectedNode->GetId()];
 				ImGui::Text( "Orientation" );
 				ImGui::SliderAngle( "Roll",&transform.roll,-180.0f,180.0f );
 				ImGui::SliderAngle( "Pitch",&transform.pitch,-180.0f,180.0f );
@@ -169,7 +170,8 @@ public:
 	}
 	dx::XMMATRIX GetTransform() const noexcept
 	{
-		const auto& transform = transforms.at( *selectedIndex );
+		assert( pSelectedNode != nullptr );
+		const auto& transform = transforms.at( pSelectedNode->GetId() );
 		return 
 			dx::XMMatrixRotationRollPitchYaw( transform.roll,transform.pitch,transform.yaw ) *
 			dx::XMMatrixTranslation( transform.x,transform.y,transform.z );
@@ -179,7 +181,6 @@ public:
 		return pSelectedNode;
 	}
 private:
-	std::optional<int> selectedIndex;
 	Node* pSelectedNode;
 	struct TransformParameters
 	{

hw3d/Mesh.h

@@ -41,7 +41,7 @@ public:
 	int GetId() const noexcept;
 private:
 	void AddChild( std::unique_ptr<Node> pChild ) noxnd;
-	void ShowTree( std::optional<int>& selectedIndex,Node*& pSelectedNode ) const noexcept;
+	void ShowTree( Node*& pSelectedNode ) const noexcept;
 private:
 	std::string name;
 	int id;