Add system graph (wip)

src/Nazara/Core/Systems/SystemGraph.cpp

@@ -0,0 +1,37 @@
+// Copyright (C) 2022 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Core module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Core/Systems/SystemGraph.hpp>
+#include <Nazara/Core/Debug.hpp>
+
+namespace Nz
+{
+	SystemGraph::NodeBase::~NodeBase() = default;
+
+	void SystemGraph::Update()
+	{
+		return Update(m_clock.Restart() / 1'000'000.f);
+	}
+
+	void SystemGraph::Update(float elapsedTime)
+	{
+		if (!m_systemOrderUpdated)
+		{
+			m_orderedNodes.clear();
+			m_orderedNodes.reserve(m_nodes.size());
+			for (auto& nodePtr : m_nodes)
+				m_orderedNodes.emplace_back(nodePtr.get());
+
+			std::sort(m_orderedNodes.begin(), m_orderedNodes.end(), [](const NodeBase* a, const NodeBase* b)
+			{
+				return a->executionOrder < b->executionOrder;
+			});
+
+			m_systemOrderUpdated = true;
+		}
+
+		for (NodeBase* node : m_orderedNodes)
+			node->Update(elapsedTime);
+	}
+}