Introducing application layers

This feature is not really used yet but will help in the future simplify the propegation of events

YoggieEngine/src/Application.cpp

@@ -38,7 +38,7 @@ namespace YoggieEngine {
 
 
 	void Application::Run() {
-		std::cout << "No run function implemented!";
+		
 	}
 
 
@@ -81,6 +81,12 @@ namespace YoggieEngine {
 		}
 	}
 
+	void Application::PushLayer(Layer* layer)
+	{
+		AppLayerstack.PushLayer(layer);
+		layer->OnAttach();
+	}
+
 	Application::~Application() {
 
 		ImGui_ImplOpenGL3_Shutdown();

YoggieEngine/src/Application.h

@@ -1,5 +1,6 @@
 #pragma once
 #include "YoggieEngine.h"
+#include "LayerStack.h"
 
 
 namespace YoggieEngine {
@@ -17,11 +18,16 @@ namespace YoggieEngine {
 		void GuiBegin();
 		void GuiEnd();
 
+		void PushLayer(Layer* layer);
+
+
 
 	protected:
 		std::string m_AppName;
 		NativeWindow* appWindow;
-		friend class ApplicationRuntime;
+		
+		LayerStack AppLayerstack;
+
 	};
 
 };

YoggieEngine/src/Layer.h

@@ -0,0 +1,29 @@
+#pragma once
+
+class Layer {
+
+public:
+	~Layer() { OnDestroy(); }
+	Layer() { OnCreate(); }
+
+	Layer(const std::string name ) 
+		: Name(name) {}
+
+
+	virtual void OnUpdate(){}
+	virtual void OnUI(){}
+	virtual void OnStartup(){}
+
+	virtual void OnAttach() {}
+	virtual void OnDetach() {}
+
+
+	virtual void OnCreate() {}
+	virtual void OnDestroy(){}
+
+private:
+
+	std::string Name;
+
+
+};

YoggieEngine/src/LayerStack.cpp

@@ -0,0 +1,27 @@
+#include "YoggieEngine.h"
+#include "LayerStack.h"
+
+LayerStack::~LayerStack()
+{
+	for (Layer* layer : layers) {
+		layer->OnDetach();
+		delete layer;
+	}
+}
+
+
+void LayerStack::PushLayer(Layer* layer) {
+	layers.emplace(layers.begin() + insertion_index, layer);
+	insertion_index++;
+}
+
+
+void LayerStack::PopLayer(Layer* layer) {
+	auto it = std::find(layers.begin(), layers.begin() + insertion_index, layer);
+	if (it != layers.begin() + insertion_index) {
+		layer->OnDetach();
+		layers.erase(it);
+		insertion_index--;
+
+	}
+}

YoggieEngine/src/LayerStack.h

@@ -0,0 +1,22 @@
+#pragma once
+#include "Layer.h"
+#include <vector>
+
+class LayerStack{
+public:
+	LayerStack() = default;
+	~LayerStack();
+
+	void PushLayer(Layer* layer);
+	void PopLayer(Layer* layer);
+
+	std::vector<Layer*>::iterator begin() { return layers.begin(); }
+	std::vector<Layer*>::iterator end() { return layers.end(); }
+	std::vector<Layer*>::reverse_iterator rbegin() { return layers.rbegin(); }
+	std::vector<Layer*>::reverse_iterator rend() { return layers.rend(); }
+
+
+private:
+	std::vector<Layer*> layers;
+	int insertion_index = 0;
+};