added layer and layerstack class

SakuraVNE/src/Layer.cpp

@@ -0,0 +1,6 @@
+#include "Layer.h"
+#include <string>
+
+namespace SakuraVNE {
+Layer::Layer(const std::string &name) : m_LayerName(name) {}
+} // namespace SakuraVNE

SakuraVNE/src/Layer.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <string>
+
+namespace SakuraVNE {
+class Layer {
+public:
+    Layer(const std::string &name = "Layer");
+    virtual ~Layer() = default;
+
+    virtual void OnStart() {}
+    virtual void OnFrame(float timestamp) {}
+    virtual void OnEnd() {}
+    virtual void OnEvent() {}
+    virtual void OnAttach() {}
+    virtual void OnDetach() {}
+
+    const std::string &GetName() const { return m_LayerName; }
+
+protected:
+    std::string m_LayerName;
+};
+} // namespace SakuraVNE

SakuraVNE/src/LayerStack.cpp

@@ -0,0 +1,30 @@
+#include "LayerStack.h"
+#include <algorithm>
+#include <vector>
+
+namespace SakuraVNE {
+void LayerStack::PushLayer(Layer *layer) {
+    m_LayerStack.emplace(m_LayerStack.begin() + m_LayerIndex, layer);
+    m_LayerIndex++;
+}
+
+void LayerStack::PopLayer(Layer *layer) {
+    auto match = std::find(m_LayerStack.begin(), m_LayerStack.begin() + m_LayerIndex, layer);
+    if (match != m_LayerStack.begin() + m_LayerIndex) {
+        layer->OnDetach();
+        m_LayerStack.erase(match);
+        m_LayerIndex--;
+    }
+}
+
+void LayerStack::PushOverLay(Layer *layer) { m_LayerStack.emplace_back(layer); }
+
+void LayerStack::PopOverlay(Layer *layer) {
+    auto match = std::find(m_LayerStack.begin() + m_LayerIndex, m_LayerStack.end(), layer);
+
+    if (match != m_LayerStack.end()) {
+        layer->OnDetach();
+        m_LayerStack.erase(match);
+    }
+}
+} // namespace SakuraVNE

SakuraVNE/src/LayerStack.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "Layer.h"
+#include <vector>
+
+namespace SakuraVNE {
+class LayerStack {
+public:
+    LayerStack() = default;
+    ~LayerStack();
+
+    void PushLayer(Layer *layer);
+    void PopLayer(Layer *layer);
+    void PushOverLay(Layer *layer);
+    void PopOverlay(Layer *layer);
+
+private:
+    std::vector<Layer *> m_LayerStack;
+    unsigned int m_LayerIndex = 0;
+};
+} // namespace SakuraVNE