day-night loop, dynamic skybox, clock on debug panel

src/frontend/graphics/Skybox.h

@@ -0,0 +1,30 @@
+#ifndef FRONTEND_GRAPHICS_SKYBOX_H_
+#define FRONTEND_GRAPHICS_SKYBOX_H_
+
+#include "../../typedefs.h"
+
+class Mesh;
+class Shader;
+
+class Skybox {
+    uint fbo;
+    uint cubemap;
+    uint size;
+    Mesh* mesh;
+    Shader* shader;
+    bool ready = false;
+public:
+    Skybox(uint size, Shader* shader);
+    ~Skybox();
+
+    void draw(Shader* shader);
+
+    void refresh(float t, float mie, uint quality);
+    void bind() const;
+    void unbind() const;
+    bool isReady() const {
+        return ready;
+    }
+};
+
+#endif // FRONTEND_GRAPHICS_SKYBOX_H_