camera notify

include/td/render/Camera.h

@@ -1,11 +1,20 @@
 #pragma once
 
 #include <td/Maths.h>
+#include <td/misc/ObjectNotifier.h>
 
 namespace td {
 namespace render {
 
-class Camera {
+class ICameraListener {
+  public:
+	virtual void OnPerspectiveChange() {}
+	virtual void OnViewChange() {}
+};
+
+using CameraNotifier = utils::ObjectNotifier<ICameraListener>;
+
+class Camera : public CameraNotifier {
   private:
 	Mat4f m_ViewMatrix;
 	Mat4f m_ProjectionMatrix;