New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/drape_frontend/animation/base_interpolator.hpp

@@ -0,0 +1,24 @@
+#pragma once
+
+namespace df
+{
+class BaseInterpolator
+{
+public:
+  explicit BaseInterpolator(double duration, double delay = 0);
+  virtual ~BaseInterpolator();
+
+  bool IsFinished() const;
+  virtual void Advance(double elapsedSeconds);
+
+protected:
+  double GetT() const;
+  double GetElapsedTime() const;
+  double GetDuration() const;
+
+private:
+  double m_elapsedTime;
+  double m_duration;
+  double m_delay;
+};
+}  // namespace df