New cpp folder structure

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

libs/drape_frontend/animation/base_interpolator.cpp

@@ -0,0 +1,52 @@
+#include "drape_frontend/animation/base_interpolator.hpp"
+#include "drape_frontend/animation/interpolation_holder.hpp"
+
+#include "base/assert.hpp"
+#include "base/math.hpp"
+
+#include <algorithm>
+
+namespace df
+{
+BaseInterpolator::BaseInterpolator(double duration, double delay)
+  : m_elapsedTime(0.0)
+  , m_duration(duration)
+  , m_delay(delay)
+{
+  ASSERT(m_duration > 0.0, ());
+  InterpolationHolder::Instance().RegisterInterpolator(this);
+}
+
+BaseInterpolator::~BaseInterpolator()
+{
+  InterpolationHolder::Instance().DeregisterInterpolator(this);
+}
+
+bool BaseInterpolator::IsFinished() const
+{
+  return m_elapsedTime > (m_duration + m_delay);
+}
+
+void BaseInterpolator::Advance(double elapsedSeconds)
+{
+  m_elapsedTime += elapsedSeconds;
+}
+
+double BaseInterpolator::GetT() const
+{
+  if (IsFinished())
+    return 1.0;
+
+  return std::max(m_elapsedTime - m_delay, 0.0) / m_duration;
+}
+
+double BaseInterpolator::GetElapsedTime() const
+{
+  return m_elapsedTime;
+}
+
+double BaseInterpolator::GetDuration() const
+{
+  return m_duration;
+}
+}  // namespace df