New cpp folder structure

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

libs/drape_frontend/tile_key.hpp

@@ -0,0 +1,58 @@
+#pragma once
+
+#include "drape_frontend/batcher_bucket.hpp"
+
+#include "geometry/rect2d.hpp"
+#include "geometry/screenbase.hpp"
+
+#include "base/matrix.hpp"
+
+#include <string>
+
+namespace df
+{
+struct TileKey
+{
+  TileKey();
+  TileKey(int x, int y, uint8_t zoomLevel);
+  TileKey(TileKey const & key, uint64_t generation, uint64_t userMarksGeneration);
+
+  // Operators < and == do not consider parameter m_generation.
+  // m_generation is used to determine a generation of geometry for this tile key.
+  // Geometry with different generations must be able to group by (x, y, zoomlevel).
+  bool operator < (TileKey const & other) const;
+  bool operator == (TileKey const & other) const;
+
+  // These methods implement strict comparison of tile keys. It's necessary to merger of
+  // batches which must not merge batches with different m_generation.
+  bool LessStrict(TileKey const & other) const;
+  bool EqualStrict(TileKey const & other) const;
+
+  m2::RectD GetGlobalRect(bool clipByDataMaxZoom = true) const;
+
+  math::Matrix<float, 4, 4> GetTileBasedModelView(ScreenBase const & screen) const;
+
+  m2::PointI GetTileCoords() const;
+
+  uint64_t GetHashValue(BatcherBucket bucket) const;
+
+  std::string Coord2String() const;
+
+  int m_x;
+  int m_y;
+  uint8_t m_zoomLevel;
+
+  uint64_t m_generation;
+  uint64_t m_userMarksGeneration;
+};
+
+struct TileKeyStrictComparator
+{
+  bool operator() (TileKey const & lhs, TileKey const & rhs) const
+  {
+    return lhs.LessStrict(rhs);
+  }
+};
+
+std::string DebugPrint(TileKey const & key);
+}  // namespace df