refactor waterline

src/Waterline.h

@@ -1,11 +1,18 @@
 #pragma once
-#include "Entity.h"
+#include <string>
+#include <vector>
 
 class Waterline {
 private:
+  static constexpr int WATERLINE_Y = 5;
+  static constexpr char WATERLINE_COLOR = 'c';
+
   size_t x, y;
   std::vector<std::string> shape;
-  void shiftString(std::string &, int direction);
+  std::vector<std::string> colorLines;
+
+  void shiftString(std::string &str, int direction);
+  void initializeShape();
 
 public:
   Waterline();