#include <cstdlib>
 
-Sea::Sea(WaterSurface& surface) : m_surface{surface}
+#include "watersurface.h"
+
+Sea::Sea(WaterSurfacePtr surface) : m_surface{surface}
 {
 }
 
 void Sea::update()
 {
-  for (int y = 0; y < m_surface.size(); ++y) {
-    for (int x = 0; x < m_surface.size(); ++x) {
-      m_surface.at(x, y)
+  for (int y = 0; y < m_surface->size(); ++y) {
+    for (int x = 0; x < m_surface->size(); ++x) {
+      m_surface->at(x, y)
        .setHeight(((double)std::rand()/(double)RAND_MAX));
     }
   }
 
 const int LATTICE_SIZE = 10;
 const int LATTICE_UNIT = 1;
 
-WaterSurface surface(LATTICE_SIZE);
-Sea sea(surface);
+SeaPtr sea;
+WaterSurfacePtr surface;
 
 void drawSingleTile(int x, int y)
 {
   glBegin(GL_TRIANGLES);
 
-  glVertex3f(x, y, surface.at(x, y).getHeight());
-  glVertex3f(x+1, y, surface.at(x+1, y).getHeight());
-  glVertex3f(x+1, y+1, surface.at(x+1, y+1).getHeight());
+  glVertex3f(x, y, surface->at(x, y).getHeight());
+  glVertex3f(x+1, y, surface->at(x+1, y).getHeight());
+  glVertex3f(x+1, y+1, surface->at(x+1, y+1).getHeight());
 
-  glVertex3f(x, y, surface.at(x, y).getHeight());
-  glVertex3f(x, y+1, surface.at(x, y+1).getHeight());
-  glVertex3f(x+1, y+1, surface.at(x+1, y+1).getHeight());
+  glVertex3f(x, y, surface->at(x, y).getHeight());
+  glVertex3f(x, y+1, surface->at(x, y+1).getHeight());
+  glVertex3f(x+1, y+1, surface->at(x+1, y+1).getHeight());
 
   glEnd();
 }
 
   glClear(GL_COLOR_BUFFER_BIT);
 
-  sea.update();
+  sea->update();
 
   glScalef(LATTICE_UNIT, LATTICE_UNIT, 1.0f);
   glTranslatef(-(float)(LATTICE_SIZE-1)/2, -(float)(LATTICE_SIZE-1)/2, 0);
 {
   std::srand(std::time(0));
 
+  surface = std::make_shared<WaterSurface>(LATTICE_SIZE);
+  sea = std::make_shared<Sea>(surface);
+
   glutInit(&argc, argv);
   glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB|GLUT_DEPTH);
   glEnable(GL_DEPTH_TEST);