message: Store SeedLander position internally as a Point
diff: @@ -14,8 +14,7 @@ public:
  SeedLander() = delete;
  SeedLander(int x, int y) :
  Structure(constants::SEED_LANDER, "structures/seed_0.sprite", StructureClass::CLASS_LANDER),
  - mX(x),
  - mY(y)
  + mPosition{x, y}
  {
  sprite().play(constants::STRUCTURE_STATE_CONSTRUCTION);
  maxAge(50);
  @@ -29,8 +28,7 @@ public:
  void position(int x, int y)
  {
  - mX = x;
  - mY = y;
  + mPosition = {x, y};
  }
  Callback& deployCallback() { return mDeploy; }
  @@ -41,14 +39,13 @@ protected:
  if (age() == turnsToBuild())
  {
  // Logic guard, probably not necessary.
  - if (mX == 0 && mY == 0) { return; }
  + if (mPosition == NAS2D::Point{0, 0}) { return; }
  - mDeploy({mX, mY});
  + mDeploy(mPosition);
  }
  }
  private:
  Callback mDeploy;
  -
  - int mX = 0, mY = 0;
  + NAS2D::Point<int> mPosition;
  };
  