unsigned get_width() const { return width; }
unsigned get_height() const { return height; }
unsigned get_depth() const { return depth; }
unsigned get_width() const { return width; }
unsigned get_height() const { return height; }
unsigned get_depth() const { return depth; }
void get_level_size(unsigned, unsigned &, unsigned &, unsigned &);
public:
void get_level_size(unsigned, unsigned &, unsigned &, unsigned &);
public: