text: //this head file inclue some function to help calculate;
  #ifndef BUBG_CLASSES_TOOL_MATH_TOOL_H_
  #define BUBG_CLASSES_TOOL_MATH_TOOL_H_
  #include "cocos2d.h"
  
  //this function is transformed the score of the ball to the size of the ball;
  double ScoreToSize(unsigned int score);
  
  //the funtion return the square of the two Vec2;
  double calDistence(const cocos2d::Vec2 &i, const cocos2d::Vec2 &j);
  double ScoreToSpeed(int score);
  
  double getDoubleRand(int range);
  
  class ControledBall;
  bool compareControledBall(ControledBall* i, ControledBall* j);
  
  #endif // !BUBG_CLASSES_TOOL_MATH_TOOL_H_
  
  