Source: dpoints.h

/***************************************************************************
                          dpoints.h  -  description
                             -------------------
    begin                : Fri Feb 4 2000
    copyright            : (C) 2000 by Daniel Roberge
    email                : droberge@uvic.ca
 ***************************************************************************/

#ifndef _DPOINTS_H
#define _DPOINTS_H

/**Keeps track of a variable value with a maximum possible value. Archetypical example is
  hit points.
  *@author Daniel Roberge
  */

class DepletablePoints
{
 private:
  int current, maximum;

  /**Keeps the current value less than the maximum value*/
  void MakeValid(void) {if (current > maximum) current = maximum;};

 public:
 /*---------------Constructors-----------------------*/
  /**Creates a DepletablePoints with maximum 0*/
  DepletablePoints(void);

  /**Creates a DepletablePoints with maximum val*/
  DepletablePoints(int val);

  /**Creates a DepletablePoints with maximum max but a current value curr*/
  DepletablePoints(int curr,int max);

 /*-------------Modification Methods----------------*/
  /**Increases the current value by delta and enforces the maximum. Returns the new current value*/
  int Change(int delta);

  /**Changes the current value to val and enforces the maximum. Returns the new current value*/
  int SetCurrent(int val);

  /**Sets the maximum value to val and enforces it. Returns the new current value*/
  int SetMax(int val);

  /**Increases the maximum value by delta and enforces it. Returns the new current value*/
  int ChangeMax(int delta);

  /**Makes the current and maximum values equal to the corresponding values in the argument. */
  void become(DepletablePoints arg);

 /*-----------------Information Methods-----------*/
  /**Returns the current value of the object*/
  int GetCurrent(void) const { return current; };

  /**Returns the maximum value*/
  int GetMax(void) const { return maximum; };

  /**What do you think?*/
  bool IsPositive(void) const { return (current > 0); };

 /*------------------Operators------------------------------*/
  /**Increments the current value of the DepletablePoints.*/
  DepletablePoints operator++ () {current++; MakeValid(); return *this;};

  /**Decrements the current value of the DepletablePoints.*/
  DepletablePoints operator-- () {current--; return *this;};

  /**Adds the argument to the current value and returns it. Non-destructive. */
  int operator+ (int arg) const {return current + arg;};

  /**Subtracts the argument from the current value and returns it.*/
  int operator- (int arg) const {return current - arg;};

  /**Assigns the argument to the current value. */
  DepletablePoints operator= (int arg) {current = arg; MakeValid(); return *this;};

  /**Assigns the current value of the argument to the current value.*/
  DepletablePoints operator= (DepletablePoints arg)
  	{current = arg.current; MakeValid(); return *this; };
  	
  /**Increases the current value by the argument. */
  DepletablePoints operator+= (int arg) {current += arg; MakeValid(); return *this;};

  /**Decreases the current value by the argument. */
  DepletablePoints operator-= (int arg) {current -= arg; return *this;};
};

typedef DepletablePoints& RDepletablePoints;
typedef DepletablePoints* PDepletablePoints;

#endif