source: orxonox.OLD/branches/terrain/src/lib/util/loading/fast_factory.h @ 10764

/*!
 * @file fast_factory.h
 * The ObjectManager (FastFactory) is designed, to automatically generate and remove
 * (without to much overhead) many instances of different classes.
 *
 * It is especially usefull for objects, that come only for a short time into existence,
 * and get killed after a small amount of time (like shots).
 *
 * The Creation of an Object is usually done in the Weapon Class, where one subscribes
 * a Projectile with:
 * this->bulletFactory = tFastFactory<TestBullet>::getFastFactory(CL_TEST_BULLET, "TestBullet");
 * (this might change over time).
 * Then you can at loading time initialize an amount of the class with something like:
 * this->bulletFactory->prepare(100); // creates 100 entities of TestBullet (dead ones)
 * afterwards one can just retrieve an Object form the Class with
 * this->bulletFactory->resurrect();  // this returns a BaseObject an Object of the class.
 *
 * The big difference to the FastFactory-class is, that this one is used more for the purpose
 * of fast game-interaction than for loading. althought one can also load FastFactorized classes
 * it is not the main topic.
 */

#ifndef _FAST_FACTORY_H
#define _FAST_FACTORY_H

#include "base_object.h"
/**
 * Creates a FastFactory to a Createable FastFactory.
 */
#define CREATE_FAST_FACTORY(CLASS_NAME, CLASS_ID) \
  FastFactory* global_##CLASS_NAME##_FastFactory = tFastFactory<CLASS_NAME>::getFastFactory(CLASS_ID, #CLASS_NAME)
/**
 * Creates a FastFactory for a Class' static function named ClassName::fastFactory.
 * @param CLASS_NAME the name of the Class to create the fast-factory for.
 * @param CLASS_ID the ID of the class to create the fast-factory for @see "class_id_DEPRECATED.h"
 *
 * notice, that the Class to be called, must implement:
 * static FastFactory*         fastFactory;
 */
#define CREATE_FAST_FACTORY_STATIC(CLASS_NAME) \
  FastFactory* CLASS_NAME::fastFactory = tFastFactory<CLASS_NAME>::getFastFactory(CLASS_NAME::staticClassID(), #CLASS_NAME)

//! A struct, that holds Lists of Objects of a certain type.
typedef struct FastObjectMember
{
  BaseObject*          objectPointer;      //!< Pointer to the Object Stored in this Class (if it is the DeadList, else it is bork)

  FastObjectMember*    next;               //!< the next stored FastObjectMember. (or NULL if this is the last one stored in either the deadList or the unusedContainers)
};

//! The FastFactory is a fast loadable object creator, and Dynamic List of dead object handler.
/**
 * The ObjectManager (FastFactory) is designed, to automatically generate and remove
 * (without to much overhead) many instances of different classes.
 *
 * FastFactory is needed to glue all the tFastFactories together.
 * It is also the general class that implements the necessary functions
 * to generate, resurrect kill and stuff...
 */
class FastFactory : public BaseObject
{
  ObjectListDeclaration(FastFactory);

public:
  virtual ~FastFactory ();
  static void deleteAll();

  // functions to push and pop elements of this class
  BaseObject* resurrect();
  static BaseObject* resurrect(const ClassID& classID);
  void kill(BaseObject* object);
  static void kill(BaseObject* object, bool searchForFastFactory);

  void prepare(unsigned int count);

  static void flushAll(bool hardFLUSH = false);
  void flush(bool hardFLUSH = false);

  /** @returns the first FastFactory */
  inline static FastFactory* getFirst() { return FastFactory::first; };

  static FastFactory* searchFastFactory(const ClassID& classID);
  static FastFactory* searchFastFactory(const std::string& fastFactoryName);

  const ClassID& getStoredID() const { return this->storedClassID; };

protected:
  FastFactory (const ClassID& classID, const std::string& fastFactoryName = "");

  /** sets the Next factory in the list @param nextFactory the next factory */
  inline void setNext( FastFactory* nextFastFactory) { this->next = nextFastFactory; };
  /** @returns the next FastFactory */
  FastFactory* getNext() const { return this->next; };

  /** generates a new Object of the Class T */
  virtual void fabricate() = 0;

private:
  static void registerFastFactory(FastFactory* fastFactory);

protected:
  ClassID            storedClassID;        //!< The classID of the specified class.
  unsigned int          storedDeadObjects;    //!< How many dead objects are stored in this class

  FastObjectMember*     deadList;             //!< A List of all stored dead Objects of this class.
  FastObjectMember*     unusedContainers;     //!< This is a List of unused containers, that will be reused by kill.

private:
  static FastFactory*   first;                //!< A pointer to the first FastFactory.

  FastFactory*          next;                 //!< pointer to the next FastFactory.
};



/**
 *  a FastFactory that is able to load any kind of Object from a ClassID
 * (this is a Functor)
 */
template<class T>
class tFastFactory : public FastFactory
{
public:
  static tFastFactory<T>* getFastFactory(const ClassID& classID, const std::string& fastFactoryName);

private:
  tFastFactory(const ClassID& classID, const std::string& fastFactoryName);

  virtual void fabricate();
};

/**
 * construnts a FastFactory with
 * @param fastFactoryName the name of the FastFactory
 * @param fastFactory the ID of the class
 * @todo (can this be written in another form??)
 */
template<class T>
tFastFactory<T>::tFastFactory(const ClassID& classID, const std::string& fastFactoryName)
    : FastFactory(classID, fastFactoryName)
{}

/**
 * creates (if not existent) a Factory of Class T, and assigns some values to it
 * @param classID the ClassID to assign to this class
 * @param fastFactoryName the name to assign
 * @returns The FastFactory if existent a new Factory if not.
 */
template<class T>
tFastFactory<T>* tFastFactory<T>::getFastFactory(const ClassID& classID, const std::string& fastFactoryName)
{
  tFastFactory<T>* tmpFac = NULL;
  if (FastFactory::getFirst() != NULL)
    tmpFac = static_cast<tFastFactory<T>*>(FastFactory::getFirst()->searchFastFactory(classID));

  if (tmpFac != NULL)
    return tmpFac;
  else
    return new tFastFactory<T>(classID, fastFactoryName);
}

/**
 * fabricates an Object of Class T, that corresponds to classID.
 */
template<class T>
void tFastFactory<T>::fabricate()
{
  FastObjectMember* tmpFirstDead = new FastObjectMember;
  tmpFirstDead->objectPointer = new T();
  tmpFirstDead->next = this->deadList;
  ++this->storedDeadObjects;

  this->deadList = tmpFirstDead;
}

#endif /* _FAST_FACTORY_H */