97 lines
2.6 KiB
C++
97 lines
2.6 KiB
C++
// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-
|
||
|
||
//-----------------------------------------------------------------------------
|
||
// eoRnd.h
|
||
// (c) GeNeura Team, 1998
|
||
//-----------------------------------------------------------------------------
|
||
|
||
#ifndef _EORND_H
|
||
#define _EORND_H
|
||
|
||
//-----------------------------------------------------------------------------
|
||
|
||
#include <eoObject.h>
|
||
|
||
//-----------------------------------------------------------------------------
|
||
// Class eoRnd
|
||
//-----------------------------------------------------------------------------
|
||
|
||
#include <stdlib.h> // srand
|
||
#include <time.h> // time
|
||
#include <stdexcept> // runtime_error
|
||
|
||
//-----------------------------------------------------------------------------
|
||
|
||
#include <eoPersistent.h>
|
||
|
||
//-----------------------------------------------------------------------------
|
||
/**
|
||
* Base class for a family of random number generators. Generates numbers
|
||
* according to the parameters given in the constructor. Uses the machine's
|
||
* own random number generators. Which is not too good, after all.
|
||
*/
|
||
template<class T>
|
||
class eoRnd: public eoObject, public eoPersistent
|
||
{
|
||
public:
|
||
|
||
/// default constructor
|
||
eoRnd(unsigned _seed = 0) {
|
||
if ( !started ) {
|
||
srand(_seed?_seed:time(0));
|
||
started = true;
|
||
}
|
||
}
|
||
|
||
/// Copy cotor
|
||
eoRnd(const eoRnd& _r ) {srand(time(0));};
|
||
|
||
/** Main function: random generators act as functors, that return random numbers.
|
||
It´s non-const because it might modify a seed
|
||
@return return a random number
|
||
*/
|
||
virtual T operator()() = 0;
|
||
|
||
/** Return the class id.
|
||
@return the class name as a string
|
||
*/
|
||
virtual string className() const { return "eoRandom"; };
|
||
|
||
/**
|
||
* Read object.
|
||
* @param is A istream.
|
||
* @throw runtime_exception If a valid object can't be read.
|
||
*/
|
||
virtual void readFrom(istream& _is);
|
||
|
||
/**
|
||
* print object. Prints just the ID, since the seed is not accesible.
|
||
* @param is A ostream.
|
||
*/
|
||
void printOn(ostream& _os) const { _os << endl; };
|
||
|
||
private:
|
||
/// true if the RNG has been started already. If it starts every time, means trouble.
|
||
static bool started;
|
||
};
|
||
|
||
template<class T> bool eoRnd<T>::started = false;
|
||
|
||
|
||
//--------------------------------------------------------------------------
|
||
|
||
/**
|
||
* Read object.
|
||
* @param is A istream.
|
||
* @throw runtime_exception If a valid object can't be read.
|
||
*/
|
||
template<class T>
|
||
void eoRnd<T>::readFrom(istream& _is) {
|
||
if (!_is)
|
||
throw runtime_error("Problems reading from stream in eoRnd");
|
||
long seed;
|
||
_is >> seed;
|
||
srand(seed);
|
||
}
|
||
|
||
#endif
|