Detailed Description

Description:: This class is available in release 4.0 and later only.

This class has interfaces for srand() and rand() methods of VC++ and other functions for random number generation. The srand() and rand() methods from stdlib.h have two main problems:

a) It's not satisfactorily random. The rand() function returns a pseudorandom integer in the range 0 to 0x7fff=32767. If we need a lot of random numbers using rand() (i.e. for generating 100,000 particles), we run out of continuity of random numbers. Generated random numbers becomes too discrete.

b) The rand() method is global function, not class object. Hence it is shared between all modules of your plug-in. Changes in one module may change randomness pattern in other independent module. To solve this contradiction, rand methods have to be implemented as a class object.

The RandGenerator does exactly that. It has much more random numbers: RAND_MAX = 0xFFFFFFFF = 4,294,967,295. Also, using instances of the class, it's much easier to create separate threads of random numbers for a specific module.

Data Members:: static const DWORD32 RAND_MAX

This definition is used to override the VC++ rand methods.

#include <randgenerator.h>

Inheritance diagram for RandGenerator:

Public Member Functions
CoreExport	RandGenerator ()
CoreExport void	srand (DWORD32 seed)
CoreExport DWORD32	rand (void)
CoreExport int	RandSign (void)
CoreExport float	Rand01 (void)
CoreExport float	Rand11 (void)
CoreExport float	Rand55 (void)
CoreExport int	Rand0X (int maxnum)
const bool	Valid (void) const
Static Public Attributes
static CoreExport const DWORD32	RAND_MAX

Constructor & Destructor Documentation

CoreExport RandGenerator ( )

CoreExport void srand ( DWORD32 seed )

Remarks:: This method sets the starting point for generating a series of pseudorandom integers. To reinitialize the generator, use 1 as the seed argument. Any other value for seed sets the generator to a random starting point. rand() retrieves the pseudorandom numbers that are generated. Calling rand() before any call to this method generates the same sequence as calling it with seed passed as 1.

CoreExport DWORD32 rand ( void )

Remarks:: This method returns a pseudorandom integer in the range 0 to RAND_MAX

CoreExport int RandSign ( void )

CoreExport float Rand01 ( void )

CoreExport float Rand11 ( void )

CoreExport float Rand55 ( void )

CoreExport int Rand0X ( int maxnum )

const bool Valid ( void ) const [inline]

Remarks:: This method returns TRUE if the random number generator has been explicitly initialized by the srand() method.

                                        { 
            return m_explicitelyInitialized; 
        }

CoreExport const DWORD32 RAND_MAX [static]