PCG32I Struct Reference

Public Types
typedef unsigned	result_type

Public Member Functions
	PCG32I (const unsigned s, const unsigned ss=2891336453u)
void	seed (const unsigned s, const unsigned ss)
unsigned	sample ()
unsigned	sample_range (const unsigned range)
unsigned	operator() ()

Static Public Member Functions
static constexpr unsigned	min ()
static constexpr unsigned	max ()

Public Attributes
unsigned	x
unsigned	key

Detailed Description

Definition at line 95 of file pcg.h.

Member Typedef Documentation

result_type

typedef unsigned PCG32I::result_type

Definition at line 136 of file pcg.h.

Constructor & Destructor Documentation

PCG32I() [1/2]

PCG32I::PCG32I ( )

inline

Definition at line 97 of file pcg.h.

: x(), key() { seed(0x46b56677u, 2891336453u); }

PCG32I() [2/2]

PCG32I::PCG32I ( const unsigned s, const unsigned ss = 2891336453u )

inline

Definition at line 98 of file pcg.h.

: x(), key() { seed(s, ss); }

Member Function Documentation

seed()

void PCG32I::seed ( const unsigned s, const unsigned ss )

inline

Definition at line 100 of file pcg.h.

    {
        key= (ss << 1) | 1;
        x= s + key;
        sample();
    }

sample()

unsigned PCG32I::sample ( )

inline

Definition at line 109 of file pcg.h.

    {
        unsigned xx= x;
        x= x * 747796405u + key;
        
        unsigned tmp= ((x >> ((x >> 28u) + 4u)) ^ x) * 277803737u;
        return (tmp >> 22u) ^ tmp;
    }

sample_range()

unsigned PCG32I::sample_range ( const unsigned range )

inline

Definition at line 118 of file pcg.h.

    {
        // Efficiently Generating a Number in a Range
        // cf http://www.pcg-random.org/posts/bounded-rands.html
        unsigned divisor= ((-range) / range) + 1; // (2^32) / range
        if(divisor == 0) return 0;
        
        while(true)
        {
            unsigned x= sample() / divisor;
            if(x < range) return x;
        }
    }

operator()()

unsigned PCG32I::operator() ( )

inline

Definition at line 133 of file pcg.h.

{ return sample(); }

min()

constexpr unsigned PCG32I::min ( )

inlinestaticconstexpr

Definition at line 134 of file pcg.h.

{ return 0; }

max()

constexpr unsigned PCG32I::max ( )

inlinestaticconstexpr

Definition at line 135 of file pcg.h.

{ return ~unsigned(0); }

Member Data Documentation

x

unsigned PCG32I::x

Definition at line 138 of file pcg.h.

key

unsigned PCG32I::key

Definition at line 139 of file pcg.h.

---

The documentation for this struct was generated from the following file:

• src/gKit/pcg.h