File indexing completed on 2024-05-12 15:58:39

 /*
  *  This file is part of the KDE project
  *
  *  SPDX-FileCopyrightText: 2008, 2009 Cyrille Berger <cberger@cberger.net>
  *  SPDX-FileCopyrightText: 2009 Matthew Woehlke <mw_triad@users.sourceforge.net>
  *
  *  SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #include "kis_random_generator.h"
 
 /* Mac OS X doesn't define a number of UINT* macros without this before stdlib.h */
 #define __STDC_LIMIT_MACROS
 
 #include <stdlib.h>
 #include <stdint.h>
 #include <math.h>
 
 #include "rand_salt.h"
 
 inline quint64 permuteWhole(quint64 n, quint64 a, quint64 b)
 {
     return ((n * a) + b);
 }
 
 inline quint64 part(quint64 n1, quint64 n2, int p)
 {
     int b = p * 8;
     int i = (n1 >> b) & 0xFF;
     int j = (n2 >> b) & 0xFF;
     return quint64(salt[i][j]) << b;
 }
 
 struct Q_DECL_HIDDEN KisRandomGenerator::Private {
     quint64 seed;
 };
 
 KisRandomGenerator::KisRandomGenerator(quint64 seed) : d(new Private)
 {
     d->seed = seed;
 }
 
 KisRandomGenerator::~KisRandomGenerator()
 {
     delete d;
 }
 
 quint64 KisRandomGenerator::randomAt(qint64 x, qint64 y)
 {
     const quint64 kxa = 427140578808118991LL;
     const quint64 kya = 166552399647317237LL;
     const quint64 kxb = 48058817213113801LL;
     const quint64 kyb = 9206429469018994469LL;
 
     // Generate salts
     quint64 n1 = (quint64(x + 5) * kxa) * d->seed;
     quint64 n2 = (quint64(y + 7) * kya) + (d->seed * 1040097393733LL);
     n1 = permuteWhole(n1, 8759824322359LL, 13);
     n2 = permuteWhole(n2, 200560490131LL, 2707);
     n1 = (n1 >> 32) ^ (n1 << 32);
     n2 = (n2 >> 32) ^ (n2 << 32);
     n1 ^= x ^ (quint64(y ^ d->seed) * kyb);
     n2 ^= y ^ (quint64(x + 13)   * kxb);
 
     // Combine salts
     quint64 v = 0;
     for (int p = 0; p < 8; ++p)
         v |= part(n1, n2, p);
     return v;
 }
 
 double KisRandomGenerator::doubleRandomAt(qint64 x, qint64 y)
 {
     return randomAt(x, y) / (double)UINT64_MAX;
 }