Added new function break_fp().

[mutilities/MUtilities.git] / src / Global.cpp

diff --git a/src/Global.cpp b/src/Global.cpp
index 026ddff..2028e69 100644 (file)
--- a/src/Global.cpp
+++ b/src/Global.cpp
@@ -63,13 +63,12 @@
 //Per-thread init flag
 static QThreadStorage<bool> g_srand_flag;
 
+//32-Bit wrapper for qrand()
+#define QRAND() ((static_cast<quint32>(qrand()) & 0xFFFF) | (static_cast<quint32>(qrand()) << 16U))
+
 //Robert Jenkins' 96 bit Mix Function
-static quint32 mix_function(const quint32 x, const quint32 y, const quint32 z)
+static quint32 mix_function(quint32 a, quint32 b, quint32 c)
 {
-       quint32 a = x;
-       quint32 b = y;
-       quint32 c = z;
-       
        a=a-b;  a=a-c;  a=a^(c >> 13);
        b=b-c;  b=b-a;  b=b^(a <<  8); 
        c=c-a;  c=c-b;  c=c^(b >> 13);
@@ -86,24 +85,30 @@ static quint32 mix_function(const quint32 x, const quint32 y, const quint32 z)
 static void seed_rand(void)
 {
        QDateTime build(MUtils::Version::lib_build_date(), MUtils::Version::lib_build_time());
-       const quint32 seed = mix_function(MUtils::OS::process_id(), MUtils::OS::thread_id(), build.toMSecsSinceEpoch());
-       qsrand(mix_function(clock(), time(NULL), seed));
+       const quint32 seed_0 = mix_function(MUtils::OS::process_id(), MUtils::OS::thread_id(), build.toMSecsSinceEpoch());
+       qsrand(mix_function(clock(), time(NULL), seed_0));
 }
 
 static quint32 rand_fallback(void)
 {
-       Q_ASSERT(RAND_MAX >= 0xFFF);
+       Q_ASSERT(RAND_MAX >= 0x7FFF);
+
        if (!(g_srand_flag.hasLocalData() && g_srand_flag.localData()))
        {
                seed_rand();
                g_srand_flag.setLocalData(true);
        }
-       quint32 rnd = 0x32288EA3;
-       for (size_t i = 0; i < 3; i++)
+
+       quint32 rnd_val = mix_function(0x32288EA3, clock(), time(NULL));
+
+       for (size_t i = 0; i < 42; i++)
        {
-               rnd = (rnd << 12) ^ qrand();
+               rnd_val = mix_function(rnd_val, QRAND(), QRAND());
+               rnd_val = mix_function(QRAND(), rnd_val, QRAND());
+               rnd_val = mix_function(QRAND(), QRAND(), rnd_val);
        }
-       return rnd;
+
+       return rnd_val;
 }
 
 quint32 MUtils::next_rand_u32(void)
@@ -802,6 +807,17 @@ QStringList MUtils::available_codepages(const bool &noAliases)
 }
 
 ///////////////////////////////////////////////////////////////////////////////
+// FP MATH SUPPORT
+///////////////////////////////////////////////////////////////////////////////
+
+MUtils::fp_parts_t MUtils::break_fp(const double value)
+{
+       fp_parts_t result;
+       result.fractpart = modf(value, &result.intpart);
+       return result;
+}
+
+///////////////////////////////////////////////////////////////////////////////
 // SELF-TEST
 ///////////////////////////////////////////////////////////////////////////////