You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
122 lines
3.4 KiB
122 lines
3.4 KiB
14 years ago
|
/*==LICENSE==*
|
||
|
|
|
||
|
|
CyanWorlds.com Engine - MMOG client, server and tools
|
||
|
|
Copyright (C) 2011 Cyan Worlds, Inc.
|
||
|
|
|
||
|
|
This program is free software: you can redistribute it and/or modify
|
||
|
|
it under the terms of the GNU General Public License as published by
|
||
|
|
the Free Software Foundation, either version 3 of the License, or
|
||
|
|
(at your option) any later version.
|
||
|
|
|
||
|
|
This program is distributed in the hope that it will be useful,
|
||
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
GNU General Public License for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU General Public License
|
||
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
|
||
|
|
You can contact Cyan Worlds, Inc. by email legal@cyan.com
|
||
|
|
or by snail mail at:
|
||
|
|
Cyan Worlds, Inc.
|
||
|
|
14617 N Newport Hwy
|
||
|
|
Mead, WA 99021
|
||
|
|
|
||
|
|
*==LICENSE==*/
|
||
|
|
|
||
|
|
#ifndef plRandom_inc
|
||
|
|
#define plRandom_inc
|
||
|
|
|
||
|
|
// FAST_Q is basically lifted from Numerical Recipes.
|
||
|
|
// The RandZeroToOne and RandMinusOneToOne were "enhanced"
|
||
|
|
// a bit, but tested out nicely to generate sequences with
|
||
|
|
// appropriate maxs, mins, and means.
|
||
|
|
// FAST_Q depends on IEEE floating point format. Undefine
|
||
|
|
// it for any platform which doesn't satisfy this, or
|
||
|
|
// come up with the appropriate constants for that platform.
|
||
|
|
#define FAST_Q
|
||
|
|
|
||
|
|
|
||
|
|
class plRandom
|
||
|
|
{
|
||
|
|
protected:
|
||
|
|
mutable UInt32 fSeed;
|
||
|
|
public:
|
||
|
|
inline float RandNorm() const;
|
||
|
|
inline int Rand() const;
|
||
|
|
inline int RandRangeI(int lo, int hi) const;
|
||
|
|
inline float RandRangeF(float lo, float hi) const;
|
||
|
|
inline float RandMinusOneToOne() const;
|
||
|
|
inline float RandZeroToOne() const;
|
||
|
|
|
||
|
|
UInt32 GetSeed() const { return fSeed; }
|
||
|
|
void SetSeed(int seed) { fSeed = seed; }
|
||
|
|
|
||
|
|
plRandom(int seed = 1) : fSeed(seed) {}
|
||
|
|
};
|
||
|
|
|
||
|
|
inline float plRandom::RandNorm() const
|
||
|
|
{
|
||
|
|
#ifndef FAST_Q
|
||
|
|
return 1.f / 32767.f;
|
||
|
|
#else // FAST_Q
|
||
|
|
return (1.f / float(~0UL));
|
||
|
|
#endif // FAST_Q
|
||
|
|
}
|
||
|
|
|
||
|
|
inline int plRandom::Rand() const
|
||
|
|
{
|
||
|
|
#ifndef FAST_Q
|
||
|
|
register int temp;
|
||
|
|
fSeed = fSeed * 1103515245 + 12345;
|
||
|
|
temp = (int)((fSeed/65536)&32767);
|
||
|
|
return (temp);
|
||
|
|
#else // FAST_Q
|
||
|
|
return fSeed = 1664525L * fSeed + 1013904223L;
|
||
|
|
#endif // FAST_Q
|
||
|
|
}
|
||
|
|
|
||
|
|
// RandZeroToOne - take our usual random UInt32.
|
||
|
|
// We're going to mask in an exponent to make it
|
||
|
|
// a float in range [1..2). Then subtract 1.f to
|
||
|
|
// make it [0..1). We shift our random UInt32 down
|
||
|
|
// by 9 because the upper bits are the most random.
|
||
|
|
inline float plRandom::RandZeroToOne() const
|
||
|
|
{
|
||
|
|
#ifndef FAST_Q
|
||
|
|
return Rand() * RandNorm();
|
||
|
|
#else // FAST_Q
|
||
|
|
const UInt32 kOneExp = 0x3f800000;
|
||
|
|
register UInt32 temp = kOneExp | (UInt32(Rand()) >> 9);
|
||
|
|
return (*(float*)&temp) - 1.f;
|
||
|
|
#endif // FAST_Q
|
||
|
|
}
|
||
|
|
|
||
|
|
// RandMinusOneToOne - same as RandZeroToOne, but we
|
||
|
|
// mask in an exponent putting it in range [2..4),
|
||
|
|
// then subtract 3 to give [-1..1).
|
||
|
|
inline float plRandom::RandMinusOneToOne() const
|
||
|
|
{
|
||
|
|
#ifndef FAST_Q
|
||
|
|
return RandZeroToOne() * 2.f - 1.f;
|
||
|
|
#else // FAST_Q
|
||
|
|
const UInt32 kTwoExp = 0x40000000;
|
||
|
|
register UInt32 temp = kTwoExp | (UInt32(Rand()) >> 9);
|
||
|
|
return (*(float*)&temp) - 3.f;
|
||
|
|
#endif // FAST_Q
|
||
|
|
}
|
||
|
|
|
||
|
|
inline float plRandom::RandRangeF(float lo, float hi) const
|
||
|
|
{
|
||
|
|
return lo + RandZeroToOne() * (hi - lo);
|
||
|
|
}
|
||
|
|
|
||
|
|
inline int plRandom::RandRangeI(int lo, int hi) const
|
||
|
|
{
|
||
|
|
return lo + int(RandZeroToOne() * float(hi + 1 - lo));
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
#endif // plRandom_inc
|
||
|
|
|