mirror of
https://github.com/ZDoom/qzdoom-gpl.git
synced 2024-11-17 09:41:21 +00:00
400 lines
12 KiB
C++
400 lines
12 KiB
C++
/*
|
|
** m_random.cpp
|
|
** Random number generators
|
|
**
|
|
**---------------------------------------------------------------------------
|
|
** Copyright 2002-2009 Randy Heit
|
|
** All rights reserved.
|
|
**
|
|
** Redistribution and use in source and binary forms, with or without
|
|
** modification, are permitted provided that the following conditions
|
|
** are met:
|
|
**
|
|
** 1. Redistributions of source code must retain the above copyright
|
|
** notice, this list of conditions and the following disclaimer.
|
|
** 2. Redistributions in binary form must reproduce the above copyright
|
|
** notice, this list of conditions and the following disclaimer in the
|
|
** documentation and/or other materials provided with the distribution.
|
|
** 3. The name of the author may not be used to endorse or promote products
|
|
** derived from this software without specific prior written permission.
|
|
**
|
|
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
**---------------------------------------------------------------------------
|
|
**
|
|
** This file employs the techniques for improving demo sync and backward
|
|
** compatibility that Lee Killough introduced with BOOM. However, none of
|
|
** the actual code he wrote is left. In contrast to BOOM, each RNG source
|
|
** in ZDoom is implemented as a separate class instance that provides an
|
|
** interface to the high-quality Mersenne Twister. See
|
|
** <http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/index.html>.
|
|
**
|
|
** As Killough's description from m_random.h is still mostly relevant,
|
|
** here it is:
|
|
** killough 2/16/98:
|
|
**
|
|
** Make every random number generator local to each control-equivalent block.
|
|
** Critical for demo sync. The random number generators are made local to
|
|
** reduce the chances of sync problems. In Doom, if a single random number
|
|
** generator call was off, it would mess up all random number generators.
|
|
** This reduces the chances of it happening by making each RNG local to a
|
|
** control flow block.
|
|
**
|
|
** Notes to developers: if you want to reduce your demo sync hassles, follow
|
|
** this rule: for each call to P_Random you add, add a new class to the enum
|
|
** type below for each block of code which calls P_Random. If two calls to
|
|
** P_Random are not in "control-equivalent blocks", i.e. there are any cases
|
|
** where one is executed, and the other is not, put them in separate classes.
|
|
*/
|
|
|
|
// HEADER FILES ------------------------------------------------------------
|
|
|
|
#include <assert.h>
|
|
|
|
#include "doomstat.h"
|
|
#include "m_random.h"
|
|
#include "farchive.h"
|
|
#include "b_bot.h"
|
|
#include "m_png.h"
|
|
#include "m_crc32.h"
|
|
#include "i_system.h"
|
|
#include "c_dispatch.h"
|
|
#include "files.h"
|
|
|
|
// MACROS ------------------------------------------------------------------
|
|
|
|
#define RAND_ID MAKE_ID('r','a','N','d')
|
|
|
|
// TYPES -------------------------------------------------------------------
|
|
|
|
// EXTERNAL FUNCTION PROTOTYPES --------------------------------------------
|
|
|
|
// PUBLIC FUNCTION PROTOTYPES ----------------------------------------------
|
|
|
|
// PRIVATE FUNCTION PROTOTYPES ---------------------------------------------
|
|
|
|
// EXTERNAL DATA DECLARATIONS ----------------------------------------------
|
|
|
|
extern FRandom pr_spawnmobj;
|
|
extern FRandom pr_acs;
|
|
extern FRandom pr_chase;
|
|
extern FRandom pr_exrandom;
|
|
extern FRandom pr_damagemobj;
|
|
|
|
// PUBLIC DATA DEFINITIONS -------------------------------------------------
|
|
|
|
FRandom M_Random;
|
|
|
|
// Global seed. This is modified predictably to initialize every RNG.
|
|
DWORD rngseed;
|
|
|
|
// PRIVATE DATA DEFINITIONS ------------------------------------------------
|
|
|
|
FRandom *FRandom::RNGList;
|
|
static TDeletingArray<FRandom *> NewRNGs;
|
|
|
|
// CODE --------------------------------------------------------------------
|
|
|
|
//==========================================================================
|
|
//
|
|
// FRandom - Nameless constructor
|
|
//
|
|
// Constructing an RNG in this way means it won't be stored in savegames.
|
|
//
|
|
//==========================================================================
|
|
|
|
FRandom::FRandom ()
|
|
: NameCRC (0)
|
|
{
|
|
#ifndef NDEBUG
|
|
Name = NULL;
|
|
initialized = false;
|
|
#endif
|
|
Next = RNGList;
|
|
RNGList = this;
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// FRandom - Named constructor
|
|
//
|
|
// This is the standard way to construct RNGs.
|
|
//
|
|
//==========================================================================
|
|
|
|
FRandom::FRandom (const char *name)
|
|
{
|
|
NameCRC = CalcCRC32 ((const BYTE *)name, (unsigned int)strlen (name));
|
|
#ifndef NDEBUG
|
|
initialized = false;
|
|
Name = name;
|
|
// A CRC of 0 is reserved for nameless RNGs that don't get stored
|
|
// in savegames. The chance is very low that you would get a CRC of 0,
|
|
// but it's still possible.
|
|
assert (NameCRC != 0);
|
|
#endif
|
|
|
|
// Insert the RNG in the list, sorted by CRC
|
|
FRandom **prev = &RNGList, *probe = RNGList;
|
|
|
|
while (probe != NULL && probe->NameCRC < NameCRC)
|
|
{
|
|
prev = &probe->Next;
|
|
probe = probe->Next;
|
|
}
|
|
|
|
#ifndef NDEBUG
|
|
if (probe != NULL)
|
|
{
|
|
// Because RNGs are identified by their CRCs in save games,
|
|
// no two RNGs can have names that hash to the same CRC.
|
|
// Obviously, this means every RNG must have a unique name.
|
|
assert (probe->NameCRC != NameCRC);
|
|
}
|
|
#endif
|
|
|
|
Next = probe;
|
|
*prev = this;
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// FRandom - Destructor
|
|
//
|
|
//==========================================================================
|
|
|
|
FRandom::~FRandom ()
|
|
{
|
|
FRandom *rng, **prev;
|
|
|
|
FRandom *last = NULL;
|
|
|
|
prev = &RNGList;
|
|
rng = RNGList;
|
|
|
|
while (rng != NULL && rng != this)
|
|
{
|
|
last = rng;
|
|
rng = rng->Next;
|
|
}
|
|
|
|
if (rng != NULL)
|
|
{
|
|
*prev = rng->Next;
|
|
}
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// FRandom :: StaticClearRandom
|
|
//
|
|
// Initialize every RNGs. RNGs are seeded based on the global seed and their
|
|
// name, so each different RNG can have a different starting value despite
|
|
// being derived from a common global seed.
|
|
//
|
|
//==========================================================================
|
|
|
|
void FRandom::StaticClearRandom ()
|
|
{
|
|
// go through each RNG and set each starting seed differently
|
|
for (FRandom *rng = FRandom::RNGList; rng != NULL; rng = rng->Next)
|
|
{
|
|
rng->Init(rngseed);
|
|
}
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// FRandom :: Init
|
|
//
|
|
// Initialize a single RNG with a given seed.
|
|
//
|
|
//==========================================================================
|
|
|
|
void FRandom::Init(DWORD seed)
|
|
{
|
|
// [RH] Use the RNG's name's CRC to modify the original seed.
|
|
// This way, new RNGs can be added later, and it doesn't matter
|
|
// which order they get initialized in.
|
|
DWORD seeds[2] = { NameCRC, seed };
|
|
InitByArray(seeds, 2);
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// FRandom :: StaticSumSeeds
|
|
//
|
|
// This function produces a DWORD that can be used to check the consistancy
|
|
// of network games between different machines. Only a select few RNGs are
|
|
// used for the sum, because not all RNGs are important to network sync.
|
|
//
|
|
//==========================================================================
|
|
|
|
DWORD FRandom::StaticSumSeeds ()
|
|
{
|
|
return
|
|
pr_spawnmobj.sfmt.u[0] + pr_spawnmobj.idx +
|
|
pr_acs.sfmt.u[0] + pr_acs.idx +
|
|
pr_chase.sfmt.u[0] + pr_chase.idx +
|
|
pr_damagemobj.sfmt.u[0] + pr_damagemobj.idx;
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// FRandom :: StaticWriteRNGState
|
|
//
|
|
// Stores the state of every RNG into a savegame.
|
|
//
|
|
//==========================================================================
|
|
|
|
void FRandom::StaticWriteRNGState (FILE *file)
|
|
{
|
|
FRandom *rng;
|
|
FPNGChunkArchive arc (file, RAND_ID);
|
|
|
|
arc << rngseed;
|
|
|
|
for (rng = FRandom::RNGList; rng != NULL; rng = rng->Next)
|
|
{
|
|
// Only write those RNGs that have names
|
|
if (rng->NameCRC != 0)
|
|
{
|
|
arc << rng->NameCRC << rng->idx;
|
|
for (int i = 0; i < SFMT::N32; ++i)
|
|
{
|
|
arc << rng->sfmt.u[i];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// FRandom :: StaticReadRNGState
|
|
//
|
|
// Restores the state of every RNG from a savegame. RNGs that were added
|
|
// since the savegame was created are cleared to their initial value.
|
|
//
|
|
//==========================================================================
|
|
|
|
void FRandom::StaticReadRNGState (PNGHandle *png)
|
|
{
|
|
FRandom *rng;
|
|
|
|
size_t len = M_FindPNGChunk (png, RAND_ID);
|
|
|
|
if (len != 0)
|
|
{
|
|
const size_t sizeof_rng = sizeof(rng->NameCRC) + sizeof(rng->idx) + sizeof(rng->sfmt.u);
|
|
const int rngcount = (int)((len-4) / sizeof_rng);
|
|
int i;
|
|
DWORD crc;
|
|
|
|
FPNGChunkArchive arc (png->File->GetFile(), RAND_ID, len);
|
|
|
|
arc << rngseed;
|
|
FRandom::StaticClearRandom ();
|
|
|
|
for (i = rngcount; i; --i)
|
|
{
|
|
arc << crc;
|
|
for (rng = FRandom::RNGList; rng != NULL; rng = rng->Next)
|
|
{
|
|
if (rng->NameCRC == crc)
|
|
{
|
|
arc << rng->idx;
|
|
for (int i = 0; i < SFMT::N32; ++i)
|
|
{
|
|
arc << rng->sfmt.u[i];
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
if (rng == NULL)
|
|
{ // The RNG was removed. Skip it.
|
|
int idx;
|
|
DWORD sfmt;
|
|
arc << idx;
|
|
for (int i = 0; i < SFMT::N32; ++i)
|
|
{
|
|
arc << sfmt;
|
|
}
|
|
}
|
|
}
|
|
png->File->ResetFilePtr();
|
|
}
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// FRandom :: StaticFindRNG
|
|
//
|
|
// This function attempts to find an RNG with the given name.
|
|
// If it can't it will create a new one. Duplicate CRCs will
|
|
// be ignored and if it happens map to the same RNG.
|
|
// This is for use by DECORATE.
|
|
//
|
|
//==========================================================================
|
|
|
|
FRandom *FRandom::StaticFindRNG (const char *name)
|
|
{
|
|
DWORD NameCRC = CalcCRC32 ((const BYTE *)name, (unsigned int)strlen (name));
|
|
|
|
// Use the default RNG if this one happens to have a CRC of 0.
|
|
if (NameCRC == 0) return &pr_exrandom;
|
|
|
|
// Find the RNG in the list, sorted by CRC
|
|
FRandom **prev = &RNGList, *probe = RNGList;
|
|
|
|
while (probe != NULL && probe->NameCRC < NameCRC)
|
|
{
|
|
prev = &probe->Next;
|
|
probe = probe->Next;
|
|
}
|
|
// Found one so return it.
|
|
if (probe == NULL || probe->NameCRC != NameCRC)
|
|
{
|
|
// A matching RNG doesn't exist yet so create it.
|
|
probe = new FRandom(name);
|
|
|
|
// Store the new RNG for destruction when ZDoom quits.
|
|
NewRNGs.Push(probe);
|
|
}
|
|
return probe;
|
|
}
|
|
|
|
//==========================================================================
|
|
//
|
|
// FRandom :: StaticPrintSeeds
|
|
//
|
|
// Prints a snapshot of the current RNG states. This is probably wrong.
|
|
//
|
|
//==========================================================================
|
|
|
|
#ifndef NDEBUG
|
|
void FRandom::StaticPrintSeeds ()
|
|
{
|
|
FRandom *rng = RNGList;
|
|
|
|
while (rng != NULL)
|
|
{
|
|
int idx = rng->idx < SFMT::N32 ? rng->idx : 0;
|
|
Printf ("%s: %08x .. %d\n", rng->Name, rng->sfmt.u[idx], idx);
|
|
rng = rng->Next;
|
|
}
|
|
}
|
|
|
|
CCMD (showrngs)
|
|
{
|
|
FRandom::StaticPrintSeeds ();
|
|
}
|
|
#endif
|
|
|