(svn r11488) -Codechange: Spilt the random functions out to seperate file

-Codechange: Make the mersenne twister more readable
-Codechange: Unify the seeding process of random

12 files changed, 1192 insertions, 188 deletions

diff --git a/projects/openttd.vcproj b/projects/openttd.vcproj
index 7ee50b846..cb4270d02 100644
--- a/projects/openttd.vcproj
+++ b/projects/openttd.vcproj
@@ -198,6 +198,9 @@
 				RelativePath=".\..\src\console_cmds.cpp">
 			</File>
 			<File
+				RelativePath=".\..\src\core\random_func.cpp">
+			</File>
+			<File
 				RelativePath=".\..\src\currency.cpp">
 			</File>
 			<File
@@ -258,9 +261,6 @@
 				RelativePath=".\..\src\md5.cpp">
 			</File>
 			<File
-				RelativePath=".\..\src\mersenne.cpp">
-			</File>
-			<File
 				RelativePath=".\..\src\minilzo.cpp">
 			</File>
 			<File
@@ -427,6 +427,9 @@
 				RelativePath=".\..\src\console.h">
 			</File>
 			<File
+				RelativePath=".\..\src\core\random_func.hpp">
+			</File>
+			<File
 				RelativePath=".\..\src\currency.h">
 			</File>
 			<File
diff --git a/projects/openttd_vs80.vcproj b/projects/openttd_vs80.vcproj
index 07ec91eea..62b4019a8 100644
--- a/projects/openttd_vs80.vcproj
+++ b/projects/openttd_vs80.vcproj
@@ -496,6 +496,10 @@
 				>
 			</File>
 			<File
+				RelativePath=".\..\src\core\random_func.cpp"
+				>
+			</File>
+			<File
 				RelativePath=".\..\src\currency.cpp"
 				>
 			</File>
@@ -576,10 +580,6 @@
 				>
 			</File>
 			<File
-				RelativePath=".\..\src\mersenne.cpp"
-				>
-			</File>
-			<File
 				RelativePath=".\..\src\minilzo.cpp"
 				>
 			</File>
@@ -800,6 +800,10 @@
 				>
 			</File>
 			<File
+				RelativePath=".\..\src\core\random_func.hpp"
+				>
+			</File>
+			<File
 				RelativePath=".\..\src\currency.h"
 				>
 			</File>
diff --git a/projects/openttd_vs90.vcproj b/projects/openttd_vs90.vcproj
index 9e23cebd3..a997e1682 100644
--- a/projects/openttd_vs90.vcproj
+++ b/projects/openttd_vs90.vcproj
@@ -493,6 +493,10 @@
 				>
 			</File>
 			<File
+				RelativePath=".\..\src\core\random_func.cpp"
+				>
+			</File>
+			<File
 				RelativePath=".\..\src\currency.cpp"
 				>
 			</File>
@@ -573,10 +577,6 @@
 				>
 			</File>
 			<File
-				RelativePath=".\..\src\mersenne.cpp"
-				>
-			</File>
-			<File
 				RelativePath=".\..\src\minilzo.cpp"
 				>
 			</File>
@@ -797,6 +797,10 @@
 				>
 			</File>
 			<File
+				RelativePath=".\..\src\core\random_func.hpp"
+				>
+			</File>
+			<File
 				RelativePath=".\..\src\currency.h"
 				>
 			</File>
diff --git a/source.list b/source.list
index a4cc2da0a..71b615a60 100644
--- a/source.list
+++ b/source.list
@@ -10,6 +10,7 @@ cargotype.cpp
 command.cpp
 console.cpp
 console_cmds.cpp
+core/random_func.cpp
 currency.cpp
 date.cpp
 debug.cpp
@@ -30,7 +31,6 @@ helpers.cpp
 landscape.cpp
 map.cpp
 md5.cpp
-mersenne.cpp
 minilzo.cpp
 misc.cpp
 mixer.cpp
@@ -108,6 +108,7 @@ cargopacket.h
 cargotype.h
 command.h
 console.h
+core/random_func.hpp
 currency.h
 date.h
 debug.h
diff --git a/src/core/random_func.cpp b/src/core/random_func.cpp
new file mode 100644
index 000000000..be22e376d
--- /dev/null
+++ b/src/core/random_func.cpp
@@ -0,0 +1,930 @@
+/* $Id$ */
+
+/** @file random_func.cpp */
+
+#include "../stdafx.h"
+#include "../macros.h"
+#include "../variables.h"
+#include "random_func.hpp"
+
+uint32 InteractiveRandom()
+{
+	const uint32 s = _random_seeds[1][0];
+	const uint32 t = _random_seeds[1][1];
+
+	_random_seeds[1][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[1][1] = ROR(s, 3) - 1;
+}
+
+uint InteractiveRandomRange(uint max)
+{
+	return GB(InteractiveRandom(), 0, 16) * max >> 16;
+}
+
+#ifdef MERSENNE_TWISTER
+// Source code for Mersenne Twister.
+// A Random number generator with much higher quality random numbers.
+
+#define N              (624)                 // length of _mt_state vector
+#define M              (397)                 // a period parameter
+#define K              (0x9908B0DFU)         // a magic constant
+#define hiBit(u)       ((u) & 0x80000000U)   // mask all but highest   bit of u
+#define loBit(u)       ((u) & 0x00000001U)   // mask all but lowest    bit of u
+#define loBits(u)      ((u) & 0x7FFFFFFFU)   // mask     the highest   bit of u
+#define mixBits(u, v)  (hiBit(u)|loBits(v))  // move hi bit of u to hi bit of v
+
+static uint32 _mt_state[N+1];     // _mt_state vector + 1 extra to not violate ANSI C
+static uint32 *_mt_next;          // _mt_next random value is computed from here
+static int    _mt_left = -1;      // can *_mt_next++ this many times before reloading
+
+void SetRandomSeed(register uint32 seed)
+{
+	register uint32 *s = _mt_state;
+	_mt_left = 0;
+
+	seed |= 1U;
+	seed &= 0xFFFFFFFFU;
+
+	*s = seed;
+
+	for (register uint i = N; i != 0; i--) {
+		seed *= 69069U;
+		*s++;
+		*s = seed & 0xFFFFFFFFU;
+	}
+}
+
+static uint32 ReloadRandom()
+{
+	if (_mt_left < -1) SetRandomSeed(4357U);
+
+	_mt_left = N - 1;
+	_mt_next = _mt_state + 1;
+
+	register uint32 *p0 = _mt_state;
+	register uint32 *p2 = _mt_state + 2;
+	register uint32 *pM = _mt_state + M;
+
+	register uint32 s0 = _mt_state[0];
+	register uint32 s1 = _mt_state[1];
+
+	register uint i = 0;
+
+	for (i = (N - M + 1); i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	pM = _mt_state;
+
+	for (i = M; i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	s1 = _mt_state[0];
+	*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+
+	s1 ^= (s1 >> 11);
+	s1 ^= (s1 <<  7) & 0x9D2C5680U;
+	s1 ^= (s1 << 15) & 0xEFC60000U;
+	s1 ^= (s1 >> 18);
+	return s1;
+}
+
+uint32 Random()
+{
+	_mt_left--;
+	if (_mt_left < 0) return ReloadRandom();
+
+	uint32 y = *_mt_next;
+	*_mt_next++;
+
+	y ^= (y >> 11);
+	y ^= (y <<  7) & 0x9D2C5680U;
+	y ^= (y << 15) & 0xEFC60000U;
+	y ^= (y >> 18);
+	return y;
+}
+
+#else /* MERSENNE_TWISTER */
+void SetRandomSeed(uint32 seed)
+{
+	_random_seeds[0][0] = seed;
+	_random_seeds[0][1] = seed;
+	_random_seeds[1][0] = seed * 0x1234567;
+	_random_seeds[1][1] = _random_seeds[1][0];
+}
+
+#ifdef RANDOM_DEBUG
+#include "network/network_data.h"
+uint32 DoRandom(int line, const char *file)
+{
+	if (_networking && (DEREF_CLIENT(0)->status != STATUS_INACTIVE || !_network_server))
+		printf("Random [%d/%d] %s:%d\n",_frame_counter, (byte)_current_player, file, line);
+#else /* RANDOM_DEBUG */
+uint32 Random()
+{
+#endif /* RANDOM_DEBUG */
+	const uint32 s = _random_seeds[0][0];
+	const uint32 t = _random_seeds[0][1];
+
+	_random_seeds[0][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[0][1] = ROR(s, 3) - 1;
+}
+#endif /* MERSENNE_TWISTER */
+
+#if defined(RANDOM_DEBUG) && !defined(MERSENNE_TWISTER)
+uint DoRandomRange(uint max, int line, const char *file)
+{
+	return GB(DoRandom(line, file), 0, 16) * max >> 16;
+}
+#else /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+uint RandomRange(uint max)
+{
+	return GB(Random(), 0, 16) * max >> 16;
+}
+#endif /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+/* $Id$ */
+
+/** @file random_func.cpp */
+
+#include "../stdafx.h"
+#include "../macros.h"
+#include "../variables.h"
+#include "random_func.hpp"
+
+uint32 InteractiveRandom()
+{
+	const uint32 s = _random_seeds[1][0];
+	const uint32 t = _random_seeds[1][1];
+
+	_random_seeds[1][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[1][1] = ROR(s, 3) - 1;
+}
+
+uint InteractiveRandomRange(uint max)
+{
+	return GB(InteractiveRandom(), 0, 16) * max >> 16;
+}
+
+#ifdef MERSENNE_TWISTER
+// Source code for Mersenne Twister.
+// A Random number generator with much higher quality random numbers.
+
+#define N              (624)                 // length of _mt_state vector
+#define M              (397)                 // a period parameter
+#define K              (0x9908B0DFU)         // a magic constant
+#define hiBit(u)       ((u) & 0x80000000U)   // mask all but highest   bit of u
+#define loBit(u)       ((u) & 0x00000001U)   // mask all but lowest    bit of u
+#define loBits(u)      ((u) & 0x7FFFFFFFU)   // mask     the highest   bit of u
+#define mixBits(u, v)  (hiBit(u)|loBits(v))  // move hi bit of u to hi bit of v
+
+static uint32 _mt_state[N+1];     // _mt_state vector + 1 extra to not violate ANSI C
+static uint32 *_mt_next;          // _mt_next random value is computed from here
+static int    _mt_left = -1;      // can *_mt_next++ this many times before reloading
+
+void SetRandomSeed(register uint32 seed)
+{
+	register uint32 *s = _mt_state;
+	_mt_left = 0;
+
+	seed |= 1U;
+	seed &= 0xFFFFFFFFU;
+
+	*s = seed;
+
+	for (register uint i = N; i != 0; i--) {
+		seed *= 69069U;
+		*s++;
+		*s = seed & 0xFFFFFFFFU;
+	}
+}
+
+static uint32 ReloadRandom()
+{
+	if (_mt_left < -1) SetRandomSeed(4357U);
+
+	_mt_left = N - 1;
+	_mt_next = _mt_state + 1;
+
+	register uint32 *p0 = _mt_state;
+	register uint32 *p2 = _mt_state + 2;
+	register uint32 *pM = _mt_state + M;
+
+	register uint32 s0 = _mt_state[0];
+	register uint32 s1 = _mt_state[1];
+
+	register uint i = 0;
+
+	for (i = (N - M + 1); i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	pM = _mt_state;
+
+	for (i = M; i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	s1 = _mt_state[0];
+	*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+
+	s1 ^= (s1 >> 11);
+	s1 ^= (s1 <<  7) & 0x9D2C5680U;
+	s1 ^= (s1 << 15) & 0xEFC60000U;
+	s1 ^= (s1 >> 18);
+	return s1;
+}
+
+uint32 Random()
+{
+	_mt_left--;
+	if (_mt_left < 0) return ReloadRandom();
+
+	uint32 y = *_mt_next;
+	*_mt_next++;
+
+	y ^= (y >> 11);
+	y ^= (y <<  7) & 0x9D2C5680U;
+	y ^= (y << 15) & 0xEFC60000U;
+	y ^= (y >> 18);
+	return y;
+}
+
+#else /* MERSENNE_TWISTER */
+void SetRandomSeed(uint32 seed)
+{
+	_random_seeds[0][0] = seed;
+	_random_seeds[0][1] = seed;
+	_random_seeds[1][0] = seed * 0x1234567;
+	_random_seeds[1][1] = _random_seeds[1][0];
+}
+
+#ifdef RANDOM_DEBUG
+#include "network/network_data.h"
+uint32 DoRandom(int line, const char *file)
+{
+	if (_networking && (DEREF_CLIENT(0)->status != STATUS_INACTIVE || !_network_server))
+		printf("Random [%d/%d] %s:%d\n",_frame_counter, (byte)_current_player, file, line);
+#else /* RANDOM_DEBUG */
+uint32 Random()
+{
+#endif /* RANDOM_DEBUG */
+	const uint32 s = _random_seeds[0][0];
+	const uint32 t = _random_seeds[0][1];
+
+	_random_seeds[0][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[0][1] = ROR(s, 3) - 1;
+}
+#endif /* MERSENNE_TWISTER */
+
+#if defined(RANDOM_DEBUG) && !defined(MERSENNE_TWISTER)
+uint DoRandomRange(uint max, int line, const char *file)
+{
+	return GB(DoRandom(line, file), 0, 16) * max >> 16;
+}
+#else /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+uint RandomRange(uint max)
+{
+	return GB(Random(), 0, 16) * max >> 16;
+}
+#endif /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+/* $Id$ */
+
+/** @file random_func.cpp */
+
+#include "../stdafx.h"
+#include "../macros.h"
+#include "../variables.h"
+#include "random_func.hpp"
+
+uint32 InteractiveRandom()
+{
+	const uint32 s = _random_seeds[1][0];
+	const uint32 t = _random_seeds[1][1];
+
+	_random_seeds[1][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[1][1] = ROR(s, 3) - 1;
+}
+
+uint InteractiveRandomRange(uint max)
+{
+	return GB(InteractiveRandom(), 0, 16) * max >> 16;
+}
+
+#ifdef MERSENNE_TWISTER
+// Source code for Mersenne Twister.
+// A Random number generator with much higher quality random numbers.
+
+#define N              (624)                 // length of _mt_state vector
+#define M              (397)                 // a period parameter
+#define K              (0x9908B0DFU)         // a magic constant
+#define hiBit(u)       ((u) & 0x80000000U)   // mask all but highest   bit of u
+#define loBit(u)       ((u) & 0x00000001U)   // mask all but lowest    bit of u
+#define loBits(u)      ((u) & 0x7FFFFFFFU)   // mask     the highest   bit of u
+#define mixBits(u, v)  (hiBit(u)|loBits(v))  // move hi bit of u to hi bit of v
+
+static uint32 _mt_state[N+1];     // _mt_state vector + 1 extra to not violate ANSI C
+static uint32 *_mt_next;          // _mt_next random value is computed from here
+static int    _mt_left = -1;      // can *_mt_next++ this many times before reloading
+
+void SetRandomSeed(register uint32 seed)
+{
+	register uint32 *s = _mt_state;
+	_mt_left = 0;
+
+	seed |= 1U;
+	seed &= 0xFFFFFFFFU;
+
+	*s = seed;
+
+	for (register uint i = N; i != 0; i--) {
+		seed *= 69069U;
+		*s++;
+		*s = seed & 0xFFFFFFFFU;
+	}
+}
+
+static uint32 ReloadRandom()
+{
+	if (_mt_left < -1) SetRandomSeed(4357U);
+
+	_mt_left = N - 1;
+	_mt_next = _mt_state + 1;
+
+	register uint32 *p0 = _mt_state;
+	register uint32 *p2 = _mt_state + 2;
+	register uint32 *pM = _mt_state + M;
+
+	register uint32 s0 = _mt_state[0];
+	register uint32 s1 = _mt_state[1];
+
+	register uint i = 0;
+
+	for (i = (N - M + 1); i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	pM = _mt_state;
+
+	for (i = M; i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	s1 = _mt_state[0];
+	*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+
+	s1 ^= (s1 >> 11);
+	s1 ^= (s1 <<  7) & 0x9D2C5680U;
+	s1 ^= (s1 << 15) & 0xEFC60000U;
+	s1 ^= (s1 >> 18);
+	return s1;
+}
+
+uint32 Random()
+{
+	_mt_left--;
+	if (_mt_left < 0) return ReloadRandom();
+
+	uint32 y = *_mt_next;
+	*_mt_next++;
+
+	y ^= (y >> 11);
+	y ^= (y <<  7) & 0x9D2C5680U;
+	y ^= (y << 15) & 0xEFC60000U;
+	y ^= (y >> 18);
+	return y;
+}
+
+#else /* MERSENNE_TWISTER */
+void SetRandomSeed(uint32 seed)
+{
+	_random_seeds[0][0] = seed;
+	_random_seeds[0][1] = seed;
+	_random_seeds[1][0] = seed * 0x1234567;
+	_random_seeds[1][1] = _random_seeds[1][0];
+}
+
+#ifdef RANDOM_DEBUG
+#include "network/network_data.h"
+uint32 DoRandom(int line, const char *file)
+{
+	if (_networking && (DEREF_CLIENT(0)->status != STATUS_INACTIVE || !_network_server))
+		printf("Random [%d/%d] %s:%d\n",_frame_counter, (byte)_current_player, file, line);
+#else /* RANDOM_DEBUG */
+uint32 Random()
+{
+#endif /* RANDOM_DEBUG */
+	const uint32 s = _random_seeds[0][0];
+	const uint32 t = _random_seeds[0][1];
+
+	_random_seeds[0][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[0][1] = ROR(s, 3) - 1;
+}
+#endif /* MERSENNE_TWISTER */
+
+#if defined(RANDOM_DEBUG) && !defined(MERSENNE_TWISTER)
+uint DoRandomRange(uint max, int line, const char *file)
+{
+	return GB(DoRandom(line, file), 0, 16) * max >> 16;
+}
+#else /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+uint RandomRange(uint max)
+{
+	return GB(Random(), 0, 16) * max >> 16;
+}
+#endif /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+/* $Id$ */
+
+/** @file random_func.cpp */
+
+#include "../stdafx.h"
+#include "../macros.h"
+#include "../variables.h"
+#include "random_func.hpp"
+
+uint32 InteractiveRandom()
+{
+	const uint32 s = _random_seeds[1][0];
+	const uint32 t = _random_seeds[1][1];
+
+	_random_seeds[1][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[1][1] = ROR(s, 3) - 1;
+}
+
+uint InteractiveRandomRange(uint max)
+{
+	return GB(InteractiveRandom(), 0, 16) * max >> 16;
+}
+
+#ifdef MERSENNE_TWISTER
+// Source code for Mersenne Twister.
+// A Random number generator with much higher quality random numbers.
+
+#define N              (624)                 // length of _mt_state vector
+#define M              (397)                 // a period parameter
+#define K              (0x9908B0DFU)         // a magic constant
+#define hiBit(u)       ((u) & 0x80000000U)   // mask all but highest   bit of u
+#define loBit(u)       ((u) & 0x00000001U)   // mask all but lowest    bit of u
+#define loBits(u)      ((u) & 0x7FFFFFFFU)   // mask     the highest   bit of u
+#define mixBits(u, v)  (hiBit(u)|loBits(v))  // move hi bit of u to hi bit of v
+
+static uint32 _mt_state[N+1];     // _mt_state vector + 1 extra to not violate ANSI C
+static uint32 *_mt_next;          // _mt_next random value is computed from here
+static int    _mt_left = -1;      // can *_mt_next++ this many times before reloading
+
+void SetRandomSeed(register uint32 seed)
+{
+	register uint32 *s = _mt_state;
+	_mt_left = 0;
+
+	seed |= 1U;
+	seed &= 0xFFFFFFFFU;
+
+	*s = seed;
+
+	for (register uint i = N; i != 0; i--) {
+		seed *= 69069U;
+		*s++;
+		*s = seed & 0xFFFFFFFFU;
+	}
+}
+
+static uint32 ReloadRandom()
+{
+	if (_mt_left < -1) SetRandomSeed(4357U);
+
+	_mt_left = N - 1;
+	_mt_next = _mt_state + 1;
+
+	register uint32 *p0 = _mt_state;
+	register uint32 *p2 = _mt_state + 2;
+	register uint32 *pM = _mt_state + M;
+
+	register uint32 s0 = _mt_state[0];
+	register uint32 s1 = _mt_state[1];
+
+	register uint i = 0;
+
+	for (i = (N - M + 1); i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	pM = _mt_state;
+
+	for (i = M; i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	s1 = _mt_state[0];
+	*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+
+	s1 ^= (s1 >> 11);
+	s1 ^= (s1 <<  7) & 0x9D2C5680U;
+	s1 ^= (s1 << 15) & 0xEFC60000U;
+	s1 ^= (s1 >> 18);
+	return s1;
+}
+
+uint32 Random()
+{
+	_mt_left--;
+	if (_mt_left < 0) return ReloadRandom();
+
+	uint32 y = *_mt_next;
+	*_mt_next++;
+
+	y ^= (y >> 11);
+	y ^= (y <<  7) & 0x9D2C5680U;
+	y ^= (y << 15) & 0xEFC60000U;
+	y ^= (y >> 18);
+	return y;
+}
+
+#else /* MERSENNE_TWISTER */
+void SetRandomSeed(uint32 seed)
+{
+	_random_seeds[0][0] = seed;
+	_random_seeds[0][1] = seed;
+	_random_seeds[1][0] = seed * 0x1234567;
+	_random_seeds[1][1] = _random_seeds[1][0];
+}
+
+#ifdef RANDOM_DEBUG
+#include "network/network_data.h"
+uint32 DoRandom(int line, const char *file)
+{
+	if (_networking && (DEREF_CLIENT(0)->status != STATUS_INACTIVE || !_network_server))
+		printf("Random [%d/%d] %s:%d\n",_frame_counter, (byte)_current_player, file, line);
+#else /* RANDOM_DEBUG */
+uint32 Random()
+{
+#endif /* RANDOM_DEBUG */
+	const uint32 s = _random_seeds[0][0];
+	const uint32 t = _random_seeds[0][1];
+
+	_random_seeds[0][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[0][1] = ROR(s, 3) - 1;
+}
+#endif /* MERSENNE_TWISTER */
+
+#if defined(RANDOM_DEBUG) && !defined(MERSENNE_TWISTER)
+uint DoRandomRange(uint max, int line, const char *file)
+{
+	return GB(DoRandom(line, file), 0, 16) * max >> 16;
+}
+#else /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+uint RandomRange(uint max)
+{
+	return GB(Random(), 0, 16) * max >> 16;
+}
+#endif /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+/* $Id$ */
+
+/** @file random_func.cpp */
+
+#include "../stdafx.h"
+#include "../macros.h"
+#include "../variables.h"
+#include "random_func.hpp"
+
+uint32 InteractiveRandom()
+{
+	const uint32 s = _random_seeds[1][0];
+	const uint32 t = _random_seeds[1][1];
+
+	_random_seeds[1][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[1][1] = ROR(s, 3) - 1;
+}
+
+uint InteractiveRandomRange(uint max)
+{
+	return GB(InteractiveRandom(), 0, 16) * max >> 16;
+}
+
+#ifdef MERSENNE_TWISTER
+// Source code for Mersenne Twister.
+// A Random number generator with much higher quality random numbers.
+
+#define N              (624)                 // length of _mt_state vector
+#define M              (397)                 // a period parameter
+#define K              (0x9908B0DFU)         // a magic constant
+#define hiBit(u)       ((u) & 0x80000000U)   // mask all but highest   bit of u
+#define loBit(u)       ((u) & 0x00000001U)   // mask all but lowest    bit of u
+#define loBits(u)      ((u) & 0x7FFFFFFFU)   // mask     the highest   bit of u
+#define mixBits(u, v)  (hiBit(u)|loBits(v))  // move hi bit of u to hi bit of v
+
+static uint32 _mt_state[N+1];     // _mt_state vector + 1 extra to not violate ANSI C
+static uint32 *_mt_next;          // _mt_next random value is computed from here
+static int    _mt_left = -1;      // can *_mt_next++ this many times before reloading
+
+void SetRandomSeed(register uint32 seed)
+{
+	register uint32 *s = _mt_state;
+	_mt_left = 0;
+
+	seed |= 1U;
+	seed &= 0xFFFFFFFFU;
+
+	*s = seed;
+
+	for (register uint i = N; i != 0; i--) {
+		seed *= 69069U;
+		*s++;
+		*s = seed & 0xFFFFFFFFU;
+	}
+}
+
+static uint32 ReloadRandom()
+{
+	if (_mt_left < -1) SetRandomSeed(4357U);
+
+	_mt_left = N - 1;
+	_mt_next = _mt_state + 1;
+
+	register uint32 *p0 = _mt_state;
+	register uint32 *p2 = _mt_state + 2;
+	register uint32 *pM = _mt_state + M;
+
+	register uint32 s0 = _mt_state[0];
+	register uint32 s1 = _mt_state[1];
+
+	register uint i = 0;
+
+	for (i = (N - M + 1); i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	pM = _mt_state;
+
+	for (i = M; i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	s1 = _mt_state[0];
+	*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+
+	s1 ^= (s1 >> 11);
+	s1 ^= (s1 <<  7) & 0x9D2C5680U;
+	s1 ^= (s1 << 15) & 0xEFC60000U;
+	s1 ^= (s1 >> 18);
+	return s1;
+}
+
+uint32 Random()
+{
+	_mt_left--;
+	if (_mt_left < 0) return ReloadRandom();
+
+	uint32 y = *_mt_next;
+	*_mt_next++;
+
+	y ^= (y >> 11);
+	y ^= (y <<  7) & 0x9D2C5680U;
+	y ^= (y << 15) & 0xEFC60000U;
+	y ^= (y >> 18);
+	return y;
+}
+
+#else /* MERSENNE_TWISTER */
+void SetRandomSeed(uint32 seed)
+{
+	_random_seeds[0][0] = seed;
+	_random_seeds[0][1] = seed;
+	_random_seeds[1][0] = seed * 0x1234567;
+	_random_seeds[1][1] = _random_seeds[1][0];
+}
+
+#ifdef RANDOM_DEBUG
+#include "network/network_data.h"
+uint32 DoRandom(int line, const char *file)
+{
+	if (_networking && (DEREF_CLIENT(0)->status != STATUS_INACTIVE || !_network_server))
+		printf("Random [%d/%d] %s:%d\n",_frame_counter, (byte)_current_player, file, line);
+#else /* RANDOM_DEBUG */
+uint32 Random()
+{
+#endif /* RANDOM_DEBUG */
+	const uint32 s = _random_seeds[0][0];
+	const uint32 t = _random_seeds[0][1];
+
+	_random_seeds[0][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[0][1] = ROR(s, 3) - 1;
+}
+#endif /* MERSENNE_TWISTER */
+
+#if defined(RANDOM_DEBUG) && !defined(MERSENNE_TWISTER)
+uint DoRandomRange(uint max, int line, const char *file)
+{
+	return GB(DoRandom(line, file), 0, 16) * max >> 16;
+}
+#else /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+uint RandomRange(uint max)
+{
+	return GB(Random(), 0, 16) * max >> 16;
+}
+#endif /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+/* $Id$ */
+
+/** @file random_func.cpp */
+
+#include "../stdafx.h"
+#include "../macros.h"
+#include "../variables.h"
+#include "random_func.hpp"
+
+uint32 InteractiveRandom()
+{
+	const uint32 s = _random_seeds[1][0];
+	const uint32 t = _random_seeds[1][1];
+
+	_random_seeds[1][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[1][1] = ROR(s, 3) - 1;
+}
+
+uint InteractiveRandomRange(uint max)
+{
+	return GB(InteractiveRandom(), 0, 16) * max >> 16;
+}
+
+#ifdef MERSENNE_TWISTER
+// Source code for Mersenne Twister.
+// A Random number generator with much higher quality random numbers.
+
+#define N              (624)                 // length of _mt_state vector
+#define M              (397)                 // a period parameter
+#define K              (0x9908B0DFU)         // a magic constant
+#define hiBit(u)       ((u) & 0x80000000U)   // mask all but highest   bit of u
+#define loBit(u)       ((u) & 0x00000001U)   // mask all but lowest    bit of u
+#define loBits(u)      ((u) & 0x7FFFFFFFU)   // mask     the highest   bit of u
+#define mixBits(u, v)  (hiBit(u)|loBits(v))  // move hi bit of u to hi bit of v
+
+static uint32 _mt_state[N+1];     // _mt_state vector + 1 extra to not violate ANSI C
+static uint32 *_mt_next;          // _mt_next random value is computed from here
+static int    _mt_left = -1;      // can *_mt_next++ this many times before reloading
+
+void SetRandomSeed(register uint32 seed)
+{
+	register uint32 *s = _mt_state;
+	_mt_left = 0;
+
+	seed |= 1U;
+	seed &= 0xFFFFFFFFU;
+
+	*s = seed;
+
+	for (register uint i = N; i != 0; i--) {
+		seed *= 69069U;
+		*s++;
+		*s = seed & 0xFFFFFFFFU;
+	}
+}
+
+static uint32 ReloadRandom()
+{
+	if (_mt_left < -1) SetRandomSeed(4357U);
+
+	_mt_left = N - 1;
+	_mt_next = _mt_state + 1;
+
+	register uint32 *p0 = _mt_state;
+	register uint32 *p2 = _mt_state + 2;
+	register uint32 *pM = _mt_state + M;
+
+	register uint32 s0 = _mt_state[0];
+	register uint32 s1 = _mt_state[1];
+
+	register uint i = 0;
+
+	for (i = (N - M + 1); i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	pM = _mt_state;
+
+	for (i = M; i != 0; i--) {
+		s0 = s1;
+		s1 = *p2;
+		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+		*p0++;
+		*p2++;
+		*pM++;
+	}
+
+	s1 = _mt_state[0];
+	*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+
+	s1 ^= (s1 >> 11);
+	s1 ^= (s1 <<  7) & 0x9D2C5680U;
+	s1 ^= (s1 << 15) & 0xEFC60000U;
+	s1 ^= (s1 >> 18);
+	return s1;
+}
+
+uint32 Random()
+{
+	_mt_left--;
+	if (_mt_left < 0) return ReloadRandom();
+
+	uint32 y = *_mt_next;
+	*_mt_next++;
+
+	y ^= (y >> 11);
+	y ^= (y <<  7) & 0x9D2C5680U;
+	y ^= (y << 15) & 0xEFC60000U;
+	y ^= (y >> 18);
+	return y;
+}
+
+#else /* MERSENNE_TWISTER */
+void SetRandomSeed(uint32 seed)
+{
+	_random_seeds[0][0] = seed;
+	_random_seeds[0][1] = seed;
+	_random_seeds[1][0] = seed * 0x1234567;
+	_random_seeds[1][1] = _random_seeds[1][0];
+}
+
+#ifdef RANDOM_DEBUG
+#include "network/network_data.h"
+uint32 DoRandom(int line, const char *file)
+{
+	if (_networking && (DEREF_CLIENT(0)->status != STATUS_INACTIVE || !_network_server))
+		printf("Random [%d/%d] %s:%d\n",_frame_counter, (byte)_current_player, file, line);
+#else /* RANDOM_DEBUG */
+uint32 Random()
+{
+#endif /* RANDOM_DEBUG */
+	const uint32 s = _random_seeds[0][0];
+	const uint32 t = _random_seeds[0][1];
+
+	_random_seeds[0][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
+	return _random_seeds[0][1] = ROR(s, 3) - 1;
+}
+#endif /* MERSENNE_TWISTER */
+
+#if defined(RANDOM_DEBUG) && !defined(MERSENNE_TWISTER)
+uint DoRandomRange(uint max, int line, const char *file)
+{
+	return GB(DoRandom(line, file), 0, 16) * max >> 16;
+}
+#else /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+uint RandomRange(uint max)
+{
+	return GB(Random(), 0, 16) * max >> 16;
+}
+#endif /* RANDOM_DEBUG & !MERSENNE_TWISTER */
diff --git a/src/core/random_func.hpp b/src/core/random_func.hpp
new file mode 100644
index 000000000..2169c11fb
--- /dev/null
+++ b/src/core/random_func.hpp
@@ -0,0 +1,234 @@
+/* $Id$ */
+
+/** @file random_func.h */
+
+#ifndef RANDOM_FUNC_HPP
+#define RANDOM_FUNC_HPP
+
+/**************
+ * Warning: DO NOT enable this unless you understand what it does
+ *
+ * If enabled, in a network game all randoms will be dumped to the
+ *  stdout if the first client joins (or if you are a client). This
+ *  is to help finding desync problems.
+ *
+ * Warning: DO NOT enable this unless you understand what it does
+ **************/
+
+//#define RANDOM_DEBUG
+
+
+// Enable this to produce higher quality random numbers.
+// Doesn't work with network yet.
+// #define MERSENNE_TWISTER
+
+void SetRandomSeed(uint32 seed);
+#ifdef RANDOM_DEBUG
+	#define Random() DoRandom(__LINE__, __FILE__)
+	uint32 DoRandom(int line, const char *file);
+	#define RandomRange(max) DoRandomRange(max, __LINE__, __FILE__)
+	uint DoRandomRange(uint max, int line, const char *file);
+#else
+	uint32 Random();
+	uint RandomRange(uint max);
+#endif
+
+uint32 InteractiveRandom(); // Used for random sequences that are not the same on the other end of the multiplayer link
+uint InteractiveRandomRange(uint max);
+
+#endif /* RANDOM_FUNC_HPP */
+/* $Id$ */
+
+/** @file random_func.h */
+
+#ifndef RANDOM_FUNC_HPP
+#define RANDOM_FUNC_HPP
+
+/**************
+ * Warning: DO NOT enable this unless you understand what it does
+ *
+ * If enabled, in a network game all randoms will be dumped to the
+ *  stdout if the first client joins (or if you are a client). This
+ *  is to help finding desync problems.
+ *
+ * Warning: DO NOT enable this unless you understand what it does
+ **************/
+
+//#define RANDOM_DEBUG
+
+
+// Enable this to produce higher quality random numbers.
+// Doesn't work with network yet.
+// #define MERSENNE_TWISTER
+
+void SetRandomSeed(uint32 seed);
+#ifdef RANDOM_DEBUG
+	#define Random() DoRandom(__LINE__, __FILE__)
+	uint32 DoRandom(int line, const char *file);
+	#define RandomRange(max) DoRandomRange(max, __LINE__, __FILE__)
+	uint DoRandomRange(uint max, int line, const char *file);
+#else
+	uint32 Random();
+	uint RandomRange(uint max);
+#endif
+
+uint32 InteractiveRandom(); // Used for random sequences that are not the same on the other end of the multiplayer link
+uint InteractiveRandomRange(uint max);
+
+#endif /* RANDOM_FUNC_HPP */
+/* $Id$ */
+
+/** @file random_func.h */
+
+#ifndef RANDOM_FUNC_HPP
+#define RANDOM_FUNC_HPP
+
+/**************
+ * Warning: DO NOT enable this unless you understand what it does
+ *
+ * If enabled, in a network game all randoms will be dumped to the
+ *  stdout if the first client joins (or if you are a client). This
+ *  is to help finding desync problems.
+ *
+ * Warning: DO NOT enable this unless you understand what it does
+ **************/
+
+//#define RANDOM_DEBUG
+
+
+// Enable this to produce higher quality random numbers.
+// Doesn't work with network yet.
+// #define MERSENNE_TWISTER
+
+void SetRandomSeed(uint32 seed);
+#ifdef RANDOM_DEBUG
+	#define Random() DoRandom(__LINE__, __FILE__)
+	uint32 DoRandom(int line, const char *file);
+	#define RandomRange(max) DoRandomRange(max, __LINE__, __FILE__)
+	uint DoRandomRange(uint max, int line, const char *file);
+#else
+	uint32 Random();
+	uint RandomRange(uint max);
+#endif
+
+uint32 InteractiveRandom(); // Used for random sequences that are not the same on the other end of the multiplayer link
+uint InteractiveRandomRange(uint max);
+
+#endif /* RANDOM_FUNC_HPP */
+/* $Id$ */
+
+/** @file random_func.h */
+
+#ifndef RANDOM_FUNC_HPP
+#define RANDOM_FUNC_HPP
+
+/**************
+ * Warning: DO NOT enable this unless you understand what it does
+ *
+ * If enabled, in a network game all randoms will be dumped to the
+ *  stdout if the first client joins (or if you are a client). This
+ *  is to help finding desync problems.
+ *
+ * Warning: DO NOT enable this unless you understand what it does
+ **************/
+
+//#define RANDOM_DEBUG
+
+
+// Enable this to produce higher quality random numbers.
+// Doesn't work with network yet.
+// #define MERSENNE_TWISTER
+
+void SetRandomSeed(uint32 seed);
+#ifdef RANDOM_DEBUG
+	#define Random() DoRandom(__LINE__, __FILE__)
+	uint32 DoRandom(int line, const char *file);
+	#define RandomRange(max) DoRandomRange(max, __LINE__, __FILE__)
+	uint DoRandomRange(uint max, int line, const char *file);
+#else
+	uint32 Random();
+	uint RandomRange(uint max);
+#endif
+
+uint32 InteractiveRandom(); // Used for random sequences that are not the same on the other end of the multiplayer link
+uint InteractiveRandomRange(uint max);
+
+#endif /* RANDOM_FUNC_HPP */
+/* $Id$ */
+
+/** @file random_func.h */
+
+#ifndef RANDOM_FUNC_HPP
+#define RANDOM_FUNC_HPP
+
+/**************
+ * Warning: DO NOT enable this unless you understand what it does
+ *
+ * If enabled, in a network game all randoms will be dumped to the
+ *  stdout if the first client joins (or if you are a client). This
+ *  is to help finding desync problems.
+ *
+ * Warning: DO NOT enable this unless you understand what it does
+ **************/
+
+//#define RANDOM_DEBUG
+
+
+// Enable this to produce higher quality random numbers.
+// Doesn't work with network yet.
+// #define MERSENNE_TWISTER
+
+void SetRandomSeed(uint32 seed);
+#ifdef RANDOM_DEBUG
+	#define Random() DoRandom(__LINE__, __FILE__)
+	uint32 DoRandom(int line, const char *file);
+	#define RandomRange(max) DoRandomRange(max, __LINE__, __FILE__)
+	uint DoRandomRange(uint max, int line, const char *file);
+#else
+	uint32 Random();
+	uint RandomRange(uint max);
+#endif
+
+uint32 InteractiveRandom(); // Used for random sequences that are not the same on the other end of the multiplayer link
+uint InteractiveRandomRange(uint max);
+
+#endif /* RANDOM_FUNC_HPP */
+/* $Id$ */
+
+/** @file random_func.h */
+
+#ifndef RANDOM_FUNC_HPP
+#define RANDOM_FUNC_HPP
+
+/**************
+ * Warning: DO NOT enable this unless you understand what it does
+ *
+ * If enabled, in a network game all randoms will be dumped to the
+ *  stdout if the first client joins (or if you are a client). This
+ *  is to help finding desync problems.
+ *
+ * Warning: DO NOT enable this unless you understand what it does
+ **************/
+
+//#define RANDOM_DEBUG
+
+
+// Enable this to produce higher quality random numbers.
+// Doesn't work with network yet.
+// #define MERSENNE_TWISTER
+
+void SetRandomSeed(uint32 seed);
+#ifdef RANDOM_DEBUG
+	#define Random() DoRandom(__LINE__, __FILE__)
+	uint32 DoRandom(int line, const char *file);
+	#define RandomRange(max) DoRandomRange(max, __LINE__, __FILE__)
+	uint DoRandomRange(uint max, int line, const char *file);
+#else
+	uint32 Random();
+	uint RandomRange(uint max);
+#endif
+
+uint32 InteractiveRandom(); // Used for random sequences that are not the same on the other end of the multiplayer link
+uint InteractiveRandomRange(uint max);
+
+#endif /* RANDOM_FUNC_HPP */
diff --git a/src/functions.h b/src/functions.h
index ec680e7e8..191ad7708 100644
--- a/src/functions.h
+++ b/src/functions.h
@@ -7,6 +7,7 @@
 
 #include "gfx.h"
 #include "viewport.h"
+#include "core/random_func.hpp"
 
 void UpdateTownMaxPass(Town *t);
 
@@ -32,52 +33,9 @@ void ShowInfo(const char *str);
 void CDECL ShowInfoF(const char *str, ...);
 
 /* openttd.cpp */
-
-/**************
- * Warning: DO NOT enable this unless you understand what it does
- *
- * If enabled, in a network game all randoms will be dumped to the
- *  stdout if the first client joins (or if you are a client). This
- *  is to help finding desync problems.
- *
- * Warning: DO NOT enable this unless you understand what it does
- **************/
-
-//#define RANDOM_DEBUG
-
-
-// Enable this to produce higher quality random numbers.
-// Doesn't work with network yet.
-//#define MERSENNE_TWISTER
-
-// Mersenne twister functions
-void SeedMT(uint32 seed);
-uint32 RandomMT();
-
-
-#ifdef MERSENNE_TWISTER
-	static inline uint32 Random() { return RandomMT(); }
-	uint RandomRange(uint max);
-#else
-
-#ifdef RANDOM_DEBUG
-	#define Random() DoRandom(__LINE__, __FILE__)
-	uint32 DoRandom(int line, const char *file);
-	#define RandomRange(max) DoRandomRange(max, __LINE__, __FILE__)
-	uint DoRandomRange(uint max, int line, const char *file);
-#else
-	uint32 Random();
-	uint RandomRange(uint max);
-#endif
-#endif // MERSENNE_TWISTER
-
 static inline TileIndex RandomTileSeed(uint32 r) { return TILE_MASK(r); }
 static inline TileIndex RandomTile() { return TILE_MASK(Random()); }
 
-
-uint32 InteractiveRandom(); // Used for random sequences that are not the same on the other end of the multiplayer link
-uint InteractiveRandomRange(uint max);
-
 /* texteff.cpp */
 void AddAnimatedTile(TileIndex tile);
 void DeleteAnimatedTile(TileIndex tile);
diff --git a/src/mersenne.cpp b/src/mersenne.cpp
deleted file mode 100644
index 70a443149..000000000
--- a/src/mersenne.cpp
+++ /dev/null
@@ -1,76 +0,0 @@
-/* $Id$ */
-
-/** @file mersenne.cpp */
-
-#include "stdafx.h"
-#include "openttd.h"
-
-#ifdef MERSENNE_TWISTER
-
-// Source code for Mersenne Twister.
-// A Random number generator with much higher quality random numbers.
-
-#define N              (624)                 // length of _mt_state vector
-#define M              (397)                 // a period parameter
-#define K              (0x9908B0DFU)         // a magic constant
-#define hiBit(u)       ((u) & 0x80000000U)   // mask all but highest   bit of u
-#define loBit(u)       ((u) & 0x00000001U)   // mask all but lowest    bit of u
-#define loBits(u)      ((u) & 0x7FFFFFFFU)   // mask     the highest   bit of u
-#define mixBits(u, v)  (hiBit(u)|loBits(v))  // move hi bit of u to hi bit of v
-
-static uint32   _mt_state[N+1];     // _mt_state vector + 1 extra to not violate ANSI C
-static uint32   *_mt_next;          // _mt_next random value is computed from here
-static int      _mt_left = -1;      // can *_mt_next++ this many times before reloading
-
-void SeedMT(uint32 seed)
-{
-    register uint32 x = (seed | 1U) & 0xFFFFFFFFU, *s = _mt_state;
-    register int    j;
-
-    for (_mt_left=0, *s++=x, j=N; --j;
-        *s++ = (x*=69069U) & 0xFFFFFFFFU);
- }
-
-
-static uint32 ReloadMT()
- {
-    register uint32 *p0=_mt_state, *p2=_mt_state+2, *pM=_mt_state+M, s0, s1;
-    register int    j;
-
-    if (_mt_left < -1)
-        SeedMT(4357U);
-
-    _mt_left=N-1, _mt_next=_mt_state+1;
-
-    for (s0=_mt_state[0], s1=_mt_state[1], j=N-M+1; --j; s0=s1, s1=*p2++)
-        *p0++ = *pM++ ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
-
-    for (pM=_mt_state, j=M; --j; s0=s1, s1=*p2++)
-        *p0++ = *pM++ ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
-
-    s1=_mt_state[0], *p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
-    s1 ^= (s1 >> 11);
-    s1 ^= (s1 <<  7) & 0x9D2C5680U;
-    s1 ^= (s1 << 15) & 0xEFC60000U;
-    return(s1 ^ (s1 >> 18));
- }
-
-
-uint32 RandomMT()
-{
-	uint32 y;
-
-	if (--_mt_left < 0)
-		return ReloadMT();
-
-	y  = *_mt_next++;
-	y ^= (y >> 11);
-	y ^= (y <<  7) & 0x9D2C5680U;
-	y ^= (y << 15) & 0xEFC60000U;
-	return y ^ (y >> 18);
-}
-#else
-
-void SeedMT(uint32 seed) {}
-
-#endif /* MERSENNE_TWISTER */
diff --git a/src/misc.cpp b/src/misc.cpp
index 10fd76ecf..52cd764e8 100644
--- a/src/misc.cpp
+++ b/src/misc.cpp
@@ -27,57 +27,6 @@
 
 char _name_array[512][32];
 
-#ifndef MERSENNE_TWISTER
-
-#ifdef RANDOM_DEBUG
-#include "network/network_data.h"
-uint32 DoRandom(int line, const char *file)
-#else // RANDOM_DEBUG
-uint32 Random()
-#endif // RANDOM_DEBUG
-{
-
-uint32 s;
-uint32 t;
-
-#ifdef RANDOM_DEBUG
-	if (_networking && (DEREF_CLIENT(0)->status != STATUS_INACTIVE || !_network_server))
-		printf("Random [%d/%d] %s:%d\n",_frame_counter, (byte)_current_player, file, line);
-#endif
-
-	s = _random_seeds[0][0];
-	t = _random_seeds[0][1];
-	_random_seeds[0][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
-	return _random_seeds[0][1] = ROR(s, 3) - 1;
-}
-#endif // MERSENNE_TWISTER
-
-#if defined(RANDOM_DEBUG) && !defined(MERSENNE_TWISTER)
-uint DoRandomRange(uint max, int line, const char *file)
-{
-	return GB(DoRandom(line, file), 0, 16) * max >> 16;
-}
-#else
-uint RandomRange(uint max)
-{
-	return GB(Random(), 0, 16) * max >> 16;
-}
-#endif
-
-
-uint32 InteractiveRandom()
-{
-	uint32 t = _random_seeds[1][1];
-	uint32 s = _random_seeds[1][0];
-	_random_seeds[1][0] = s + ROR(t ^ 0x1234567F, 7) + 1;
-	return _random_seeds[1][1] = ROR(s, 3) - 1;
-}
-
-uint InteractiveRandomRange(uint max)
-{
-	return GB(InteractiveRandom(), 0, 16) * max >> 16;
-}
-
 void InitializeVehicles();
 void InitializeWaypoints();
 void InitializeDepots();
diff --git a/src/os2.cpp b/src/os2.cpp
index 7f2626587..7ffccf09a 100644
--- a/src/os2.cpp
+++ b/src/os2.cpp
@@ -163,7 +163,7 @@ void ShowOSErrorBox(const char *buf)
 
 int CDECL main(int argc, char* argv[])
 {
-	_random_seeds[1][1] = _random_seeds[1][0] = _random_seeds[0][1] = _random_seeds[0][0] = time(NULL);
+	SetRandomSeed(time(NULL));
 
 	return ttd_main(argc, argv);
 }
diff --git a/src/unix.cpp b/src/unix.cpp
index 3933352e6..aa9a361eb 100644
--- a/src/unix.cpp
+++ b/src/unix.cpp
@@ -136,8 +136,7 @@ int CDECL main(int argc, char* argv[])
 	}
 #endif
 
-	_random_seeds[1][1] = _random_seeds[1][0] = _random_seeds[0][1] = _random_seeds[0][0] = time(NULL);
-	SeedMT(_random_seeds[0][1]);
+	SetRandomSeed(time(NULL));
 
 	signal(SIGPIPE, SIG_IGN);
 
diff --git a/src/win32.cpp b/src/win32.cpp
index c0479f64a..e0298a0f8 100644
--- a/src/win32.cpp
+++ b/src/win32.cpp
@@ -971,9 +971,7 @@ int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLi
 #endif
 
 	/* setup random seed to something quite random */
-	_random_seeds[1][0] = _random_seeds[0][0] = GetTickCount();
-	_random_seeds[1][1] = _random_seeds[0][1] = _random_seeds[0][0] * 0x1234567;
-	SeedMT(_random_seeds[0][0]);
+	SetRandomSeed(GetTickCount());
 
 	argc = ParseCommandLine(cmdline, argv, lengthof(argv));