[Fix] #38796 マーフォーク用の rgold_adj を追加。 / Add to rgold_adj for Merfolk.

[hengband/hengband.git] / src / z-rand.c

diff --git a/src/z-rand.c b/src/z-rand.c
index a418734..7ddd76f 100644 (file)
--- a/src/z-rand.c
+++ b/src/z-rand.c
@@ -1,4 +1,4 @@
-/* File: z-rand.c */
+/* File: z-rand.c */
 
 /*
  * Copyright (c) 1997 Ben Harrison, and others
@@ -11,6 +11,10 @@
 
 /* Purpose: a simple random number generator -BEN- */
 
+#if defined(WINDOWS)
+#include <Windows.h>
+#endif
+
 #include "z-rand.h"
 
 
@@ -66,14 +70,18 @@ u32b Rand_state[RAND_DEG] = {
 };
 
 
+static u32b u32b_rotl(const u32b x, int k)
+{
+       return (x << k) | (x >> (32 - k));
+}
+
 /*
- * Initialize Xorshift Algorithm state
+ * Initialize RNG state
  */
-static void Rand_Xorshift_init(u32b seed, u32b* state)
+static void Rand_seed(u32b seed, u32b* state)
 {
        int i;
 
-       /* Initialize Xorshift Algorithm RNG */
        for (i = 1; i <= 4; ++ i) {
                seed = 1812433253UL * (seed ^ (seed >> 30)) + i;
                state[i-1] = seed;
@@ -81,27 +89,73 @@ static void Rand_Xorshift_init(u32b seed, u32b* state)
 }
 
 /*
- * Xorshift Algorithm
+ * Xoshiro128** Algorithm
  */
-static u32b Rand_Xorshift(u32b* state)
+static u32b Rand_Xoshiro128starstar(u32b *state)
 {
-       u32b t = state[0] ^ (state[0] << 11);
+       const u32b result = u32b_rotl(state[0] * 5, 7) * 9;
 
-       state[0] = state[1];
-       state[1] = state[2];
-       state[2] = state[3];
+       const u32b t = state[1] << 9;
 
-       state[3] = (state[3] ^ (state[3] >> 19)) ^ (t ^ (t >> 8));
+       state[2] ^= state[0];
+       state[3] ^= state[1];
+       state[1] ^= state[2];
+       state[0] ^= state[3];
 
-       return state[3];
+       state[2] ^= t;
+
+       state[3] = u32b_rotl(state[3], 11);
+
+       return result;
 }
 
+static const u32b Rand_Xorshift_max = 0xFFFFFFFF;
+
 /*
  * Initialize the RNG using a new seed
  */
-void Rand_state_init(u32b seed)
+void Rand_state_set(u32b seed)
 {
-       Rand_Xorshift_init(seed, Rand_state);
+       Rand_seed(seed, Rand_state);
+}
+
+void Rand_state_init(void)
+{
+#ifdef RNG_DEVICE
+
+       FILE *fp = fopen(RNG_DEVICE, "r");
+       int n;
+       
+       do {
+               n = fread(Rand_state, sizeof(Rand_state[0]), 4, fp);
+       } while (n != 4 || (Rand_state[0] | Rand_state[1] | Rand_state[2] | Rand_state[3]) == 0);
+       
+       fclose(fp);
+
+#elif defined(WINDOWS)
+
+       HCRYPTPROV hProvider;
+
+       CryptAcquireContext(&hProvider, NULL, NULL, PROV_RSA_FULL, 0);
+
+       do {
+               CryptGenRandom(hProvider, sizeof(Rand_state[0]) * 4, (BYTE*)Rand_state);
+       } while ((Rand_state[0] | Rand_state[1] | Rand_state[2] | Rand_state[3]) == 0);
+
+       CryptReleaseContext(hProvider, 0);      
+
+#else
+
+       /* Basic seed */
+       u32b seed = (time(NULL));
+#ifdef SET_UID
+       /* Mutate the seed on Unix machines */
+       seed = ((seed >> 3) * (getpid() << 1));
+#endif
+       /* Seed the RNG */
+       Rand_state_set(seed);
+
+#endif
 }
 
 /*
@@ -132,13 +186,28 @@ void Rand_state_restore(u32b* backup_state)
 /*
  * Extract a "random" number from 0 to m-1, via "division"
  */
-s32b Rand_div(u32b m)
+static s32b Rand_div_impl(s32b m, u32b* state)
 {
+       u32b scaling;
+       u32b past;
+       u32b ret;
+
        /* Hack -- simple case */
        if (m <= 1) return (0);
 
-       /* Use the value */
-       return Rand_Xorshift(Rand_state) % m;
+       scaling = Rand_Xorshift_max / m;
+       past = scaling * m;
+
+       do {
+               ret = Rand_Xoshiro128starstar(state);
+       } while (ret >= past);
+
+       return ret / scaling;
+}
+
+s32b Rand_div(s32b m)
+{
+       return Rand_div_impl(m, Rand_state);
 }
 
 
@@ -226,7 +295,7 @@ s16b randnor(int mean, int stand)
        s16b high = RANDNOR_NUM;
 
        /* Paranoia */
-       if (stand < 1) return (mean);
+       if (stand < 1) return (s16b)(mean);
 
        /* Roll for probability */
        tmp = (s16b)randint0(32768);
@@ -245,7 +314,7 @@ s16b randnor(int mean, int stand)
                /* Move left otherwise */
                else
                {
-                       high = mid;
+                       high = (s16b)mid;
                }
        }
 
@@ -264,18 +333,18 @@ s16b randnor(int mean, int stand)
 /*
  * Generates damage for "2d6" style dice rolls
  */
-s16b damroll(int num, int sides)
+s16b damroll(DICE_NUMBER num, DICE_SID sides)
 {
        int i, sum = 0;
        for (i = 0; i < num; i++) sum += randint1(sides);
-       return (sum);
+       return (s16b)(sum);
 }
 
 
 /*
  * Same as above, but always maximal
  */
-s16b maxroll(int num, int sides)
+s16b maxroll(DICE_NUMBER num, DICE_SID sides)
 {
        return (num * sides);
 }
@@ -317,9 +386,9 @@ s32b div_round(s32b n, s32b d)
  * "external" program parts like the main-*.c files.  It preserves
  * the current RNG state to prevent influences on game-play.
  *
- * Could also use rand() from <stdlib.h> directly. XXX XXX XXX
+ * Could also use rand() from <stdlib.h> directly. 
  */
-u32b Rand_external(u32b m)
+s32b Rand_external(s32b m)
 {
        static bool initialized = FALSE;
        static u32b Rand_state_external[4];
@@ -327,10 +396,10 @@ u32b Rand_external(u32b m)
        if (!initialized)
        {
                /* Initialize with new seed */
-               u32b seed = time(NULL);
-               Rand_Xorshift_init(seed, Rand_state_external);
+               u32b seed = (u32b)time(NULL);
+               Rand_seed(seed, Rand_state_external);
                initialized = TRUE;
        }
 
-       return Rand_Xorshift(Rand_state_external) % m;
+       return Rand_div_impl(m, Rand_state_external);
 }