From 54062e0ad62457e8bec161a6192d4d6894c521f1 Mon Sep 17 00:00:00 2001
From: nhmall <nhmall@nethack.org>
Date: Mon, 28 Jan 2019 19:54:18 -0500
Subject: [PATCH] include the rnd.c bits

---
 src/rnd.c | 79 ++++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 58 insertions(+), 21 deletions(-)

diff --git a/src/rnd.c b/src/rnd.c
index 551f33637..fa8ce0e20 100644
--- a/src/rnd.c
+++ b/src/rnd.c
@@ -7,28 +7,71 @@
 #ifdef USE_ISAAC64
 #include "isaac64.h"
 
+#if 0
 static isaac64_ctx rng_state;
+#endif
+
+struct rnglist_t {
+    int FDECL((*fn), (int));
+    boolean init;
+    isaac64_ctx rng_state;
+};
+
+enum {CORE = 0, DISP};
+
+static struct rnglist_t rnglist[] = {
+    {rn2, FALSE, {0}},                      /* CORE */
+    {rn2_on_display_rng, FALSE, {0}},       /* DISP */
+};
+
+int
+whichrng(fn)
+int (*fn)(int);
+{
+    int i;
+
+    for (i = 0; i < SIZE(rnglist); ++i)
+        if (rnglist[i].fn == fn)
+            return i;
+    return -1;
+}
 
 void
-init_isaac64(unsigned long seed)
+init_isaac64(seed, fn)
+unsigned long seed;
+int FDECL((*fn),(int));
 {
     unsigned char new_rng_state[sizeof(seed)];
-    int i;
+    int i, rngindx = whichrng(fn);
+
+    if (rngindx < 0)
+        panic("Bad rng function passed to init_isaac64().");
+
     for (i=0; i<sizeof(seed); i++) {
         new_rng_state[i]= (unsigned char)(seed & 0xFF);
         seed >>= 8;
     }
-
-    isaac64_init(&rng_state, new_rng_state, sizeof(seed));
+    isaac64_init(&rnglist[rngindx].rng_state, new_rng_state, sizeof(seed));
 }
 
 static int
 RND(int x)
 {
-    return (isaac64_next_uint64(&rng_state) % x);
+    return (isaac64_next_uint64(&rnglist[CORE].rng_state) % x);
 }
 
-#else
+/* 0 <= rn2(x) < x, but on a different sequence from the "main" rn2;
+   used in cases where the answer doesn't affect gameplay and we don't
+   want to give users easy control over the main RNG sequence. */
+int
+rn2_on_display_rng(x)
+register int x;
+{
+    return (isaac64_next_uint64(&rnglist[DISP].rng_state) % x);
+}
+
+#else   /* USE_ISAAC64 */
+
 /* "Rand()"s definition is determined by [OS]conf.h */
 #if defined(LINT) && defined(UNIX) /* rand() is long... */
 extern int NDECL(rand);
@@ -41,7 +84,15 @@ extern int NDECL(rand);
 #define RND(x) ((int) ((Rand() >> 3) % (x)))
 #endif
 #endif /* LINT */
-#endif
+int
+rn2_on_display_rng(x)
+register int x;
+{
+    static unsigned seed = 1;
+    seed *= 2739110765;
+    return (int)((seed >> 16) % (unsigned)x);
+}
+#endif  /* USE_ISAAC64 */
 
 /* 0 <= rn2(x) < x */
 int
@@ -60,20 +111,6 @@ register int x;
 #endif
 }
 
-/* 0 <= rn2(x) < x, but on a different sequence from the "main" rn2;
-   used in cases where the answer doesn't affect gameplay and we don't
-   want to give users easy control over the main RNG sequence. This is
-   an intentionally low-quality RNG to discourage its use for anything
-   gameplay-affecting; please use a better RNG in that case. */
-int
-rn2_on_display_rng(x)
-register int x;
-{
-    static unsigned seed = 1;
-    seed *= 2739110765;
-    return (int)((seed >> 16) % (unsigned)x);
-}
-
 /* 0 <= rnl(x) < x; sometimes subtracting Luck;
    good luck approaches 0, bad luck approaches (x-1) */
 int
-- 
2.40.0