added handling 64-bit random value bug with old tapes in EM engine

[rocksndiamonds.git] / src / game_em / logic.c

diff --git a/src/game_em/logic.c b/src/game_em/logic.c
index ba9c05e5301b331f4cb64afc8398aff3d84190ca..ba823a0ca86b20e6855ad35ba49d80862e5b36e6 100644 (file)
--- a/src/game_em/logic.c
+++ b/src/game_em/logic.c
@@ -12,6 +12,8 @@
 #define ACID_ROLL      /* rolling objects go into acid rather than remove it */
 #define ACID_PLAYER    /* player gets killed by acid, but without explosion */
 
+#define RANDOM_BUG     /* handle problem with old tapes using 64-bit random */
+
 #define RANDOM(x)      ((seed = seed << 31 | seed >> 1) % x)
 
 static short **cave, **next, **boom;
@@ -165,7 +167,7 @@ static void Lboom_eater(int x, int y)
   boom[x][y+1]   = lev.eater_array[lev.eater_pos][7];
   boom[x+1][y+1] = lev.eater_array[lev.eater_pos][8];
 
-  lev.eater_pos = (lev.eater_pos + 1) % 8;
+  lev.eater_pos = (lev.eater_pos + 1) % lev.num_eater_arrays;
 
 #if PLAY_ELEMENT_SOUND
   play_element_sound(x, y, SOUND_boom, Xeater_n);
@@ -7485,7 +7487,11 @@ static void logic_globals(void)
   int x;
   int y;
   int count;
-  unsigned int random;
+#ifdef RANDOM_BUG
+  uint64_t random;
+#else
+  uint32_t random;
+#endif
 
   cave = lev.cave;
   next = lev.next;
@@ -7531,6 +7537,11 @@ static void logic_globals(void)
       Lamoeba(x, y);
 
     random = random * 129 + 1;
+
+#ifdef RANDOM_BUG
+    if (!game_em.use_random_bug)
+      random = (uint32_t)random;
+#endif
   }
 
   game_em.random = random;