X-Git-Url: https://jxself.org/git/?a=blobdiff_plain;f=misc.c;h=b87c76913f6aab68b500979b20adce84fb05d443;hb=31837249f82629048f9010a0bf29112397a036f8;hp=6987d254788a4f961269de5d4060724bfc2aaab0;hpb=484ca4e9fd956e431c64d0465dbacd59215d23e4;p=open-adventure.git

diff --git a/misc.c b/misc.c
index 6987d25..b87c769 100644
--- a/misc.c
+++ b/misc.c
@@ -723,7 +723,7 @@ L2:	ATDWRF=I;
 
 
 
-/*  Utility routines (SETBIT, TSTBIT, RAN, RNDVOC, BUG) */
+/*  Utility routines (SETBIT, TSTBIT, set_seed_from_time, get_next_lcg_value, randrange, RNDVOC, BUG) */
 
 #undef SETBIT
 long fSETBIT(long BIT) {
@@ -757,31 +757,29 @@ long TSTBIT;
 
 
 #define TSTBIT(MASK,BIT) fTSTBIT(MASK,BIT)
-#undef RAN
-long fRAN(long RANGE) {
-static long D, R = 0, RAN, T;
-
-/*  Since the ran function in LIB40 seems to be a real lose, we'll use one of
- *  our own.  It's been run through many of the tests in Knuth vol. 2 and
- *  seems to be quite reliable.  RAN returns a value uniformly selected
- *  between 0 and range-1. */
-
-
-	D=1;
-	if(R != 0 && RANGE >= 0) goto L1;
-	DATIME(D,T);
-	R=MOD(T+5,1048576L);
-	D=1000+MOD(D,1000);
-L1:	for (T=1; T<=D; T++) {
-	R=MOD(R*1093L+221587L,1048576L);
-	} /* end loop */
-	RAN=(RANGE*R)/1048576;
-	return(RAN);
+
+void set_seed_from_time(void)
+{
+  /* Use the current system time to get seed the ISO rand() function, from which we get a seed for the LCG. */
+  srand(time(NULL));
+  lcgstate.x = (unsigned long) rand() % lcgstate.m;
 }
 
+unsigned long get_next_lcg_value(void)
+{
+  /* Return the LCG's current value, and then iterate it. */
+  unsigned long old_x = lcgstate.x;
+  lcgstate.x = (lcgstate.a * lcgstate.x + lcgstate.c) % lcgstate.m;
+  return(old_x);
+}
 
+long randrange(long range)
+{
+  /* Return a random integer from [0, range). */
+  long result = range * get_next_lcg_value() / lcgstate.m;
+  return(result);
+}
 
-#define RAN(RANGE) fRAN(RANGE)
 #undef RNDVOC
 long fRNDVOC(long CHAR, long FORCE) {
 long DIV, I, J, RNDVOC;
@@ -795,7 +793,7 @@ long DIV, I, J, RNDVOC;
 	RNDVOC=FORCE;
 	if(RNDVOC != 0) goto L3;
 	for (I=1; I<=5; I++) {
-	J=11+RAN(26);
+	J=11+randrange(26);
 	if(I == 2)J=CHAR;
 	RNDVOC=RNDVOC*64+J;
 	} /* end loop */
@@ -886,7 +884,7 @@ long I, VAL;
 
 	if(MAP2[1] == 0)MPINIT();
 
-	if (!oldstyle && isatty(0) && !SETUP)
+	if (!oldstyle && SETUP)
 	    fputs("> ", stdout);
 	IGNORE(fgets(INLINE+1,sizeof(INLINE)-1,OPENED));
 	if (feof(OPENED)) {