ones which follow shorter than average lines are least likely; use
same workaround as for rumors: pad the shortest lines; result isn't
uniforn distribution but is better (tradeoff vs size; see makedefs)
+make selection of random rumors, engravings, epitaphs, and hallucinatory monst
+ names have uniform distribution by handling long lines specially
Fixes to 3.7.0-x Problems that Were Exposed Via git Repository
/* ### rumors.c ### */
extern char *getrumor(int, char *, boolean);
-extern char *get_rnd_text(const char *, char *, int(*)(int));
+extern char *get_rnd_text(const char *, char *, int(*)(int), unsigned);
extern void outrumor(int, int);
extern void outoracle(boolean, boolean);
extern void save_oracles(NHFILE *);
#include <stdio.h>
/*
- * Files expected to exist in the playground directory.
+ * Files expected to exist in the playground directory (possibly inside
+ * a dlb container file).
*/
#define RECORD "record" /* file containing list of topscorers */
#define TRIBUTEFILE "tribute" /* 3.6 tribute to Terry Pratchett */
#define LEV_EXT ".lua" /* extension for special level files */
+/* padding amounts for files that have lines chosen by fseek to random spot,
+ advancing to the next line, and using that line; makedefs forces shorter
+ lines to be padded to these lengths; value of 0 will inhibit any padding,
+ avoiding an increase in files' sizes, but resulting in biased selection;
+ used by makedefs while building and by core's callers of get_rnd_text() */
+#define MD_PAD_RUMORS 60u /* for RUMORFILE, EPITAPHFILE, and ENGRAVEFILE */
+#define MD_PAD_BOGONS 20u /* for BOGUSMONFILE */
+
/* Assorted definitions that may depend on selections in config.h. */
/*
if (code)
*code = '\0';
/* might fail (return empty buf[]) if the file isn't available */
- get_rnd_text(BOGUSMONFILE, buf, rn2_on_display_rng);
+ get_rnd_text(BOGUSMONFILE, buf, rn2_on_display_rng, MD_PAD_BOGONS);
if (!*mnam) {
Strcpy(buf, "bogon");
} else if (index(bogon_codes, *mnam)) { /* strip prefix if present */
/* a random engraving may come from the "rumors" file,
or from the "engrave" file (formerly in an array here) */
if (!rn2(4) || !(rumor = getrumor(0, outbuf, TRUE)) || !*rumor)
- (void) get_rnd_text(ENGRAVEFILE, outbuf, rn2);
+ (void) get_rnd_text(ENGRAVEFILE, outbuf, rn2, MD_PAD_RUMORS);
wipeout_text(outbuf, (int) (strlen(outbuf) / 4), 0);
return outbuf;
/* Engrave the headstone */
del_engr_at(x, y);
if (!str)
- str = get_rnd_text(EPITAPHFILE, buf, rn2);
+ str = get_rnd_text(EPITAPHFILE, buf, rn2, MD_PAD_RUMORS);
make_engr_at(x, y, str, 0L, HEADSTONE);
return;
}
/* Gets a random line of text from file 'fname', and returns it.
rng is the random number generator to use, and should act like rn2 does. */
char *
-get_rnd_text(const char* fname, char* buf, int (*rng)(int))
+get_rnd_text(
+ const char *fname,
+ char *buf,
+ int (*rng)(int),
+ unsigned padlength)
{
dlb *fh;
if (fh) {
/* TODO: cache sizetxt, starttxt, endtxt. maybe cache file contents? */
long sizetxt = 0L, starttxt = 0L, endtxt = 0L, tidbit = 0L;
+ int trylimit;
char *endp, line[BUFSZ], xbuf[BUFSZ];
/* skip "don't edit" comment */
that save and restore might fix the problem wouldn't be useful */
if (sizetxt < 1L)
return buf;
- tidbit = (*rng)(sizetxt);
+ /* 'rumors' is about 3/4 of the way to the limit on a 16-bit config */
+ nhassert(sizetxt <= INT_MAX); /* essential for rn2(sizetxt) */
- /* position randomly which will probably be in the middle of a line;
- read the rest of that line, then use the next one; if there's no
- next one (ie, end of file), go back to beginning and use first */
- (void) dlb_fseek(fh, starttxt + tidbit, SEEK_SET);
- (void) dlb_fgets(line, sizeof line, fh);
+ /*
+ * Position randomly which will probably be in the middle of a line.
+ * Read the rest of that line, then use the next one. If there's no
+ * next line (ie, end of file), go back to beginning and use first.
+ *
+ * When short lines have been padded to length N, only accept long
+ * lines if we land within last N+1 characters (+1 is for newline
+ * which hasn't been stripped away yet), effectively shortening
+ * them to normal length. That yields even selection distribution.
+ */
+ for (trylimit = 5; trylimit > 0; --trylimit) {
+ tidbit = (long) (*rng)((int) sizetxt);
+ (void) dlb_fseek(fh, starttxt + tidbit, SEEK_SET);
+ (void) dlb_fgets(line, sizeof line, fh);
+ if (!padlength || (unsigned) strlen(line) <= padlength + 1)
+ break;
+ }
+ /* use next line */
if (!dlb_fgets(line, sizeof line, fh)) {
+ /* assume failure is due to end-of-file; go back to start */
(void) dlb_fseek(fh, starttxt, SEEK_SET);
(void) dlb_fgets(line, sizeof line, fh);
}
#endif /* else !MAC */
#endif /* else !AMIGA */
-/*
- * For files where entries are selected by seeking to a random position,
- * skipping to newline, and then using the next line, lines that follow
- * long ones are more likely to be selected than average and lines that
- * follow short ones are less likely to be selected than average.
- * We make selection be more evenly distributed by padding the shortest
- * lines, at the cost of making the data files bigger. The larger these
- * values are, the more uniform the selection will become but the more
- * space will be needed for data used for something which is relatively
- * inconsequential to actual game play. A value of 0 would suppress the
- * padding because every line is already at least that long.
- */
-#define PAD_RUMORS_TO 60u /* also used for epitaphs and engravings */
-#define PAD_BOGONS_TO 20u /* hallucinatory monsters */
-
static const char
*Dont_Edit_Code =
"/* This source file is generated by 'makedefs'. Do not edit. */\n",
do_rnd_access_file(EPITAPHFILE,
/* default epitaph: parody of the default engraving */
"No matter where I went, here I am.",
- PAD_RUMORS_TO);
+ MD_PAD_RUMORS); /* '_RUMORS' is correct here */
do_rnd_access_file(ENGRAVEFILE,
/* default engraving: popularized by "The Adventures of
Buckaroo Bonzai Across the 8th Dimenstion" but predates
that 1984 movie; some attribute it to Confucius */
"No matter where you go, there you are.",
- PAD_RUMORS_TO);
+ MD_PAD_RUMORS); /* '_RUMORS' used here too */
do_rnd_access_file(BOGUSMONFILE,
/* default bogusmon: iconic monster that isn't in nethack */
- "grue", PAD_BOGONS_TO);
+ "grue", MD_PAD_BOGONS);
break;
case 'h':
case 'H':
* follow short-line rumors are least likely to be chosen.
* We ameliorate the latter by padding the shortest lines,
* increasing the chance of the random seek landing in them.
+ * The core's get_rnd_text() handles long lines in a way
+ * that results in even selection distribution.
*
* Random epitaphs, engravings, and hallucinatory monster
* names are in the same boat.
false_rumor_offset = read_rumors_file(".tru", &true_rumor_count,
&true_rumor_size, true_rumor_offset,
- PAD_RUMORS_TO);
+ MD_PAD_RUMORS);
if (!false_rumor_offset)
goto rumors_failure;
eof_offset = read_rumors_file(".fal", &false_rumor_count,
&false_rumor_size, false_rumor_offset,
- PAD_RUMORS_TO);
+ MD_PAD_RUMORS);
if (!eof_offset)
goto rumors_failure;
projects / nethack / commitdiff