ascii tetris!

12 files changed, 2053 insertions, 0 deletions

diff --git a/tetris/Makefile b/tetris/Makefile
new file mode 100644
index 00000000..88a59c38
--- /dev/null
+++ b/tetris/Makefile
@@ -0,0 +1,10 @@
+#	@(#)Makefile	8.1 (Berkeley) 5/31/93
+
+PROG=	tetris
+SRCS=	input.c screen.c shapes.c scores.c tetris.c
+MAN6=	tetris.0
+DPADD=	${LIBTERM}
+LDADD=	-ltermcap
+HIDEGAME=hidegame
+
+.include <bsd.prog.mk>
diff --git a/tetris/input.c b/tetris/input.c
new file mode 100644
index 00000000..48da0884
--- /dev/null
+++ b/tetris/input.c
@@ -0,0 +1,180 @@
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek and Darren F. Provine.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)input.c	8.1 (Berkeley) 5/31/93
+ */
+
+/*
+ * Tetris input.
+ */
+
+#include <sys/types.h>
+#include <sys/time.h>
+
+#include <errno.h>
+#include <unistd.h>
+
+#include "input.h"
+#include "tetris.h"
+
+/* return true iff the given timeval is positive */
+#define	TV_POS(tv) \
+	((tv)->tv_sec > 0 || ((tv)->tv_sec == 0 && (tv)->tv_usec > 0))
+
+/* subtract timeval `sub' from `res' */
+#define	TV_SUB(res, sub) \
+	(res)->tv_sec -= (sub)->tv_sec; \
+	(res)->tv_usec -= (sub)->tv_usec; \
+	if ((res)->tv_usec < 0) { \
+		(res)->tv_usec += 1000000; \
+		(res)->tv_sec--; \
+	}
+
+/*
+ * Do a `read wait': select for reading from stdin, with timeout *tvp.
+ * On return, modify *tvp to reflect the amount of time spent waiting.
+ * It will be positive only if input appeared before the time ran out;
+ * otherwise it will be zero or perhaps negative.
+ *
+ * If tvp is nil, wait forever, but return if select is interrupted.
+ *
+ * Return 0 => no input, 1 => can read() from stdin
+ */
+int
+rwait(tvp)
+	register struct timeval *tvp;
+{
+	int i;
+	struct timeval starttv, endtv, *s;
+	extern int errno;
+#define	NILTZ ((struct timezone *)0)
+
+	/*
+	 * Someday, select() will do this for us.
+	 * Just in case that day is now, and no one has
+	 * changed this, we use a temporary.
+	 */
+	if (tvp) {
+		(void) gettimeofday(&starttv, NILTZ);
+		endtv = *tvp;
+		s = &endtv;
+	} else
+		s = 0;
+again:
+	i = 1;
+	switch (select(1, (fd_set *)&i, (fd_set *)0, (fd_set *)0, s)) {
+
+	case -1:
+		if (tvp == 0)
+			return (-1);
+		if (errno == EINTR)
+			goto again;
+		stop("select failed, help");
+		/* NOTREACHED */
+
+	case 0:	/* timed out */
+		tvp->tv_sec = 0;
+		tvp->tv_usec = 0;
+		return (0);
+	}
+	if (tvp) {
+		/* since there is input, we may not have timed out */
+		(void) gettimeofday(&endtv, NILTZ);
+		TV_SUB(&endtv, &starttv);
+		TV_SUB(tvp, &endtv);	/* adjust *tvp by elapsed time */
+	}
+	return (1);
+}
+
+/*
+ * `sleep' for the current turn time (using select).
+ * Eat any input that might be available.
+ */
+void
+tsleep()
+{
+	struct timeval tv;
+	char c;
+
+	tv.tv_sec = 0;
+	tv.tv_usec = fallrate;
+	while (TV_POS(&tv))
+		if (rwait(&tv) && read(0, &c, 1) != 1)
+			break;
+}
+
+/*
+ * Eat up any input (used at end of game).
+ */
+void
+eat_input()
+{
+	struct timeval tv;
+	char c;
+
+	do {
+		tv.tv_sec = tv.tv_usec = 0;
+	} while (rwait(&tv) && read(0, &c, 1) == 1);
+}
+
+/*
+ * getchar with timeout.
+ */
+int
+tgetchar()
+{
+	static struct timeval timeleft;
+	char c;
+
+	/*
+	 * Reset timeleft to fallrate whenever it is not positive.
+	 * In any case, wait to see if there is any input.  If so,
+	 * take it, and update timeleft so that the next call to
+	 * tgetchar() will not wait as long.  If there is no input,
+	 * make timeleft zero or negative, and return -1.
+	 *
+	 * Most of the hard work is done by rwait().
+	 */
+	if (!TV_POS(&timeleft)) {
+		faster();	/* go faster */
+		timeleft.tv_sec = 0;
+		timeleft.tv_usec = fallrate;
+	}
+	if (!rwait(&timeleft))
+		return (-1);
+	if (read(0, &c, 1) != 1)
+		stop("end of file, help");
+	return ((int)(unsigned char)c);
+}
diff --git a/tetris/input.h b/tetris/input.h
new file mode 100644
index 00000000..733182d7
--- /dev/null
+++ b/tetris/input.h
@@ -0,0 +1,42 @@
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek and Darren F. Provine.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)input.h	8.1 (Berkeley) 5/31/93
+ */
+
+void	eat_input __P((void));
+int	rwait __P((struct timeval *));
+int	tgetchar __P((void));
+void	tsleep __P((void));
diff --git a/tetris/pathnames.h b/tetris/pathnames.h
new file mode 100644
index 00000000..ba08dd11
--- /dev/null
+++ b/tetris/pathnames.h
@@ -0,0 +1,39 @@
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek and Darren F. Provine.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)pathnames.h	8.1 (Berkeley) 5/31/93
+ */
+
+#define _PATH_SCOREFILE	"/var/games/tetris.scores"
diff --git a/tetris/scores.c b/tetris/scores.c
new file mode 100644
index 00000000..e7e6bb59
--- /dev/null
+++ b/tetris/scores.c
@@ -0,0 +1,472 @@
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek and Darren F. Provine.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)scores.c	8.1 (Berkeley) 5/31/93
+ */
+
+/*
+ * Score code for Tetris, by Darren Provine (kilroy@gboro.glassboro.edu)
+ * modified 22 January 1992, to limit the number of entries any one
+ * person has.
+ *
+ * Major whacks since then.
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+/*
+ * XXX - need a <termcap.h>
+ */
+int	tputs __P((const char *, int, int (*)(int)));
+
+#include "pathnames.h"
+#include "screen.h"
+#include "scores.h"
+#include "tetris.h"
+
+/*
+ * Within this code, we can hang onto one extra "high score", leaving
+ * room for our current score (whether or not it is high).
+ *
+ * We also sometimes keep tabs on the "highest" score on each level.
+ * As long as the scores are kept sorted, this is simply the first one at
+ * that level.
+ */
+#define NUMSPOTS (MAXHISCORES + 1)
+#define	NLEVELS (MAXLEVEL + 1)
+
+static time_t now;
+static int nscores;
+static int gotscores;
+static struct highscore scores[NUMSPOTS];
+
+static int checkscores __P((struct highscore *, int));
+static int cmpscores __P((const void *, const void *));
+static void getscores __P((FILE **));
+static void printem __P((int, int, struct highscore *, int, const char *));
+static char *thisuser __P((void));
+
+/*
+ * Read the score file.  Can be called from savescore (before showscores)
+ * or showscores (if savescore will not be called).  If the given pointer
+ * is not NULL, sets *fpp to an open file pointer that corresponds to a
+ * read/write score file that is locked with LOCK_EX.  Otherwise, the
+ * file is locked with LOCK_SH for the read and closed before return.
+ *
+ * Note, we assume closing the stdio file releases the lock.
+ */
+static void
+getscores(fpp)
+	FILE **fpp;
+{
+	int sd, mint, lck;
+	char *mstr, *human;
+	FILE *sf;
+
+	if (fpp != NULL) {
+		mint = O_RDWR | O_CREAT;
+		mstr = "r+";
+		human = "read/write";
+		lck = LOCK_EX;
+	} else {
+		mint = O_RDONLY;
+		mstr = "r";
+		human = "reading";
+		lck = LOCK_SH;
+	}
+	sd = open(_PATH_SCOREFILE, mint, 0666);
+	if (sd < 0) {
+		if (fpp == NULL) {
+			nscores = 0;
+			return;
+		}
+		(void)fprintf(stderr, "tetris: cannot open %s for %s: %s\n",
+		    _PATH_SCOREFILE, human, strerror(errno));
+		exit(1);
+	}
+	if ((sf = fdopen(sd, mstr)) == NULL) {
+		(void)fprintf(stderr, "tetris: cannot fdopen %s for %s: %s\n",
+		    _PATH_SCOREFILE, human, strerror(errno));
+		exit(1);
+	}
+
+	/*
+	 * Grab a lock.
+	 */
+	if (flock(sd, lck))
+		(void)fprintf(stderr,
+		    "tetris: warning: score file %s cannot be locked: %s\n",
+		    _PATH_SCOREFILE, strerror(errno));
+
+	nscores = fread(scores, sizeof(scores[0]), MAXHISCORES, sf);
+	if (ferror(sf)) {
+		(void)fprintf(stderr, "tetris: error reading %s: %s\n",
+		    _PATH_SCOREFILE, strerror(errno));
+		exit(1);
+	}
+
+	if (fpp)
+		*fpp = sf;
+	else
+		(void)fclose(sf);
+}
+
+void
+savescore(level)
+	int level;
+{
+	register struct highscore *sp;
+	register int i;
+	int change;
+	FILE *sf;
+	const char *me;
+
+	getscores(&sf);
+	gotscores = 1;
+	(void)time(&now);
+
+	/*
+	 * Allow at most one score per person per level -- see if we
+	 * can replace an existing score, or (easiest) do nothing.
+	 * Otherwise add new score at end (there is always room).
+	 */
+	change = 0;
+	me = thisuser();
+	for (i = 0, sp = &scores[0]; i < nscores; i++, sp++) {
+		if (sp->hs_level != level || strcmp(sp->hs_name, me) != 0)
+			continue;
+		if (score > sp->hs_score) {
+			(void)printf("%s bettered %s %d score of %d!\n",
+			    "\nYou", "your old level", level,
+			    sp->hs_score * sp->hs_level);
+			sp->hs_score = score;	/* new score */
+			sp->hs_time = now;	/* and time */
+			change = 1;
+		} else if (score == sp->hs_score) {
+			(void)printf("%s tied %s %d high score.\n",
+			    "\nYou", "your old level", level);
+			sp->hs_time = now;	/* renew it */
+			change = 1;		/* gotta rewrite, sigh */
+		} /* else new score < old score: do nothing */
+		break;
+	}
+	if (i >= nscores) {
+		strcpy(sp->hs_name, me);
+		sp->hs_level = level;
+		sp->hs_score = score;
+		sp->hs_time = now;
+		nscores++;
+		change = 1;
+	}
+
+	if (change) {
+		/*
+		 * Sort & clean the scores, then rewrite.
+		 */
+		nscores = checkscores(scores, nscores);
+		rewind(sf);
+		if (fwrite(scores, sizeof(*sp), nscores, sf) != nscores ||
+		    fflush(sf) == EOF)
+			(void)fprintf(stderr,
+			    "tetris: error writing %s: %s -- %s\n",
+			    _PATH_SCOREFILE, strerror(errno),
+			    "high scores may be damaged");
+	}
+	(void)fclose(sf);	/* releases lock */
+}
+
+/*
+ * Get login name, or if that fails, get something suitable.
+ * The result is always trimmed to fit in a score.
+ */
+static char *
+thisuser()
+{
+	register const char *p;
+	register struct passwd *pw;
+	register size_t l;
+	static char u[sizeof(scores[0].hs_name)];
+
+	if (u[0])
+		return (u);
+	p = getlogin();
+	if (p == NULL || *p == '\0') {
+		pw = getpwuid(getuid());
+		if (pw != NULL)
+			p = pw->pw_name;
+		else
+			p = "  ???";
+	}
+	l = strlen(p);
+	if (l >= sizeof(u))
+		l = sizeof(u) - 1;
+	bcopy(p, u, l);
+	u[l] = '\0';
+	return (u);
+}
+
+/*
+ * Score comparison function for qsort.
+ *
+ * If two scores are equal, the person who had the score first is
+ * listed first in the highscore file.
+ */
+static int
+cmpscores(x, y)
+	const void *x, *y;
+{
+	register const struct highscore *a, *b;
+	register long l;
+
+	a = x;
+	b = y;
+	l = (long)b->hs_level * b->hs_score - (long)a->hs_level * a->hs_score;
+	if (l < 0)
+		return (-1);
+	if (l > 0)
+		return (1);
+	if (a->hs_time < b->hs_time)
+		return (-1);
+	if (a->hs_time > b->hs_time)
+		return (1);
+	return (0);
+}
+
+/*
+ * If we've added a score to the file, we need to check the file and ensure
+ * that this player has only a few entries.  The number of entries is
+ * controlled by MAXSCORES, and is to ensure that the highscore file is not
+ * monopolised by just a few people.  People who no longer have accounts are
+ * only allowed the highest score.  Scores older than EXPIRATION seconds are
+ * removed, unless they are someone's personal best.
+ * Caveat:  the highest score on each level is always kept.
+ */
+static int
+checkscores(hs, num)
+	register struct highscore *hs;
+	int num;
+{
+	register struct highscore *sp;
+	register int i, j, k, numnames;
+	int levelfound[NLEVELS];
+	struct peruser {
+		char *name;
+		int times;
+	} count[NUMSPOTS];
+	register struct peruser *pu;
+
+	/*
+	 * Sort so that highest totals come first.
+	 *
+	 * levelfound[i] becomes set when the first high score for that
+	 * level is encountered.  By definition this is the highest score.
+	 */
+	qsort((void *)hs, nscores, sizeof(*hs), cmpscores);
+	for (i = MINLEVEL; i < NLEVELS; i++)
+		levelfound[i] = 0;
+	numnames = 0;
+	for (i = 0, sp = hs; i < num;) {
+		/*
+		 * This is O(n^2), but do you think we care?
+		 */
+		for (j = 0, pu = count; j < numnames; j++, pu++)
+			if (strcmp(sp->hs_name, pu->name) == 0)
+				break;
+		if (j == numnames) {
+			/*
+			 * Add new user, set per-user count to 1.
+			 */
+			pu->name = sp->hs_name;
+			pu->times = 1;
+			numnames++;
+		} else {
+			/*
+			 * Two ways to keep this score:
+			 * - Not too many (per user), still has acct, &
+			 *	score not dated; or
+			 * - High score on this level.
+			 */
+			if ((pu->times < MAXSCORES &&
+			     getpwnam(sp->hs_name) != NULL &&
+			     sp->hs_time + EXPIRATION >= now) ||
+			    levelfound[sp->hs_level] == 0)
+				pu->times++;
+			else {
+				/*
+				 * Delete this score, do not count it,
+				 * do not pass go, do not collect $200.
+				 */
+				num--;
+				for (k = i; k < num; k++)
+					hs[k] = hs[k + 1];
+				continue;
+			}
+		}
+		levelfound[sp->hs_level] = 1;
+		i++, sp++;
+	}
+	return (num > MAXHISCORES ? MAXHISCORES : num);
+}
+
+/*
+ * Show current scores.  This must be called after savescore, if
+ * savescore is called at all, for two reasons:
+ * - Showscores munches the time field.
+ * - Even if that were not the case, a new score must be recorded
+ *   before it can be shown anyway.
+ */
+void
+showscores(level)
+	int level;
+{
+	register struct highscore *sp;
+	register int i, n, c;
+	const char *me;
+	int levelfound[NLEVELS];
+
+	if (!gotscores)
+		getscores((FILE **)NULL);
+	(void)printf("\n\t\t\t    Tetris High Scores\n");
+
+	/*
+	 * If level == 0, the person has not played a game but just asked for
+	 * the high scores; we do not need to check for printing in highlight
+	 * mode.  If SOstr is null, we can't do highlighting anyway.
+	 */
+	me = level && SOstr ? thisuser() : NULL;
+
+	/*
+	 * Set times to 0 except for high score on each level.
+	 */
+	for (i = MINLEVEL; i < NLEVELS; i++)
+		levelfound[i] = 0;
+	for (i = 0, sp = scores; i < nscores; i++, sp++) {
+		if (levelfound[sp->hs_level])
+			sp->hs_time = 0;
+		else {
+			sp->hs_time = 1;
+			levelfound[sp->hs_level] = 1;
+		}
+	}
+
+	/*
+	 * Page each screenful of scores.
+	 */
+	for (i = 0, sp = scores; i < nscores; sp += n) {
+		n = 40;
+		if (i + n > nscores)
+			n = nscores - i;
+		printem(level, i + 1, sp, n, me);
+		if ((i += n) < nscores) {
+			(void)printf("\nHit RETURN to continue.");
+			(void)fflush(stdout);
+			while ((c = getchar()) != '\n')
+				if (c == EOF)
+					break;
+			(void)printf("\n");
+		}
+	}
+}
+
+static void
+printem(level, offset, hs, n, me)
+	int level, offset;
+	register struct highscore *hs;
+	register int n;
+	const char *me;
+{
+	register struct highscore *sp;
+	int nrows, row, col, item, i, highlight;
+	char buf[100];
+#define	TITLE "Rank  Score   Name     (points/level)"
+
+	/*
+	 * This makes a nice two-column sort with headers, but it's a bit
+	 * convoluted...
+	 */
+	printf("%s   %s\n", TITLE, n > 1 ? TITLE : "");
+
+	highlight = 0;
+	nrows = (n + 1) / 2;
+
+	for (row = 0; row < nrows; row++) {
+		for (col = 0; col < 2; col++) {
+			item = col * nrows + row;
+			if (item >= n) {
+				/*
+				 * Can only occur on trailing columns.
+				 */
+				(void)putchar('\n');
+				continue;
+			}
+			(void)printf(item + offset < 10 ? "  " : " ");
+			sp = &hs[item];
+			(void)sprintf(buf,
+			    "%d%c %6d  %-11s (%d on %d)",
+			    item + offset, sp->hs_time ? '*' : ' ',
+			    sp->hs_score * sp->hs_level,
+			    sp->hs_name, sp->hs_score, sp->hs_level);
+			/*
+			 * Highlight if appropriate.  This works because
+			 * we only get one score per level.
+			 */
+			if (me != NULL &&
+			    sp->hs_level == level &&
+			    sp->hs_score == score &&
+			    strcmp(sp->hs_name, me) == 0) {
+				putpad(SOstr);
+				highlight = 1;
+			}
+			(void)printf("%s", buf);
+			if (highlight) {
+				putpad(SEstr);
+				highlight = 0;
+			}
+
+			/* fill in spaces so column 1 lines up */
+			if (col == 0)
+				for (i = 40 - strlen(buf); --i >= 0;)
+					(void)putchar(' ');
+			else /* col == 1 */
+				(void)putchar('\n');
+		}
+	}
+}
diff --git a/tetris/scores.h b/tetris/scores.h
new file mode 100644
index 00000000..7a4865ad
--- /dev/null
+++ b/tetris/scores.h
@@ -0,0 +1,54 @@
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek and Darren F. Provine.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)scores.h	8.1 (Berkeley) 5/31/93
+ */
+
+/*
+ * Tetris scores.
+ */
+struct highscore {
+	char	hs_name[20];	/* login name */
+	int	hs_score;	/* raw score */
+	int	hs_level;	/* play level */
+	time_t	hs_time;	/* time at game end */
+};
+
+#define MAXHISCORES	80
+#define MAXSCORES	9	/* maximum high score entries per person */
+#define	EXPIRATION	(5L * 365 * 24 * 60 * 60)
+
+void	savescore __P((int));
+void	showscores __P((int));
diff --git a/tetris/screen.c b/tetris/screen.c
new file mode 100644
index 00000000..41e3f4a8
--- /dev/null
+++ b/tetris/screen.c
@@ -0,0 +1,454 @@
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek and Darren F. Provine.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)screen.c	8.1 (Berkeley) 5/31/93
+ */
+
+/*
+ * Tetris screen control.
+ */
+
+#include <sgtty.h>
+#include <sys/ioctl.h>
+
+#include <setjmp.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifndef sigmask
+#define sigmask(s) (1 << ((s) - 1))
+#endif
+
+#include "screen.h"
+#include "tetris.h"
+
+/*
+ * XXX - need a <termcap.h>
+ */
+int	tgetent __P((char *, const char *));
+int	tgetflag __P((const char *));
+int	tgetnum __P((const char *));
+int	tputs __P((const char *, int, int (*)(int)));
+
+static cell curscreen[B_SIZE];	/* 1 => standout (or otherwise marked) */
+static int curscore;
+static int isset;		/* true => terminal is in game mode */
+static struct sgttyb oldtt;
+static void (*tstp)();
+
+char	*tgetstr(), *tgoto();
+
+
+/*
+ * Capabilities from TERMCAP.
+ */
+char	PC, *BC, *UP;		/* tgoto requires globals: ugh! */
+short	ospeed;
+
+static char
+	*bcstr,			/* backspace char */
+	*CEstr,			/* clear to end of line */
+	*CLstr,			/* clear screen */
+	*CMstr,			/* cursor motion string */
+#ifdef unneeded
+	*CRstr,			/* "\r" equivalent */
+#endif
+	*HOstr,			/* cursor home */
+	*LLstr,			/* last line, first column */
+	*pcstr,			/* pad character */
+	*TEstr,			/* end cursor motion mode */
+	*TIstr;			/* begin cursor motion mode */
+char
+	*SEstr,			/* end standout mode */
+	*SOstr;			/* begin standout mode */
+static int
+	COnum,			/* co# value */
+	LInum,			/* li# value */
+	MSflag;			/* can move in standout mode */
+
+
+struct tcsinfo {	/* termcap string info; some abbrevs above */
+	char tcname[3];
+	char **tcaddr;
+} tcstrings[] = {
+	"bc", &bcstr,
+	"ce", &CEstr,
+	"cl", &CLstr,
+	"cm", &CMstr,
+#ifdef unneeded
+	"cr", &CRstr,
+#endif
+	"le", &BC,		/* move cursor left one space */
+	"pc", &pcstr,
+	"se", &SEstr,
+	"so", &SOstr,
+	"te", &TEstr,
+	"ti", &TIstr,
+	"up", &UP,		/* cursor up */
+	0
+};
+
+/* This is where we will actually stuff the information */
+
+static char combuf[1024], tbuf[1024];
+
+
+/*
+ * Routine used by tputs().
+ */
+int
+put(c)
+	int c;
+{
+
+	return (putchar(c));
+}
+
+/*
+ * putstr() is for unpadded strings (either as in termcap(5) or
+ * simply literal strings); putpad() is for padded strings with
+ * count=1.  (See screen.h for putpad().)
+ */
+#define	putstr(s)	(void)fputs(s, stdout)
+#define	moveto(r, c)	putpad(tgoto(CMstr, c, r))
+
+/*
+ * Set up from termcap.
+ */
+void
+scr_init()
+{
+	static int bsflag, xsflag, sgnum;
+#ifdef unneeded
+	static int ncflag;
+#endif
+	char *term, *fill;
+	static struct tcninfo {	/* termcap numeric and flag info */
+		char tcname[3];
+		int *tcaddr;
+	} tcflags[] = {
+		"bs", &bsflag,
+		"ms", &MSflag,
+#ifdef unneeded
+		"nc", &ncflag,
+#endif
+		"xs", &xsflag,
+		0
+	}, tcnums[] = {
+		"co", &COnum,
+		"li", &LInum,
+		"sg", &sgnum,
+		0
+	};
+	
+	if ((term = getenv("TERM")) == NULL)
+		stop("you must set the TERM environment variable");
+	if (tgetent(tbuf, term) <= 0)
+		stop("cannot find your termcap");
+	fill = combuf;
+	{
+		register struct tcsinfo *p;
+
+		for (p = tcstrings; p->tcaddr; p++)
+			*p->tcaddr = tgetstr(p->tcname, &fill);
+	}
+	{
+		register struct tcninfo *p;
+
+		for (p = tcflags; p->tcaddr; p++)
+			*p->tcaddr = tgetflag(p->tcname);
+		for (p = tcnums; p->tcaddr; p++)
+			*p->tcaddr = tgetnum(p->tcname);
+	}
+	if (bsflag)
+		BC = "\b";
+	else if (BC == NULL && bcstr != NULL)
+		BC = bcstr;
+	if (CLstr == NULL)
+		stop("cannot clear screen");
+	if (CMstr == NULL || UP == NULL || BC == NULL)
+		stop("cannot do random cursor positioning via tgoto()");
+	PC = pcstr ? *pcstr : 0;
+	if (sgnum >= 0 || xsflag)
+		SOstr = SEstr = NULL;
+#ifdef unneeded
+	if (ncflag)
+		CRstr = NULL;
+	else if (CRstr == NULL)
+		CRstr = "\r";
+#endif
+}
+
+/* this foolery is needed to modify tty state `atomically' */
+static jmp_buf scr_onstop;
+
+#define	sigunblock(mask) sigsetmask(sigblock(0) & ~(mask))
+
+static void
+stopset(sig)
+	int sig;
+{
+	(void) signal(sig, SIG_DFL);
+	(void) kill(getpid(), sig);
+	(void) sigunblock(sigmask(sig));
+	longjmp(scr_onstop, 1);
+}
+
+static void
+scr_stop()
+{
+	scr_end();
+	(void) kill(getpid(), SIGTSTP);
+	(void) sigunblock(sigmask(SIGTSTP));
+	scr_set();
+	scr_msg(key_msg, 1);
+}
+
+/*
+ * Set up screen mode.
+ */
+void
+scr_set()
+{
+	struct winsize ws;
+	struct sgttyb newtt;
+	volatile int omask;
+	void (*ttou)();
+
+	omask = sigblock(sigmask(SIGTSTP) | sigmask(SIGTTOU));
+	if ((tstp = signal(SIGTSTP, stopset)) == SIG_IGN)
+		(void) signal(SIGTSTP, SIG_IGN);
+	if ((ttou = signal(SIGTSTP, stopset)) == SIG_IGN)
+		(void) signal(SIGTSTP, SIG_IGN);
+	/*
+	 * At last, we are ready to modify the tty state.  If
+	 * we stop while at it, stopset() above will longjmp back
+	 * to the setjmp here and we will start over.
+	 */
+	(void) setjmp(scr_onstop);
+	(void) sigsetmask(omask);
+	Rows = 0, Cols = 0;
+	if (ioctl(0, TIOCGWINSZ, &ws) == 0) {
+		Rows = ws.ws_row;
+		Cols = ws.ws_col;
+	}
+	if (Rows == 0)
+		Rows = LInum;
+	if (Cols == 0)
+	Cols = COnum;
+	if (Rows < MINROWS || Cols < MINCOLS) {
+		(void) fprintf(stderr,
+		    "the screen is too small: must be at least %d x %d",
+		    MINROWS, MINCOLS);
+		stop("");	/* stop() supplies \n */
+	}
+	if (ioctl(0, TIOCGETP, &oldtt))
+		stop("ioctl(TIOCGETP) fails");
+	newtt = oldtt;
+	newtt.sg_flags = (newtt.sg_flags | CBREAK) & ~(CRMOD | ECHO);
+	if ((newtt.sg_flags & TBDELAY) == XTABS)
+		newtt.sg_flags &= ~TBDELAY;
+	if (ioctl(0, TIOCSETN, &newtt))
+		stop("ioctl(TIOCSETN) fails");
+	ospeed = newtt.sg_ospeed;
+	omask = sigblock(sigmask(SIGTSTP) | sigmask(SIGTTOU));
+
+	/*
+	 * We made it.  We are now in screen mode, modulo TIstr
+	 * (which we will fix immediately).
+	 */
+	if (TIstr)
+		putstr(TIstr);	/* termcap(5) says this is not padded */
+	if (tstp != SIG_IGN)
+		(void) signal(SIGTSTP, scr_stop);
+	(void) signal(SIGTTOU, ttou);
+
+	isset = 1;
+	(void) sigsetmask(omask);
+	scr_clear();
+}
+
+/*
+ * End screen mode.
+ */
+void
+scr_end()
+{
+	int omask = sigblock(sigmask(SIGTSTP) | sigmask(SIGTTOU));
+
+	/* move cursor to last line */
+	if (LLstr)
+		putstr(LLstr);	/* termcap(5) says this is not padded */
+	else
+		moveto(Rows - 1, 0);
+	/* exit screen mode */
+	if (TEstr)
+		putstr(TEstr);	/* termcap(5) says this is not padded */
+	(void) fflush(stdout);
+	(void) ioctl(0, TIOCSETN, &oldtt);
+	isset = 0;
+	/* restore signals */
+	(void) signal(SIGTSTP, tstp);
+	(void) sigsetmask(omask);
+}
+
+void
+stop(why)
+	char *why;
+{
+
+	if (isset)
+		scr_end();
+	(void) fprintf(stderr, "aborting: %s\n", why);
+	exit(1);
+}
+
+/*
+ * Clear the screen, forgetting the current contents in the process.
+ */
+void
+scr_clear()
+{
+
+	putpad(CLstr);
+	curscore = -1;
+	bzero((char *)curscreen, sizeof(curscreen));
+}
+
+#if vax && !__GNUC__
+typedef int regcell;	/* pcc is bad at `register char', etc */
+#else
+typedef cell regcell;
+#endif
+
+/*
+ * Update the screen.
+ */
+void
+scr_update()
+{
+	register cell *bp, *sp;
+	register regcell so, cur_so = 0;
+	register int i, ccol, j;
+	int omask = sigblock(sigmask(SIGTSTP));
+
+	/* always leave cursor after last displayed point */
+	curscreen[D_LAST * B_COLS - 1] = -1;
+
+	if (score != curscore) {
+		if (HOstr)
+			putpad(HOstr);
+		else
+			moveto(0, 0);
+		(void) printf("%d", score);
+		curscore = score;
+	}
+
+	bp = &board[D_FIRST * B_COLS];
+	sp = &curscreen[D_FIRST * B_COLS];
+	for (j = D_FIRST; j < D_LAST; j++) {
+		ccol = -1;
+		for (i = 0; i < B_COLS; bp++, sp++, i++) {
+			if (*sp == (so = *bp))
+				continue;
+			*sp = so;
+			if (i != ccol) {
+				if (cur_so && MSflag) {
+					putpad(SEstr);
+					cur_so = 0;
+				}
+				moveto(RTOD(j), CTOD(i));
+			}
+			if (SOstr) {
+				if (so != cur_so) {
+					putpad(so ? SOstr : SEstr);
+					cur_so = so;
+				}
+				putstr("  ");
+			} else
+				putstr(so ? "XX" : "  ");
+			ccol = i + 1;
+			/*
+			 * Look ahead a bit, to avoid extra motion if
+			 * we will be redrawing the cell after the next.
+			 * Motion probably takes four or more characters,
+			 * so we save even if we rewrite two cells
+			 * `unnecessarily'.  Skip it all, though, if
+			 * the next cell is a different color.
+			 */
+#define	STOP (B_COLS - 3)
+			if (i > STOP || sp[1] != bp[1] || so != bp[1])
+				continue;
+			if (sp[2] != bp[2])
+				sp[1] = -1;
+			else if (i < STOP && so == bp[2] && sp[3] != bp[3]) {
+				sp[2] = -1;
+				sp[1] = -1;
+			}
+		}
+	}
+	if (cur_so)
+		putpad(SEstr);
+	(void) fflush(stdout);
+	(void) sigsetmask(omask);
+}
+
+/*
+ * Write a message (set!=0), or clear the same message (set==0).
+ * (We need its length in case we have to overwrite with blanks.)
+ */
+void
+scr_msg(s, set)
+	register char *s;
+	int set;
+{
+	
+	if (set || CEstr == NULL) {
+		register int l = strlen(s);
+
+		moveto(Rows - 2, ((Cols - l) >> 1) - 1);
+		if (set)
+			putstr(s);
+		else
+			while (--l >= 0)
+				(void) putchar(' ');
+	} else {
+		moveto(Rows - 2, 0);
+		putpad(CEstr);
+	}
+}
diff --git a/tetris/screen.h b/tetris/screen.h
new file mode 100644
index 00000000..fd6793d1
--- /dev/null
+++ b/tetris/screen.h
@@ -0,0 +1,56 @@
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek and Darren F. Provine.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)screen.h	8.1 (Berkeley) 5/31/93
+ */
+
+/*
+ * Capabilities from TERMCAP (used in the score code).
+ */
+char *SEstr;			/* end standout mode */
+char *SOstr;			/* begin standout mode */
+
+/*
+ * putpad() is for padded strings with count=1.
+ */
+#define	putpad(s)	tputs(s, 1, put)
+
+int	put __P((int));		/* just calls putchar; for tputs */
+void	scr_clear __P((void));
+void	scr_end __P((void));
+void	scr_init __P((void));
+void	scr_msg __P((char *, int));
+void	scr_set __P((void));
+void	scr_update __P((void));
diff --git a/tetris/shapes.c b/tetris/shapes.c
new file mode 100644
index 00000000..39ba3788
--- /dev/null
+++ b/tetris/shapes.c
@@ -0,0 +1,111 @@
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek and Darren F. Provine.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)shapes.c	8.1 (Berkeley) 5/31/93
+ */
+
+/*
+ * Tetris shapes and related routines.
+ *
+ * Note that the first 7 are `well known'.
+ */
+
+#include <sys/cdefs.h>
+#include "tetris.h"
+
+#define	TL	-B_COLS-1	/* top left */
+#define	TC	-B_COLS		/* top center */
+#define	TR	-B_COLS+1	/* top right */
+#define	ML	-1		/* middle left */
+#define	MR	1		/* middle right */
+#define	BL	B_COLS-1	/* bottom left */
+#define	BC	B_COLS		/* bottom center */
+#define	BR	B_COLS+1	/* bottom right */
+
+struct shape shapes[] = {
+	/* 0*/	7,	TL, TC, MR,
+	/* 1*/	8,	TC, TR, ML,
+	/* 2*/	9,	ML, MR, BC,
+	/* 3*/	3,	TL, TC, ML,
+	/* 4*/	12,	ML, BL, MR,
+	/* 5*/	15,	ML, BR, MR,
+	/* 6*/	18,	ML, MR, /* sticks out */ 2,
+	/* 7*/	0,	TC, ML, BL,
+	/* 8*/	1,	TC, MR, BR,
+	/* 9*/	10,	TC, MR, BC,
+	/*10*/	11,	TC, ML, MR,
+	/*11*/	2,	TC, ML, BC,
+	/*12*/	13,	TC, BC, BR,
+	/*13*/	14,	TR, ML, MR,
+	/*14*/	4,	TL, TC, BC,
+	/*15*/	16,	TR, TC, BC,
+	/*16*/	17,	TL, MR, ML,
+	/*17*/	5,	TC, BC, BL,
+	/*18*/	6,	TC, BC, /* sticks out */ 2*B_COLS,
+};
+
+/*
+ * Return true iff the given shape fits in the given position,
+ * taking the current board into account.
+ */
+int
+fits_in(shape, pos)
+	struct shape *shape;
+	register int pos;
+{
+	register int *o = shape->off;
+
+	if (board[pos] || board[pos + *o++] || board[pos + *o++] ||
+	    board[pos + *o])
+		return 0;
+	return 1;
+}
+
+/*
+ * Write the given shape into the current board, turning it on
+ * if `onoff' is 1, and off if `onoff' is 0.
+ */
+void
+place(shape, pos, onoff)
+	struct shape *shape;
+	register int pos, onoff;
+{
+	register int *o = shape->off;
+
+	board[pos] = onoff;
+	board[pos + *o++] = onoff;
+	board[pos + *o++] = onoff;
+	board[pos + *o] = onoff;
+}
diff --git a/tetris/tetris.6 b/tetris/tetris.6
new file mode 100644
index 00000000..9513ca05
--- /dev/null
+++ b/tetris/tetris.6
@@ -0,0 +1,154 @@
+.\" Copyright (c) 1992, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" Nancy L. Tinkham and Darren F. Provine.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)tetris.6	8.1 (Berkeley) 5/31/93
+.\"
+.Dd "May 31, 1993"
+.Dt TETRIS 6
+.Os
+.Sh NAME
+.Nm tetris
+.Nd the game of tetris
+.Sh SYNOPSIS
+.Nm
+.Op Fl s
+.Op Fl k Ar keys
+.Op Fl l Ar level
+.Sh DESCRIPTION
+The
+.Nm
+command runs display-based game which must be played on a CRT terminal.
+The object is to fit the shapes together forming complete rows,
+which then vanish.
+When the shapes fill up to the top, the game ends.
+You can optionally select a level of play, or custom-select control keys.
+.Pp
+The default level of play is 2.
+.Pp
+The default control keys are as follows:
+.Pp
+.Bl -tag -width "<space>" -compact -offset indent
+.It j
+move left
+.It k
+rotate 1/4 turn counterclockwise
+.It l
+move right
+.It <space>
+drop
+.It p
+pause
+.It q
+quit
+.El
+.Pp
+The options are as follows:
+.Bl -tag -width indent
+.It Fl k
+The default control keys can be changed using the
+.Fl k option.
+The
+.Ar keys
+argument must have the six keys in order, and, remember to quote any
+space or tab characters from the shell.
+For example:
+.sp
+.Dl "tetris -l 2 -k 'jkl pq'"
+.sp
+will play the default games, i.e. level 2 and with the default
+control keys.
+The current key settings are displayed at the bottom of the screen
+during play.
+.It Fl l
+Select a level of play.
+.It Fl s
+Display the top scores.
+.El
+.Pp
+.Sh PLAY
+At the start of the game, a shape will appear at the top of the screen,
+falling one square at a time.
+The speed at which it falls is determined directly by the level:
+if you select level 2, the blocks will fall twice per second;
+at level 9, they fall 9 times per second.
+(As the game goes on, things speed up,
+no matter what your initial selection.)
+When this shape
+.Dq "touches down"
+on the bottom of the field, another will appear at the top.
+.Pp
+You can move shapes to the left or right, rotate them counterclockwise,
+or drop them to the bottom by pressing the appropriate keys.
+As you fit them together, completed horizontal rows vanish,
+and any blocks above fall down to fill in.
+When the blocks stack up to the top of the screen, the game is over.
+.Sh SCORING
+You get one point for every block you fit into the stack,
+and one point for every space a block falls when you hit the drop key.
+(Dropping the blocks is therefore a good way to increase your score.)
+Your total score is the product of the level of play
+and your accumulated
+.ie t points\(em200
+.el points -- 200
+points on level 3 gives you a score of 600.
+Each player gets at most one entry on any level,
+for a total of nine scores in the high scores file.
+Players who no longer have accounts are limited to one score.
+Also, scores over 5 years old are expired.
+The exception to these conditions is that the highest score on a given
+level is
+.Em always
+kept,
+so that following generations can pay homage to those who have
+wasted serious amounts of time.
+.Pp
+The score list is produced at the end of the game.
+The printout includes each player's overall ranking,
+name, score, and how many points were scored on what level.
+Scores which are the highest on a given level
+are marked with asterisks
+.Dq * .
+.Sh FILES
+.Bl -tag -width /var/games/tetris.scoresxx
+.It /var/games/tetris.scores
+high score file
+.El
+.Sh BUGS
+The higher levels are unplayable without a fast terminal connection.
+.Sh AUTHORS
+Adapted from a 1989 International Obfuscated C Code Contest winner by
+Chris Torek and Darren F. Provine.
+.Pp
+Manual adapted from the original entry written by Nancy L. Tinkham and
+Darren F. Provine.
diff --git a/tetris/tetris.c b/tetris/tetris.c
new file mode 100644
index 00000000..63265bc6
--- /dev/null
+++ b/tetris/tetris.c
@@ -0,0 +1,312 @@
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek and Darren F. Provine.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)tetris.c	8.1 (Berkeley) 5/31/93
+ */
+
+#ifndef lint
+static char copyright[] =
+"@(#) Copyright (c) 1992, 1993\n\
+	The Regents of the University of California.  All rights reserved.\n";
+#endif /* not lint */
+
+/*
+ * Tetris (or however it is spelled).
+ */
+
+#include <sys/time.h>
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "input.h"
+#include "scores.h"
+#include "screen.h"
+#include "tetris.h"
+
+void onintr __P((int));
+void usage __P((void));
+
+/*
+ * Set up the initial board.  The bottom display row is completely set,
+ * along with another (hidden) row underneath that.  Also, the left and
+ * right edges are set.
+ */
+static void
+setup_board()
+{
+	register int i;
+	register cell *p;
+
+	p = board;
+	for (i = B_SIZE; i; i--)
+#ifndef mips
+		*p++ = i <= (2 * B_COLS) || (i % B_COLS) < 2;
+#else /* work around compiler bug */
+		*p++ = i <= (2 * B_COLS) || (i % B_COLS) < 2 ? 1 : 0;
+#endif
+}
+
+/*
+ * Elide any full active rows.
+ */
+static void
+elide()
+{
+	register int i, j, base;
+	register cell *p;
+
+	for (i = A_FIRST; i < A_LAST; i++) {
+		base = i * B_COLS + 1;
+		p = &board[base];
+		for (j = B_COLS - 2; *p++ != 0;) {
+			if (--j <= 0) {
+				/* this row is to be elided */
+				bzero(&board[base], B_COLS - 2);
+				scr_update();
+				tsleep();
+				while (--base != 0)
+					board[base + B_COLS] = board[base];
+				scr_update();
+				tsleep();
+				break;
+			}
+		}
+	}
+}
+
+int
+main(argc, argv)
+	int argc;
+	char *argv[];
+{
+	register int pos, c;
+	register struct shape *curshape;
+	register char *keys;
+	register int level = 2;
+	char key_write[6][10];
+	int ch, i, j;
+
+	keys = "jkl pq";
+
+	while ((ch = getopt(argc, argv, "k:l:s")) != EOF)
+		switch(ch) {
+		case 'k':
+			if (strlen(keys = optarg) != 6)
+				usage();
+			break;
+		case 'l':
+			level = atoi(optarg);
+			if (level < MINLEVEL || level > MAXLEVEL) {
+				(void)fprintf(stderr,
+				    "tetris: level must be from %d to %d",
+				    MINLEVEL, MAXLEVEL);
+				exit(1);
+			}
+			break;
+		case 's':
+			showscores(0);
+			exit(0);
+		case '?':
+		default:
+			usage();
+		}
+
+	argc -= optind;
+	argv += optind;
+
+	if (argc)
+		usage();
+
+	fallrate = 1000000 / level;
+
+	for (i = 0; i <= 5; i++) {
+		for (j = i+1; j <= 5; j++) {
+			if (keys[i] == keys[j]) {
+				(void)fprintf(stderr,
+				    "%s: Duplicate command keys specified.\n",
+				    argv[0]);
+				exit (1);
+			}
+		}
+		if (keys[i] == ' ')
+			strcpy(key_write[i], "<space>");
+		else {
+			key_write[i][0] = keys[i];
+			key_write[i][1] = '\0';
+		}
+	}
+
+	sprintf(key_msg,
+"%s - left   %s - rotate   %s - right   %s - drop   %s - pause   %s - quit",
+		key_write[0], key_write[1], key_write[2], key_write[3],
+		key_write[4], key_write[5]);
+
+	(void)signal(SIGINT, onintr);
+	scr_init();
+	setup_board();
+
+	srandom(getpid());
+	scr_set();
+
+	pos = A_FIRST*B_COLS + (B_COLS/2)-1;
+	curshape = randshape();
+
+	scr_msg(key_msg, 1);
+
+	for (;;) {
+		place(curshape, pos, 1);
+		scr_update();
+		place(curshape, pos, 0);
+		c = tgetchar();
+		if (c < 0) {
+			/*
+			 * Timeout.  Move down if possible.
+			 */
+			if (fits_in(curshape, pos + B_COLS)) {
+				pos += B_COLS;
+				continue;
+			}
+
+			/*
+			 * Put up the current shape `permanently',
+			 * bump score, and elide any full rows.
+			 */
+			place(curshape, pos, 1);
+			score++;
+			elide();
+
+			/*
+			 * Choose a new shape.  If it does not fit,
+			 * the game is over.
+			 */
+			curshape = randshape();
+			pos = A_FIRST*B_COLS + (B_COLS/2)-1;
+			if (!fits_in(curshape, pos))
+				break;
+			continue;
+		}
+
+		/*
+		 * Handle command keys.
+		 */
+		if (c == keys[5]) {
+			/* quit */
+			break;
+		}
+		if (c == keys[4]) {
+			static char msg[] =
+			    "paused - press RETURN to continue";
+
+			place(curshape, pos, 1);
+			do {
+				scr_update();
+				scr_msg(key_msg, 0);
+				scr_msg(msg, 1);
+				(void) fflush(stdout);
+			} while (rwait((struct timeval *)NULL) == -1);
+			scr_msg(msg, 0);
+			scr_msg(key_msg, 1);
+			place(curshape, pos, 0);
+			continue;
+		}
+		if (c == keys[0]) {
+			/* move left */
+			if (fits_in(curshape, pos - 1))
+				pos--;
+			continue;
+		}
+		if (c == keys[1]) {
+			/* turn */
+			struct shape *new = &shapes[curshape->rot];
+
+			if (fits_in(new, pos))
+				curshape = new;
+			continue;
+		}
+		if (c == keys[2]) {
+			/* move right */
+			if (fits_in(curshape, pos + 1))
+				pos++;
+			continue;
+		}
+		if (c == keys[3]) {
+			/* move to bottom */
+			while (fits_in(curshape, pos + B_COLS)) {
+				pos += B_COLS;
+				score++;
+			}
+			continue;
+		}
+		if (c == '\f')
+			scr_clear();
+	}
+
+	scr_clear();
+	scr_end();
+
+	(void)printf("Your score:  %d point%s  x  level %d  =  %d\n",
+	    score, score == 1 ? "" : "s", level, score * level);
+	savescore(level);
+
+	printf("\nHit RETURN to see high scores, ^C to skip.\n");
+
+	while ((i = getchar()) != '\n')
+		if (i == EOF)
+			break;
+
+	showscores(level);
+
+	exit(0);
+}
+
+void
+onintr(signo)
+	int signo;
+{
+	scr_clear();
+	scr_end();
+	exit(0);
+}
+
+void
+usage()
+{
+	(void)fprintf(stderr, "usage: tetris [-s] [-l level] [-keys]\n");
+	exit(1);
+}
diff --git a/tetris/tetris.h b/tetris/tetris.h
new file mode 100644
index 00000000..b95627bb
--- /dev/null
+++ b/tetris/tetris.h
@@ -0,0 +1,169 @@
+/*-
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek and Darren F. Provine.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)tetris.h	8.1 (Berkeley) 5/31/93
+ */
+
+/*
+ * Definitions for Tetris.
+ */
+
+/*
+ * The display (`board') is composed of 23 rows of 12 columns of characters
+ * (numbered 0..22 and 0..11), stored in a single array for convenience.
+ * Columns 1 to 10 of rows 1 to 20 are the actual playing area, where
+ * shapes appear.  Columns 0 and 11 are always occupied, as are all
+ * columns of rows 21 and 22.  Rows 0 and 22 exist as boundary areas
+ * so that regions `outside' the visible area can be examined without
+ * worrying about addressing problems.
+ */
+
+	/* the board */
+#define	B_COLS	12
+#define	B_ROWS	23
+#define	B_SIZE	(B_ROWS * B_COLS)
+
+typedef unsigned char cell;
+cell	board[B_SIZE];		/* 1 => occupied, 0 => empty */
+
+	/* the displayed area (rows) */
+#define	D_FIRST	1
+#define	D_LAST	22
+
+	/* the active area (rows) */
+#define	A_FIRST	1
+#define	A_LAST	21
+
+/*
+ * Minimum display size.
+ */
+#define	MINROWS	23
+#define	MINCOLS	40
+
+int	Rows, Cols;		/* current screen size */
+
+/*
+ * Translations from board coordinates to display coordinates.
+ * As with board coordinates, display coordiates are zero origin.
+ */
+#define	RTOD(x)	((x) - 1)
+#define	CTOD(x)	((x) * 2 + (((Cols - 2 * B_COLS) >> 1) - 1))
+
+/*
+ * A `shape' is the fundamental thing that makes up the game.  There
+ * are 7 basic shapes, each consisting of four `blots':
+ *
+ *	X.X	  X.X		X.X
+ *	  X.X	X.X	X.X.X	X.X	X.X.X	X.X.X	X.X.X.X
+ *			  X		X	    X
+ *
+ *	  0	  1	  2	  3	  4	  5	  6
+ *
+ * Except for 3 and 6, the center of each shape is one of the blots.
+ * This blot is designated (0,0).  The other three blots can then be
+ * described as offsets from the center.  Shape 3 is the same under
+ * rotation, so its center is effectively irrelevant; it has been chosen
+ * so that it `sticks out' upward and leftward.  Except for shape 6,
+ * all the blots are contained in a box going from (-1,-1) to (+1,+1);
+ * shape 6's center `wobbles' as it rotates, so that while it `sticks out'
+ * rightward, its rotation---a vertical line---`sticks out' downward.
+ * The containment box has to include the offset (2,0), making the overall
+ * containment box range from offset (-1,-1) to (+2,+1).  (This is why
+ * there is only one row above, but two rows below, the display area.)
+ *
+ * The game works by choosing one of these shapes at random and putting
+ * its center at the middle of the first display row (row 1, column 5).
+ * The shape is moved steadily downward until it collides with something:
+ * either  another shape, or the bottom of the board.  When the shape can
+ * no longer be moved downwards, it is merged into the current board.
+ * At this time, any completely filled rows are elided, and blots above
+ * these rows move down to make more room.  A new random shape is again
+ * introduced at the top of the board, and the whole process repeats.
+ * The game ends when the new shape will not fit at (1,5).
+ *
+ * While the shapes are falling, the user can rotate them counterclockwise
+ * 90 degrees (in addition to moving them left or right), provided that the
+ * rotation puts the blots in empty spaces.  The table of shapes is set up
+ * so that each shape contains the index of the new shape obtained by
+ * rotating the current shape.  Due to symmetry, each shape has exactly
+ * 1, 2, or 4 rotations total; the first 7 entries in the table represent
+ * the primary shapes, and the remaining 12 represent their various
+ * rotated forms.
+ */
+struct shape {
+	int	rot;	/* index of rotated version of this shape */
+	int	off[3];	/* offsets to other blots if center is at (0,0) */
+};
+
+extern struct shape shapes[];
+#define	randshape() (&shapes[random() % 7])
+
+/*
+ * Shapes fall at a rate faster than once per second.
+ *
+ * The initial rate is determined by dividing 1 million microseconds
+ * by the game `level'.  (This is at most 1 million, or one second.)
+ * Each time the fall-rate is used, it is decreased a little bit,
+ * depending on its current value, via the `faster' macro below.
+ * The value eventually reaches a limit, and things stop going faster,
+ * but by then the game is utterly impossible.
+ */
+long	fallrate;		/* less than 1 million; smaller => faster */
+#define	faster() (fallrate -= fallrate / 3000)
+
+/*
+ * Game level must be between 1 and 9.  This controls the initial fall rate
+ * and affects scoring.
+ */
+#define	MINLEVEL	1
+#define	MAXLEVEL	9
+
+/*
+ * Scoring is as follows:
+ *
+ * When the shape comes to rest, and is integrated into the board,
+ * we score one point.  If the shape is high up (at a low-numbered row),
+ * and the user hits the space bar, the shape plummets all the way down,
+ * and we score a point for each row it falls (plus one more as soon as
+ * we find that it is at rest and integrate it---until then, it can
+ * still be moved or rotated).
+ */
+int	score;			/* the obvious thing */
+
+char	key_msg[100];
+
+int	fits_in __P((struct shape *, int));
+void	place __P((struct shape *, int, int));
+void	stop __P((char *));