ascii tetris!

1 files changed, 180 insertions, 0 deletions

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);
+}