NetBSD/games/tetris/input.c
dholland bbc67e0f7a ANSIfy function declarations.
Some object file diffs, but they are harmless. (Mostly they seem to
come from internal counters in gcc... and in one case the order of two
instructions was harmlessly swapped, which is odd and annoying.)
2009-05-25 04:33:53 +00:00

163 lines
4.4 KiB
C

/* $NetBSD: input.c,v 1.11 2009/05/25 04:33:53 dholland Exp $ */
/*-
* 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. 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 <sys/poll.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': poll 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 poll is interrupted.
*
* Return 0 => no input, 1 => can read() from stdin
*/
int
rwait(struct timeval *tvp)
{
struct pollfd set[1];
struct timeval starttv, endtv;
int timeout;
#define NILTZ ((struct timezone *)0)
if (tvp) {
(void) gettimeofday(&starttv, NILTZ);
endtv = *tvp;
timeout = tvp->tv_sec * 1000 + tvp->tv_usec / 1000;
} else
timeout = INFTIM;
again:
set[0].fd = STDIN_FILENO;
set[0].events = POLLIN;
switch (poll(set, 1, timeout)) {
case -1:
if (tvp == 0)
return (-1);
if (errno == EINTR)
goto again;
stop("poll failed, help");
/* NOTREACHED */
case 0: /* timed out */
if (tvp) {
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.
* Eat any input that might be available.
*/
void
tsleep(void)
{
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;
}
/*
* getchar with timeout.
*/
int
tgetchar(void)
{
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);
}