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| Rev | Author | Line No. | Line |
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| 1419 | jermar | 1 | /* $OpenBSD: input.c,v 1.12 2005/04/13 02:33:08 deraadt Exp $ */ |
| 2 | /* $NetBSD: input.c,v 1.3 1996/02/06 22:47:33 jtc Exp $ */ |
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| 3 | |||
| 4 | /*- |
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| 5 | * Copyright (c) 1992, 1993 |
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| 6 | * The Regents of the University of California. All rights reserved. |
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| 7 | * |
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| 8 | * This code is derived from software contributed to Berkeley by |
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| 9 | * Chris Torek and Darren F. Provine. |
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| 10 | * |
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| 11 | * Redistribution and use in source and binary forms, with or without |
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| 12 | * modification, are permitted provided that the following conditions |
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| 13 | * are met: |
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| 14 | * 1. Redistributions of source code must retain the above copyright |
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| 15 | * notice, this list of conditions and the following disclaimer. |
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| 16 | * 2. Redistributions in binary form must reproduce the above copyright |
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| 17 | * notice, this list of conditions and the following disclaimer in the |
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| 18 | * documentation and/or other materials provided with the distribution. |
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| 19 | * 3. Neither the name of the University nor the names of its contributors |
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| 20 | * may be used to endorse or promote products derived from this software |
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| 21 | * without specific prior written permission. |
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| 22 | * |
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| 23 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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| 24 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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| 25 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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| 26 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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| 27 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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| 28 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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| 29 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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| 30 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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| 31 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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| 32 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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| 33 | * SUCH DAMAGE. |
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| 34 | * |
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| 35 | * @(#)input.c 8.1 (Berkeley) 5/31/93 |
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| 36 | */ |
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| 37 | |||
| 38 | /* |
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| 39 | * Tetris input. |
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| 40 | */ |
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| 41 | |||
| 42 | #include <sys/types.h> |
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| 43 | #include <sys/time.h> |
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| 44 | |||
| 45 | #include <errno.h> |
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| 46 | #include <unistd.h> |
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| 47 | #include <string.h> |
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| 48 | |||
| 49 | #include "input.h" |
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| 50 | #include "tetris.h" |
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| 51 | |||
| 52 | /* return true iff the given timeval is positive */ |
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| 53 | #define TV_POS(tv) \ |
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| 54 | ((tv)->tv_sec > 0 || ((tv)->tv_sec == 0 && (tv)->tv_usec > 0)) |
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| 55 | |||
| 56 | /* subtract timeval `sub' from `res' */ |
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| 57 | #define TV_SUB(res, sub) \ |
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| 58 | (res)->tv_sec -= (sub)->tv_sec; \ |
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| 59 | (res)->tv_usec -= (sub)->tv_usec; \ |
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| 60 | if ((res)->tv_usec < 0) { \ |
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| 61 | (res)->tv_usec += 1000000; \ |
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| 62 | (res)->tv_sec--; \ |
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| 63 | } |
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| 64 | |||
| 65 | /* |
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| 66 | * Do a `read wait': select for reading from stdin, with timeout *tvp. |
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| 67 | * On return, modify *tvp to reflect the amount of time spent waiting. |
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| 68 | * It will be positive only if input appeared before the time ran out; |
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| 69 | * otherwise it will be zero or perhaps negative. |
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| 70 | * |
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| 71 | * If tvp is nil, wait forever, but return if select is interrupted. |
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| 72 | * |
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| 73 | * Return 0 => no input, 1 => can read() from stdin |
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| 74 | */ |
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| 75 | int |
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| 76 | rwait(struct timeval *tvp) |
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| 77 | { |
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| 78 | struct timeval starttv, endtv, *s; |
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| 79 | fd_set fds; |
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| 80 | |||
| 81 | #define NILTZ ((struct timezone *)0) |
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| 82 | |||
| 83 | /* |
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| 84 | * Someday, select() will do this for us. |
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| 85 | * Just in case that day is now, and no one has |
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| 86 | * changed this, we use a temporary. |
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| 87 | */ |
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| 88 | if (tvp) { |
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| 89 | (void) gettimeofday(&starttv, NILTZ); |
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| 90 | endtv = *tvp; |
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| 91 | s = &endtv; |
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| 92 | } else |
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| 93 | s = NULL; |
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| 94 | again: |
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| 95 | FD_ZERO(&fds); |
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| 96 | FD_SET(STDIN_FILENO, &fds); |
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| 97 | switch (select(STDIN_FILENO + 1, &fds, (fd_set *)0, (fd_set *)0, s)) { |
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| 98 | |||
| 99 | case -1: |
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| 100 | if (tvp == 0) |
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| 101 | return (-1); |
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| 102 | if (errno == EINTR) |
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| 103 | goto again; |
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| 104 | stop("select failed, help"); |
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| 105 | /* NOTREACHED */ |
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| 106 | |||
| 107 | case 0: /* timed out */ |
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| 108 | tvp->tv_sec = 0; |
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| 109 | tvp->tv_usec = 0; |
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| 110 | return (0); |
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| 111 | } |
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| 112 | if (tvp) { |
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| 113 | /* since there is input, we may not have timed out */ |
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| 114 | (void) gettimeofday(&endtv, NILTZ); |
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| 115 | TV_SUB(&endtv, &starttv); |
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| 116 | TV_SUB(tvp, &endtv); /* adjust *tvp by elapsed time */ |
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| 117 | } |
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| 118 | return (1); |
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| 119 | } |
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| 120 | |||
| 121 | /* |
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| 122 | * `sleep' for the current turn time (using select). |
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| 123 | * Eat any input that might be available. |
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| 124 | */ |
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| 125 | void |
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| 126 | tsleep(void) |
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| 127 | { |
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| 128 | struct timeval tv; |
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| 129 | char c; |
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| 130 | |||
| 131 | tv.tv_sec = 0; |
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| 132 | tv.tv_usec = fallrate; |
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| 133 | while (TV_POS(&tv)) |
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| 134 | if (rwait(&tv) && read(STDIN_FILENO, &c, 1) != 1) |
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| 135 | break; |
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| 136 | } |
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| 137 | |||
| 138 | /* |
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| 139 | * getchar with timeout. |
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| 140 | */ |
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| 141 | int |
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| 142 | tgetchar(void) |
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| 143 | { |
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| 144 | static struct timeval timeleft; |
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| 145 | char c; |
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| 146 | |||
| 147 | /* |
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| 148 | * Reset timeleft to fallrate whenever it is not positive. |
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| 149 | * In any case, wait to see if there is any input. If so, |
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| 150 | * take it, and update timeleft so that the next call to |
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| 151 | * tgetchar() will not wait as long. If there is no input, |
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| 152 | * make timeleft zero or negative, and return -1. |
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| 153 | * |
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| 154 | * Most of the hard work is done by rwait(). |
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| 155 | */ |
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| 156 | if (!TV_POS(&timeleft)) { |
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| 157 | faster(); /* go faster */ |
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| 158 | timeleft.tv_sec = 0; |
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| 159 | timeleft.tv_usec = fallrate; |
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| 160 | } |
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| 161 | if (!rwait(&timeleft)) |
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| 162 | return (-1); |
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| 163 | if (read(STDIN_FILENO, &c, 1) != 1) |
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| 164 | stop("end of file, help"); |
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| 165 | return ((int)(unsigned char)c); |
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| 166 | } |