projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| bc443be7 | 1 | /*- |
| 6601dd48 KB |
2 | * Copyright (c) 1992, 1993 |
| 3 | * The Regents of the University of California. All rights reserved. | |
| bc443be7 | 4 | * |
| 05932cb9 KB |
5 | * This code is derived from software contributed to Berkeley by |
| 6 | * Chris Torek and Darren F. Provine. | |
| 7 | * | |
| bc443be7 KB |
8 | * %sccs.include.redist.c% |
| 9 | * | |
| 6601dd48 | 10 | * @(#)input.c 8.1 (Berkeley) %G% |
| bc443be7 KB |
11 | */ |
| 12 | ||
| 13 | /* | |
| 14 | * Tetris input. | |
| 15 | */ | |
| 16 | ||
| 17 | #include <sys/types.h> | |
| 18 | #include <sys/time.h> | |
| 05932cb9 | 19 | |
| bc443be7 KB |
20 | #include <errno.h> |
| 21 | #include <unistd.h> | |
| 22 | ||
| 23 | #include "input.h" | |
| 24 | #include "tetris.h" | |
| 25 | ||
| 26 | /* return true iff the given timeval is positive */ | |
| 27 | #define TV_POS(tv) \ | |
| 28 | ((tv)->tv_sec > 0 || ((tv)->tv_sec == 0 && (tv)->tv_usec > 0)) | |
| 29 | ||
| 30 | /* subtract timeval `sub' from `res' */ | |
| 31 | #define TV_SUB(res, sub) \ | |
| 32 | (res)->tv_sec -= (sub)->tv_sec; \ | |
| 33 | (res)->tv_usec -= (sub)->tv_usec; \ | |
| 34 | if ((res)->tv_usec < 0) { \ | |
| 35 | (res)->tv_usec += 1000000; \ | |
| 36 | (res)->tv_sec--; \ | |
| 37 | } | |
| 38 | ||
| 39 | /* | |
| 40 | * Do a `read wait': select for reading from stdin, with timeout *tvp. | |
| 41 | * On return, modify *tvp to reflect the amount of time spent waiting. | |
| 42 | * It will be positive only if input appeared before the time ran out; | |
| 43 | * otherwise it will be zero or perhaps negative. | |
| 44 | * | |
| 45 | * If tvp is nil, wait forever, but return if select is interrupted. | |
| 46 | * | |
| 47 | * Return 0 => no input, 1 => can read() from stdin | |
| 48 | */ | |
| 49 | int | |
| 50 | rwait(tvp) | |
| 51 | register struct timeval *tvp; | |
| 52 | { | |
| 53 | int i; | |
| 54 | struct timeval starttv, endtv, *s; | |
| 55 | extern int errno; | |
| 56 | #define NILTZ ((struct timezone *)0) | |
| 57 | ||
| 58 | /* | |
| 59 | * Someday, select() will do this for us. | |
| 60 | * Just in case that day is now, and no one has | |
| 61 | * changed this, we use a temporary. | |
| 62 | */ | |
| 63 | if (tvp) { | |
| 64 | (void) gettimeofday(&starttv, NILTZ); | |
| 65 | endtv = *tvp; | |
| 66 | s = &endtv; | |
| 67 | } else | |
| 68 | s = 0; | |
| 69 | again: | |
| 70 | i = 1; | |
| 71 | switch (select(1, (fd_set *)&i, (fd_set *)0, (fd_set *)0, s)) { | |
| 72 | ||
| 73 | case -1: | |
| 74 | if (tvp == 0) | |
| 75 | return (-1); | |
| 76 | if (errno == EINTR) | |
| 77 | goto again; | |
| 78 | stop("select failed, help"); | |
| 79 | /* NOTREACHED */ | |
| 80 | ||
| 81 | case 0: /* timed out */ | |
| 82 | tvp->tv_sec = 0; | |
| 83 | tvp->tv_usec = 0; | |
| 84 | return (0); | |
| 85 | } | |
| 86 | if (tvp) { | |
| 87 | /* since there is input, we may not have timed out */ | |
| 88 | (void) gettimeofday(&endtv, NILTZ); | |
| 89 | TV_SUB(&endtv, &starttv); | |
| 90 | TV_SUB(tvp, &endtv); /* adjust *tvp by elapsed time */ | |
| 91 | } | |
| 92 | return (1); | |
| 93 | } | |
| 94 | ||
| 95 | /* | |
| 96 | * `sleep' for the current turn time (using select). | |
| 97 | * Eat any input that might be available. | |
| 98 | */ | |
| 99 | void | |
| 100 | tsleep() | |
| 101 | { | |
| 102 | struct timeval tv; | |
| 103 | char c; | |
| 104 | ||
| 105 | tv.tv_sec = 0; | |
| 106 | tv.tv_usec = fallrate; | |
| 107 | while (TV_POS(&tv)) | |
| 108 | if (rwait(&tv) && read(0, &c, 1) != 1) | |
| 109 | break; | |
| 110 | } | |
| 111 | ||
| 112 | /* | |
| 113 | * Eat up any input (used at end of game). | |
| 114 | */ | |
| 115 | void | |
| 116 | eat_input() | |
| 117 | { | |
| 118 | struct timeval tv; | |
| 119 | char c; | |
| 120 | ||
| 121 | do { | |
| 122 | tv.tv_sec = tv.tv_usec = 0; | |
| 123 | } while (rwait(&tv) && read(0, &c, 1) == 1); | |
| 124 | } | |
| 125 | ||
| 126 | /* | |
| 127 | * getchar with timeout. | |
| 128 | */ | |
| 129 | int | |
| 130 | tgetchar() | |
| 131 | { | |
| 132 | static struct timeval timeleft; | |
| 133 | char c; | |
| 134 | ||
| 135 | /* | |
| 136 | * Reset timeleft to fallrate whenever it is not positive. | |
| 137 | * In any case, wait to see if there is any input. If so, | |
| 138 | * take it, and update timeleft so that the next call to | |
| 139 | * tgetchar() will not wait as long. If there is no input, | |
| 140 | * make timeleft zero or negative, and return -1. | |
| 141 | * | |
| 142 | * Most of the hard work is done by rwait(). | |
| 143 | */ | |
| 144 | if (!TV_POS(&timeleft)) { | |
| 145 | faster(); /* go faster */ | |
| 146 | timeleft.tv_sec = 0; | |
| 147 | timeleft.tv_usec = fallrate; | |
| 148 | } | |
| 149 | if (!rwait(&timeleft)) | |
| 150 | return (-1); | |
| 151 | if (read(0, &c, 1) != 1) | |
| 152 | stop("end of file, help"); | |
| 153 | return ((int)(unsigned char)c); | |
| 154 | } |