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  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 $    */
  3.  
  4. /*-
  5.  * Copyright (c) 1992, 1993
  6.  *  The Regents of the University of California.  All rights reserved.
  7.  *
  8.  * This code is derived from software contributed to Berkeley by
  9.  * Chris Torek and Darren F. Provine.
  10.  *
  11.  * Redistribution and use in source and binary forms, with or without
  12.  * modification, are permitted provided that the following conditions
  13.  * are met:
  14.  * 1. Redistributions of source code must retain the above copyright
  15.  *    notice, this list of conditions and the following disclaimer.
  16.  * 2. Redistributions in binary form must reproduce the above copyright
  17.  *    notice, this list of conditions and the following disclaimer in the
  18.  *    documentation and/or other materials provided with the distribution.
  19.  * 3. Neither the name of the University nor the names of its contributors
  20.  *    may be used to endorse or promote products derived from this software
  21.  *    without specific prior written permission.
  22.  *
  23.  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24.  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25.  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26.  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27.  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28.  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29.  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30.  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31.  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32.  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33.  * SUCH DAMAGE.
  34.  *
  35.  *  @(#)input.c 8.1 (Berkeley) 5/31/93
  36.  */
  37.  
  38. /** @addtogroup tetris
  39.  * @{
  40.  */
  41. /** @file
  42.  */
  43.  
  44. /*
  45.  * Tetris input.
  46.  */
  47.  
  48. #include <sys/types.h>
  49. #include <sys/time.h>
  50. #include <stdio.h>
  51.  
  52. #include <errno.h>
  53. #include <unistd.h>
  54. #include <string.h>
  55.  
  56. #include "input.h"
  57. #include "tetris.h"
  58.  
  59. #include <async.h>
  60. #include <vfs/vfs.h>
  61. #include <io/console.h>
  62. #include <ipc/console.h>
  63.  
  64. /* return true iff the given timeval is positive */
  65. #define TV_POS(tv) \
  66.     ((tv)->tv_sec > 0 || ((tv)->tv_sec == 0 && (tv)->tv_usec > 0))
  67.  
  68. /* subtract timeval `sub' from `res' */
  69. #define TV_SUB(res, sub) \
  70.     (res)->tv_sec -= (sub)->tv_sec; \
  71.     (res)->tv_usec -= (sub)->tv_usec; \
  72.     if ((res)->tv_usec < 0) { \
  73.         (res)->tv_usec += 1000000; \
  74.         (res)->tv_sec--; \
  75.     }
  76.  
  77. /* We will use a hack here - if lastchar is non-zero, it is
  78.  * the last character read. We will somehow simulate the select
  79.  * semantics.
  80.  */
  81. static aid_t getchar_inprog = 0;
  82. static char lastchar = '\0';
  83.  
  84. /*
  85.  * Do a `read wait': select for reading from stdin, with timeout *tvp.
  86.  * On return, modify *tvp to reflect the amount of time spent waiting.
  87.  * It will be positive only if input appeared before the time ran out;
  88.  * otherwise it will be zero or perhaps negative.
  89.  *
  90.  * If tvp is nil, wait forever, but return if select is interrupted.
  91.  *
  92.  * Return 0 => no input, 1 => can read() from stdin
  93.  *
  94.  */
  95. int rwait(struct timeval *tvp)
  96. {
  97.     struct timeval starttv, endtv, *s;
  98.     static ipc_call_t charcall;
  99.     ipcarg_t rc;
  100.    
  101.     /*
  102.      * Someday, select() will do this for us.
  103.      * Just in case that day is now, and no one has
  104.      * changed this, we use a temporary.
  105.      */
  106.     if (tvp) {
  107.         (void) gettimeofday(&starttv, NULL);
  108.         endtv = *tvp;
  109.         s = &endtv;
  110.     } else
  111.         s = NULL;
  112.    
  113.     if (!lastchar) {
  114. again:
  115.         if (!getchar_inprog) {
  116.             getchar_inprog = async_send_0(fphone(stdin),
  117.                 CONSOLE_GET_EVENT, &charcall);
  118.         }
  119.        
  120.         if (!s)
  121.             async_wait_for(getchar_inprog, &rc);
  122.         else if (async_wait_timeout(getchar_inprog, &rc, s->tv_usec) == ETIMEOUT) {
  123.             tvp->tv_sec = 0;
  124.             tvp->tv_usec = 0;
  125.             return (0);
  126.         }
  127.        
  128.         getchar_inprog = 0;
  129.         if (rc)
  130.             stop("end of file, help");
  131.        
  132.         if (IPC_GET_ARG1(charcall) == KEY_RELEASE)
  133.             goto again;
  134.        
  135.         lastchar = IPC_GET_ARG4(charcall);
  136.     }
  137.    
  138.     if (tvp) {
  139.         /* since there is input, we may not have timed out */
  140.         (void) gettimeofday(&endtv, NULL);
  141.         TV_SUB(&endtv, &starttv);
  142.         TV_SUB(tvp, &endtv);  /* adjust *tvp by elapsed time */
  143.     }
  144.    
  145.     return 1;
  146. }
  147.  
  148. /*
  149.  * `sleep' for the current turn time (using select).
  150.  * Eat any input that might be available.
  151.  */
  152. void tsleep(void)
  153. {
  154.     struct timeval tv;
  155.    
  156.     tv.tv_sec = 0;
  157.     tv.tv_usec = fallrate;
  158.     while (TV_POS(&tv))
  159.         if (rwait(&tv)) {
  160.             lastchar = '\0';
  161.         } else
  162.             break;
  163. }
  164.  
  165. /*
  166.  * getchar with timeout.
  167.  */
  168. int tgetchar(void)
  169. {
  170.     static struct timeval timeleft;
  171.     char c;
  172.    
  173.     /*
  174.      * Reset timeleft to fallrate whenever it is not positive.
  175.      * In any case, wait to see if there is any input.  If so,
  176.      * take it, and update timeleft so that the next call to
  177.      * tgetchar() will not wait as long.  If there is no input,
  178.      * make timeleft zero or negative, and return -1.
  179.      *
  180.      * Most of the hard work is done by rwait().
  181.      */
  182.     if (!TV_POS(&timeleft)) {
  183.         faster();  /* go faster */
  184.         timeleft.tv_sec = 0;
  185.         timeleft.tv_usec = fallrate;
  186.     }
  187.    
  188.     if (!rwait(&timeleft))
  189.         return -1;
  190.    
  191.     c = lastchar;
  192.     lastchar = '\0';
  193.     return ((int) (unsigned char) c);
  194. }
  195.  
  196. /** @}
  197.  */
  198.