apps/plugins/frotz/sound.c

   1 /* sound.c - Sound effect function
   2  *      Copyright (c) 1995-1997 Stefan Jokisch
   3  *
   4  * This file is part of Frotz.
   5  *
   6  * Frotz is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * Frotz is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  19  */
  20
  21 #include "frotz.h"
  22
  23 #ifdef DJGPP
  24 #include "djfrotz.h"
  25 #endif
  26
  27 #define EFFECT_PREPARE 1
  28 #define EFFECT_PLAY 2
  29 #define EFFECT_STOP 3
  30 #define EFFECT_FINISH_WITH 4
  31
  32 extern int direct_call (zword);
  33
  34 static zword routine = 0;
  35
  36 static int next_sample = 0;
  37 static int next_volume = 0;
  38
  39 static bool locked = FALSE;
  40 static bool playing = FALSE;
  41
  42 /*
  43  * init_sound
  44  *
  45  * Initialize sound variables.
  46  *
  47  */
  48
  49 void init_sound (void)
  50 {
  51     locked = FALSE;
  52     playing = FALSE;
  53 } /* init_sound */
  54
  55
  56 /*
  57  * start_sample
  58  *
  59  * Call the IO interface to play a sample.
  60  *
  61  */
  62
  63 static void start_sample (int number, int volume, int repeats, zword eos)
  64 {
  65
  66     static zbyte lh_repeats[] = {
  67         0x00, 0x00, 0x00, 0x01, 0xff,
  68         0x00, 0x01, 0x01, 0x01, 0x01,
  69         0xff, 0x01, 0x01, 0xff, 0x00,
  70         0xff, 0xff, 0xff, 0xff, 0xff
  71     };
  72
  73     if (story_id == LURKING_HORROR)
  74         repeats = lh_repeats[number];
  75
  76     os_start_sample (number, volume, repeats, eos);
  77
  78     routine = eos;
  79     playing = TRUE;
  80
  81 }/* start_sample */
  82
  83 /*
  84  * start_next_sample
  85  *
  86  * Play a sample that has been delayed until the previous sound effect has
  87  * finished.  This is necessary for two samples in The Lurking Horror that
  88  * immediately follow other samples.
  89  *
  90  */
  91
  92 static void start_next_sample (void)
  93 {
  94
  95     if (next_sample != 0)
  96         start_sample (next_sample, next_volume, 0, 0);
  97
  98     next_sample = 0;
  99     next_volume = 0;
 100
 101 }/* start_next_sample */
 102
 103 /*
 104  * end_of_sound
 105  *
 106  * Call the Z-code routine which was given as the last parameter of
 107  * a sound_effect call. This function may be called from a hardware
 108  * interrupt (which requires extremely careful programming).
 109  *
 110  */
 111
 112 void end_of_sound (void)
 113 {
 114
 115 #if defined(DJGPP) && defined(SOUND_SUPPORT)
 116     end_of_sound_flag = 0;
 117 #endif
 118
 119     playing = FALSE;
 120
 121     if (!locked) {
 122
 123         if (story_id == LURKING_HORROR)
 124             start_next_sample ();
 125
 126         direct_call (routine);
 127
 128     }
 129
 130 }/* end_of_sound */
 131
 132 /*
 133  * z_sound_effect, load / play / stop / discard a sound effect.
 134  *
 135  *      zargs[0] = number of bleep (1 or 2) or sample
 136  *      zargs[1] = operation to perform (samples only)
 137  *      zargs[2] = repeats and volume (play sample only)
 138  *      zargs[3] = end-of-sound routine (play sample only, optional)
 139  *
 140  * Note: Volumes range from 1 to 8, volume 255 is the default volume.
 141  *       Repeats are stored in the high byte, 255 is infinite loop.
 142  *
 143  */
 144
 145 void z_sound_effect (void)
 146 {
 147     zword number = zargs[0];
 148     zword effect = zargs[1];
 149     zword volume = zargs[2];
 150
 151     /* By default play sound 1 at volume 8 */
 152     if (zargc < 1)
 153         number = 1;
 154     if (zargc < 2)
 155         effect = EFFECT_PLAY;
 156     if (zargc < 3)
 157         volume = 8;
 158
 159     if (number >= 3 || number == 0) {
 160
 161         locked = TRUE;
 162
 163         if (story_id == LURKING_HORROR && (number == 9 || number == 16)) {
 164
 165             if (effect == EFFECT_PLAY) {
 166
 167                 next_sample = number;
 168                 next_volume = volume;
 169
 170                 locked = FALSE;
 171
 172                 if (!playing)
 173                     start_next_sample ();
 174
 175             } else locked = FALSE;
 176
 177             return;
 178
 179         }
 180
 181         playing = FALSE;
 182
 183         switch (effect) {
 184
 185         case EFFECT_PREPARE:
 186             os_prepare_sample (number);
 187             break;
 188         case EFFECT_PLAY:
 189             start_sample (number, lo (volume), hi (volume), (zargc == 4) ? zargs[3] : 0);
 190             break;
 191         case EFFECT_STOP:
 192             os_stop_sample (number);
 193             break;
 194         case EFFECT_FINISH_WITH:
 195             os_finish_with_sample (number);
 196             break;
 197
 198         }
 199
 200         locked = FALSE;
 201
 202     } else os_beep (number);
 203
 204 }/* z_sound_effect */