Merge pull request #173 from Hondarer/enable-io-sound

Add "Enable io sound" core option

libretro.c

@@ -66,6 +66,7 @@ static bool msx_ym2413_enable;
 static bool use_overscan = true;
 int msx2_dif = 0;
 
+static void reevaluate_variables_io_sound(bool setToMixer);
 
 void retro_set_video_refresh(retro_video_refresh_t cb) { video_cb = cb; }
 void retro_set_input_poll(retro_input_poll_t cb) { input_poll_cb = cb; }
@@ -821,13 +822,39 @@ static void check_variables(void)
    else
       auto_rewind_cas = true;
 
+   if (properties != NULL) // Avoid first run (check_variables() is called before propCreate())
+   {
+      reevaluate_variables_io_sound(true);
+   }
+
    if (geometry_update)
    {
       retro_get_system_av_info(&av_info);
       environ_cb(RETRO_ENVIRONMENT_SET_GEOMETRY, &av_info);
    }
 }
 
+static void reevaluate_variables_io_sound(bool setToMixer)
+{
+   struct retro_variable var;
+
+   var.key = "bluemsx_sound_io_enable";
+   var.value = NULL;
+
+   if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value)
+   {
+      if (!strcmp(var.value, "disabled"))
+         properties->sound.mixerChannel[MIXER_CHANNEL_IO].enable = 0;
+      else if (!strcmp(var.value, "enabled"))
+         properties->sound.mixerChannel[MIXER_CHANNEL_IO].enable = 1;
+   }
+   else
+      properties->sound.mixerChannel[MIXER_CHANNEL_IO].enable = 0;
+
+   if (setToMixer)
+      mixerEnableChannelType(mixer, MIXER_CHANNEL_IO, properties->sound.mixerChannel[MIXER_CHANNEL_IO].enable);
+}
+
 bool retro_load_game(const struct retro_game_info *info)
 {
    const char *save_dir = NULL;
@@ -937,6 +964,7 @@ bool retro_load_game(const struct retro_game_info *info)
 #endif
 
    emulatorRestartSound();
+   reevaluate_variables_io_sound(false);
 
    for (i = 0; i < MIXER_CHANNEL_TYPE_COUNT; i++)
    {

libretro_core_options.h

@@ -148,6 +148,17 @@ struct retro_core_option_definition option_defs_us[] = {
       },
       "ON"
    },
+   {
+      "bluemsx_sound_io_enable",
+      "I/O Sound Enable",
+      "Enable the I/O sound (floppy disk access sound).",
+      {
+         { "enabled",   NULL },
+         { "disabled",   NULL },
+         { NULL, NULL },
+      },
+      "disabled"
+   },
    { NULL, NULL, NULL, {{0}}, NULL },
 };