persist chosen audio device in config file #353

Write `gopts.audio_dev` to the option `Sound/AudioDevice`.

Clear `gopts.audio_dev` when resetting the driver, because we cannot
assume anything about device enumeration order across sound drivers.

Signed-off-by: Rafael Kitover <rkitover@gmail.com>

src/wx/guiinit.cpp

@@ -1571,6 +1571,7 @@ static class SoundConfig_t : public wxEvtHandler {
         if (newapi == lastapi)
             return;
 
+        gopts.audio_dev = "";
         FillDev(newapi);
     }
 } sound_config_handler;

src/wx/opts.cpp

@@ -261,6 +261,7 @@ opt_desc opts[] = {
 /// Sound
 
     ENUMOPT("Sound/AudioAPI", "", wxTRANSLATE("Sound API; if unsupported, default API will be used"), gopts.audio_api, wxTRANSLATE("sdl|openal|directsound|xaudio2|faudio")),
+    STROPT("Sound/AudioDevice", "", wxTRANSLATE("Device ID of chosen audio device for chosen driver"), gopts.audio_dev),
     INTOPT("Sound/Buffers", "", wxTRANSLATE("Number of sound buffers"), gopts.audio_buffers, 2, 10),
     INTOPT("Sound/Enable", "", wxTRANSLATE("Bit mask of sound channels to enable"), gopts.sound_en, 0, 0x30f),
     INTOPT("Sound/GBAFiltering", "", wxTRANSLATE("GBA sound filtering (%)"), gopts.gba_sound_filter, 0, 100),