Fix #588. Crash when changing default audio device (#668)

Due to SDL not allowing population of the available devices until the audio system is loaded the audio tries to set the device to a nullptr. Instead we load the default audio device and then immediately close it. This allows SDL to load correctly

CHANGELOG.md

@@ -2,6 +2,7 @@
 ------------------------------------------------------------------------
 - Feature: [#569] Option/cheat to disable AI companies entirely.
 - Fix: [#573] Crash caused by opening Road construction window.
+- Fix: [#588] Crash caused by changing default audio device.
 - Fix: [#595] Implementation mistake in CreateVehicle could lead to crashes.
 - Fix: [#635] Land tool not working properly, due to tool drag events not passing on coordinates.
 - Fix: [#648] Fix crash in vehicle update head caused by CreateVehicle.

src/OpenLoco/Audio/Audio.cpp

@@ -288,6 +288,21 @@ namespace OpenLoco::Audio
     // 0x00404E53
     void initialiseDSound()
     {
+        if (_devices.empty())
+        {
+            // If devices is empty we need to load the default audio device to initliase the audio system
+            // this will then allow populating the devices
+            auto& format = _outputFormat;
+            format.frequency = MIX_DEFAULT_FREQUENCY;
+            format.format = MIX_DEFAULT_FORMAT;
+            format.channels = MIX_DEFAULT_CHANNELS;
+            if (Mix_OpenAudioDevice(format.frequency, format.format, format.channels, 1024, nullptr, 0) != 0)
+            {
+                Console::error("Mix_OpenAudio failed: %s", Mix_GetError());
+                return;
+            }
+            Mix_CloseAudio();
+        }
         const char* deviceName = nullptr;
         const auto& cfg = Config::getNew();
         if (!cfg.audio.device.empty())
@@ -349,7 +364,11 @@ namespace OpenLoco::Audio
     {
         _devices.clear();
 #ifdef __HAS_DEFAULT_DEVICE__
-        _devices.push_back(getDefaultDeviceName());
+        auto defaultDevice = getDefaultDeviceName();
+        if (defaultDevice != nullptr)
+        {
+            _devices.push_back(getDefaultDeviceName());
+        }
 #endif
         auto count = SDL_GetNumAudioDevices(0);
         for (auto i = 0; i < count; i++)