libretro: Add rumble interface

src/duckstation-libretro/libretro_host_interface.cpp

@@ -63,6 +63,14 @@ LibretroHostInterface::~LibretroHostInterface()
   }
 }
 
+void LibretroHostInterface::InitInterfaces()
+{
+  SetCoreOptions();
+  InitLogging();
+  InitDiskControlInterface();
+  InitRumbleInterface();
+}
+
 void LibretroHostInterface::InitLogging()
 {
   if (s_libretro_log_callback_registered)
@@ -650,6 +658,11 @@ void LibretroHostInterface::CheckForSettingsChanges(const Settings& old_settings
     UpdateLogging();
 }
 
+void LibretroHostInterface::InitRumbleInterface()
+{
+  m_rumble_interface_valid = g_retro_environment_callback(RETRO_ENVIRONMENT_GET_RUMBLE_INTERFACE, &m_rumble_interface);
+}
+
 void LibretroHostInterface::UpdateControllers()
 {
   g_retro_input_poll_callback();
@@ -745,6 +758,17 @@ void LibretroHostInterface::UpdateControllersAnalogController(u32 index)
     const int16_t state = g_retro_input_state_callback(index, RETRO_DEVICE_ANALOG, it.second.first, it.second.second);
     controller->SetAxisState(static_cast<s32>(it.first), std::clamp(static_cast<float>(state) / 32767.0f, -1.0f, 1.0f));
   }
+
+  if (m_rumble_interface_valid)
+  {
+    const u32 motor_count = controller->GetVibrationMotorCount();
+    for (u32 i = 0; i < motor_count; i++)
+    {
+      const float strength = controller->GetVibrationMotorStrength(i);
+      m_rumble_interface.set_rumble_state(index, RETRO_RUMBLE_STRONG,
+                                          static_cast<u16>(static_cast<u32>(strength * 65565.0f)));
+    }
+  }
 }
 
 static std::optional<GPURenderer> RetroHwContextToRenderer(retro_hw_context_type type)

src/duckstation-libretro/libretro_host_interface.h

@@ -11,10 +11,7 @@ public:
   LibretroHostInterface();
   ~LibretroHostInterface() override;
 
-  static void InitLogging();
-  static bool SetCoreOptions();
-  static bool HasCoreVariablesChanged();
-  static void InitDiskControlInterface();
+  void InitInterfaces();
 
   ALWAYS_INLINE u32 GetResolutionScale() const { return g_settings.gpu_resolution_scale; }
 
@@ -51,6 +48,12 @@ protected:
   void CheckForSettingsChanges(const Settings& old_settings) override;
 
 private:
+  bool SetCoreOptions();
+  bool HasCoreVariablesChanged();
+  void InitLogging();
+  void InitDiskControlInterface();
+  void InitRumbleInterface();
+
   void LoadSettings();
   void UpdateSettings();
   void UpdateControllers();
@@ -86,6 +89,9 @@ private:
   bool m_hw_render_callback_valid = false;
   bool m_using_hardware_renderer = false;
   std::optional<u32> m_next_disc_index;
+
+  retro_rumble_interface m_rumble_interface = {};
+  bool m_rumble_interface_valid = false;
 };
 
 extern LibretroHostInterface g_libretro_host_interface;

src/duckstation-libretro/main.cpp

@@ -122,12 +122,7 @@ RETRO_API size_t retro_get_memory_size(unsigned id)
 RETRO_API void retro_set_environment(retro_environment_t f)
 {
   g_retro_environment_callback = f;
-
-  if (!g_libretro_host_interface.SetCoreOptions())
-    Log_WarningPrintf("Failed to set core options, settings will not be changeable.");
-
-  g_libretro_host_interface.InitLogging();
-  g_libretro_host_interface.InitDiskControlInterface();
+  g_libretro_host_interface.InitInterfaces();
 }
 
 RETRO_API void retro_set_video_refresh(retro_video_refresh_t f)