DigitalController: Store button state/transfer state in save states

src/core/digital_controller.cpp

@@ -1,5 +1,6 @@
 #include "digital_controller.h"
 #include "common/assert.h"
+#include "common/state_wrapper.h"
 
 DigitalController::DigitalController() = default;
 
@@ -20,6 +21,21 @@ std::optional<s32> DigitalController::GetButtonCodeByName(std::string_view butto
   return StaticGetButtonCodeByName(button_name);
 }
 
+void DigitalController::Reset()
+{
+  m_transfer_state = TransferState::Idle;
+}
+
+bool DigitalController::DoState(StateWrapper& sw)
+{
+  if (!Controller::DoState(sw))
+    return false;
+
+  sw.Do(&m_button_state);
+  sw.Do(&m_transfer_state);
+  return true;
+}
+
 void DigitalController::SetAxisState(s32 axis_code, float value) {}
 
 void DigitalController::SetButtonState(Button button, bool pressed)

src/core/digital_controller.h

@@ -42,6 +42,9 @@ public:
   std::optional<s32> GetAxisCodeByName(std::string_view axis_name) const override;
   std::optional<s32> GetButtonCodeByName(std::string_view button_name) const override;
 
+  void Reset() override;
+  bool DoState(StateWrapper& sw) override;
+
   void SetAxisState(s32 axis_code, float value) override;
   void SetButtonState(s32 button_code, bool pressed) override;
 

src/core/save_state_version.h

@@ -2,7 +2,7 @@
 #include "types.h"
 
 static constexpr u32 SAVE_STATE_MAGIC = 0x43435544;
-static constexpr u32 SAVE_STATE_VERSION = 26;
+static constexpr u32 SAVE_STATE_VERSION = 27;
 
 #pragma pack(push, 4)
 struct SAVE_STATE_HEADER