Let's try this

src/backend/core/mmio/CMakeLists.txt

@@ -1,8 +1,11 @@
 file(GLOB_RECURSE SOURCES *.cpp)
 file(GLOB_RECURSE HEADERS *.hpp)
 
-find_package(gainput REQUIRED)
+set(GAINPUT_SAMPLES OFF)
+set(GAINPUT_TESTS OFF)
+add_subdirectory(../../../../external/gainput gainput)
 
 add_library(mmio ${SOURCES} ${HEADERS} ../../../../external/cic_nus_6105/n64_cic_nus_6105.cpp)
 
+target_include_directories(mmio PRIVATE ../../../../external/gainput/lib/include)
 target_link_libraries(mmio PRIVATE gainput)

src/backend/core/mmio/PIF.cpp

@@ -27,6 +27,28 @@ void PIF::Reset() {
   }
 
   mempakOpen = false;
+
+  inputManager.SetDisplaySize(640, 480);
+  keyboardId = inputManager.CreateDevice<gainput::InputDeviceKeyboard>();
+
+  inputMap.MapBool(BtnZ, keyboardId, gainput::KeyZ);
+  inputMap.MapBool(BtnA, keyboardId, gainput::KeyX);
+  inputMap.MapBool(BtnB, keyboardId, gainput::KeyC);
+  inputMap.MapBool(BtnL, keyboardId, gainput::KeyA);
+  inputMap.MapBool(BtnR, keyboardId, gainput::KeyS);
+  inputMap.MapBool(BtnStart, keyboardId, gainput::KeyReturn);
+  inputMap.MapBool(BtnDUp, keyboardId, gainput::KeyI);
+  inputMap.MapBool(BtnDDown, keyboardId, gainput::KeyK);
+  inputMap.MapBool(BtnDLeft, keyboardId, gainput::KeyJ);
+  inputMap.MapBool(BtnDRight, keyboardId, gainput::KeyL);
+  inputMap.MapBool(BtnCUp, keyboardId, gainput::KeyKpUp);
+  inputMap.MapBool(BtnCDown, keyboardId, gainput::KeyKpDown);
+  inputMap.MapBool(BtnCLeft, keyboardId, gainput::KeyKpLeft);
+  inputMap.MapBool(BtnCRight, keyboardId, gainput::KeyKpRight);
+  inputMap.MapBool(AxisUp, keyboardId, gainput::KeyUp);
+  inputMap.MapBool(AxisDown, keyboardId, gainput::KeyDown);
+  inputMap.MapBool(AxisLeft, keyboardId, gainput::KeyLeft);
+  inputMap.MapBool(AxisRight, keyboardId, gainput::KeyRight);
 }
 
 void PIF::MaybeLoadMempak() {
@@ -186,7 +208,6 @@ void PIF::ProcessCommands(Mem &mem) {
             channel++;
             break;
           case 1:
-            UpdateController();
             if(!ReadButtons(res)) {
               cmd[1] |= 0x80;
             }
@@ -335,7 +356,22 @@ void PIF::EepromWrite(const u8* cmd, u8* res, const Mem& mem) {
 }
 
 void PIF::UpdateController() {
-  //joybusDevices[channel].controller = value;
+  inputManager.Update();
+  joybusDevices[channel].controller.a = inputMap.GetBool(BtnA);
+  joybusDevices[channel].controller.b = inputMap.GetBool(BtnB);
+  joybusDevices[channel].controller.z = inputMap.GetBool(BtnZ);
+  joybusDevices[channel].controller.l = inputMap.GetBool(BtnL);
+  joybusDevices[channel].controller.r = inputMap.GetBool(BtnR);
+  joybusDevices[channel].controller.dp_up = inputMap.GetBool(BtnDUp);
+  joybusDevices[channel].controller.dp_down = inputMap.GetBool(BtnDDown);
+  joybusDevices[channel].controller.dp_left = inputMap.GetBool(BtnDLeft);
+  joybusDevices[channel].controller.dp_right = inputMap.GetBool(BtnDRight);
+  joybusDevices[channel].controller.c_up = inputMap.GetBool(BtnCUp);
+  joybusDevices[channel].controller.c_down = inputMap.GetBool(BtnCDown);
+  joybusDevices[channel].controller.c_left = inputMap.GetBool(BtnCLeft);
+  joybusDevices[channel].controller.c_right = inputMap.GetBool(BtnCRight);
+  joybusDevices[channel].controller.joy_x = inputMap.GetBool(AxisLeft) ? -127 : inputMap.GetBool(AxisRight) ? 127 : 0;
+  joybusDevices[channel].controller.joy_y = inputMap.GetBool(AxisUp) ? -127 : inputMap.GetBool(AxisDown) ? 127 : 0;
 
   if (joybusDevices[channel].controller.joy_reset) {
     joybusDevices[channel].controller.start = false;

src/backend/core/mmio/PIF.hpp

@@ -1,6 +1,6 @@
 #pragma once
 #include <MemoryRegions.hpp>
-#include <SDL_gamecontroller.h>
+#include <gainput/gainput.h>
 #include <GameDB.hpp>
 #include <filesystem>
 #include <mio/mmap.hpp>
@@ -104,6 +104,16 @@ enum CICType {
   CIC_NUS_6106_7106
 };
 
+enum Button {
+  BtnA, BtnB, BtnZ, BtnL, BtnR, BtnStart,
+  BtnCUp, BtnCDown, BtnCLeft, BtnCRight,
+  BtnDUp, BtnDDown, BtnDLeft, BtnDRight,
+};
+
+enum Axis {
+  AxisLeft, AxisRight, AxisUp, AxisDown
+};
+
 struct PIF {
   PIF() = default;
   ~PIF() = default;
@@ -125,7 +135,9 @@ struct PIF {
   std::vector<u8> Serialize();
 
   bool gamepadConnected = false, mempakOpen = false;
-  SDL_GameController* gamepad{};
+  gainput::InputManager inputManager;
+  gainput::InputMap inputMap{ inputManager };
+  gainput::DeviceId keyboardId, padId;
   JoybusDevice joybusDevices[6]{};
   u8 bootrom[PIF_BOOTROM_SIZE]{}, ram[PIF_RAM_SIZE]{};
   mio::mmap_sink mempak, eeprom;

src/frontend/EmuThread.cpp

@@ -10,6 +10,7 @@ EmuThread::EmuThread(std::unique_ptr<QtInstanceFactory>&& instance, std::unique_
   LoadParallelRDP(core.cpu->mem.GetRDRAM());
   while (true) {
     if (!core.pause) {
+      core.cpu->mem.mmio.si.pif.UpdateController();
       core.Run(0.5, 0.5);
       if(core.render) {
         UpdateScreenParallelRdp(core, core.cpu->mem.mmio.vi);

src/frontend/KaizenQt.cpp

@@ -13,8 +13,6 @@ KaizenQt::KaizenQt() noexcept : QWidget(nullptr) {
     std::move(mainWindow->view.vulkanWidget->windowInfo),
     mainWindow);
 
-  mainWindow->emuThread = emuThread;
-
   ConnectMainWindowSignalsToSlots();
 
   setAcceptDrops(true);

src/frontend/MainWindow.hpp

@@ -12,7 +12,6 @@ public:
   MainWindowController() noexcept;
 
   Ui::MainWindow view;
-  EmuThread* emuThread = nullptr;
 private:
   void ConnectSignalsToSlots() noexcept;