ControllerInterface: Add XInput controller backend

src/frontend-common/xinput_controller_interface.h

@@ -0,0 +1,89 @@
+#pragma once
+#include "common/windows_headers.h"
+#include "controller_interface.h"
+#include "core/types.h"
+#include <Xinput.h>
+#include <array>
+#include <functional>
+#include <mutex>
+#include <vector>
+
+class XInputControllerInterface final : public ControllerInterface
+{
+public:
+  XInputControllerInterface();
+  ~XInputControllerInterface() override;
+
+  Backend GetBackend() const override;
+  bool Initialize(CommonHostInterface* host_interface) override;
+  void Shutdown() override;
+
+  // Removes all bindings. Call before setting new bindings.
+  void ClearBindings() override;
+
+  // Binding to events. If a binding for this axis/button already exists, returns false.
+  bool BindControllerAxis(int controller_index, int axis_number, AxisCallback callback) override;
+  bool BindControllerButton(int controller_index, int button_number, ButtonCallback callback) override;
+  bool BindControllerAxisToButton(int controller_index, int axis_number, bool direction,
+                                  ButtonCallback callback) override;
+
+  // Changing rumble strength.
+  u32 GetControllerRumbleMotorCount(int controller_index) override;
+  void SetControllerRumbleStrength(int controller_index, const float* strengths, u32 num_motors) override;
+
+  // Set scaling that will be applied on axis-to-axis mappings
+  bool SetControllerAxisScale(int controller_index, float scale = 1.00f) override;
+
+  // Set deadzone that will be applied on axis-to-button mappings
+  bool SetControllerDeadzone(int controller_index, float size = 0.25f) override;
+
+  void PollEvents() override;
+
+private:
+  enum : u32
+  {
+    NUM_AXISES = 6,
+    NUM_BUTTONS = 15,
+    NUM_RUMBLE_MOTORS = 2
+  };
+  enum class Axis : u32
+  {
+    LeftX,
+    LeftY,
+    RightX,
+    RightY,
+    LeftTrigger,
+    RightTrigger
+  };
+
+  struct ControllerData
+  {
+    XINPUT_STATE last_state = {};
+    bool connected = false;
+    bool supports_rumble = false;
+
+    // Scaling value of 1.30f to 1.40f recommended when using recent controllers
+    float axis_scale = 1.00f;
+    float deadzone = 0.25f;
+
+    std::array<AxisCallback, MAX_NUM_AXISES> axis_mapping;
+    std::array<ButtonCallback, MAX_NUM_BUTTONS> button_mapping;
+    std::array<std::array<ButtonCallback, 2>, MAX_NUM_AXISES> axis_button_mapping;
+  };
+
+  using ControllerDataArray = std::array<ControllerData, XUSER_MAX_COUNT>;
+
+  void CheckForStateChanges(u32 index, const XINPUT_STATE& new_state);
+  void UpdateCapabilities(u32 index);
+  bool HandleAxisEvent(u32 index, Axis axis, s32 value);
+  bool HandleButtonEvent(u32 index, u32 button, bool pressed);
+
+  ControllerDataArray m_controllers;
+
+  HMODULE m_xinput_module{};
+  DWORD(WINAPI* m_xinput_get_state)(DWORD, XINPUT_STATE*);
+  DWORD(WINAPI* m_xinput_get_capabilities)(DWORD, DWORD, XINPUT_CAPABILITIES*);
+  DWORD(WINAPI* m_xinput_set_state)(DWORD, XINPUT_VIBRATION*);
+  std::mutex m_event_intercept_mutex;
+  Hook::Callback m_event_intercept_callback;
+};