Android: Add controller interface class

android/app/src/cpp/android_controller_interface.h

@@ -0,0 +1,67 @@
+#pragma once
+#include "frontend-common/controller_interface.h"
+#include "core/types.h"
+#include <array>
+#include <functional>
+#include <mutex>
+#include <vector>
+
+class AndroidControllerInterface final : public ControllerInterface
+{
+public:
+  AndroidControllerInterface();
+  ~AndroidControllerInterface() 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, AxisSide axis_side, 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;
+  bool BindControllerHatToButton(int controller_index, int hat_number, std::string_view hat_position,
+                                 ButtonCallback callback) override;
+  bool BindControllerButtonToAxis(int controller_index, int button_number, AxisCallback callback) override;
+
+  // Changing rumble strength.
+  u32 GetControllerRumbleMotorCount(int controller_index) override;
+  void SetControllerRumbleStrength(int controller_index, const float* strengths, u32 num_motors) 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;
+
+  bool HandleAxisEvent(u32 index, u32 axis, float value);
+  bool HandleButtonEvent(u32 index, u32 button, bool pressed);
+
+private:
+  enum : u32
+  {
+    NUM_CONTROLLERS = 1,
+    NUM_AXISES = 10,
+    NUM_BUTTONS = 18
+  };
+
+  struct ControllerData
+  {
+    float deadzone = 0.25f;
+
+    std::array<std::array<AxisCallback, 3>, NUM_AXISES> axis_mapping;
+    std::array<ButtonCallback, NUM_BUTTONS> button_mapping;
+    std::array<std::array<ButtonCallback, 2>, NUM_AXISES> axis_button_mapping;
+    std::array<AxisCallback, NUM_BUTTONS> button_axis_mapping;
+  };
+
+  using ControllerDataArray = std::array<ControllerData, NUM_CONTROLLERS>;
+
+  ControllerDataArray m_controllers;
+
+  std::mutex m_event_intercept_mutex;
+  Hook::Callback m_event_intercept_callback;
+};