Fix input sensing with SDL2

src/input/input_manager.cpp

@@ -133,6 +133,8 @@ void InputManager::update(float dt)
             case SDL_JOYAXISMOTION:
             {
                 auto& controller = m_sdl_controller.at(event.jaxis.which);
+                if (m_mode == INPUT_SENSE_GAMEPAD)
+                    controller->handleAxisInputSense(event);
                 if (controller->handleAxis(event))
                     input(controller->getEvent());
                 break;

src/input/input_manager.hpp

@@ -71,9 +71,6 @@ private:
     */
     int m_mouse_val_x, m_mouse_val_y;
 
-    void   dispatchInput(Input::InputType, int deviceID, int btnID,
-                         Input::AxisDirection direction, int value,
-                         bool shift_mask = false);
     void   handleStaticAction(int id0, int value);
     void   inputSensing(Input::InputType type, int deviceID, int btnID,
                         Input::AxisDirection axisDirection,  int value);
@@ -117,6 +114,10 @@ public:
      *  re-plugging later with the same ID. */
     size_t getGamepadCount() const { return m_sdl_controller.size(); }
 #endif
+
+    void   dispatchInput(Input::InputType, int deviceID, int btnID,
+                         Input::AxisDirection direction, int value,
+                         bool shift_mask = false);
 };
 
 extern InputManager *input_manager;

src/input/sdl_controller.cpp

@@ -33,6 +33,8 @@ SDLController::SDLController(int device_id)
 {
     m_irr_event = {};
     m_irr_event.EventType = irr::EET_JOYSTICK_INPUT_EVENT;
+    memset(m_prev_axes, 0,
+        irr::SEvent::SJoystickEvent::NUMBER_OF_AXES * sizeof(int16_t));
     m_game_controller = NULL;
     m_joystick = NULL;
     m_id = -1;
@@ -128,6 +130,9 @@ SDLController::SDLController(int device_id)
         m_hats = 0;
     else
         m_buttons += m_hats * 4;
+    // Save previous axes values for input sensing
+    for (int i = 0; i < m_axes; i++)
+        m_prev_axes[i] = SDL_JoystickGetAxis(m_joystick, i);
 
     DeviceManager* dm = input_manager->getDeviceManager();
     GamepadConfig* cfg = NULL;
@@ -177,4 +182,19 @@ SDLController::~SDLController()
     m_gamepad->setConnected(false);
 }   // ~SDLController
 
+// ----------------------------------------------------------------------------
+/** SDL only sends event when axis moves, so we need to send previously saved
+ *  event for correct input sensing. */
+void SDLController::handleAxisInputSense(const SDL_Event& event)
+{
+    int axis_idx = event.jaxis.axis;
+    if (axis_idx > m_axes)
+        return;
+    if (event.jaxis.value == m_prev_axes[axis_idx])
+        return;
+    input_manager->dispatchInput(Input::IT_STICKMOTION,
+        m_irr_event.JoystickEvent.Joystick, axis_idx, Input::AD_NEUTRAL,
+        m_prev_axes[axis_idx]);
+}   // handleAxisInputSense
+
 #endif

src/input/sdl_controller.hpp

@@ -44,6 +44,8 @@ private:
     SDL_JoystickID m_id;
 
     irr::SEvent m_irr_event;
+
+    int16_t m_prev_axes[irr::SEvent::SJoystickEvent::NUMBER_OF_AXES];
 public:
     // ------------------------------------------------------------------------
     SDLController(int device_id);
@@ -54,12 +56,16 @@ public:
     // ------------------------------------------------------------------------
     SDL_JoystickID getInstanceID() const                       { return m_id; }
     // ------------------------------------------------------------------------
+    void handleAxisInputSense(const SDL_Event& event);
+    // ------------------------------------------------------------------------
     bool handleAxis(const SDL_Event& event)
     {
-        if (event.jaxis.axis > m_axes)
+        int axis_idx = event.jaxis.axis;
+        if (axis_idx > m_axes)
             return false;
-        m_irr_event.JoystickEvent.Axis[event.jaxis.axis] = event.jaxis.value;
+        m_irr_event.JoystickEvent.Axis[axis_idx] = event.jaxis.value;
-        uint32_t value = 1 << event.jaxis.axis;
+        m_prev_axes[axis_idx] = event.jaxis.value;
+        uint32_t value = 1 << axis_idx;
         m_irr_event.JoystickEvent.AxisChanged = value;
         return true;
     }   // handleAxis