Merge pull request #11363 from TheConfuZzledDude/xinput2-scroll-axis

InputCommon/XInput2: Added an axis output for the scroll wheel

2 files changed, 80 insertions, 31 deletions

diff --git a/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.cpp b/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.cpp
index 0c5f5ffb01..c0594b6662 100644
--- a/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.cpp
+++ b/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.cpp
@@ -49,6 +49,13 @@
 // more responsive. This might be useful as a user-customizable option.
 #define MOUSE_AXIS_SMOOTHING 1.5f
 
+// The scroll axis value should decay a lot faster than the mouse axes since
+// it should ideally register each click of the scroll wheel. Decreasing this
+// value makes it more likely that a scroll wheel input is registered, but less
+// likely to differentiate between different inputs, while increasing it will
+// more cleanly separate each scroll wheel click, but risks dropping some inputs
+#define SCROLL_AXIS_DECAY 1.1f
+
 namespace ciface::XInput2
 {
 // This function will add zero or more KeyboardMouse objects to devices.
@@ -74,6 +81,7 @@ void PopulateDevices(void* const hwnd)
 
   XIDeviceInfo* all_masters;
   XIDeviceInfo* current_master;
+  double scroll_increment = 1.0f;
   int num_masters;
 
   all_masters = XIQueryDevice(dpy, XIAllMasterDevices, &num_masters);
@@ -81,12 +89,26 @@ void PopulateDevices(void* const hwnd)
   for (int i = 0; i < num_masters; i++)
   {
     current_master = &all_masters[i];
+
     if (current_master->use == XIMasterPointer)
     {
+      // We need to query the master for the scroll wheel's increment, since the increment used
+      // varies depending on what input driver is being used. For example, xf86-libinput uses 120.0.
+      for (int j = 0; j < current_master->num_classes; j++)
+      {
+        if (current_master->classes[j]->type == XIScrollClass)
+        {
+          XIScrollClassInfo* scroll_event =
+              reinterpret_cast<XIScrollClassInfo*>(current_master->classes[j]);
+          scroll_increment = scroll_event->increment;
+          break;
+        }
+      }
       // Since current_master is a master pointer, its attachment must
       // be a master keyboard.
-      g_controller_interface.AddDevice(std::make_shared<KeyboardMouse>(
-          (Window)hwnd, xi_opcode, current_master->deviceid, current_master->attachment));
+      g_controller_interface.AddDevice(
+          std::make_shared<KeyboardMouse>((Window)hwnd, xi_opcode, current_master->deviceid,
+                                          current_master->attachment, scroll_increment));
     }
   }
 
@@ -128,8 +150,10 @@ void KeyboardMouse::SelectEventsForDevice(XIEventMask* mask, int deviceid)
   XIFreeDeviceInfo(all_slaves);
 }
 
-KeyboardMouse::KeyboardMouse(Window window, int opcode, int pointer, int keyboard)
-    : m_window(window), xi_opcode(opcode), pointer_deviceid(pointer), keyboard_deviceid(keyboard)
+KeyboardMouse::KeyboardMouse(Window window, int opcode, int pointer, int keyboard,
+                             double scroll_increment)
+    : m_window(window), xi_opcode(opcode), pointer_deviceid(pointer), keyboard_deviceid(keyboard),
+      scroll_increment(scroll_increment)
 {
   // The cool thing about each KeyboardMouse object having its own Display
   // is that each one gets its own separate copy of the X11 event stream,
@@ -195,14 +219,21 @@ KeyboardMouse::KeyboardMouse(Window window, int opcode, int pointer, int keyboar
   for (int i = 0; i != 4; ++i)
     AddInput(new Cursor(!!(i & 2), !!(i & 1), (i & 2) ? &m_state.cursor.y : &m_state.cursor.x));
 
-  // Mouse Axis, X-/+ and Y-/+
-  for (int i = 0; i != 4; ++i)
-    AddInput(new Axis(!!(i & 2), !!(i & 1), (i & 2) ? &m_state.axis.y : &m_state.axis.x));
-
-  // Relative Mouse, X-/+ and Y-/+
-  for (int i = 0; i != 4; ++i)
-    AddInput(new RelativeMouse(!!(i & 2), !!(i & 1),
-                               (i & 2) ? &m_state.relative_mouse.y : &m_state.relative_mouse.x));
+  // Mouse Axis, X-/+, Y-/+ and Z-/+
+  AddInput(new Axis(0, false, &m_state.axis.x));
+  AddInput(new Axis(0, true, &m_state.axis.x));
+  AddInput(new Axis(1, false, &m_state.axis.y));
+  AddInput(new Axis(1, true, &m_state.axis.y));
+  AddInput(new Axis(2, false, &m_state.axis.z));
+  AddInput(new Axis(2, true, &m_state.axis.z));
+
+  // Relative Mouse, X-/+, Y-/+ and Z-/+
+  AddInput(new RelativeMouse(0, false, &m_state.relative_mouse.x));
+  AddInput(new RelativeMouse(0, true, &m_state.relative_mouse.x));
+  AddInput(new RelativeMouse(1, false, &m_state.relative_mouse.y));
+  AddInput(new RelativeMouse(1, true, &m_state.relative_mouse.y));
+  AddInput(new RelativeMouse(2, false, &m_state.relative_mouse.z));
+  AddInput(new RelativeMouse(2, true, &m_state.relative_mouse.z));
 }
 
 KeyboardMouse::~KeyboardMouse()
@@ -256,7 +287,7 @@ void KeyboardMouse::UpdateInput()
   XFlush(m_display);
 
   // for the axis controls
-  float delta_x = 0.0f, delta_y = 0.0f;
+  float delta_x = 0.0f, delta_y = 0.0f, delta_z = 0.0f;
   double delta_delta;
   bool mouse_moved = false;
 
@@ -293,26 +324,39 @@ void KeyboardMouse::UpdateInput()
       m_state.keyboard[dev_event->detail / 8] &= ~(1 << (dev_event->detail % 8));
       break;
     case XI_RawMotion:
+    {
       mouse_moved = true;
 
-      // always safe because there is always at least one byte in
-      // raw_event->valuators.mask, and if a bit is set in the mask,
-      // then the value in raw_values is also available.
-      if (XIMaskIsSet(raw_event->valuators.mask, 0))
-      {
-        delta_delta = raw_event->raw_values[0];
-        // test for inf and nan
-        if (delta_delta == delta_delta && 1 + delta_delta != delta_delta)
-          delta_x += delta_delta;
-      }
-      if (XIMaskIsSet(raw_event->valuators.mask, 1))
+      float values[4] = {};
+      size_t value_idx = 0;
+
+      // We only care about the first 4 axes, which should always be available at minimum
+      for (int i = 0; i < 4; ++i)
       {
-        delta_delta = raw_event->raw_values[1];
-        // test for inf and nan
-        if (delta_delta == delta_delta && 1 + delta_delta != delta_delta)
-          delta_y += delta_delta;
+        if (XIMaskIsSet(raw_event->valuators.mask, i))
+        {
+          values[i] = raw_event->raw_values[value_idx++];
+        }
       }
+
+      delta_delta = values[0];
+      // test for inf and nan
+      if (delta_delta == delta_delta && 1 + delta_delta != delta_delta)
+        delta_x += delta_delta;
+
+      delta_delta = values[1];
+      // test for inf and nan
+      if (delta_delta == delta_delta && 1 + delta_delta != delta_delta)
+        delta_y += delta_delta;
+
+      // Scroll wheel input gets scaled to be similar to the mouse axes
+      delta_delta = values[3] * 8.0 / scroll_increment;
+      // test for inf and nan
+      if (delta_delta == delta_delta && 1 + delta_delta != delta_delta)
+        delta_z += delta_delta;
+
       break;
+    }
     case XI_FocusOut:
       // Clear keyboard state on FocusOut as we will not be receiving KeyRelease events.
       m_state.keyboard.fill(0);
@@ -324,6 +368,7 @@ void KeyboardMouse::UpdateInput()
 
   m_state.relative_mouse.x = delta_x;
   m_state.relative_mouse.y = delta_y;
+  m_state.relative_mouse.z = delta_z;
 
   // apply axis smoothing
   m_state.axis.x *= MOUSE_AXIS_SMOOTHING;
@@ -332,6 +377,8 @@ void KeyboardMouse::UpdateInput()
   m_state.axis.y *= MOUSE_AXIS_SMOOTHING;
   m_state.axis.y += delta_y;
   m_state.axis.y /= MOUSE_AXIS_SMOOTHING + 1.0f;
+  m_state.axis.z += delta_z;
+  m_state.axis.z /= SCROLL_AXIS_DECAY;
 
   // Get the absolute position of the mouse pointer
   const bool should_center_mouse =
diff --git a/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.h b/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.h
index b07f6325c7..ff2c787b1d 100644
--- a/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.h
+++ b/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.h
@@ -28,8 +28,8 @@ private:
     std::array<char, 32> keyboard;
     unsigned int buttons;
     Common::Vec2 cursor;
-    Common::Vec2 axis;
-    Common::Vec2 relative_mouse;
+    Common::Vec3 axis;
+    Common::Vec3 relative_mouse;
   };
 
   class Key : public Input
@@ -113,7 +113,8 @@ private:
 public:
   void UpdateInput() override;
 
-  KeyboardMouse(Window window, int opcode, int pointer_deviceid, int keyboard_deviceid);
+  KeyboardMouse(Window window, int opcode, int pointer_deviceid, int keyboard_deviceid,
+                double scroll_increment);
   ~KeyboardMouse();
 
   std::string GetName() const override;
@@ -126,6 +127,7 @@ private:
   const int xi_opcode;
   const int pointer_deviceid;
   const int keyboard_deviceid;
+  const double scroll_increment;
   std::string name;
 };
 }  // namespace ciface::XInput2