InputCommon / DolphinQt / Core: Add a "RelativeMouse" input which provides the raw delta mouse input

Co-authored-by: Jordan Woyak <jordan.woyak@gmail.com>

2 files changed, 36 insertions, 0 deletions

diff --git a/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.cpp b/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.cpp
index a60edc3282..996673becb 100644
--- a/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.cpp
+++ b/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.cpp
@@ -197,6 +197,11 @@ KeyboardMouse::KeyboardMouse(Window window, int opcode, int pointer, int keyboar
   // 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));
 }
 
 KeyboardMouse::~KeyboardMouse()
@@ -302,6 +307,9 @@ void KeyboardMouse::UpdateInput()
     XFreeEventData(m_display, &event.xcookie);
   }
 
+  m_state.relative_mouse.x = delta_x;
+  m_state.relative_mouse.y = delta_y;
+
   // apply axis smoothing
   m_state.axis.x *= MOUSE_AXIS_SMOOTHING;
   m_state.axis.x += delta_x;
@@ -391,8 +399,20 @@ KeyboardMouse::Axis::Axis(u8 index, bool positive, const float* axis)
   name = fmt::format("Axis {}{}", static_cast<char>('X' + m_index), (m_positive ? '+' : '-'));
 }
 
+KeyboardMouse::RelativeMouse::RelativeMouse(u8 index, bool positive, const float* axis)
+    : m_axis(axis), m_index(index), m_positive(positive)
+{
+  name =
+      fmt::format("RelativeMouse {}{}", static_cast<char>('X' + m_index), (m_positive ? '+' : '-'));
+}
+
 ControlState KeyboardMouse::Axis::GetState() const
 {
   return std::max(0.0f, *m_axis / (m_positive ? MOUSE_AXIS_SENSITIVITY : -MOUSE_AXIS_SENSITIVITY));
 }
+
+ControlState KeyboardMouse::RelativeMouse::GetState() const
+{
+  return std::max(0.0f, *m_axis / (m_positive ? MOUSE_AXIS_SENSITIVITY : -MOUSE_AXIS_SENSITIVITY));
+}
 }  // namespace ciface::XInput2
diff --git a/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.h b/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.h
index a9442b6332..71681a3e10 100644
--- a/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.h
+++ b/Source/Core/InputCommon/ControllerInterface/Xlib/XInput2.h
@@ -30,6 +30,7 @@ private:
     unsigned int buttons;
     Common::Vec2 cursor;
     Common::Vec2 axis;
+    Common::Vec2 relative_mouse;
   };
 
   class Key : public Input
@@ -91,6 +92,21 @@ private:
     std::string name;
   };
 
+  class RelativeMouse : public Input
+  {
+  public:
+    std::string GetName() const override { return name; }
+    bool IsDetectable() const override { return false; }
+    RelativeMouse(u8 index, bool positive, const float* axis);
+    ControlState GetState() const override;
+
+  private:
+    const float* m_axis;
+    const u8 m_index;
+    const bool m_positive;
+    std::string name;
+  };
+
 private:
   void SelectEventsForDevice(XIEventMask* mask, int deviceid);
   void UpdateCursor();