evdev: Provide the relative pointer motion event deltas

Compositors need more detailed information about motion events. Make it
possible to retrieve this information when running the evdev backend by
adding the information to the backend specific event struct.

https://bugzilla.gnome.org/show_bug.cgi?id=752752

clutter/evdev/clutter-device-manager-evdev.c

@@ -403,11 +403,11 @@ keyboard_repeat (gpointer data)
   return G_SOURCE_CONTINUE;
 }
 
-static void
+static ClutterEvent *
-notify_absolute_motion (ClutterInputDevice *input_device,
+new_absolute_motion_event (ClutterInputDevice *input_device,
-			guint32             time_,
+                           guint32             time_,
-			gfloat              x,
+                           gfloat              x,
-			gfloat              y)
+                           gfloat              y)
 {
   gfloat stage_width, stage_height;
   ClutterDeviceManagerEvdev *manager_evdev;
@@ -452,18 +452,35 @@ notify_absolute_motion (ClutterInputDevice *input_device,
   seat->pointer_x = x;
   seat->pointer_y = y;
 
+  return event;
+}
+
+static void
+notify_absolute_motion (ClutterInputDevice *input_device,
+			guint32             time_,
+			gfloat              x,
+			gfloat              y)
+{
+  ClutterEvent *event;
+
+  event = new_absolute_motion_event (input_device, time_, x, y);
+
   queue_event (event);
 }
 
 static void
 notify_relative_motion (ClutterInputDevice *input_device,
-                        guint32             time_,
+                        struct libinput_event_pointer *pointer_event)
-                        double              dx,
-                        double              dy)
 {
+  guint time;
+  double dx;
+  double dy;
+  double dx_unaccel;
+  double dy_unaccel;
   gfloat new_x, new_y;
   ClutterInputDeviceEvdev *device_evdev;
   ClutterSeatEvdev *seat;
+  ClutterEvent *event;
 
   /* We can drop the event on the floor if no stage has been
    * associated with the device yet. */
@@ -473,10 +490,21 @@ notify_relative_motion (ClutterInputDevice *input_device,
   device_evdev = CLUTTER_INPUT_DEVICE_EVDEV (input_device);
   seat = _clutter_input_device_evdev_get_seat (device_evdev);
 
+  dx = libinput_event_pointer_get_dx (pointer_event);
+  dy = libinput_event_pointer_get_dy (pointer_event);
   new_x = seat->pointer_x + dx;
   new_y = seat->pointer_y + dy;
 
-  notify_absolute_motion (input_device, time_, new_x, new_y);
+  time = libinput_event_pointer_get_time (pointer_event);
+  event = new_absolute_motion_event (input_device, time, new_x, new_y);
+
+  dx_unaccel = libinput_event_pointer_get_dx_unaccelerated (pointer_event);
+  dy_unaccel = libinput_event_pointer_get_dy_unaccelerated (pointer_event);
+  _clutter_evdev_event_set_relative_motion (event,
+                                            dx, dy,
+                                            dx_unaccel, dy_unaccel);
+
+  queue_event (event);
 }
 
 static ClutterScrollDirection
@@ -1407,16 +1435,11 @@ process_device_event (ClutterDeviceManagerEvdev *manager_evdev,
 
     case LIBINPUT_EVENT_POINTER_MOTION:
       {
-        guint32 time;
-        double dx, dy;
         struct libinput_event_pointer *motion_event =
           libinput_event_get_pointer_event (event);
         device = libinput_device_get_user_data (libinput_device);
 
-        time = libinput_event_pointer_get_time (motion_event);
+        notify_relative_motion (device, motion_event);
-        dx = libinput_event_pointer_get_dx (motion_event);
-        dy = libinput_event_pointer_get_dy (motion_event);
-        notify_relative_motion (device, time, dx, dy);
 
         break;
       }

clutter/evdev/clutter-evdev.h

@@ -134,6 +134,13 @@ void clutter_evdev_warp_pointer (ClutterInputDevice   *pointer_device,
 CLUTTER_AVAILABLE_IN_1_26
 guint32 clutter_evdev_event_get_event_code (const ClutterEvent *event);
 
+CLUTTER_AVAILABLE_IN_1_26
+gboolean clutter_evdev_event_get_relative_motion (const ClutterEvent *event,
+                                                  double             *dx,
+                                                  double             *dy,
+                                                  double             *dx_unaccel,
+                                                  double             *dy_unaccel);
+
 G_END_DECLS
 
 #endif /* __CLUTTER_EVDEV_H__ */

clutter/evdev/clutter-event-evdev.c

@@ -32,6 +32,12 @@ typedef struct _ClutterEventEvdev ClutterEventEvdev;
 struct _ClutterEventEvdev
 {
   guint32 evcode;
+
+  gboolean has_relative_motion;
+  double dx;
+  double dy;
+  double dx_unaccel;
+  double dy_unaccel;
 };
 
 static ClutterEventEvdev *
@@ -80,6 +86,23 @@ _clutter_evdev_event_set_event_code (ClutterEvent *event,
   event_evdev->evcode = evcode;
 }
 
+void
+_clutter_evdev_event_set_relative_motion (ClutterEvent *event,
+                                          double        dx,
+                                          double        dy,
+                                          double        dx_unaccel,
+                                          double        dy_unaccel)
+{
+  ClutterEventEvdev *event_evdev;
+
+  event_evdev = clutter_evdev_event_ensure_platform_data (event);
+  event_evdev->dx = dx;
+  event_evdev->dy = dy;
+  event_evdev->dx_unaccel = dx_unaccel;
+  event_evdev->dy_unaccel = dy_unaccel;
+  event_evdev->has_relative_motion = TRUE;
+}
+
 /**
  * clutter_evdev_event_get_event_code:
  * @event: a #ClutterEvent
@@ -99,3 +122,39 @@ clutter_evdev_event_get_event_code (const ClutterEvent *event)
 
   return 0;
 }
+
+/**
+ * clutter_evdev_event_get_pointer_motion
+ * @event: a #ClutterEvent
+ *
+ * If available, the normal and unaccelerated motion deltas are written
+ * to the dx, dy, dx_unaccel and dy_unaccel and TRUE is returned.
+ *
+ * If unavailable, FALSE is returned.
+ *
+ * Returns: TRUE on success, otherwise FALSE.
+ **/
+gboolean
+clutter_evdev_event_get_relative_motion (const ClutterEvent *event,
+                                         double             *dx,
+                                         double             *dy,
+                                         double             *dx_unaccel,
+                                         double             *dy_unaccel)
+{
+  ClutterEventEvdev *event_evdev = _clutter_event_get_platform_data (event);
+
+  if (event_evdev && event_evdev->has_relative_motion)
+    {
+      if (dx)
+        *dx = event_evdev->dx;
+      if (dy)
+        *dy = event_evdev->dy;
+      if (dx_unaccel)
+        *dx_unaccel = event_evdev->dx_unaccel;
+      if (dy_unaccel)
+        *dy_unaccel = event_evdev->dy_unaccel;
+      return TRUE;
+    }
+  else
+    return FALSE;
+}

clutter/evdev/clutter-input-device-evdev.h

@@ -91,6 +91,12 @@ void                      _clutter_event_evdev_free                   (ClutterEv
 void                      _clutter_evdev_event_set_event_code         (ClutterEvent      *event,
                                                                        guint32            evcode);
 
+void  			  _clutter_evdev_event_set_relative_motion (ClutterEvent *event,
+								    double        dx,
+								    double        dy,
+								    double        dx_unaccel,
+								    double        dy_unaccel);
+
 G_END_DECLS
 
 #endif /* __CLUTTER_INPUT_DEVICE_EVDEV_H__ */