[gtk+/wip/wayland-tablet: 21/23] Wayland: Translate tilt/pressure/distance axes in motion events

[Carlos Garnacho <carlosg src gnome org>]

commit fbf60d1efd7fd18567b74e95318c987021ace518
Author: Stephen Chandler Paul <thatslyude gmail com>
Date:   Mon Jun 22 18:02:50 2015 +0200

    Wayland: Translate tilt/pressure/distance axes in motion events
    
    On wayland, such axes are per-tool, we must update device capabilities
    on the fly as new tools enter proximity, first the slave device so
    it matches the current tool, and then the master device so it looks
    the same than the current slave device.

 gdk/wayland/gdkdevice-wayland.c |  140 ++++++++++++++++++++++++++++++++++++++-
 1 files changed, 137 insertions(+), 3 deletions(-)
---
diff --git a/gdk/wayland/gdkdevice-wayland.c b/gdk/wayland/gdkdevice-wayland.c
index 68443c6..cb71f4d 100644
--- a/gdk/wayland/gdkdevice-wayland.c
+++ b/gdk/wayland/gdkdevice-wayland.c
@@ -83,6 +83,12 @@ struct _GdkWaylandDeviceTabletPair
 
   GdkWaylandDeviceData *wd;
   GdkWaylandPointerData pointer_info;
+
+  gint pressure_axis_index;
+  gint xtilt_axis_index;
+  gint ytilt_axis_index;
+  gint distance_axis_index;
+  gdouble *axes;
 };
 
 struct _GdkWaylandDeviceData
@@ -1684,11 +1690,83 @@ _gdk_wayland_device_manager_remove_tablet (GdkWaylandDeviceTabletPair *device_pa
   g_object_unref (device_pair->eraser_device);
   g_free (device_pair);
 
+  if (device_pair->axes)
+    g_free (device_pair->axes);
+
   device_manager->tablet_pairs =
     g_list_remove (device_manager->tablet_pairs, device_pair);
 }
 
 static void
+gdk_wayland_device_tablet_clone_tool_axes (GdkWaylandDeviceTabletPair *tablet,
+                                           GdkDeviceTool              *tool)
+{
+  gint axis_pos;
+
+  g_object_freeze_notify (G_OBJECT (tablet->current_device));
+  _gdk_device_reset_axes (tablet->current_device);
+
+  _gdk_device_add_axis (tablet->current_device, GDK_NONE, GDK_AXIS_X, 0, 0, 0);
+  _gdk_device_add_axis (tablet->current_device, GDK_NONE, GDK_AXIS_Y, 0, 0, 0);
+
+  if (tool->tool_axes & (GDK_AXIS_FLAG_XTILT | GDK_AXIS_FLAG_YTILT))
+    {
+      axis_pos = _gdk_device_add_axis (tablet->current_device, GDK_NONE,
+                                       GDK_AXIS_XTILT, -65535, 65535, 0);
+      tablet->xtilt_axis_index = axis_pos;
+
+      axis_pos = _gdk_device_add_axis (tablet->current_device, GDK_NONE,
+                                       GDK_AXIS_YTILT, -65535, 65535, 0);
+      tablet->ytilt_axis_index = axis_pos;
+    }
+  if (tool->tool_axes & GDK_AXIS_FLAG_DISTANCE)
+    {
+      axis_pos = _gdk_device_add_axis (tablet->current_device, GDK_NONE,
+                                       GDK_AXIS_DISTANCE, 0, 65535, 0);
+      tablet->distance_axis_index = axis_pos;
+    }
+  if (tool->tool_axes & GDK_AXIS_FLAG_PRESSURE)
+    {
+      axis_pos = _gdk_device_add_axis (tablet->current_device, GDK_NONE,
+                                       GDK_AXIS_PRESSURE, 0, 65535, 0);
+      tablet->pressure_axis_index = axis_pos;
+    }
+
+  if (tablet->axes)
+    g_free(tablet->axes);
+
+  tablet->axes =
+    g_new0 (gdouble, gdk_device_get_n_axes (tablet->current_device));
+
+  g_object_thaw_notify (G_OBJECT (tablet->current_device));
+}
+
+static void
+gdk_wayland_mimic_device_axes (GdkDevice *master,
+                               GdkDevice *slave)
+{
+  gdouble axis_min, axis_max, axis_resolution;
+  GdkAtom axis_label;
+  GdkAxisUse axis_use;
+  gint axis_count;
+  gint i;
+
+  g_object_freeze_notify (G_OBJECT (master));
+  _gdk_device_reset_axes (master);
+  axis_count = gdk_device_get_n_axes (slave);
+
+  for (i = 0; i < axis_count; i++)
+    {
+      _gdk_device_get_axis_info (slave, i, &axis_label, &axis_use, &axis_min,
+                                 &axis_max, &axis_resolution);
+      _gdk_device_add_axis (master, axis_label, axis_use, axis_min,
+                            axis_max, axis_resolution);
+    }
+
+  g_object_thaw_notify (G_OBJECT (master));
+}
+
+static void
 tablet_handle_proximity_in (void                  *data,
                             struct wl_tablet      *wl_tablet,
                             uint32_t               serial,
@@ -1722,6 +1800,8 @@ tablet_handle_proximity_in (void                  *data,
     gdk_device_add_tool (device_pair->current_device, tool);
 
   gdk_device_update_tool (device_pair->current_device, tool);
+  gdk_wayland_device_tablet_clone_tool_axes (device_pair, tool);
+  gdk_wayland_mimic_device_axes (device_pair->master, device_pair->current_device);
 
   event = gdk_event_new (GDK_PROXIMITY_IN);
   event->proximity.type = GDK_PROXIMITY_IN;
@@ -1828,6 +1908,56 @@ tablet_handle_motion (void             *data,
 }
 
 static void
+tablet_handle_pressure (void             *data,
+                        struct wl_tablet *wl_tablet,
+                        uint32_t          time,
+                        wl_fixed_t        pressure)
+{
+  GdkWaylandDeviceTabletPair *device_pair = data;
+  gint axis_index = device_pair->pressure_axis_index;
+
+  device_pair->pointer_info.time = time;
+  _gdk_device_translate_axis (device_pair->current_device, axis_index,
+                              wl_fixed_to_double (pressure),
+                              &device_pair->axes[axis_index]);
+}
+
+static void
+tablet_handle_distance (void             *data,
+                        struct wl_tablet *wl_tablet,
+                        uint32_t          time,
+                        wl_fixed_t        distance)
+{
+  GdkWaylandDeviceTabletPair *device_pair = data;
+  gint axis_index = device_pair->distance_axis_index;
+
+  device_pair->pointer_info.time = time;
+  _gdk_device_translate_axis (device_pair->current_device, axis_index,
+                              wl_fixed_to_double (distance),
+                              &device_pair->axes[axis_index]);
+}
+
+static void
+tablet_handle_tilt (void             *data,
+                    struct wl_tablet *wl_tablet,
+                    uint32_t          time,
+                    wl_fixed_t        x,
+                    wl_fixed_t        y)
+{
+  GdkWaylandDeviceTabletPair *device_pair = data;
+  gint xtilt_axis_index = device_pair->xtilt_axis_index;
+  gint ytilt_axis_index = device_pair->ytilt_axis_index;
+
+  device_pair->pointer_info.time = time;
+  _gdk_device_translate_axis (device_pair->current_device, xtilt_axis_index,
+                              wl_fixed_to_double (x),
+                              &device_pair->axes[xtilt_axis_index]);
+  _gdk_device_translate_axis (device_pair->current_device, ytilt_axis_index,
+                              wl_fixed_to_double (y),
+                              &device_pair->axes[ytilt_axis_index]);
+}
+
+static void
 tablet_handle_frame (void             *data,
                      struct wl_tablet *wl_tablet)
 {
@@ -1844,6 +1974,10 @@ tablet_handle_frame (void             *data,
   gdk_event_set_device (event, device_pair->master);
   gdk_event_set_source_device (event, device_pair->current_device);
   event->motion.time = device_pair->pointer_info.time;
+  event->motion.axes =
+    g_memdup (device_pair->axes,
+              sizeof (gdouble) *
+              gdk_device_get_n_axes (device_pair->current_device));
   event->motion.state = device_get_modifiers (device_pair->master);
   event->motion.is_hint = FALSE;
   gdk_event_set_screen (event, display->screen);
@@ -1908,9 +2042,9 @@ static const struct wl_tablet_listener tablet_listener = {
   tablet_handle_motion,
   tablet_handler_placeholder, /* down */
   tablet_handler_placeholder, /* up */
-  tablet_handler_placeholder, /* pressure */
-  tablet_handler_placeholder, /* distance */
-  tablet_handler_placeholder, /* tilt */
+  tablet_handle_pressure,
+  tablet_handle_distance,
+  tablet_handle_tilt,
   tablet_handler_placeholder, /* button */
   tablet_handle_frame,
   tablet_handle_removed