gdk: Convert mouse position to doubles, add new getterswip/window-scales

We've long had double precision mouse coordinates on wayland (e.g.
when rotating a window) but with the new scaling we even have it on
X (and, its also in Xinput2), so convert all the internal mouse/device
position getters to use doubles and add new accessors for the
public APIs that take doubles instead of ints.

23 files changed, 381 insertions, 247 deletions

diff --git a/gdk/broadway/gdkdevice-broadway.c b/gdk/broadway/gdkdevice-broadway.c
index f8dec2308b..3c89479bb6 100644
--- a/gdk/broadway/gdkdevice-broadway.c
+++ b/gdk/broadway/gdkdevice-broadway.c
@@ -38,16 +38,16 @@ static void gdk_broadway_device_set_window_cursor (GdkDevice *device,
 						   GdkCursor *cursor);
 static void gdk_broadway_device_warp (GdkDevice *device,
 				      GdkScreen *screen,
-				      gint       x,
-				      gint       y);
+				      gdouble    x,
+				      gdouble    y);
 static void gdk_broadway_device_query_state (GdkDevice        *device,
                                              GdkWindow        *window,
                                              GdkWindow       **root_window,
                                              GdkWindow       **child_window,
-                                             gint             *root_x,
-                                             gint             *root_y,
-                                             gint             *win_x,
-                                             gint             *win_y,
+                                             gdouble          *root_x,
+                                             gdouble          *root_y,
+                                             gdouble          *win_x,
+                                             gdouble          *win_y,
                                              GdkModifierType  *mask);
 static GdkGrabStatus gdk_broadway_device_grab   (GdkDevice     *device,
 						 GdkWindow     *window,
@@ -59,8 +59,8 @@ static GdkGrabStatus gdk_broadway_device_grab   (GdkDevice     *device,
 static void          gdk_broadway_device_ungrab (GdkDevice     *device,
 						 guint32        time_);
 static GdkWindow * gdk_broadway_device_window_at_position (GdkDevice       *device,
-							   gint            *win_x,
-							   gint            *win_y,
+							   gdouble         *win_x,
+							   gdouble         *win_y,
 							   GdkModifierType *mask,
 							   gboolean         get_toplevel);
 static void      gdk_broadway_device_select_window_events (GdkDevice       *device,
@@ -114,14 +114,14 @@ gdk_broadway_device_get_state (GdkDevice       *device,
 			       gdouble         *axes,
 			       GdkModifierType *mask)
 {
-  gint x_int, y_int;
+  gdouble x, y;
 
-  gdk_window_get_device_position (window, device, &x_int, &y_int, mask);
+  gdk_window_get_device_position_double (window, device, &x, &y, mask);
 
   if (axes)
     {
-      axes[0] = x_int;
-      axes[1] = y_int;
+      axes[0] = x;
+      axes[1] = y;
     }
 }
 
@@ -135,8 +135,8 @@ gdk_broadway_device_set_window_cursor (GdkDevice *device,
 static void
 gdk_broadway_device_warp (GdkDevice *device,
 			  GdkScreen *screen,
-			  gint       x,
-			  gint       y)
+			  gdouble    x,
+			  gdouble    y)
 {
 }
 
@@ -145,10 +145,10 @@ gdk_broadway_device_query_state (GdkDevice        *device,
 				 GdkWindow        *window,
 				 GdkWindow       **root_window,
 				 GdkWindow       **child_window,
-				 gint             *root_x,
-				 gint             *root_y,
-				 gint             *win_x,
-				 gint             *win_y,
+				 gdouble          *root_x,
+				 gdouble          *root_y,
+				 gdouble          *win_x,
+				 gdouble          *win_y,
 				 GdkModifierType  *mask)
 {
   GdkWindow *toplevel;
@@ -335,8 +335,8 @@ gdk_broadway_device_ungrab (GdkDevice *device,
 
 static GdkWindow *
 gdk_broadway_device_window_at_position (GdkDevice       *device,
-					gint            *win_x,
-					gint            *win_y,
+					gdouble         *win_x,
+					gdouble         *win_y,
 					GdkModifierType *mask,
 					gboolean         get_toplevel)
 {
diff --git a/gdk/broadway/gdkwindow-broadway.c b/gdk/broadway/gdkwindow-broadway.c
index fe7396ec72..03d52dfca2 100644
--- a/gdk/broadway/gdkwindow-broadway.c
+++ b/gdk/broadway/gdkwindow-broadway.c
@@ -750,8 +750,8 @@ gdk_broadway_window_get_frame_extents (GdkWindow    *window,
 static gboolean
 gdk_window_broadway_get_device_state (GdkWindow       *window,
 				      GdkDevice       *device,
-				      gint            *x,
-				      gint            *y,
+				      gdouble         *x,
+				      gdouble         *y,
 				      GdkModifierType *mask)
 {
   GdkWindow *child;
diff --git a/gdk/gdkdevice.c b/gdk/gdkdevice.c
index 3147d9e6a0..ced0976ec9 100644
--- a/gdk/gdkdevice.c
+++ b/gdk/gdkdevice.c
@@ -24,6 +24,9 @@
 #include "gdkinternals.h"
 #include "gdkintl.h"
 
+/* for the use of round() */
+#include "fallback-c89.c"
+
 /**
  * SECTION:gdkdevice
  * @Short_description: Object representing an input device
@@ -406,28 +409,28 @@ gdk_device_get_state (GdkDevice       *device,
 }
 
 /**
- * gdk_device_get_position:
+ * gdk_device_get_position_double:
  * @device: pointer device to query status about.
  * @screen: (out) (transfer none) (allow-none): location to store the #GdkScreen
  *          the @device is on, or %NULL.
  * @x: (out) (allow-none): location to store root window X coordinate of @device, or %NULL.
  * @y: (out) (allow-none): location to store root window Y coordinate of @device, or %NULL.
  *
- * Gets the current location of @device. As a slave device
+ * Gets the current location of @device in double precision. As a slave device
  * coordinates are those of its master pointer, This function
  * may not be called on devices of type %GDK_DEVICE_TYPE_SLAVE,
  * unless there is an ongoing grab on them, see gdk_device_grab().
  *
- * Since: 3.0
+ * Since: 3.10
  **/
 void
-gdk_device_get_position (GdkDevice        *device,
-                         GdkScreen       **screen,
-                         gint             *x,
-                         gint             *y)
+gdk_device_get_position_double (GdkDevice        *device,
+                                GdkScreen       **screen,
+                                gdouble          *x,
+                                gdouble          *y)
 {
   GdkDisplay *display;
-  gint tmp_x, tmp_y;
+  gdouble tmp_x, tmp_y;
   GdkScreen *default_screen;
   GdkWindow *root;
 
@@ -456,15 +459,47 @@ gdk_device_get_position (GdkDevice        *device,
 }
 
 /**
- * gdk_device_get_window_at_position:
+ * gdk_device_get_position:
+ * @device: pointer device to query status about.
+ * @screen: (out) (transfer none) (allow-none): location to store the #GdkScreen
+ *          the @device is on, or %NULL.
+ * @x: (out) (allow-none): location to store root window X coordinate of @device, or %NULL.
+ * @y: (out) (allow-none): location to store root window Y coordinate of @device, or %NULL.
+ *
+ * Gets the current location of @device. As a slave device
+ * coordinates are those of its master pointer, This function
+ * may not be called on devices of type %GDK_DEVICE_TYPE_SLAVE,
+ * unless there is an ongoing grab on them, see gdk_device_grab().
+ *
+ * Since: 3.0
+ **/
+void
+gdk_device_get_position (GdkDevice        *device,
+                         GdkScreen       **screen,
+                         gint             *x,
+                         gint             *y)
+{
+  gdouble tmp_x, tmp_y;
+
+  gdk_device_get_position_double (device, screen, &tmp_x, &tmp_y);
+  if (x)
+    *x = round (tmp_x);
+  if (y)
+    *y = round (tmp_y);
+}
+
+
+/**
+ * gdk_device_get_window_at_position_double:
  * @device: pointer #GdkDevice to query info to.
  * @win_x: (out) (allow-none): return location for the X coordinate of the device location,
  *         relative to the window origin, or %NULL.
  * @win_y: (out) (allow-none): return location for the Y coordinate of the device location,
  *         relative to the window origin, or %NULL.
  *
- * Obtains the window underneath @device, returning the location of the device in @win_x and @win_y. Returns
- * %NULL if the window tree under @device is not known to GDK (for example, belongs to another application).
+ * Obtains the window underneath @device, returning the location of the device in @win_x and @win_y in
+ * double precision. Returns %NULL if the window tree under @device is not known to GDK (for example,
+ * belongs to another application).
  *
  * As a slave device coordinates are those of its master pointer, This
  * function may not be called on devices of type %GDK_DEVICE_TYPE_SLAVE,
@@ -475,11 +510,11 @@ gdk_device_get_position (GdkDevice        *device,
  * Since: 3.0
  **/
 GdkWindow *
-gdk_device_get_window_at_position (GdkDevice  *device,
-                                   gint       *win_x,
-                                   gint       *win_y)
+gdk_device_get_window_at_position_double (GdkDevice  *device,
+                                          gdouble    *win_x,
+                                          gdouble    *win_y)
 {
-  gint tmp_x, tmp_y;
+  gdouble tmp_x, tmp_y;
   GdkWindow *window;
 
   g_return_val_if_fail (GDK_IS_DEVICE (device), NULL);
@@ -492,15 +527,9 @@ gdk_device_get_window_at_position (GdkDevice  *device,
   /* This might need corrections, as the native window returned
      may contain client side children */
   if (window)
-    {
-      double xx, yy;
-
-      window = _gdk_window_find_descendant_at (window,
-					       tmp_x, tmp_y,
-					       &xx, &yy);
-      tmp_x = floor (xx + 0.5);
-      tmp_y = floor (yy + 0.5);
-    }
+    window = _gdk_window_find_descendant_at (window,
+                                             tmp_x, tmp_y,
+                                             &tmp_x, &tmp_y);
 
   if (win_x)
     *win_x = tmp_x;
@@ -511,6 +540,44 @@ gdk_device_get_window_at_position (GdkDevice  *device,
 }
 
 /**
+ * gdk_device_get_window_at_position:
+ * @device: pointer #GdkDevice to query info to.
+ * @win_x: (out) (allow-none): return location for the X coordinate of the device location,
+ *         relative to the window origin, or %NULL.
+ * @win_y: (out) (allow-none): return location for the Y coordinate of the device location,
+ *         relative to the window origin, or %NULL.
+ *
+ * Obtains the window underneath @device, returning the location of the device in @win_x and @win_y. Returns
+ * %NULL if the window tree under @device is not known to GDK (for example, belongs to another application).
+ *
+ * As a slave device coordinates are those of its master pointer, This
+ * function may not be called on devices of type %GDK_DEVICE_TYPE_SLAVE,
+ * unless there is an ongoing grab on them, see gdk_device_grab().
+ *
+ * Returns: (transfer none): the #GdkWindow under the device position, or %NULL.
+ *
+ * Since: 3.0
+ **/
+GdkWindow *
+gdk_device_get_window_at_position (GdkDevice  *device,
+                                   gint       *win_x,
+                                   gint       *win_y)
+{
+  gdouble tmp_x, tmp_y;
+  GdkWindow *window;
+
+  window =
+    gdk_device_get_window_at_position_double (device, &tmp_x, &tmp_y);
+
+  if (win_x)
+    *win_x = round (tmp_x);
+  if (win_y)
+    *win_y = round (tmp_y);
+
+  return window;
+}
+
+/**
  * gdk_device_get_history: (skip)
  * @device: a #GdkDevice
  * @window: the window with respect to which which the event coordinates will be reported
@@ -1535,8 +1602,8 @@ _gdk_device_translate_window_coord (GdkDevice *device,
 gboolean
 _gdk_device_translate_screen_coord (GdkDevice *device,
                                     GdkWindow *window,
-                                    gint       window_root_x,
-                                    gint       window_root_y,
+                                    gdouble    window_root_x,
+                                    gdouble    window_root_y,
                                     guint      index_,
                                     gdouble    value,
                                     gdouble   *axis_value)
@@ -1616,10 +1683,10 @@ _gdk_device_query_state (GdkDevice        *device,
                          GdkWindow        *window,
                          GdkWindow       **root_window,
                          GdkWindow       **child_window,
-                         gint             *root_x,
-                         gint             *root_y,
-                         gint             *win_x,
-                         gint             *win_y,
+                         gdouble          *root_x,
+                         gdouble          *root_y,
+                         gdouble          *win_x,
+                         gdouble          *win_y,
                          GdkModifierType  *mask)
 {
   GDK_DEVICE_GET_CLASS (device)->query_state (device,
@@ -1635,8 +1702,8 @@ _gdk_device_query_state (GdkDevice        *device,
 
 GdkWindow *
 _gdk_device_window_at_position (GdkDevice        *device,
-                                gint             *win_x,
-                                gint             *win_y,
+                                gdouble          *win_x,
+                                gdouble          *win_y,
                                 GdkModifierType  *mask,
                                 gboolean          get_toplevel)
 {
diff --git a/gdk/gdkdevice.h b/gdk/gdkdevice.h
index dfa7051209..3350a2d1d1 100644
--- a/gdk/gdkdevice.h
+++ b/gdk/gdkdevice.h
@@ -198,6 +198,17 @@ GdkWindow *
                                  (GdkDevice         *device,
                                   gint              *win_x,
                                   gint              *win_y);
+GDK_AVAILABLE_IN_3_10
+void     gdk_device_get_position_double (GdkDevice         *device,
+                                         GdkScreen        **screen,
+                                         gdouble           *x,
+                                         gdouble           *y);
+GDK_AVAILABLE_IN_3_10
+GdkWindow *
+         gdk_device_get_window_at_position_double
+                                 (GdkDevice         *device,
+                                  gdouble           *win_x,
+                                  gdouble           *win_y);
 GDK_AVAILABLE_IN_ALL
 gboolean gdk_device_get_history  (GdkDevice         *device,
                                   GdkWindow         *window,
diff --git a/gdk/gdkdeviceprivate.h b/gdk/gdkdeviceprivate.h
index f30dbdb2a0..a8526b545b 100644
--- a/gdk/gdkdeviceprivate.h
+++ b/gdk/gdkdeviceprivate.h
@@ -80,16 +80,16 @@ struct _GdkDeviceClass
 
   void (* warp)              (GdkDevice  *device,
                               GdkScreen  *screen,
-                              gint        x,
-                              gint        y);
+                              gdouble     x,
+                              gdouble     y);
   void (* query_state)       (GdkDevice       *device,
                               GdkWindow       *window,
                               GdkWindow      **root_window,
                               GdkWindow      **child_window,
-                              gint             *root_x,
-                              gint             *root_y,
-                              gint             *win_x,
-                              gint             *win_y,
+                              gdouble          *root_x,
+                              gdouble          *root_y,
+                              gdouble          *win_x,
+                              gdouble          *win_y,
                               GdkModifierType  *mask);
   GdkGrabStatus (* grab)     (GdkDevice        *device,
                               GdkWindow        *window,
@@ -102,8 +102,8 @@ struct _GdkDeviceClass
                               guint32           time_);
 
   GdkWindow * (* window_at_position) (GdkDevice       *device,
-                                      gint            *win_x,
-                                      gint            *win_y,
+                                      double          *win_x,
+                                      double          *win_y,
                                       GdkModifierType *mask,
                                       gboolean         get_toplevel);
   void (* select_window_events)      (GdkDevice       *device,
@@ -140,8 +140,8 @@ gboolean   _gdk_device_translate_window_coord (GdkDevice *device,
 
 gboolean   _gdk_device_translate_screen_coord (GdkDevice *device,
                                                GdkWindow *window,
-                                               gint       window_root_x,
-                                               gint       window_root_y,
+                                               gdouble    window_root_x,
+                                               gdouble    window_root_y,
                                                guint      index,
                                                gdouble    value,
                                                gdouble   *axis_value);
@@ -162,14 +162,14 @@ void _gdk_device_query_state                  (GdkDevice        *device,
                                                GdkWindow        *window,
                                                GdkWindow       **root_window,
                                                GdkWindow       **child_window,
-                                               gint             *root_x,
-                                               gint             *root_y,
-                                               gint             *win_x,
-                                               gint             *win_y,
+                                               gdouble          *root_x,
+                                               gdouble          *root_y,
+                                               gdouble          *win_x,
+                                               gdouble          *win_y,
                                                GdkModifierType  *mask);
 GdkWindow * _gdk_device_window_at_position    (GdkDevice        *device,
-                                               gint             *win_x,
-                                               gint             *win_y,
+                                               gdouble          *win_x,
+                                               gdouble          *win_y,
                                                GdkModifierType  *mask,
                                                gboolean          get_toplevel);
 
diff --git a/gdk/gdkdisplay.c b/gdk/gdkdisplay.c
index 1c14d3e617..10928698fd 100644
--- a/gdk/gdkdisplay.c
+++ b/gdk/gdkdisplay.c
@@ -32,8 +32,11 @@
 #include "gdkmarshalers.h"
 #include "gdkscreen.h"
 
+#include <math.h>
 #include <glib.h>
 
+/* for the use of round() */
+#include "fallback-c89.c"
 
 /**
  * SECTION:gdkdisplay
@@ -546,7 +549,7 @@ gdk_display_get_pointer (GdkDisplay      *display,
 {
   GdkScreen *default_screen;
   GdkWindow *root;
-  gint tmp_x, tmp_y;
+  gdouble tmp_x, tmp_y;
   GdkModifierType tmp_mask;
 
   g_return_if_fail (GDK_IS_DISPLAY (display));
@@ -569,9 +572,9 @@ gdk_display_get_pointer (GdkDisplay      *display,
   if (screen)
     *screen = gdk_window_get_screen (root);
   if (x)
-    *x = tmp_x;
+    *x = round (tmp_x);
   if (y)
-    *y = tmp_y;
+    *y = round (tmp_y);
   if (mask)
     *mask = tmp_mask;
 }
@@ -792,7 +795,7 @@ synthesize_crossing_events (GdkDisplay      *display,
 {
   GdkWindow *src_toplevel, *dest_toplevel;
   GdkModifierType state;
-  int x, y;
+  double x, y;
 
   if (src_window)
     src_toplevel = gdk_window_get_toplevel (src_window);
@@ -810,9 +813,9 @@ synthesize_crossing_events (GdkDisplay      *display,
       src_toplevel == dest_toplevel)
     {
       /* Same toplevels */
-      gdk_window_get_device_position (dest_toplevel,
-                                      device,
-			              &x, &y, &state);
+      gdk_window_get_device_position_double (dest_toplevel,
+                                             device,
+                                             &x, &y, &state);
       _gdk_synthesize_crossing_events (display,
 				       src_window,
 				       dest_window,
@@ -825,9 +828,9 @@ synthesize_crossing_events (GdkDisplay      *display,
     }
   else if (dest_toplevel == NULL)
     {
-      gdk_window_get_device_position (src_toplevel,
-                                      device,
-			              &x, &y, &state);
+      gdk_window_get_device_position_double (src_toplevel,
+                                             device,
+                                             &x, &y, &state);
       _gdk_synthesize_crossing_events (display,
                                        src_window,
                                        NULL,
@@ -841,9 +844,9 @@ synthesize_crossing_events (GdkDisplay      *display,
   else
     {
       /* Different toplevels */
-      gdk_window_get_device_position (src_toplevel,
-                                      device,
-			              &x, &y, &state);
+      gdk_window_get_device_position_double (src_toplevel,
+                                             device,
+                                             &x, &y, &state);
       _gdk_synthesize_crossing_events (display,
 				       src_window,
 				       NULL,
@@ -853,9 +856,9 @@ synthesize_crossing_events (GdkDisplay      *display,
 				       time,
 				       NULL,
 				       serial, FALSE);
-      gdk_window_get_device_position (dest_toplevel,
-                                      device,
-			              &x, &y, &state);
+      gdk_window_get_device_position_double (dest_toplevel,
+                                             device,
+                                             &x, &y, &state);
       _gdk_synthesize_crossing_events (display,
 				       NULL,
 				       dest_window,
@@ -876,7 +879,7 @@ get_current_toplevel (GdkDisplay      *display,
 		      GdkModifierType *state_out)
 {
   GdkWindow *pointer_window;
-  int x, y;
+  gdouble x, y;
   GdkModifierType state;
 
   pointer_window = _gdk_device_window_at_position (device, &x, &y, &state, TRUE);
@@ -887,8 +890,8 @@ get_current_toplevel (GdkDisplay      *display,
        GDK_WINDOW_TYPE (pointer_window) == GDK_WINDOW_FOREIGN))
     pointer_window = NULL;
 
-  *x_out = x;
-  *y_out = y;
+  *x_out = round (x);
+  *y_out = round (y);
   *state_out = state;
 
   return pointer_window;
diff --git a/gdk/gdkinternals.h b/gdk/gdkinternals.h
index e7eb9d5b40..87d9941874 100644
--- a/gdk/gdkinternals.h
+++ b/gdk/gdkinternals.h
@@ -358,7 +358,7 @@ void _gdk_window_invalidate_for_expose (GdkWindow       *window,
                                         cairo_region_t       *region);
 
 GdkWindow * _gdk_window_find_child_at (GdkWindow *window,
-                                       int x, int y);
+                                       double x, double y);
 GdkWindow * _gdk_window_find_descendant_at (GdkWindow *toplevel,
                                             double x, double y,
                                             double *found_x,
@@ -380,8 +380,8 @@ void _gdk_synthesize_crossing_events (GdkDisplay                 *display,
                                       GdkDevice                  *device,
                                       GdkDevice                  *source_device,
 				      GdkCrossingMode             mode,
-				      gint                        toplevel_x,
-				      gint                        toplevel_y,
+				      gdouble                     toplevel_x,
+				      gdouble                     toplevel_y,
 				      GdkModifierType             mask,
 				      guint32                     time_,
 				      GdkEvent                   *event_in_queue,
diff --git a/gdk/gdkoffscreenwindow.c b/gdk/gdkoffscreenwindow.c
index 454ca8944c..86b77a190c 100644
--- a/gdk/gdkoffscreenwindow.c
+++ b/gdk/gdkoffscreenwindow.c
@@ -280,12 +280,12 @@ gdk_offscreen_window_get_root_coords (GdkWindow *window,
 static gboolean
 gdk_offscreen_window_get_device_state (GdkWindow       *window,
                                        GdkDevice       *device,
-                                       gint            *x,
-                                       gint            *y,
+                                       gdouble         *x,
+                                       gdouble         *y,
                                        GdkModifierType *mask)
 {
   GdkOffscreenWindow *offscreen;
-  int tmpx, tmpy;
+  double tmpx, tmpy;
   double dtmpx, dtmpy;
   GdkModifierType tmpmask;
 
@@ -296,18 +296,18 @@ gdk_offscreen_window_get_device_state (GdkWindow       *window,
   offscreen = GDK_OFFSCREEN_WINDOW (window->impl);
   if (offscreen->embedder != NULL)
     {
-      gdk_window_get_device_position (offscreen->embedder, device, &tmpx, &tmpy, &tmpmask);
+      gdk_window_get_device_position_double (offscreen->embedder, device, &tmpx, &tmpy, &tmpmask);
       from_embedder (window,
 		     tmpx, tmpy,
 		     &dtmpx, &dtmpy);
-      tmpx = floor (dtmpx + 0.5);
-      tmpy = floor (dtmpy + 0.5);
+      tmpx = dtmpx;
+      tmpy = dtmpy;
     }
 
   if (x)
-    *x = tmpx;
+    *x = round (tmpx);
   if (y)
-    *y = tmpy;
+    *y = round (tmpy);
   if (mask)
     *mask = tmpmask;
   return TRUE;
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index fa8732566b..9fe3fe7c6c 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -4425,30 +4425,30 @@ gdk_window_get_pointer (GdkWindow	  *window,
 }
 
 /**
- * gdk_window_get_device_position:
+ * gdk_window_get_device_position_double:
  * @window: a #GdkWindow.
  * @device: pointer #GdkDevice to query to.
  * @x: (out) (allow-none): return location for the X coordinate of @device, or %NULL.
  * @y: (out) (allow-none): return location for the Y coordinate of @device, or %NULL.
  * @mask: (out) (allow-none): return location for the modifier mask, or %NULL.
  *
- * Obtains the current device position and modifier state.
+ * Obtains the current device position in doubles and modifier state.
  * The position is given in coordinates relative to the upper left
  * corner of @window.
  *
  * Return value: (transfer none): The window underneath @device (as with
  * gdk_device_get_window_at_position()), or %NULL if the window is not known to GDK.
  *
- * Since: 3.0
+ * Since: 3.10
  **/
 GdkWindow *
-gdk_window_get_device_position (GdkWindow       *window,
-                                GdkDevice       *device,
-                                gint            *x,
-                                gint            *y,
-                                GdkModifierType *mask)
+gdk_window_get_device_position_double (GdkWindow       *window,
+                                       GdkDevice       *device,
+                                       double          *x,
+                                       double          *y,
+                                       GdkModifierType *mask)
 {
-  gint tmp_x, tmp_y;
+  gdouble tmp_x, tmp_y;
   GdkModifierType tmp_mask;
   gboolean normal_child;
 
@@ -4479,6 +4479,44 @@ gdk_window_get_device_position (GdkWindow       *window,
 }
 
 /**
+ * gdk_window_get_device_position:
+ * @window: a #GdkWindow.
+ * @device: pointer #GdkDevice to query to.
+ * @x: (out) (allow-none): return location for the X coordinate of @device, or %NULL.
+ * @y: (out) (allow-none): return location for the Y coordinate of @device, or %NULL.
+ * @mask: (out) (allow-none): return location for the modifier mask, or %NULL.
+ *
+ * Obtains the current device position and modifier state.
+ * The position is given in coordinates relative to the upper left
+ * corner of @window.
+ *
+ * Use gdk_window_get_device_position_double() if you need subpixel precision.
+ *
+ * Return value: (transfer none): The window underneath @device (as with
+ * gdk_device_get_window_at_position()), or %NULL if the window is not known to GDK.
+ *
+ * Since: 3.0
+ **/
+GdkWindow *
+gdk_window_get_device_position (GdkWindow       *window,
+                                GdkDevice       *device,
+                                gint            *x,
+                                gint            *y,
+                                GdkModifierType *mask)
+{
+  gdouble tmp_x, tmp_y;
+
+  window = gdk_window_get_device_position_double (window, device,
+                                                  &tmp_x, &tmp_y, mask);
+  if (x)
+    *x = round (tmp_x);
+  if (y)
+    *y = round (tmp_y);
+
+  return window;
+}
+
+/**
  * gdk_get_default_root_window:
  *
  * Obtains the root window (parent all other windows are inside)
@@ -6953,8 +6991,8 @@ pick_embedded_child (GdkWindow *window,
 
 GdkWindow *
 _gdk_window_find_child_at (GdkWindow *window,
-			   int        x,
-                           int        y)
+			   double     x,
+                           double     y)
 {
   GdkWindow *sub;
   double child_x, child_y;
@@ -7395,8 +7433,8 @@ send_crossing_event (GdkDisplay                 *display,
 		     GdkWindow                  *subwindow,
                      GdkDevice                  *device,
                      GdkDevice                  *source_device,
-		     gint                        toplevel_x,
-		     gint                        toplevel_y,
+		     gdouble                     toplevel_x,
+		     gdouble                     toplevel_y,
 		     GdkModifierType             mask,
 		     guint32                     time_,
 		     GdkEvent                   *event_in_queue,
@@ -7511,8 +7549,8 @@ _gdk_synthesize_crossing_events (GdkDisplay                 *display,
                                  GdkDevice                  *device,
                                  GdkDevice                  *source_device,
 				 GdkCrossingMode             mode,
-				 gint                        toplevel_x,
-				 gint                        toplevel_y,
+				 double                      toplevel_x,
+				 double                      toplevel_y,
 				 GdkModifierType             mask,
 				 guint32                     time_,
 				 GdkEvent                   *event_in_queue,
diff --git a/gdk/gdkwindow.h b/gdk/gdkwindow.h
index 0c394d8c4d..eff71783cc 100644
--- a/gdk/gdkwindow.h
+++ b/gdk/gdkwindow.h
@@ -845,6 +845,12 @@ GdkWindow *   gdk_window_get_device_position (GdkWindow       *window,
                                               gint            *x,
                                               gint            *y,
                                               GdkModifierType *mask);
+GDK_AVAILABLE_IN_3_10
+GdkWindow *   gdk_window_get_device_position_double (GdkWindow       *window,
+                                                     GdkDevice       *device,
+                                                     gdouble         *x,
+                                                     gdouble         *y,
+                                                     GdkModifierType *mask);
 GDK_AVAILABLE_IN_ALL
 GdkWindow *   gdk_window_get_parent      (GdkWindow       *window);
 GDK_AVAILABLE_IN_ALL
diff --git a/gdk/gdkwindowimpl.h b/gdk/gdkwindowimpl.h
index 7f136a59bb..b1117a7177 100644
--- a/gdk/gdkwindowimpl.h
+++ b/gdk/gdkwindowimpl.h
@@ -98,8 +98,8 @@ struct _GdkWindowImplClass
                                          gint            *root_y);
   gboolean     (* get_device_state)     (GdkWindow       *window,
                                          GdkDevice       *device,
-                                         gint            *x,
-                                         gint            *y,
+                                         gdouble         *x,
+                                         gdouble         *y,
                                          GdkModifierType *mask);
   gboolean    (* begin_paint_region)    (GdkWindow       *window,
 					 const cairo_region_t *region);
diff --git a/gdk/quartz/gdkdevice-core-quartz.c b/gdk/quartz/gdkdevice-core-quartz.c
index 8598cf62a7..b28662096d 100644
--- a/gdk/quartz/gdkdevice-core-quartz.c
+++ b/gdk/quartz/gdkdevice-core-quartz.c
@@ -58,10 +58,10 @@ static void gdk_quartz_device_core_query_state (GdkDevice        *device,
                                                 GdkWindow        *window,
                                                 GdkWindow       **root_window,
                                                 GdkWindow       **child_window,
-                                                gint             *root_x,
-                                                gint             *root_y,
-                                                gint             *win_x,
-                                                gint             *win_y,
+                                                gdouble          *root_x,
+                                                gdouble          *root_y,
+                                                gdouble          *win_x,
+                                                gdouble          *win_y,
                                                 GdkModifierType  *mask);
 static GdkGrabStatus gdk_quartz_device_core_grab   (GdkDevice     *device,
                                                     GdkWindow     *window,
@@ -73,8 +73,8 @@ static GdkGrabStatus gdk_quartz_device_core_grab   (GdkDevice     *device,
 static void          gdk_quartz_device_core_ungrab (GdkDevice     *device,
                                                     guint32        time_);
 static GdkWindow * gdk_quartz_device_core_window_at_position (GdkDevice       *device,
-                                                              gint            *win_x,
-                                                              gint            *win_y,
+                                                              gdouble         *win_x,
+                                                              gdouble         *win_y,
                                                               GdkModifierType *mask,
                                                               gboolean         get_toplevel);
 static void      gdk_quartz_device_core_select_window_events (GdkDevice       *device,
@@ -181,8 +181,8 @@ gdk_quartz_device_core_set_window_cursor (GdkDevice *device,
 static void
 gdk_quartz_device_core_warp (GdkDevice *device,
                              GdkScreen *screen,
-                             gint       x,
-                             gint       y)
+                             gdouble    x,
+                             gdouble    y)
 {
   CGDisplayMoveCursorToPoint (CGMainDisplayID (), CGPointMake (x, y));
 }
@@ -190,8 +190,8 @@ gdk_quartz_device_core_warp (GdkDevice *device,
 static GdkWindow *
 gdk_quartz_device_core_query_state_helper (GdkWindow       *window,
                                            GdkDevice       *device,
-                                           gint            *x,
-                                           gint            *y,
+                                           gdouble         *x,
+                                           gdouble         *y,
                                            GdkModifierType *mask)
 {
   GdkWindow *toplevel;
@@ -260,10 +260,10 @@ gdk_quartz_device_core_query_state (GdkDevice        *device,
                                     GdkWindow        *window,
                                     GdkWindow       **root_window,
                                     GdkWindow       **child_window,
-                                    gint             *root_x,
-                                    gint             *root_y,
-                                    gint             *win_x,
-                                    gint             *win_y,
+                                    gdouble          *root_x,
+                                    gdouble          *root_y,
+                                    gdouble          *win_x,
+                                    gdouble          *win_y,
                                     GdkModifierType  *mask)
 {
   GdkWindow *found_window;
@@ -318,8 +318,8 @@ gdk_quartz_device_core_ungrab (GdkDevice *device,
 
 static GdkWindow *
 gdk_quartz_device_core_window_at_position (GdkDevice       *device,
-                                           gint            *win_x,
-                                           gint            *win_y,
+                                           gdouble         *win_x,
+                                           gdouble         *win_y,
                                            GdkModifierType *mask,
                                            gboolean         get_toplevel)
 {
diff --git a/gdk/quartz/gdkwindow-quartz.c b/gdk/quartz/gdkwindow-quartz.c
index d6f45bbb30..05b3b77beb 100644
--- a/gdk/quartz/gdkwindow-quartz.c
+++ b/gdk/quartz/gdkwindow-quartz.c
@@ -1818,8 +1818,8 @@ gdk_quartz_window_get_root_origin (GdkWindow *window,
 static GdkWindow *
 gdk_window_quartz_get_device_state_helper (GdkWindow       *window,
                                            GdkDevice       *device,
-                                           gint            *x,
-                                           gint            *y,
+                                           gdouble         *x,
+                                           gdouble         *y,
                                            GdkModifierType *mask)
 {
   NSPoint point;
@@ -1880,8 +1880,8 @@ gdk_window_quartz_get_device_state_helper (GdkWindow       *window,
 static gboolean
 gdk_window_quartz_get_device_state (GdkWindow       *window,
                                     GdkDevice       *device,
-                                    gint            *x,
-                                    gint            *y,
+                                    gdouble          *x,
+                                    gdouble          *y,
                                     GdkModifierType *mask)
 {
   return gdk_window_quartz_get_device_state_helper (window,
diff --git a/gdk/wayland/gdkdevice-wayland.c b/gdk/wayland/gdkdevice-wayland.c
index cd4a6955aa..292509660d 100644
--- a/gdk/wayland/gdkdevice-wayland.c
+++ b/gdk/wayland/gdkdevice-wayland.c
@@ -135,14 +135,14 @@ gdk_wayland_device_get_state (GdkDevice       *device,
                               gdouble         *axes,
                               GdkModifierType *mask)
 {
-  gint x_int, y_int;
+  gdouble x, y;
 
-  gdk_window_get_device_position (window, device, &x_int, &y_int, mask);
+  gdk_window_get_device_position_double (window, device, &x, &y, mask);
 
   if (axes)
     {
-      axes[0] = x_int;
-      axes[1] = y_int;
+      axes[0] = x;
+      axes[1] = y;
     }
 }
 
@@ -228,8 +228,8 @@ gdk_wayland_device_set_window_cursor (GdkDevice *device,
 static void
 gdk_wayland_device_warp (GdkDevice *device,
                          GdkScreen *screen,
-                         gint       x,
-                         gint       y)
+                         gdouble    x,
+                         gdouble    y)
 {
 }
 
@@ -238,10 +238,10 @@ gdk_wayland_device_query_state (GdkDevice        *device,
                                 GdkWindow        *window,
                                 GdkWindow       **root_window,
                                 GdkWindow       **child_window,
-                                gint             *root_x,
-                                gint             *root_y,
-                                gint             *win_x,
-                                gint             *win_y,
+                                gdouble          *root_x,
+                                gdouble          *root_y,
+                                gdouble          *win_x,
+                                gdouble          *win_y,
                                 GdkModifierType  *mask)
 {
   GdkWaylandDeviceData *wd;
@@ -345,8 +345,8 @@ gdk_wayland_device_ungrab (GdkDevice *device,
 
 static GdkWindow *
 gdk_wayland_device_window_at_position (GdkDevice       *device,
-                                       gint            *win_x,
-                                       gint            *win_y,
+                                       gdouble         *win_x,
+                                       gdouble         *win_y,
                                        GdkModifierType *mask,
                                        gboolean         get_toplevel)
 {
diff --git a/gdk/wayland/gdkscreen-wayland.c b/gdk/wayland/gdkscreen-wayland.c
index 7fa9add755..6768fabea1 100644
--- a/gdk/wayland/gdkscreen-wayland.c
+++ b/gdk/wayland/gdkscreen-wayland.c
@@ -928,7 +928,7 @@ output_handle_done(void *data,
 static void
 output_handle_scale(void *data,
 		    struct wl_output *wl_output,
-		    uint32_t factor)
+		    int32_t factor)
 {
   GdkWaylandMonitor *monitor = (GdkWaylandMonitor *)data;
 
diff --git a/gdk/wayland/gdkwindow-wayland.c b/gdk/wayland/gdkwindow-wayland.c
index f872049d04..a6e68d5f66 100644
--- a/gdk/wayland/gdkwindow-wayland.c
+++ b/gdk/wayland/gdkwindow-wayland.c
@@ -1237,8 +1237,8 @@ gdk_window_wayland_get_root_coords (GdkWindow *window,
 static gboolean
 gdk_window_wayland_get_device_state (GdkWindow       *window,
 				     GdkDevice       *device,
-				     gint            *x,
-				     gint            *y,
+				     gdouble         *x,
+				     gdouble         *y,
 				     GdkModifierType *mask)
 {
   gboolean return_val;
diff --git a/gdk/win32/gdkdevice-virtual.c b/gdk/win32/gdkdevice-virtual.c
index 3a779dc5b2..028a8f5c51 100644
--- a/gdk/win32/gdkdevice-virtual.c
+++ b/gdk/win32/gdkdevice-virtual.c
@@ -47,10 +47,10 @@ static void gdk_device_virtual_query_state (GdkDevice        *device,
 					    GdkWindow        *window,

 					    GdkWindow       **root_window,

 					    GdkWindow       **child_window,

-					    gint             *root_x,

-					    gint             *root_y,

-					    gint             *win_x,

-					    gint             *win_y,

+					    gdouble          *root_x,

+					    gdouble          *root_y,

+					    gdouble          *win_x,

+					    gdouble          *win_y,

 					    GdkModifierType  *mask);

 static GdkGrabStatus gdk_device_virtual_grab   (GdkDevice     *device,

 						GdkWindow     *window,

@@ -62,8 +62,8 @@ static GdkGrabStatus gdk_device_virtual_grab   (GdkDevice     *device,
 static void          gdk_device_virtual_ungrab (GdkDevice     *device,

 						guint32        time_);

 static GdkWindow * gdk_device_virtual_window_at_position (GdkDevice       *device,

-							  gint            *win_x,

-							  gint            *win_y,

+							  gdouble         *win_x,

+							  gdouble         *win_y,

 							  GdkModifierType *mask,

 							  gboolean         get_toplevel);

 static void      gdk_device_virtual_select_window_events (GdkDevice       *device,

@@ -245,10 +245,10 @@ gdk_device_virtual_query_state (GdkDevice        *device,
 				GdkWindow        *window,

 				GdkWindow       **root_window,

 				GdkWindow       **child_window,

-				gint             *root_x,

-				gint             *root_y,

-				gint             *win_x,

-				gint             *win_y,

+				gdouble          *root_x,

+				gdouble          *root_y,

+				gdouble          *win_x,

+				gdouble          *win_y,

 				GdkModifierType  *mask)

 {

   GdkDeviceVirtual *virtual = GDK_DEVICE_VIRTUAL (device);

@@ -342,8 +342,8 @@ screen_to_client (HWND hwnd, POINT screen_pt, POINT *client_pt)
 

 static GdkWindow *

 gdk_device_virtual_window_at_position (GdkDevice       *device,

-				       gint            *win_x,

-				       gint            *win_y,

+				       gdouble         *win_x,

+				       gdouble         *win_y,

 				       GdkModifierType *mask,

 				       gboolean         get_toplevel)

 {

diff --git a/gdk/win32/gdkdevice-win32.c b/gdk/win32/gdkdevice-win32.c
index 042ef349a2..8be4d1d3c7 100644
--- a/gdk/win32/gdkdevice-win32.c
+++ b/gdk/win32/gdkdevice-win32.c
@@ -47,10 +47,10 @@ static void gdk_device_win32_query_state (GdkDevice        *device,
                                           GdkWindow        *window,
                                           GdkWindow       **root_window,
                                           GdkWindow       **child_window,
-                                          gint             *root_x,
-                                          gint             *root_y,
-                                          gint             *win_x,
-                                          gint             *win_y,
+                                          gdouble          *root_x,
+                                          gdouble          *root_y,
+                                          gdouble          *win_x,
+                                          gdouble          *win_y,
                                           GdkModifierType  *mask);
 static GdkGrabStatus gdk_device_win32_grab   (GdkDevice     *device,
                                               GdkWindow     *window,
@@ -62,8 +62,8 @@ static GdkGrabStatus gdk_device_win32_grab   (GdkDevice     *device,
 static void          gdk_device_win32_ungrab (GdkDevice     *device,
                                               guint32        time_);
 static GdkWindow * gdk_device_win32_window_at_position (GdkDevice       *device,
-                                                        gint            *win_x,
-                                                        gint            *win_y,
+                                                        gdouble         *win_x,
+                                                        gdouble         *win_y,
                                                         GdkModifierType *mask,
                                                         gboolean         get_toplevel);
 static void      gdk_device_win32_select_window_events (GdkDevice       *device,
@@ -138,8 +138,8 @@ gdk_device_win32_set_window_cursor (GdkDevice *device,
 static void
 gdk_device_win32_warp (GdkDevice *device,
                        GdkScreen *screen,
-                       gint       x,
-                       gint       y)
+                       gdouble    x,
+                       gdouble    y)
 {
 }
 
@@ -174,10 +174,10 @@ gdk_device_win32_query_state (GdkDevice        *device,
                               GdkWindow        *window,
                               GdkWindow       **root_window,
                               GdkWindow       **child_window,
-                              gint             *root_x,
-                              gint             *root_y,
-                              gint             *win_x,
-                              gint             *win_y,
+                              gdouble          *root_x,
+                              gdouble          *root_y,
+                              gdouble          *win_x,
+                              gdouble          *win_y,
                               GdkModifierType  *mask)
 {
   POINT point;
@@ -259,8 +259,8 @@ screen_to_client (HWND hwnd, POINT screen_pt, POINT *client_pt)
 
 static GdkWindow *
 gdk_device_win32_window_at_position (GdkDevice       *device,
-                                     gint            *win_x,
-                                     gint            *win_y,
+                                     gdouble         *win_x,
+                                     gdouble         *win_y,
                                      GdkModifierType *mask,
                                      gboolean         get_toplevel)
 {
diff --git a/gdk/win32/gdkdevice-wintab.c b/gdk/win32/gdkdevice-wintab.c
index 6af23bad43..369821cb08 100644
--- a/gdk/win32/gdkdevice-wintab.c
+++ b/gdk/win32/gdkdevice-wintab.c
@@ -46,10 +46,10 @@ static void gdk_device_wintab_query_state (GdkDevice        *device,
                                            GdkWindow        *window,
                                            GdkWindow       **root_window,
                                            GdkWindow       **child_window,
-                                           gint             *root_x,
-                                           gint             *root_y,
-                                           gint             *win_x,
-                                           gint             *win_y,
+                                           gdouble          *root_x,
+                                           gdouble          *root_y,
+                                           gdouble          *win_x,
+                                           gdouble          *win_y,
                                            GdkModifierType  *mask);
 static GdkGrabStatus gdk_device_wintab_grab   (GdkDevice     *device,
                                                GdkWindow     *window,
@@ -61,8 +61,8 @@ static GdkGrabStatus gdk_device_wintab_grab   (GdkDevice     *device,
 static void          gdk_device_wintab_ungrab (GdkDevice     *device,
                                                guint32        time_);
 static GdkWindow * gdk_device_wintab_window_at_position (GdkDevice       *device,
-                                                         gint            *win_x,
-                                                         gint            *win_y,
+                                                         gdouble         *win_x,
+                                                         gdouble         *win_y,
                                                          GdkModifierType *mask,
                                                          gboolean         get_toplevel);
 static void      gdk_device_wintab_select_window_events (GdkDevice       *device,
@@ -180,10 +180,10 @@ gdk_device_wintab_query_state (GdkDevice        *device,
                                GdkWindow        *window,
                                GdkWindow       **root_window,
                                GdkWindow       **child_window,
-                               gint             *root_x,
-                               gint             *root_y,
-                               gint             *win_x,
-                               gint             *win_y,
+                               gdouble          *root_x,
+                               gdouble          *root_y,
+                               gdouble          *win_x,
+                               gdouble          *win_y,
                                GdkModifierType  *mask)
 {
   GdkDeviceWintab *device_wintab;
@@ -268,8 +268,8 @@ gdk_device_wintab_ungrab (GdkDevice *device,
 
 static GdkWindow *
 gdk_device_wintab_window_at_position (GdkDevice       *device,
-                                      gint            *win_x,
-                                      gint            *win_y,
+                                      gdouble         *win_x,
+                                      gdouble         *win_y,
                                       GdkModifierType *mask,
                                       gboolean         get_toplevel)
 {
diff --git a/gdk/win32/gdkwindow-win32.c b/gdk/win32/gdkwindow-win32.c
index 33361743e7..273e53cf7b 100644
--- a/gdk/win32/gdkwindow-win32.c
+++ b/gdk/win32/gdkwindow-win32.c
@@ -2128,8 +2128,8 @@ gdk_win32_window_get_frame_extents (GdkWindow    *window,
 static gboolean
 gdk_window_win32_get_device_state (GdkWindow       *window,
                                    GdkDevice       *device,
-                                   gint            *x,
-                                   gint            *y,
+                                   gdouble         *x,
+                                   gdouble         *y,
                                    GdkModifierType *mask)
 {
   GdkWindow *child;
diff --git a/gdk/x11/gdkdevice-core-x11.c b/gdk/x11/gdkdevice-core-x11.c
index e21339dac0..2f87c73c2a 100644
--- a/gdk/x11/gdkdevice-core-x11.c
+++ b/gdk/x11/gdkdevice-core-x11.c
@@ -17,6 +17,7 @@
 
 #include "config.h"
 
+
 #include "gdkx11device-core.h"
 #include "gdkdeviceprivate.h"
 
@@ -25,6 +26,11 @@
 #include "gdkprivate-x11.h"
 #include "gdkasync.h"
 
+#include <math.h>
+
+/* for the use of round() */
+#include "fallback-c89.c"
+
 struct _GdkX11DeviceCore
 {
   GdkDevice parent_instance;
@@ -50,16 +56,16 @@ static void     gdk_x11_device_core_set_window_cursor (GdkDevice *device,
                                                        GdkCursor *cursor);
 static void     gdk_x11_device_core_warp (GdkDevice *device,
                                           GdkScreen *screen,
-                                          gint       x,
-                                          gint       y);
+                                          gdouble    x,
+                                          gdouble    y);
 static void gdk_x11_device_core_query_state (GdkDevice        *device,
                                              GdkWindow        *window,
                                              GdkWindow       **root_window,
                                              GdkWindow       **child_window,
-                                             gint             *root_x,
-                                             gint             *root_y,
-                                             gint             *win_x,
-                                             gint             *win_y,
+                                             gdouble          *root_x,
+                                             gdouble          *root_y,
+                                             gdouble          *win_x,
+                                             gdouble          *win_y,
                                              GdkModifierType  *mask);
 static GdkGrabStatus gdk_x11_device_core_grab   (GdkDevice     *device,
                                                  GdkWindow     *window,
@@ -71,8 +77,8 @@ static GdkGrabStatus gdk_x11_device_core_grab   (GdkDevice     *device,
 static void          gdk_x11_device_core_ungrab (GdkDevice     *device,
                                                  guint32        time_);
 static GdkWindow * gdk_x11_device_core_window_at_position (GdkDevice       *device,
-                                                           gint            *win_x,
-                                                           gint            *win_y,
+                                                           gdouble         *win_x,
+                                                           gdouble         *win_y,
                                                            GdkModifierType *mask,
                                                            gboolean         get_toplevel);
 static void      gdk_x11_device_core_select_window_events (GdkDevice       *device,
@@ -196,15 +202,14 @@ gdk_x11_device_core_get_state (GdkDevice       *device,
                                gdouble         *axes,
                                GdkModifierType *mask)
 {
-  gint x_int, y_int;
+  gdouble x, y;
 
-  /* TODO: This rounds the coords, should use double */
-  gdk_window_get_device_position (window, device, &x_int, &y_int, mask);
+  gdk_window_get_device_position_double (window, device, &x, &y, mask);
 
   if (axes)
     {
-      axes[0] = x_int;
-      axes[1] = y_int;
+      axes[0] = x;
+      axes[1] = y;
     }
 }
 
@@ -228,8 +233,8 @@ gdk_x11_device_core_set_window_cursor (GdkDevice *device,
 static void
 gdk_x11_device_core_warp (GdkDevice *device,
                           GdkScreen *screen,
-                          gint       x,
-                          gint       y)
+                          gdouble    x,
+                          gdouble    y)
 {
   Display *xdisplay;
   Window dest;
@@ -238,8 +243,8 @@ gdk_x11_device_core_warp (GdkDevice *device,
   dest = GDK_WINDOW_XID (gdk_screen_get_root_window (screen));
 
   XWarpPointer (xdisplay, None, dest, 0, 0, 0, 0,
-                x * GDK_X11_SCREEN (screen)->window_scale,
-                y * GDK_X11_SCREEN (screen)->window_scale);
+                round (x * GDK_X11_SCREEN (screen)->window_scale),
+                round (y * GDK_X11_SCREEN (screen)->window_scale));
 }
 
 static void
@@ -247,10 +252,10 @@ gdk_x11_device_core_query_state (GdkDevice        *device,
                                  GdkWindow        *window,
                                  GdkWindow       **root_window,
                                  GdkWindow       **child_window,
-                                 gint             *root_x,
-                                 gint             *root_y,
-                                 gint             *win_x,
-                                 gint             *win_y,
+                                 gdouble          *root_x,
+                                 gdouble          *root_y,
+                                 gdouble          *win_x,
+                                 gdouble          *win_y,
                                  GdkModifierType  *mask)
 {
   GdkWindowImplX11 *impl = GDK_WINDOW_IMPL_X11 (window->impl);
@@ -299,16 +304,16 @@ gdk_x11_device_core_query_state (GdkDevice        *device,
     *child_window = gdk_x11_window_lookup_for_display (display, xchild_window);
 
   if (root_x)
-    *root_x = xroot_x / impl->window_scale;
+    *root_x = (double)xroot_x / impl->window_scale;
 
   if (root_y)
-    *root_y = xroot_y / impl->window_scale;
+    *root_y = (double)xroot_y / impl->window_scale;
 
   if (win_x)
-    *win_x = xwin_x / impl->window_scale;
+    *win_x = (double)xwin_x / impl->window_scale;
 
   if (win_y)
-    *win_y = xwin_y / impl->window_scale;
+    *win_y = (double)xwin_y / impl->window_scale;
 
   if (mask)
     *mask = xmask;
@@ -416,8 +421,8 @@ gdk_x11_device_core_ungrab (GdkDevice *device,
 
 static GdkWindow *
 gdk_x11_device_core_window_at_position (GdkDevice       *device,
-                                        gint            *win_x,
-                                        gint            *win_y,
+                                        gdouble         *win_x,
+                                        gdouble         *win_y,
                                         GdkModifierType *mask,
                                         gboolean         get_toplevel)
 {
@@ -547,10 +552,10 @@ gdk_x11_device_core_window_at_position (GdkDevice       *device,
     impl = GDK_WINDOW_IMPL_X11 (window->impl);
 
   if (win_x)
-    *win_x = (window) ? xwin_x / impl->window_scale : -1;
+    *win_x = (window) ? (double)xwin_x / impl->window_scale : -1;
 
   if (win_y)
-    *win_y = (window) ? xwin_y / impl->window_scale : -1;
+    *win_y = (window) ? (double)xwin_y / impl->window_scale : -1;
 
   if (mask)
     *mask = xmask;
diff --git a/gdk/x11/gdkdevice-xi2.c b/gdk/x11/gdkdevice-xi2.c
index 4f85ba1703..8245fe4cab 100644
--- a/gdk/x11/gdkdevice-xi2.c
+++ b/gdk/x11/gdkdevice-xi2.c
@@ -29,6 +29,10 @@
 #include <X11/Xutil.h>
 #include <X11/extensions/XInput2.h>
 
+#include <math.h>
+
+/* for the use of round() */
+#include "fallback-c89.c"
 
 typedef struct _ScrollValuator ScrollValuator;
 
@@ -76,16 +80,16 @@ static void gdk_x11_device_xi2_set_window_cursor (GdkDevice *device,
                                                   GdkCursor *cursor);
 static void gdk_x11_device_xi2_warp (GdkDevice *device,
                                      GdkScreen *screen,
-                                     gint       x,
-                                     gint       y);
+                                     gdouble    x,
+                                     gdouble    y);
 static void gdk_x11_device_xi2_query_state (GdkDevice        *device,
                                             GdkWindow        *window,
                                             GdkWindow       **root_window,
                                             GdkWindow       **child_window,
-                                            gint             *root_x,
-                                            gint             *root_y,
-                                            gint             *win_x,
-                                            gint             *win_y,
+                                            gdouble          *root_x,
+                                            gdouble          *root_y,
+                                            gdouble          *win_x,
+                                            gdouble          *win_y,
                                             GdkModifierType  *mask);
 
 static GdkGrabStatus gdk_x11_device_xi2_grab   (GdkDevice     *device,
@@ -99,8 +103,8 @@ static void          gdk_x11_device_xi2_ungrab (GdkDevice     *device,
                                                 guint32        time_);
 
 static GdkWindow * gdk_x11_device_xi2_window_at_position (GdkDevice       *device,
-                                                          gint            *win_x,
-                                                          gint            *win_y,
+                                                          gdouble         *win_x,
+                                                          gdouble         *win_y,
                                                           GdkModifierType *mask,
                                                           gboolean         get_toplevel);
 static void  gdk_x11_device_xi2_select_window_events (GdkDevice    *device,
@@ -292,8 +296,8 @@ gdk_x11_device_xi2_set_window_cursor (GdkDevice *device,
 static void
 gdk_x11_device_xi2_warp (GdkDevice *device,
                          GdkScreen *screen,
-                         gint       x,
-                         gint       y)
+                         gdouble    x,
+                         gdouble    y)
 {
   GdkX11DeviceXI2 *device_xi2 = GDK_X11_DEVICE_XI2 (device);
   Window dest;
@@ -304,8 +308,8 @@ gdk_x11_device_xi2_warp (GdkDevice *device,
                  device_xi2->device_id,
                  None, dest,
                  0, 0, 0, 0,
-                 x * GDK_X11_SCREEN(screen)->window_scale,
-                 y * GDK_X11_SCREEN(screen)->window_scale);
+                 round (x * GDK_X11_SCREEN(screen)->window_scale),
+                 round (y * GDK_X11_SCREEN(screen)->window_scale));
 }
 
 static void
@@ -313,10 +317,10 @@ gdk_x11_device_xi2_query_state (GdkDevice        *device,
                                 GdkWindow        *window,
                                 GdkWindow       **root_window,
                                 GdkWindow       **child_window,
-                                gint             *root_x,
-                                gint             *root_y,
-                                gint             *win_x,
-                                gint             *win_y,
+                                gdouble          *root_x,
+                                gdouble          *root_y,
+                                gdouble          *win_x,
+                                gdouble          *win_y,
                                 GdkModifierType  *mask)
 {
   GdkWindowImplX11 *impl = GDK_WINDOW_IMPL_X11 (window->impl);
@@ -384,16 +388,16 @@ gdk_x11_device_xi2_query_state (GdkDevice        *device,
     *child_window = gdk_x11_window_lookup_for_display (display, xchild_window);
 
   if (root_x)
-    *root_x = (gint) (xroot_x / impl->window_scale);
+    *root_x = xroot_x / impl->window_scale;
 
   if (root_y)
-    *root_y = (gint) (xroot_y / impl->window_scale);
+    *root_y = xroot_y / impl->window_scale;
 
   if (win_x)
-    *win_x = (gint) (xwin_x / impl->window_scale);
+    *win_x = xwin_x / impl->window_scale;
 
   if (win_y)
-    *win_y = (gint) (xwin_y / impl->window_scale);
+    *win_y = xwin_y / impl->window_scale;
 
   if (mask)
     *mask = _gdk_x11_device_xi2_translate_state (&mod_state, &button_state, &group_state);
@@ -477,8 +481,8 @@ gdk_x11_device_xi2_ungrab (GdkDevice *device,
 
 static GdkWindow *
 gdk_x11_device_xi2_window_at_position (GdkDevice       *device,
-                                       gint            *win_x,
-                                       gint            *win_y,
+                                       gdouble         *win_x,
+                                       gdouble         *win_y,
                                        GdkModifierType *mask,
                                        gboolean         get_toplevel)
 {
@@ -633,10 +637,10 @@ gdk_x11_device_xi2_window_at_position (GdkDevice       *device,
     impl = GDK_WINDOW_IMPL_X11 (window->impl);
 
   if (win_x)
-    *win_x = (window) ? (gint) (xwin_x / impl->window_scale) : -1;
+    *win_x = (window) ? (xwin_x / impl->window_scale) : -1;
 
   if (win_y)
-    *win_y = (window) ? (gint) (xwin_y / impl->window_scale) : -1;
+    *win_y = (window) ? (xwin_y / impl->window_scale) : -1;
 
   if (mask)
     *mask = _gdk_x11_device_xi2_translate_state (&mod_state, &button_state, &group_state);
diff --git a/gdk/x11/gdkwindow-x11.c b/gdk/x11/gdkwindow-x11.c
index 49c1361ff8..f9a4335576 100644
--- a/gdk/x11/gdkwindow-x11.c
+++ b/gdk/x11/gdkwindow-x11.c
@@ -3242,8 +3242,8 @@ gdk_x11_window_get_frame_extents (GdkWindow    *window,
 static gboolean
 gdk_window_x11_get_device_state (GdkWindow       *window,
                                  GdkDevice       *device,
-                                 gint            *x,
-                                 gint            *y,
+                                 gdouble         *x,
+                                 gdouble         *y,
                                  GdkModifierType *mask)
 {
   GdkWindow *child;