From 8a6d6fe6b1107218f82ac8a9157aed5d30a0f67e Mon Sep 17 00:00:00 2001
From: Luca Bacci <luca.bacci982@gmail.com>
Date: Thu, 19 May 2022 15:04:41 +0200
Subject: [PATCH] DirectManipulation: Account for DPI scale

---
 gdk/win32/gdkinput-dmanipulation.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/gdk/win32/gdkinput-dmanipulation.c b/gdk/win32/gdkinput-dmanipulation.c
index 82b60e209b..942db6cdc2 100644
--- a/gdk/win32/gdkinput-dmanipulation.c
+++ b/gdk/win32/gdkinput-dmanipulation.c
@@ -167,8 +167,10 @@ DManipEventHandler_OnContentUpdated (IDirectManipulationViewportEventHandler *se
     {
     case GESTURE_PAN:
       {
+        GdkWin32Surface *surface_win32;
         GdkModifierType state;
         uint32_t time;
+        int scale;
         float pan_x;
         float pan_y;
         GdkEvent *event;
@@ -176,14 +178,16 @@ DManipEventHandler_OnContentUpdated (IDirectManipulationViewportEventHandler *se
         pan_x = transform[4];
         pan_y = transform[5];
 
+        surface_win32 = GDK_WIN32_SURFACE (self->surface);
+        scale = surface_win32->surface_scale;
         state = util_get_modifier_state ();
         time = (uint32_t) GetMessageTime ();
 
         event = gdk_scroll_event_new (self->surface,
                                       self->device,
                                       NULL, time, state,
-                                      self->pan_x - pan_x,
-                                      self->pan_y - pan_y,
+                                      (self->pan_x - pan_x) / scale,
+                                      (self->pan_y - pan_y) / scale,
                                       FALSE,
                                       GDK_SCROLL_UNIT_SURFACE);
         _gdk_win32_append_event (event);