From 49b4e65facbe84018c2726431e87f642339fa731 Mon Sep 17 00:00:00 2001
From: AliKet <AliDev2007@yahoo.fr>
Date: Mon, 20 Apr 2026 00:23:20 +0100
Subject: [PATCH] wxDC::LogicalToDevice{Rel}() now return unmirrored
 coordinates in RTL under wxMSW

Ditto for wxDC::DeviceToLogical{Rel}() functions.

In RTL layout, these functions always return unmirrored coordinates under wxGTK3
and wxQt. This is now the case under wxMSW too for consistency and also to fix
double-mirroring problem when passing the transformed coordinates to GDI drawing
functions. See wxGrid::Render() for example.
---
 include/wx/msw/private/dc.h | 28 ++++++++++++++++++++++++++++
 src/msw/dc.cpp              |  8 ++++++++
 2 files changed, 36 insertions(+)

diff --git a/include/wx/msw/private/dc.h b/include/wx/msw/private/dc.h
index 303cd19df6..b6355154bf 100644
--- a/include/wx/msw/private/dc.h
+++ b/include/wx/msw/private/dc.h
@@ -141,6 +141,34 @@ private:
     wxDECLARE_NO_COPY_CLASS(wxBkModeChanger);
 };
 
+// ----------------------------------------------------------------------------
+// Class to temporarily disable RTL layout if already set on the device context
+// ----------------------------------------------------------------------------
+
+// For consistency with wxGTK and wxQt, wxDC::LogicalToDevice{Rel}() and
+// DeviceToLogical{Rel}() functions should return unmirrored coordinates
+// in RTL layout to avoid double-mirroring when their results are passed
+// to GDI drawing functions.
+class wxScopedRTLDisabler
+{
+public:
+    explicit wxScopedRTLDisabler(HDC hdc)
+        : m_hdc(hdc), m_oldLayoutDir(::SetLayout(hdc, 0))
+    {
+    }
+
+    ~wxScopedRTLDisabler()
+    {
+        ::SetLayout(m_hdc, m_oldLayoutDir);
+    }
+
+private:
+    HDC m_hdc;
+    const DWORD m_oldLayoutDir;
+
+    wxDECLARE_NO_COPY_CLASS(wxScopedRTLDisabler);
+};
+
 } // namespace wxMSWImpl
 
 #endif // _MSW_PRIVATE_DC_H_
diff --git a/src/msw/dc.cpp b/src/msw/dc.cpp
index 486ba71a71..08b8bb4dc1 100644
--- a/src/msw/dc.cpp
+++ b/src/msw/dc.cpp
@@ -1969,6 +1969,8 @@ void wxMSWDCImpl::SetDeviceOrigin(wxCoord x, wxCoord y)
 
 wxPoint wxMSWDCImpl::DeviceToLogical(wxCoord x, wxCoord y) const
 {
+    wxScopedRTLDisabler disableRTL(GetHdc());
+
     POINT p;
     p.x = x;
     p.y = y;
@@ -2015,6 +2017,8 @@ wxPoint wxMSWDCImpl::DeviceToLogical(wxCoord x, wxCoord y) const
 
 wxPoint wxMSWDCImpl::LogicalToDevice(wxCoord x, wxCoord y) const
 {
+    wxScopedRTLDisabler disableRTL(GetHdc());
+
     POINT p;
     p.x = x;
     p.y = y;
@@ -2024,6 +2028,8 @@ wxPoint wxMSWDCImpl::LogicalToDevice(wxCoord x, wxCoord y) const
 
 wxSize wxMSWDCImpl::DeviceToLogicalRel(int x, int y) const
 {
+    wxScopedRTLDisabler disableRTL(GetHdc());
+
     POINT p[2];
     p[0].x = 0;
     p[0].y = 0;
@@ -2035,6 +2041,8 @@ wxSize wxMSWDCImpl::DeviceToLogicalRel(int x, int y) const
 
 wxSize wxMSWDCImpl::LogicalToDeviceRel(int x, int y) const
 {
+    wxScopedRTLDisabler disableRTL(GetHdc());
+
     POINT p[2];
     p[0].x = 0;
     p[0].y = 0;