Fix setting clipping region for wxDC with rotated coordinate system (wxMSW)

We cannot assume that axis-aligned clipping box in local coordinates will
remain axis-aligned box in device coordinates so we need to take into
account all 4 corners of the clipping rectangle to create a polygonal
clipping region in device space.

Closes #19228.

src/msw/dc.cpp

@@ -642,13 +642,29 @@ void wxMSWDCImpl::DoSetClippingRegion(wxCoord x, wxCoord y, wxCoord w, wxCoord h
         h = -h;
         y -= (h - 1);
     }
-    HRGN hrgn = ::CreateRectRgn(LogicalToDeviceX(x),
-                                LogicalToDeviceY(y),
-                                LogicalToDeviceX(x + w),
-                                LogicalToDeviceY(y + h));
+    // Because world transform can be applied to HDC and its coordiante
+    // system may be e.g. rotated we shouldn't assume that axis-aligned
+    // clipping box in local coordinates will remain axis-aligned box in
+    // device coordinates. Therefore we need to take into account all
+    // 4 corners of the rectangle to create a polygonal clipping region
+    // in device coordinates.
+    POINT rect[4];
+    wxPoint p = LogicalToDevice(x, y);
+    rect[0].x = p.x;
+    rect[0].y = p.y;
+    p = LogicalToDevice(x + w, y);
+    rect[1].x = p.x;
+    rect[1].y = p.y;
+    p = LogicalToDevice(x + w, y + h);
+    rect[2].x = p.x;
+    rect[2].y = p.y;
+    p = LogicalToDevice(x, y + h);
+    rect[3].x = p.x;
+    rect[3].y = p.y;
+    HRGN hrgn = ::CreatePolygonRgn(rect, WXSIZEOF(rect), WINDING);
     if ( !hrgn )
     {
-        wxLogLastError(wxT("CreateRectRgn"));
+        wxLogLastError(wxT("CreatePolygonRgn"));
     }
     else
     {