Avoid wxGraphicsContext offsetting on HiDPI displays

For a typical scale factor of 2, there won't be any odd-width lines,
and for any factor greater than 1.0, it won't be doing what was intended,
so just don't do it. See #17375

src/generic/graphicc.cpp

@@ -1724,7 +1724,7 @@ wxCairoContext::wxCairoContext( wxGraphicsRenderer* renderer, const wxWindowDC&
     m_width = width;
     m_height = height;
 
-    m_enableOffset = true;
+    m_enableOffset = dc.GetContentScaleFactor() <= 1;
 
 #ifdef __WXMSW__
     m_mswSurface = cairo_win32_surface_create((HDC)dc.GetHDC());
@@ -1789,7 +1789,7 @@ wxCairoContext::wxCairoContext( wxGraphicsRenderer* renderer, const wxMemoryDC&
     m_width = width;
     m_height = height;
 
-    m_enableOffset = true;
+    m_enableOffset = dc.GetContentScaleFactor() <= 1;
 
 #ifdef __WXMSW__
 
@@ -1919,7 +1919,7 @@ wxCairoContext::wxCairoContext( wxGraphicsRenderer* renderer, wxWindow *window)
     , m_mswWindowHDC(GetHwndOf(window))
 #endif
 {
-    m_enableOffset = true;    
+    m_enableOffset = window->GetContentScaleFactor() <= 1;
 #ifdef __WXGTK__
     // something along these lines (copied from dcclient)
 

src/gtk/dc.cpp

@@ -210,7 +210,7 @@ wxWindowDCImpl::wxWindowDCImpl(wxWindowDC* owner, wxWindow* window)
     {
         cairo_t* cr = gdk_cairo_create(gdkWindow);
         wxGraphicsContext* gc = wxGraphicsContext::CreateFromNative(cr);
-        gc->EnableOffset(true);
+        gc->EnableOffset(m_contentScaleFactor <= 1);
         SetGraphicsContext(gc);
         GtkAllocation a;
         gtk_widget_get_allocation(widget, &a);
@@ -255,7 +255,7 @@ wxClientDCImpl::wxClientDCImpl(wxClientDC* owner, wxWindow* window)
     {
         cairo_t* cr = gdk_cairo_create(gdkWindow);
         wxGraphicsContext* gc = wxGraphicsContext::CreateFromNative(cr);
-        gc->EnableOffset(true);
+        gc->EnableOffset(m_contentScaleFactor <= 1);
         SetGraphicsContext(gc);
         if (gtk_widget_get_has_window(widget))
         {
@@ -288,7 +288,7 @@ wxPaintDCImpl::wxPaintDCImpl(wxPaintDC* owner, wxWindow* window)
     m_height = gdk_window_get_height(gdkWindow);
     cairo_reference(cr);
     wxGraphicsContext* gc = wxGraphicsContext::CreateFromNative(cr);
-    gc->EnableOffset(true);
+    gc->EnableOffset(m_contentScaleFactor <= 1);
     SetGraphicsContext(gc);
 }
 //-----------------------------------------------------------------------------
@@ -301,7 +301,7 @@ wxScreenDCImpl::wxScreenDCImpl(wxScreenDC* owner)
     m_height = gdk_window_get_height(window);
     cairo_t* cr = gdk_cairo_create(window);
     wxGraphicsContext* gc = wxGraphicsContext::CreateFromNative(cr);
-    gc->EnableOffset(true);
+    gc->EnableOffset(m_contentScaleFactor <= 1);
     SetGraphicsContext(gc);
 }
 //-----------------------------------------------------------------------------
@@ -357,7 +357,7 @@ void wxMemoryDCImpl::Setup()
         m_contentScaleFactor = m_bitmap.GetScaleFactor();
         cairo_t* cr = m_bitmap.CairoCreate();
         gc = wxGraphicsContext::CreateFromNative(cr);
-        gc->EnableOffset(true);
+        gc->EnableOffset(m_contentScaleFactor <= 1);
     }
     SetGraphicsContext(gc);
 }
@@ -368,7 +368,7 @@ wxGTKCairoDC::wxGTKCairoDC(cairo_t* cr, wxWindow* window)
 {
     cairo_reference(cr);
     wxGraphicsContext* gc = wxGraphicsContext::CreateFromNative(cr);
-    gc->EnableOffset(true);
+    gc->EnableOffset(window->GetContentScaleFactor() <= 1);
     SetGraphicsContext(gc);
 }
 

src/osx/carbon/dcclient.cpp

@@ -76,7 +76,7 @@ wxWindowDCImpl::wxWindowDCImpl( wxDC *owner, wxWindow *window )
             CGContextTranslateCTM( cg , -window->MacGetLeftBorderSize() , -window->MacGetTopBorderSize() );
 
         wxGraphicsContext* context = wxGraphicsContext::CreateFromNative( cg );
-        context->EnableOffset(true);
+        context->EnableOffset(m_contentScaleFactor <= 1);
         SetGraphicsContext( context );
     }
     DoSetClippingRegion( 0 , 0 , m_width , m_height ) ;

src/osx/carbon/graphics.cpp

@@ -1532,7 +1532,7 @@ wxMacCoreGraphicsContext::wxMacCoreGraphicsContext( wxGraphicsRenderer* renderer
 {
     Init();
 
-    m_enableOffset = true;
+    m_enableOffset = window->GetContentScaleFactor() <= 1;
     wxSize sz = window->GetSize();
     m_width = sz.x;
     m_height = sz.y;
@@ -2622,7 +2622,7 @@ wxGraphicsContext * wxMacCoreGraphicsRenderer::CreateContext( const wxWindowDC&
         // this is the case for all wxWindowDCs except wxPaintDC
         wxMacCoreGraphicsContext *context = 
             new wxMacCoreGraphicsContext( this, cgctx, (wxDouble) w, (wxDouble) h );
-        context->EnableOffset(true);
+        context->EnableOffset(dc.GetContentScaleFactor() < 2);
         return context;
     }
     return NULL;
@@ -2639,7 +2639,7 @@ wxGraphicsContext * wxMacCoreGraphicsRenderer::CreateContext( const wxMemoryDC&
         mem_impl->GetSize( &w, &h );
         wxMacCoreGraphicsContext* context = new wxMacCoreGraphicsContext( this,
             (CGContextRef)(mem_impl->GetGraphicsContext()->GetNativeContext()), (wxDouble) w, (wxDouble) h );
-        context->EnableOffset(true);
+        context->EnableOffset(dc.GetContentScaleFactor() < 2);
         return context;
     }
 #endif

src/osx/core/dcmemory.cpp

@@ -87,7 +87,7 @@ void wxMemoryDCImpl::DoSelect( const wxBitmap& bitmap )
             CGContextSetStrokeColorSpace( bmCtx, genericColorSpace );
             SetGraphicsContext( wxGraphicsContext::CreateFromNative( bmCtx ) );
             if (m_graphicContext)
-                m_graphicContext->EnableOffset(true);
+                m_graphicContext->EnableOffset(m_contentScaleFactor <= 1);
         }
         m_ok = (m_graphicContext != NULL) ;
     }