[hidpi] Add High DPI support for all platforms

wxWidgets now supports High DPI natively.

src/wx/macsupport.mm

@@ -7,22 +7,6 @@
 #include "wxvbam.h"
 #include "drawing.h"
 
-double HiDPIAware::HiDPIScaleFactor()
-{
-    if (hidpi_scale_factor == 0) {
-        NSWindow* window = [(NSView*)GetWindow()->GetHandle() window];
-
-        if ([window respondsToSelector:@selector(backingScaleFactor)]) {
-            hidpi_scale_factor = [window backingScaleFactor];
-        }
-        else {
-            hidpi_scale_factor = 1.0;
-        }
-    }
-
-    return hidpi_scale_factor;
-}
-
 void HiDPIAware::RequestHighResolutionOpenGLSurface()
 {
     NSView* view = (NSView*)(GetWindow()->GetHandle());
@@ -32,16 +16,6 @@ void HiDPIAware::RequestHighResolutionOpenGLSurface()
     }
 }
 
-void HiDPIAware::GetRealPixelClientSize(int* x, int* y)
-{
-    NSView* view = (NSView*)(GetWindow()->GetHandle());
-
-    NSSize backing_size = [view convertSizeToBacking:view.bounds.size];
-
-    *x = backing_size.width;
-    *y = backing_size.height;
-}
-
 Quartz2DDrawingPanel::Quartz2DDrawingPanel(wxWindow* parent, int _width, int _height)
     : BasicDrawingPanel(parent, _width, _height)
 {

src/wx/panel.cpp

@@ -745,12 +745,12 @@ void GameArea::DelBorder()
 void GameArea::AdjustMinSize()
 {
     wxWindow* frame           = wxGetApp().frame;
-    double hidpi_scale_factor = HiDPIScaleFactor();
+    double hidpi_scale_factor = GetDPIScaleFactor();
 
     // note: could safely set min size to 1x or less regardless of video_scale
     // but setting it to scaled size makes resizing to default easier
-    wxSize sz((std::ceil(basic_width  * gopts.video_scale) / hidpi_scale_factor),
-              (std::ceil(basic_height * gopts.video_scale) / hidpi_scale_factor));
+    wxSize sz((std::ceil(basic_width  * gopts.video_scale) * hidpi_scale_factor),
+              (std::ceil(basic_height * gopts.video_scale) * hidpi_scale_factor));
     SetMinSize(sz);
 #if wxCHECK_VERSION(2, 8, 8)
     sz = frame->ClientToWindowSize(sz);
@@ -763,10 +763,10 @@ void GameArea::AdjustMinSize()
 void GameArea::LowerMinSize()
 {
     wxWindow* frame           = wxGetApp().frame;
-    double hidpi_scale_factor = HiDPIScaleFactor();
+    double hidpi_scale_factor = GetDPIScaleFactor();
 
-    wxSize sz(std::ceil(basic_width  / hidpi_scale_factor),
-              std::ceil(basic_height / hidpi_scale_factor));
+    wxSize sz(std::ceil(basic_width  * hidpi_scale_factor),
+              std::ceil(basic_height * hidpi_scale_factor));
 
     SetMinSize(sz);
     // do not take decorations into account
@@ -780,9 +780,9 @@ void GameArea::AdjustSize(bool force)
     if (fullscreen)
         return;
 
-    double hidpi_scale_factor = HiDPIScaleFactor();
-    const wxSize newsz((std::ceil(basic_width  * gopts.video_scale) / hidpi_scale_factor),
-                       (std::ceil(basic_height * gopts.video_scale) / hidpi_scale_factor));
+    double hidpi_scale_factor = GetDPIScaleFactor();
+    const wxSize newsz((std::ceil(basic_width  * gopts.video_scale) * hidpi_scale_factor),
+                       (std::ceil(basic_height * gopts.video_scale) * hidpi_scale_factor));
 
     if (!force) {
         wxSize sz = GetClientSize();
@@ -2251,7 +2251,7 @@ void GLDrawingPanel::AdjustViewport()
 #endif
 
     int x, y;
-    GetRealPixelClientSize(&x, &y);
+    GetClientSize(&x, &y);
     glViewport(0, 0, x, y);
 
 #ifdef DEBUG
@@ -2515,23 +2515,7 @@ void GameArea::ShowMenuBar()
 #endif
 }
 
-// stub HiDPI methods, see macsupport.mm for the Mac support
 #ifndef __WXMAC__
-double HiDPIAware::HiDPIScaleFactor()
-{
-    if (hidpi_scale_factor == 0) {
-        hidpi_scale_factor = 1.0;
-    }
-
-    return hidpi_scale_factor;
-}
-
-void HiDPIAware::RequestHighResolutionOpenGLSurface()
-{
-}
-
-void HiDPIAware::GetRealPixelClientSize(int* x, int* y)
-{
-    GetWindow()->GetClientSize(x, y);
-}
-#endif // HiDPI stubs
+// stub HiDPI method, see macsupport.mm for the Mac support
+void HiDPIAware::RequestHighResolutionOpenGLSurface() {}
+#endif  // __WXMAC__ stub

src/wx/wxvbam.h

@@ -391,13 +391,9 @@ private:
 // helper class to add HiDPI awareness (mostly for Mac OS X)
 class HiDPIAware {
 public:
-    HiDPIAware() { hidpi_scale_factor = 0; }
-    virtual double HiDPIScaleFactor();
+    HiDPIAware() =  default;
     virtual void RequestHighResolutionOpenGLSurface();
-    virtual void GetRealPixelClientSize(int* x, int* y);
     virtual wxWindow* GetWindow() = 0;
-private:
-    double hidpi_scale_factor;
 };
 
 // a class for polling joystick keys