Refactor widowing on macOS to support screen scale and highDpi mode

Source/Editor/Options/OptionsModule.cs

@@ -125,9 +125,12 @@ namespace FlaxEditor.Options
                             options.CustomSettings.Add(e.Key, JsonSerializer.Serialize(e.Value()));
                     }
 
+                    float prevInterfaceScale = Options.Interface.InterfaceScale;
                     Options = options;
                     OnOptionsChanged();
-                    Platform.CustomDpiScale = Options.Interface.InterfaceScale;
+
+                    // Scale interface relative to the current value (eg. when using system-provided Dpi Scale)
+                    Platform.CustomDpiScale *= Options.Interface.InterfaceScale / prevInterfaceScale;
                 }
                 else
                 {

Source/Editor/Windows/SplashScreen.cpp

@@ -153,7 +153,7 @@ void SplashScreen::Show()
     LOG(Info, "Showing splash screen");
 
     // Create window
-    const float dpiScale = (float)Platform::GetDpi() / (float)DefaultDPI;
+    const float dpiScale = Platform::GetDpiScale();
     CreateWindowSettings settings;
     settings.Title = TEXT("Flax Editor");
     settings.Size.X = 500 * dpiScale;

Source/Engine/Platform/Mac/MacPlatform.cpp

@@ -54,6 +54,8 @@ String UserLocale, ComputerName;
 double SecondsPerCycle;
 NSAutoreleasePool* AutoreleasePool = nullptr;
 
+float MacPlatform::ScreenScale = 1.0f;
+
 String MacUtils::ToString(CFStringRef str)
 {
     if (!str)
@@ -77,7 +79,7 @@ CFStringRef MacUtils::ToString(const StringView& str)
 Float2 MacUtils::PosToCoca(const Float2& pos)
 {
     // MacOS uses y-coordinate starting at the bottom of the screen
-    Float2 result = pos;
+    Float2 result = pos;// / MacPlatform::ScreenScale;
     result.Y *= -1;
     result += GetScreensOrigin();
     return result;
@@ -86,10 +88,10 @@ Float2 MacUtils::PosToCoca(const Float2& pos)
 Float2 MacUtils::CocaToPos(const Float2& pos)
 {
     // MacOS uses y-coordinate starting at the bottom of the screen
-    Float2 result = pos;
+    Float2 result = pos;// * MacPlatform::ScreenScale;
     result -= GetScreensOrigin();
     result.Y *= -1;
-    return result;
+    return result;// * MacPlatform::ScreenScale;
 }
 
 Float2 MacUtils::GetScreensOrigin()
@@ -100,6 +102,7 @@ Float2 MacUtils::GetScreensOrigin()
     {
         NSRect rect = [[screenArray objectAtIndex:i] frame];
         Float2 pos(rect.origin.x, rect.origin.y + rect.size.height);
+        pos *= MacPlatform::ScreenScale;
         if (pos.X < result.X)
             result.X = pos.X;
         if (pos.Y > result.Y)
@@ -423,11 +426,25 @@ bool MacPlatform::Init()
         OnPlatformUserAdd(New<User>(username));
     }
 
+    // Find the maximum scale of the display to handle high-dpi displays scaling factor
+    {
+	    NSArray* screenArray = [NSScreen screens];
+        for (int32 i = 0; i < (int32)[screenArray count]; i++)
+        {
+            if ([[screenArray objectAtIndex:i] respondsToSelector:@selector(backingScaleFactor)])
+            {
+				ScreenScale = Math::Max(ScreenScale, (float)[[screenArray objectAtIndex:i] backingScaleFactor]);
+            }
+        }
+        CustomDpiScale *= ScreenScale;
+    }
+
     // Init application
     [NSApplication sharedApplication];
     [NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
     NSMenu* mainMenu = [[[NSMenu alloc] initWithTitle:@""] autorelease];
     [NSApp setMainMenu:mainMenu];
+    // TODO: expose main menu for app (eg. to be used by Game or Editor on macOS-only)
     AutoreleasePool = [[NSAutoreleasePool alloc] init];
 
     Input::Mouse = New<MacMouse>();
@@ -479,6 +496,16 @@ void MacPlatform::Exit()
 {
 }
 
+void MacPlatform::SetHighDpiAwarenessEnabled(bool enable)
+{
+    // Disable resolution scaling in low dpi mode
+    if (!enable)
+    {
+        CustomDpiScale /= ScreenScale;
+        ScreenScale = 1.0f;
+    }
+}
+
 int32 MacPlatform::GetDpi()
 {
     CGDirectDisplayID mainDisplay = CGMainDisplayID();
@@ -551,13 +578,14 @@ void MacPlatform::SetMousePosition(const Float2& pos)
 Float2 MacPlatform::GetDesktopSize()
 {
     CGDirectDisplayID mainDisplay = CGMainDisplayID();
-    return Float2((float)CGDisplayPixelsWide(mainDisplay), (float)CGDisplayPixelsHigh(mainDisplay));
+    return Float2((float)CGDisplayPixelsWide(mainDisplay) * ScreenScale, (float)CGDisplayPixelsHigh(mainDisplay) * ScreenScale);
 }
 
 Rectangle GetDisplayBounds(CGDirectDisplayID display)
 {
     CGRect rect = CGDisplayBounds(display);
-    return Rectangle(rect.origin.x, rect.origin.y, rect.size.width, rect.size.height);
+    float screnScale = MacPlatform::ScreenScale;
+    return Rectangle(rect.origin.x * screnScale, rect.origin.y * screnScale, rect.size.width * screnScale, rect.size.height * screnScale);
 }
 
 Rectangle MacPlatform::GetMonitorBounds(const Float2& screenPos)

Source/Engine/Platform/Mac/MacPlatform.h

@@ -11,6 +11,9 @@
 /// </summary>
 class FLAXENGINE_API MacPlatform : public UnixPlatform
 {
+public:
+    static float ScreenScale;
+
 public:
 
     // [UnixPlatform]
@@ -82,6 +85,7 @@ public:
     static void Tick();
     static void BeforeExit();
     static void Exit();
+    static void SetHighDpiAwarenessEnabled(bool enable);
     static int32 GetDpi();
     static String GetUserLocaleName();
     static String GetComputerName();

Source/Engine/Platform/Mac/MacWindow.cpp

@@ -167,14 +167,14 @@ Float2 GetWindowTitleSize(const MacWindow* window)
         NSRect frameStart = [(NSWindow*)window->GetNativePtr() frameRectForContentRect:NSMakeRect(0, 0, 0, 0)];
         size.Y = frameStart.size.height;
     }
-    return size;
+    return size * MacPlatform::ScreenScale;
 }
 
 Float2 GetMousePosition(MacWindow* window, NSEvent* event)
 {
     NSRect frame = [(NSWindow*)window->GetNativePtr() frame];
     NSPoint point = [event locationInWindow];
-    return Float2(point.x, frame.size.height - point.y) - GetWindowTitleSize(window);
+    return Float2(point.x, frame.size.height - point.y) * MacPlatform::ScreenScale - GetWindowTitleSize(window);
 }
 
 class MacDropData : public IGuiData
@@ -255,17 +255,45 @@ NSDragOperation GetDragDropOperation(DragDropEffect dragDropEffect)
 
 @implementation MacWindowImpl
 
+- (void)windowDidBecomeKey:(NSNotification*)notification
+{
+	// Handle resizing to be sure that content has valid size when window was resized
+	[self windowDidResize:notification];
+
+    Window->OnGotFocus();
+}
+
+- (void)windowDidResignKey:(NSNotification*)notification
+{
+    Window->OnLostFocus();
+}
+
 - (void)windowWillClose:(NSNotification*)notification
 {
     [self setDelegate: nil];
     Window->Close(ClosingReason::User);
 }
 
+static void ConvertNSRect(NSScreen *screen, NSRect *r)
+{
+    r->origin.y = CGDisplayPixelsHigh(kCGDirectMainDisplay) - r->origin.y - r->size.height;
+}
+
 - (void)windowDidResize:(NSNotification*)notification
 {
     NSView* view = [self contentView];
-    NSRect contextRect = [view frame];
+    const float screenScale = MacPlatform::ScreenScale;
-    Window->CheckForResize((float)contextRect.size.width, (float)contextRect.size.height);
+    NSWindow* nswindow = (NSWindow*)Window->GetNativePtr();
+    NSRect rect = [nswindow contentRectForFrameRect:[nswindow frame]];
+    ConvertNSRect([nswindow screen], &rect);
+
+    // Rescale contents
+	CALayer* layer = [view layer];
+	if (layer)
+		layer.contentsScale = screenScale;
+
+    // Resize window
+    Window->CheckForResize((float)rect.size.width * screenScale, (float)rect.size.height * screenScale);
 }
 
 - (void)setWindow:(MacWindow*)window
@@ -565,6 +593,12 @@ MacWindow::MacWindow(const CreateWindowSettings& settings)
         styleMask &= ~NSWindowStyleMaskFullSizeContentView;
     }
 
+    const float screenScale = MacPlatform::ScreenScale;
+    frame.origin.x /= screenScale;
+    frame.origin.y /= screenScale;
+    frame.size.width /= screenScale;
+    frame.size.height /= screenScale;
+
     MacWindowImpl* window = [[MacWindowImpl alloc] initWithContentRect:frame
         styleMask:(styleMask)
         backing:NSBackingStoreBuffered
@@ -587,6 +621,11 @@ MacWindow::MacWindow(const CreateWindowSettings& settings)
         [view registerForDraggedTypes:@[NSPasteboardTypeFileURL, NSPasteboardTypeString]];
     }
 
+    // Rescale contents
+	CALayer* layer = [view layer];
+	if (layer)
+		layer.contentsScale = screenScale;
+
     // TODO: impl Parent for MacWindow
     // TODO: impl StartPosition for MacWindow
     // TODO: impl Fullscreen for MacWindow
@@ -618,17 +657,19 @@ void MacWindow::SetIsMouseOver(bool value)
     if (_isMouseOver == value)
         return;
     _isMouseOver = value;
+    CursorType cursor = _cursor;
     if (value)
     {
         // Refresh cursor typet
-        SetCursor(_cursor);
+        SetCursor(CursorType::Default);
+        SetCursor(cursor);
         
     }
     else
     {
 	    Input::Mouse->OnMouseLeave(this);
-        if (_cursor == CursorType::Hidden)
+        SetCursor(CursorType::Default);
-            [NSCursor unhide];
+        _cursor = cursor;
     }
 }
 
@@ -665,6 +706,8 @@ void MacWindow::Hide()
 {
     if (_visible)
     {
+        SetCursor(CursorType::Default);
+
         // Hide
         NSWindow* window = (NSWindow*)_window;
         [window orderOut:nil];
@@ -710,7 +753,7 @@ bool MacWindow::IsClosed() const
 
 bool MacWindow::IsForegroundWindow() const
 {
-    return Platform::GetHasFocus();
+    return Platform::GetHasFocus() && IsFocused();
 }
 
 void MacWindow::BringToFront(bool force)
@@ -749,7 +792,7 @@ void MacWindow::SetPosition(const Float2& position)
     NSWindow* window = (NSWindow*)_window;
     if (!window)
         return;
-    Float2 pos = MacUtils::PosToCoca(position);
+    Float2 pos = MacUtils::PosToCoca(position) / MacPlatform::ScreenScale;
     NSRect rect = [window frame];
     [window setFrameOrigin:NSMakePoint(pos.X, pos.Y - rect.size.height)];
 }
@@ -760,7 +803,7 @@ Float2 MacWindow::GetPosition() const
     if (!window)
         return Float2::Zero;
     NSRect rect = [window frame];
-    return MacUtils::CocaToPos(Float2(rect.origin.x, rect.origin.y + rect.size.height));
+    return MacUtils::CocaToPos(Float2(rect.origin.x, rect.origin.y + rect.size.height) * MacPlatform::ScreenScale);
 }
 
 Float2 MacWindow::GetSize() const
@@ -769,7 +812,7 @@ Float2 MacWindow::GetSize() const
     if (!window)
         return Float2::Zero;
     NSRect rect = [window frame];
-    return Float2(rect.size.width, rect.size.height);
+    return Float2(rect.size.width, rect.size.height) * MacPlatform::ScreenScale;
 }
 
 Float2 MacWindow::GetClientSize() const
@@ -836,6 +879,9 @@ DragDropEffect MacWindow::DoDragDrop(const StringView& data)
 
 void MacWindow::SetCursor(CursorType type)
 {
+    CursorType prev = _cursor;
+    if (prev == type)
+        return;
 	WindowBase::SetCursor(type);
     //if (!_isMouseOver)
     //    return;
@@ -874,8 +920,11 @@ void MacWindow::SetCursor(CursorType type)
     }
     if (cursor)
     {
+        if (prev == CursorType::Hidden)
+        {
+            [NSCursor unhide];
+        }
         [cursor set];
-        [NSCursor unhide];
     }
 }