[macOS, 3.2] Implement seamless display scaling.

core/bind/core_bind.cpp

@@ -320,6 +320,14 @@ int _OS::get_screen_dpi(int p_screen) const {
 	return OS::get_singleton()->get_screen_dpi(p_screen);
 }
 
+float _OS::get_screen_scale(int p_screen) const {
+	return OS::get_singleton()->get_screen_scale(p_screen);
+}
+
+float _OS::get_screen_max_scale() const {
+	return OS::get_singleton()->get_screen_max_scale();
+}
+
 Point2 _OS::get_window_position() const {
 	return OS::get_singleton()->get_window_position();
 }
@@ -1252,6 +1260,8 @@ void _OS::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_screen_position", "screen"), &_OS::get_screen_position, DEFVAL(-1));
 	ClassDB::bind_method(D_METHOD("get_screen_size", "screen"), &_OS::get_screen_size, DEFVAL(-1));
 	ClassDB::bind_method(D_METHOD("get_screen_dpi", "screen"), &_OS::get_screen_dpi, DEFVAL(-1));
+	ClassDB::bind_method(D_METHOD("get_screen_scale", "screen"), &_OS::get_screen_scale, DEFVAL(-1));
+	ClassDB::bind_method(D_METHOD("get_screen_max_scale"), &_OS::get_screen_max_scale);
 	ClassDB::bind_method(D_METHOD("get_window_position"), &_OS::get_window_position);
 	ClassDB::bind_method(D_METHOD("set_window_position", "position"), &_OS::set_window_position);
 	ClassDB::bind_method(D_METHOD("get_window_size"), &_OS::get_window_size);

core/bind/core_bind.h

@@ -178,6 +178,8 @@ class _OS : public Object {
 	virtual Point2 get_screen_position(int p_screen = -1) const;
 	virtual Size2 get_screen_size(int p_screen = -1) const;
 	virtual int get_screen_dpi(int p_screen = -1) const;
+	virtual float get_screen_scale(int p_screen = -1) const;
+	virtual float get_screen_max_scale() const;
 	virtual Point2 get_window_position() const;
 	virtual void set_window_position(const Point2 &p_position);
 	virtual Size2 get_max_window_size() const;

core/os/os.h

@@ -209,6 +209,8 @@ class OS {
 	virtual Point2 get_screen_position(int p_screen = -1) const { return Point2(); }
 	virtual Size2 get_screen_size(int p_screen = -1) const { return get_window_size(); }
 	virtual int get_screen_dpi(int p_screen = -1) const { return 72; }
+	virtual float get_screen_scale(int p_screen = -1) const { return 1.0; }
+	virtual float get_screen_max_scale() const { return 1.0; };
 	virtual Point2 get_window_position() const { return Vector2(); }
 	virtual void set_window_position(const Point2 &p_position) {}
 	virtual Size2 get_max_window_size() const { return Size2(); };

doc/classes/OS.xml

@@ -362,6 +362,15 @@
 				[b]Note:[/b] This method is implemented on Android, Linux, macOS and Windows. Returns [code]72[/code] on unsupported platforms.
 			</description>
 		</method>
+		<method name="get_screen_max_scale" qualifiers="const">
+			<return type="float">
+			</return>
+			<description>
+				Return the greatest scale factor of all screens.
+				[b]Note:[/b] On macOS returned value is [code]2.0[/code] if there is at least one hiDPI (Retina) screen in the system, and [code]1.0[/code] in all other cases.
+				[b]Note:[/b] This method is implemented on macOS.
+			</description>
+		</method>
 		<method name="get_screen_position" qualifiers="const">
 			<return type="Vector2">
 			</return>
@@ -371,6 +380,17 @@
 				Returns the position of the specified screen by index. If [code]screen[/code] is [/code]-1[/code] (the default value), the current screen will be used.
 			</description>
 		</method>
+		<method name="get_screen_scale" qualifiers="const">
+			<return type="float">
+			</return>
+			<argument index="0" name="screen" type="int" default="-1">
+			</argument>
+			<description>
+				Return the scale factor of the specified screen by index. If [code]screen[/code] is [/code]-1[/code] (the default value), the current screen will be used.
+				[b]Note:[/b] On macOS returned value is [code]2.0[/code] for hiDPI (Retina) screen, and [code]1.0[/code] for all other cases.
+				[b]Note:[/b] This method is implemented on macOS.
+			</description>
+		</method>
 		<method name="get_screen_size" qualifiers="const">
 			<return type="Vector2">
 			</return>

editor/editor_node.cpp

@@ -5652,8 +5652,12 @@ EditorNode::EditorNode() {
 		switch (display_scale) {
 			case 0: {
 				// Try applying a suitable display scale automatically
+#ifdef OSX_ENABLED
+				editor_set_scale(OS::get_singleton()->get_screen_max_scale());
+#else
 				const int screen = OS::get_singleton()->get_current_screen();
 				editor_set_scale(OS::get_singleton()->get_screen_dpi(screen) >= 192 && OS::get_singleton()->get_screen_size(screen).x > 2000 ? 2.0 : 1.0);
+#endif
 			} break;
 
 			case 1: {

editor/editor_run.cpp

@@ -112,22 +112,31 @@ Error EditorRun::run(const String &p_scene, const String &p_custom_args, const L
 	}
 
 	int window_placement = EditorSettings::get_singleton()->get("run/window_placement/rect");
+	bool hidpi_proj = ProjectSettings::get_singleton()->get("display/window/dpi/allow_hidpi");
+	int display_scale = 1;
+	if (OS::get_singleton()->is_hidpi_allowed()) {
+		if (hidpi_proj) {
+			display_scale = 1; // Both editor and project runs in hiDPI mode, do not scale.
+		} else {
+			display_scale = OS::get_singleton()->get_screen_max_scale(); // Editor is in hiDPI mode, project is not, scale down.
+		}
+	} else {
+		if (hidpi_proj) {
+			display_scale = (1.f / OS::get_singleton()->get_screen_max_scale()); // Editor is not in hiDPI mode, project is, scale up.
+		} else {
+			display_scale = 1; // Both editor and project runs in lowDPI mode, do not scale.
+		}
+	}
+	screen_rect.position /= display_scale;
+	screen_rect.size /= display_scale;
 
 	switch (window_placement) {
 		case 0: { // top left
-
 			args.push_back("--position");
 			args.push_back(itos(screen_rect.position.x) + "," + itos(screen_rect.position.y));
 		} break;
 		case 1: { // centered
-			int display_scale = 1;
-#ifdef OSX_ENABLED
-			if (OS::get_singleton()->get_screen_dpi(screen) >= 192 && OS::get_singleton()->get_screen_size(screen).x > 2000) {
-				display_scale = 2;
-			}
-#endif
-
-			Vector2 pos = screen_rect.position + ((screen_rect.size / display_scale - desired_size) / 2).floor();
+			Vector2 pos = screen_rect.position + ((screen_rect.size - desired_size) / 2).floor();
 			args.push_back("--position");
 			args.push_back(itos(pos.x) + "," + itos(pos.y));
 		} break;
@@ -142,10 +151,8 @@ Error EditorRun::run(const String &p_scene, const String &p_custom_args, const L
 			args.push_back("--position");
 			args.push_back(itos(pos.x) + "," + itos(pos.y));
 			args.push_back("--maximized");
-
 		} break;
 		case 4: { // force fullscreen
-
 			Vector2 pos = screen_rect.position;
 			args.push_back("--position");
 			args.push_back(itos(pos.x) + "," + itos(pos.y));

editor/project_manager.cpp

@@ -2406,8 +2406,12 @@ ProjectManager::ProjectManager() {
 		switch (display_scale) {
 			case 0: {
 				// Try applying a suitable display scale automatically
+#ifdef OSX_ENABLED
+				editor_set_scale(OS::get_singleton()->get_screen_max_scale());
+#else
 				const int screen = OS::get_singleton()->get_current_screen();
 				editor_set_scale(OS::get_singleton()->get_screen_dpi(screen) >= 192 && OS::get_singleton()->get_screen_size(screen).x > 2000 ? 2.0 : 1.0);
+#endif
 			} break;
 
 			case 1: editor_set_scale(0.75); break;
@@ -2425,11 +2429,8 @@ ProjectManager::ProjectManager() {
 		// Define a minimum window size to prevent UI elements from overlapping or being cut off
 		OS::get_singleton()->set_min_window_size(Size2(750, 420) * EDSCALE);
 
-#ifndef OSX_ENABLED
-		// The macOS platform implementation uses its own hiDPI window resizing code
 		// TODO: Resize windows on hiDPI displays on Windows and Linux and remove the line below
 		OS::get_singleton()->set_window_size(OS::get_singleton()->get_window_size() * MAX(1, EDSCALE));
-#endif
 	}
 
 	FileDialog::set_default_show_hidden_files(EditorSettings::get_singleton()->get("filesystem/file_dialog/show_hidden_files"));

platform/osx/os_osx.h

@@ -145,16 +145,6 @@ class OS_OSX : public OS_Unix {
 
 	CrashHandler crash_handler;
 
-	float _mouse_scale(float p_scale) {
-		if (_display_scale() > 1.0)
-			return p_scale;
-		else
-			return 1.0;
-	}
-
-	float _display_scale() const;
-	float _display_scale(id screen) const;
-
 	void _update_window();
 
 	int video_driver_index;
@@ -269,6 +259,8 @@ class OS_OSX : public OS_Unix {
 	virtual Point2 get_screen_position(int p_screen = -1) const;
 	virtual Size2 get_screen_size(int p_screen = -1) const;
 	virtual int get_screen_dpi(int p_screen = -1) const;
+	virtual float get_screen_scale(int p_screen = -1) const;
+	virtual float get_screen_max_scale() const;
 
 	virtual Point2 get_window_position() const;
 	virtual void set_window_position(const Point2 &p_position);