[macOS] Add exclusive fullscreen mode with Dock and Menu disabled.

doc/classes/DisplayServer.xml

@@ -1638,8 +1638,9 @@
 			Regardless of the platform, enabling full screen will change the window size to match the monitor's size. Therefore, make sure your project supports [url=$DOCS_URL/tutorials/rendering/multiple_resolutions.html]multiple resolutions[/url] when enabling full screen mode.
 		</constant>
 		<constant name="WINDOW_MODE_EXCLUSIVE_FULLSCREEN" value="4" enum="WindowMode">
-			Exclusive full screen window mode. This mode is implemented on Windows only. On other platforms, it is equivalent to [constant WINDOW_MODE_FULLSCREEN].
-			Only one window in exclusive full screen mode can be visible on a given screen at a time. If multiple windows are in exclusive full screen mode for the same screen, the last one being set to this mode takes precedence.
+			Exclusive full screen window mode. This mode is implemented on Windows and macOS only. On other platforms, it is equivalent to [constant WINDOW_MODE_FULLSCREEN].
+			[b]On Windows:[/b] Only one window in exclusive full screen mode can be visible on a given screen at a time. If multiple windows are in exclusive full screen mode for the same screen, the last one being set to this mode takes precedence.
+			[b]On macOS:[/b] Exclusive full-screen mode prevents Dock and Menu from showing up when the mouse pointer is hovering the edge of the screen.
 			Regardless of the platform, enabling full screen will change the window size to match the monitor's size. Therefore, make sure your project supports [url=$DOCS_URL/tutorials/rendering/multiple_resolutions.html]multiple resolutions[/url] when enabling full screen mode.
 		</constant>
 		<constant name="WINDOW_FLAG_RESIZE_DISABLED" value="0" enum="WindowFlags">

platform/macos/display_server_macos.h

@@ -106,6 +106,7 @@ class DisplayServerMacOS : public DisplayServer {
 
 		bool layered_window = false;
 		bool fullscreen = false;
+		bool exclusive_fullscreen = false;
 		bool on_top = false;
 		bool borderless = false;
 		bool resize_disabled = false;

platform/macos/display_server_macos.mm

@@ -2584,7 +2584,13 @@
 				[wd.window_object setContentMaxSize:NSMakeSize(size.x, size.y)];
 			}
 			[wd.window_object toggleFullScreen:nil];
+
+			if (old_mode == WINDOW_MODE_EXCLUSIVE_FULLSCREEN) {
+				[NSApp setPresentationOptions:NSApplicationPresentationDefault];
+			}
+
 			wd.fullscreen = false;
+			wd.exclusive_fullscreen = false;
 		} break;
 		case WINDOW_MODE_MAXIMIZED: {
 			if ([wd.window_object isZoomed]) {
@@ -2609,7 +2615,15 @@
 			[wd.window_object setContentMinSize:NSMakeSize(0, 0)];
 			[wd.window_object setContentMaxSize:NSMakeSize(FLT_MAX, FLT_MAX)];
 			[wd.window_object toggleFullScreen:nil];
+
 			wd.fullscreen = true;
+			if (p_mode == WINDOW_MODE_EXCLUSIVE_FULLSCREEN) {
+				const NSUInteger presentationOptions = NSApplicationPresentationHideDock | NSApplicationPresentationHideMenuBar;
+				[NSApp setPresentationOptions:presentationOptions];
+				wd.exclusive_fullscreen = true;
+			} else {
+				wd.exclusive_fullscreen = false;
+			}
 		} break;
 		case WINDOW_MODE_MAXIMIZED: {
 			if (![wd.window_object isZoomed]) {
@@ -2626,7 +2640,11 @@
 	const WindowData &wd = windows[p_window];
 
 	if (wd.fullscreen) { // If fullscreen, it's not in another mode.
-		return WINDOW_MODE_FULLSCREEN;
+		if (wd.exclusive_fullscreen) {
+			return WINDOW_MODE_EXCLUSIVE_FULLSCREEN;
+		} else {
+			return WINDOW_MODE_FULLSCREEN;
+		}
 	}
 	if ([wd.window_object isZoomed] && !wd.resize_disabled) {
 		return WINDOW_MODE_MAXIMIZED;

platform/macos/godot_window_delegate.mm

@@ -147,7 +147,12 @@ - (void)windowDidExitFullScreen:(NSNotification *)notification {
 	}
 
 	DisplayServerMacOS::WindowData &wd = ds->get_window(window_id);
+	if (wd.exclusive_fullscreen) {
+		[NSApp setPresentationOptions:NSApplicationPresentationDefault];
+	}
+
 	wd.fullscreen = false;
+	wd.exclusive_fullscreen = false;
 
 	[(GodotWindow *)wd.window_object setAnimDuration:-1.0f];