fix: disable renderer background when macOS effects are enabled

macos/Sources/Features/Terminal/Window Styles/TerminalWindow.swift

@@ -480,7 +480,7 @@ class TerminalWindow: NSWindow {
             backgroundColor = .white.withAlphaComponent(0.001)
 
             // Add liquid glass behind terminal content
-            if #available(macOS 26.0, *), derivedConfig.macosBackgroundStyle != .blur {
+            if #available(macOS 26.0, *), derivedConfig.macosBackgroundStyle != .defaultStyle {
                 setupGlassLayer()
             } else if let appDelegate = NSApp.delegate as? AppDelegate {
                 ghostty_set_window_background_blur(
@@ -633,7 +633,7 @@ class TerminalWindow: NSWindow {
             self.backgroundColor = NSColor.windowBackgroundColor
             self.backgroundOpacity = 1
             self.macosWindowButtons = .visible
-            self.macosBackgroundStyle = .blur
+            self.macosBackgroundStyle = .defaultStyle
             self.windowCornerRadius = 16
         }
 

macos/Sources/Ghostty/Ghostty.Config.swift

@@ -262,7 +262,7 @@ extension Ghostty {
         }
 
         var macosBackgroundStyle: MacBackgroundStyle {
-            let defaultValue = MacBackgroundStyle.blur
+            let defaultValue = MacBackgroundStyle.defaultStyle
             guard let config = self.config else { return defaultValue }
             var v: UnsafePointer<Int8>? = nil
             let key = "macos-background-style"

macos/Sources/Ghostty/Package.swift

@@ -354,7 +354,7 @@ extension Ghostty {
 
     /// Enum for the macos-background-style config option
     enum MacBackgroundStyle: String {
-        case blur
+        case defaultStyle = "default"
         case regularGlass = "regular-glass"
         case clearGlass = "clear-glass"
     }

src/config/Config.zig

@@ -3111,22 +3111,13 @@ keybind: Keybinds = .{},
 ///
 /// Valid values are:
 ///
-///   * `blur` - Uses the standard background behavior. The `background-blur`
+///   * `default` - Uses the standard background behavior. The `background-blur`
 ///     configuration will control whether blur is applied (available on all macOS versions)
 ///   * `regular-glass` - Standard glass effect with some opacity (macOS 26.0+ only)
 ///   * `clear-glass` - Highly transparent glass effect (macOS 26.0+ only)
 ///
-/// The `blur` option does not force any blur effect - it simply respects the
-/// `background-blur` configuration. The glass options override `background-blur`
-/// and apply their own visual effects.
-///
-/// On macOS versions prior to 26.0, only `blur` has an effect. The glass
-/// options will fall back to `blur` behavior on older versions.
-///
-/// The default value is `blur`.
-///
 /// Available since: 1.2.2
-@"macos-background-style": MacBackgroundStyle = .blur,
+@"macos-background-style": MacBackgroundStyle = .default,
 
 /// Put every surface (tab, split, window) into a dedicated Linux cgroup.
 ///
@@ -7714,7 +7705,7 @@ pub const MacShortcuts = enum {
 
 /// See macos-background-style
 pub const MacBackgroundStyle = enum {
-    blur,
+    default,
     @"regular-glass",
     @"clear-glass",
 };

src/renderer/generic.zig

@@ -561,6 +561,7 @@ pub fn Renderer(comptime GraphicsAPI: type) type {
             vsync: bool,
             colorspace: configpkg.Config.WindowColorspace,
             blending: configpkg.Config.AlphaBlending,
+            macos_background_style: configpkg.Config.MacBackgroundStyle,
 
             pub fn init(
                 alloc_gpa: Allocator,
@@ -633,6 +634,7 @@ pub fn Renderer(comptime GraphicsAPI: type) type {
                     .vsync = config.@"window-vsync",
                     .colorspace = config.@"window-colorspace",
                     .blending = config.@"alpha-blending",
+                    .macos_background_style = config.@"macos-background-style",
                     .arena = arena,
                 };
             }
@@ -644,6 +646,16 @@ pub fn Renderer(comptime GraphicsAPI: type) type {
             }
         };
 
+        /// Determines if the terminal background should be disabled based on platform and config.
+        /// On macOS, when background effects are enabled (background style != default), the effect
+        /// layer handles the background rendering instead of the terminal renderer.
+        fn shouldDisableBackground(config: DerivedConfig) bool {
+            return switch (builtin.os.tag) {
+                .macos => config.macos_background_style != .default,
+                else => false,
+            };
+        }
+
         pub fn init(alloc: Allocator, options: renderer.Options) !Self {
             // Initialize our graphics API wrapper, this will prepare the
             // surface provided by the apprt and set up any API-specific
@@ -716,7 +728,10 @@ pub fn Renderer(comptime GraphicsAPI: type) type {
                         options.config.background.r,
                         options.config.background.g,
                         options.config.background.b,
-                        @intFromFloat(@round(options.config.background_opacity * 255.0)),
+                        if (shouldDisableBackground(options.config))
+                            0
+                        else
+                            @intFromFloat(@round(options.config.background_opacity * 255.0)),
                     },
                     .bools = .{
                         .cursor_wide = false,
@@ -1293,7 +1308,10 @@ pub fn Renderer(comptime GraphicsAPI: type) type {
                     self.terminal_state.colors.background.r,
                     self.terminal_state.colors.background.g,
                     self.terminal_state.colors.background.b,
-                    @intFromFloat(@round(self.config.background_opacity * 255.0)),
+                    if (shouldDisableBackground(self.config))
+                        0
+                    else
+                        @intFromFloat(@round(self.config.background_opacity * 255.0)),
                 };
             }
         }