apprt/embedded: fix initialization on macOS

src/apprt/embedded.zig

@@ -283,14 +283,14 @@ pub const Surface = struct {
     inspector: ?*Inspector = null,
 
     pub const Options = extern struct {
-        /// Userdata passed to some of the callbacks.
-        userdata: ?*anyopaque = null,
-
         /// The platform that this surface is being initialized for and
         /// the associated platform-specific configuration.
         platform_tag: c_int = 0,
         platform: Platform.C = undefined,
 
+        /// Userdata passed to some of the callbacks.
+        userdata: ?*anyopaque = null,
+
         /// The scale factor of the screen.
         scale_factor: f64 = 1,
 

src/renderer/Metal.zig

@@ -466,7 +466,9 @@ pub fn finalizeSurfaceInit(self: *const Metal, surface: *apprt.Surface) !void {
         },
 
         apprt.embedded => .{
-            .view = surface.nsview,
+            .view = switch (surface.platform) {
+                .macos => |v| v.nsview,
+            },
             .scaleFactor = @floatCast(surface.content_scale.x),
         },