it draws!

include/ghostty.h

@@ -53,6 +53,7 @@ int ghostty_app_tick(ghostty_app_t);
 
 ghostty_surface_t ghostty_surface_new(ghostty_app_t, ghostty_surface_config_s*);
 void ghostty_surface_free(ghostty_surface_t);
+void ghostty_surface_set_size(ghostty_surface_t, uint32_t, uint32_t);
 
 #ifdef __cplusplus
 }

macos/Sources/TerminalSurfaceView.swift

@@ -10,17 +10,17 @@ import GhosttyKit
 /// since that is what the Metal renderer in Ghostty expects. In the future, it may make more sense to
 /// wrap an MTKView and use that, but for legacy reasons we didn't do that to begin with.
 struct TerminalSurfaceView: NSViewRepresentable {
-    @StateObject private var state: TerminalSurfaceState
+    @StateObject private var state: TerminalSurfaceView_Real
     
     init(app: ghostty_app_t) {
-        self._state = StateObject(wrappedValue: TerminalSurfaceState(app))
+        self._state = StateObject(wrappedValue: TerminalSurfaceView_Real(app))
     }
     
     func makeNSView(context: Context) -> TerminalSurfaceView_Real {
         // We need the view as part of the state to be created previously because
         // the view is sent to the Ghostty API so that it can manipulate it
         // directly since we draw on a render thread.
-        return state.view;
+        return state;
     }
     
     func updateNSView(_ view: TerminalSurfaceView_Real, context: Context) {
@@ -28,22 +28,23 @@ struct TerminalSurfaceView: NSViewRepresentable {
     }
 }
 
-/// The state for the terminal surface view.
-class TerminalSurfaceState: ObservableObject {
-    static let logger = Logger(
-        subsystem: Bundle.main.bundleIdentifier!,
-        category: String(describing: TerminalSurfaceState.self)
-    )
+// The actual NSView implementation for the terminal surface.
+class TerminalSurfaceView_Real: NSView, ObservableObject {
+    // We need to support being a first responder so that we can get input events
+    override var acceptsFirstResponder: Bool { return true }
     
-    var view: TerminalSurfaceView_Real
     private var surface: ghostty_surface_t? = nil
     private var error: Error? = nil
     
     init(_ app: ghostty_app_t) {
-        view = TerminalSurfaceView_Real()
+        // Initialize with some default frame size. The important thing is that this
+        // is non-zero so that our layer bounds are non-zero so that our renderer
+        // can do SOMETHING.
+        super.init(frame: NSMakeRect(0, 0, 800, 600))
         
+        // Setup our surface. This will also initialize all the terminal IO.
         var surface_cfg = ghostty_surface_config_s(
-            nsview: Unmanaged.passUnretained(view).toOpaque(),
+            nsview: Unmanaged.passUnretained(self).toOpaque(),
             scale_factor: 2.0)
         guard let surface = ghostty_surface_new(app, &surface_cfg) else {
             self.error = AppError.surfaceCreateError
@@ -53,17 +54,16 @@ class TerminalSurfaceState: ObservableObject {
         self.surface = surface;
     }
     
-    deinit {
-        if let surface = self.surface {
-            ghostty_surface_free(surface)
-        }
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) is not supported for this view")
+    }
+    
+    override func resize(withOldSuperviewSize oldSize: NSSize) {
+        print("LAYER: \(self.layer?.bounds)")
+        super.resize(withOldSuperviewSize: oldSize)
+        print("RESIZE: \(oldSize) NEW: \(self.bounds)")
+        print("LAYER: \(self.layer?.bounds)")
     }
-}
-
-// The actual NSView implementation for the terminal surface.
-class TerminalSurfaceView_Real: NSView {
-    // We need to support being a first responder so that we can get input events
-    override var acceptsFirstResponder: Bool { return true }
     
     override func draw(_ dirtyRect: NSRect) {
         print("DRAW: \(dirtyRect)")

src/App.zig

@@ -396,4 +396,10 @@ pub const CAPI = struct {
     export fn ghostty_surface_free(ptr: ?*Window) void {
         if (ptr) |v| v.app.closeWindow(v);
     }
+
+    /// Update the size of a surface. This will trigger resize notifications
+    /// to the pty and the renderer.
+    export fn ghostty_surface_set_size(win: *Window, w: u32, h: u32) void {
+        win.window.updateSize(w, h);
+    }
 };

src/apprt/embedded.zig

@@ -13,6 +13,8 @@ const apprt = @import("../apprt.zig");
 const CoreApp = @import("../App.zig");
 const CoreWindow = @import("../Window.zig");
 
+const log = std.log.scoped(.embedded_window);
+
 pub const App = struct {
     /// Because we only expect the embedding API to be used in embedded
     /// environments, the options are extern so that we can expose it
@@ -48,6 +50,7 @@ pub const App = struct {
 pub const Window = struct {
     nsview: objc.Object,
     scale_factor: f64,
+    core_win: *CoreWindow,
 
     pub const Options = extern struct {
         /// The pointer to the backing NSView for the surface.
@@ -59,9 +62,9 @@ pub const Window = struct {
 
     pub fn init(app: *const CoreApp, core_win: *CoreWindow, opts: Options) !Window {
         _ = app;
-        _ = core_win;
 
         return .{
+            .core_win = core_win,
             .nsview = objc.Object.fromId(opts.nsview),
             .scale_factor = opts.scale_factor,
         };
@@ -113,4 +116,17 @@ pub const Window = struct {
         _ = self;
         return false;
     }
+
+    pub fn updateSize(self: *const Window, width: u32, height: u32) void {
+        const size: apprt.WindowSize = .{
+            .width = width,
+            .height = height,
+        };
+
+        // Call the primary callback.
+        self.core_win.sizeCallback(size) catch |err| {
+            log.err("error in size callback err={}", .{err});
+            return;
+        };
+    }
 };

src/renderer/Metal.zig

@@ -568,9 +568,14 @@ pub fn render(
                     .{@as(c_ulong, 0)},
                 );
 
+                // Texture is a property of CAMetalDrawable but if you run
+                // Ghostty in XCode in debug mode it returns a CaptureMTLDrawable
+                // which ironically doesn't implement CAMetalDrawable as a
+                // property so we just send a message.
+                const texture = surface.msgSend(objc.c.id, objc.sel("texture"), .{});
                 attachment.setProperty("loadAction", @enumToInt(MTLLoadAction.clear));
                 attachment.setProperty("storeAction", @enumToInt(MTLStoreAction.store));
-                attachment.setProperty("texture", surface.getProperty(objc.c.id, "texture").?);
+                attachment.setProperty("texture", texture);
                 attachment.setProperty("clearColor", MTLClearColor{
                     .red = @intToFloat(f32, critical.bg.r) / 255,
                     .green = @intToFloat(f32, critical.bg.g) / 255,
@@ -673,18 +678,20 @@ fn drawCells(
         .{ buf.value, @as(c_ulong, 0), @as(c_ulong, 0) },
     );
 
-    encoder.msgSend(
-        void,
-        objc.sel("drawIndexedPrimitives:indexCount:indexType:indexBuffer:indexBufferOffset:instanceCount:"),
-        .{
-            @enumToInt(MTLPrimitiveType.triangle),
-            @as(c_ulong, 6),
-            @enumToInt(MTLIndexType.uint16),
-            self.buf_instance.value,
-            @as(c_ulong, 0),
-            @as(c_ulong, cells.items.len),
-        },
-    );
+    if (cells.items.len > 0) {
+        encoder.msgSend(
+            void,
+            objc.sel("drawIndexedPrimitives:indexCount:indexType:indexBuffer:indexBufferOffset:instanceCount:"),
+            .{
+                @enumToInt(MTLPrimitiveType.triangle),
+                @as(c_ulong, 6),
+                @enumToInt(MTLIndexType.uint16),
+                self.buf_instance.value,
+                @as(c_ulong, 0),
+                @as(c_ulong, cells.items.len),
+            },
+        );
+    }
 }
 
 /// Resize the screen.