core: Remove main_window in favor of users creating their own windows. Added event window_open which is called when the platform has finished initializing the window

examples/core-custom-entrypoint/App.zig

@@ -7,6 +7,7 @@ pub const mach_module = .app;
 
 pub const mach_systems = .{ .main, .init, .deinit, .tick };
 
+window: mach.ObjectID,
 title_timer: mach.time.Timer,
 pipeline: *gpu.RenderPipeline,
 
@@ -28,10 +29,25 @@ pub fn init(
     core.on_tick = app_mod.id.tick;
     core.on_exit = app_mod.id.deinit;
 
-    const main_window = core.windows.getValue(core.main_window);
+    const window = try core.windows.new(.{ .title = "core-custom-entrypoint" });
+
+    // Store our render pipeline in our module's state, so we can access it later on.
+    app.* = .{
+        .window = window,
+        .title_timer = try mach.time.Timer.start(),
+        .pipeline = undefined,
+    };
+
+    // TODO(object): window-title
+    // try updateWindowTitle(core);
+}
+
+fn setupPipeline(core: *mach.Core, app: *App, window_id: mach.ObjectID) !void {
+    _ = window_id; // autofix
+    const window = core.windows.getValue(app.window);
 
     // Create our shader module
-    const shader_module = main_window.device.createShaderModuleWGSL("shader.wgsl", @embedFile("shader.wgsl"));
+    const shader_module = window.device.createShaderModuleWGSL("shader.wgsl", @embedFile("shader.wgsl"));
     defer shader_module.release();
 
     // Blend state describes how rendered colors get blended
@@ -39,7 +55,7 @@ pub fn init(
 
     // Color target describes e.g. the pixel format of the window we are rendering to.
     const color_target = gpu.ColorTargetState{
-        .format = main_window.framebuffer_format,
+        .format = window.framebuffer_format,
         .blend = &blend,
     };
 
@@ -60,36 +76,31 @@ pub fn init(
             .entry_point = "vertex_main",
         },
     };
-    const pipeline = main_window.device.createRenderPipeline(&pipeline_descriptor);
 
-    // Store our render pipeline in our module's state, so we can access it later on.
+    app.pipeline = window.device.createRenderPipeline(&pipeline_descriptor);
-    app.* = .{
-        .title_timer = try mach.time.Timer.start(),
-        .pipeline = pipeline,
-    };
-
-    // TODO(object): window-title
-    // try updateWindowTitle(core);
 }
 
 pub fn tick(core: *mach.Core, app: *App) !void {
     while (core.nextEvent()) |event| {
         switch (event) {
+            .window_open => |ev| {
+                try setupPipeline(core, app, ev.window_id);
+            },
             .close => core.exit(),
             else => {},
         }
     }
 
-    const main_window = core.windows.getValue(core.main_window);
+    const window = core.windows.getValue(app.window);
 
     // Grab the back buffer of the swapchain
     // TODO(Core)
-    const back_buffer_view = main_window.swap_chain.getCurrentTextureView().?;
+    const back_buffer_view = window.swap_chain.getCurrentTextureView().?;
     defer back_buffer_view.release();
 
     // Create a command encoder
     const label = @tagName(mach_module) ++ ".tick";
-    const encoder = main_window.device.createCommandEncoder(&.{ .label = label });
+    const encoder = window.device.createCommandEncoder(&.{ .label = label });
     defer encoder.release();
 
     // Begin render pass
@@ -116,7 +127,7 @@ pub fn tick(core: *mach.Core, app: *App) !void {
     // Submit our commands to the queue
     var command = encoder.finish(&.{ .label = label });
     defer command.release();
-    main_window.queue.submit(&[_]*gpu.CommandBuffer{command});
+    window.queue.submit(&[_]*gpu.CommandBuffer{command});
 
     // update the window title every second
     if (app.title_timer.read() >= 1.0) {

examples/core-triangle/App.zig

@@ -14,6 +14,7 @@ pub const main = mach.schedule(.{
     .{ mach.Core, .main },
 });
 
+window: mach.ObjectID,
 title_timer: mach.time.Timer,
 pipeline: *gpu.RenderPipeline,
 
@@ -25,10 +26,24 @@ pub fn init(
     core.on_tick = app_mod.id.tick;
     core.on_exit = app_mod.id.deinit;
 
-    const main_window = core.windows.getValue(core.main_window);
+    const window = try core.windows.new(.{
+        .title = "core-triangle",
+    });
+
+    // Store our render pipeline in our module's state, so we can access it later on.
+    app.* = .{
+        .window = window,
+        .title_timer = try mach.time.Timer.start(),
+        .pipeline = undefined,
+    };
+}
+
+fn setupPipeline(core: *mach.Core, app: *App, window_id: mach.ObjectID) !void {
+    var window = core.windows.getValue(window_id);
+    defer core.windows.setValueRaw(window_id, window);
 
     // Create our shader module
-    const shader_module = main_window.device.createShaderModuleWGSL("shader.wgsl", @embedFile("shader.wgsl"));
+    const shader_module = window.device.createShaderModuleWGSL("shader.wgsl", @embedFile("shader.wgsl"));
     defer shader_module.release();
 
     // Blend state describes how rendered colors get blended
@@ -36,7 +51,7 @@ pub fn init(
 
     // Color target describes e.g. the pixel format of the window we are rendering to.
     const color_target = gpu.ColorTargetState{
-        .format = main_window.framebuffer_format,
+        .format = window.framebuffer_format,
         .blend = &blend,
     };
 
@@ -57,13 +72,7 @@ pub fn init(
             .entry_point = "vertex_main",
         },
     };
-    const pipeline = main_window.device.createRenderPipeline(&pipeline_descriptor);
+    app.pipeline = window.device.createRenderPipeline(&pipeline_descriptor);
-
-    // Store our render pipeline in our module's state, so we can access it later on.
-    app.* = .{
-        .title_timer = try mach.time.Timer.start(),
-        .pipeline = pipeline,
-    };
 }
 
 // TODO(object): window-title
@@ -72,19 +81,22 @@ pub fn init(
 pub fn tick(app: *App, core: *mach.Core) void {
     while (core.nextEvent()) |event| {
         switch (event) {
+            .window_open => |ev| {
+                try setupPipeline(core, app, ev.window_id);
+            },
             .key_press => |ev| {
                 switch (ev.key) {
                     .right => {
-                        core.windows.set(core.main_window, .width, core.windows.get(core.main_window, .width) + 10);
+                        core.windows.set(app.window, .width, core.windows.get(app.window, .width) + 10);
                     },
                     .left => {
-                        core.windows.set(core.main_window, .width, core.windows.get(core.main_window, .width) - 10);
+                        core.windows.set(app.window, .width, core.windows.get(app.window, .width) - 10);
                     },
                     .up => {
-                        core.windows.set(core.main_window, .height, core.windows.get(core.main_window, .height) + 10);
+                        core.windows.set(app.window, .height, core.windows.get(app.window, .height) + 10);
                     },
                     .down => {
-                        core.windows.set(core.main_window, .height, core.windows.get(core.main_window, .height) - 10);
+                        core.windows.set(app.window, .height, core.windows.get(app.window, .height) - 10);
                     },
                     else => {},
                 }
@@ -94,17 +106,17 @@ pub fn tick(app: *App, core: *mach.Core) void {
         }
     }
 
-    const main_window = core.windows.getValue(core.main_window);
+    const window = core.windows.getValue(app.window);
 
     // Grab the back buffer of the swapchain
     // TODO(Core)
-    const back_buffer_view = main_window.swap_chain.getCurrentTextureView().?;
+    const back_buffer_view = window.swap_chain.getCurrentTextureView().?;
     defer back_buffer_view.release();
 
     // Create a command encoder
     const label = @tagName(mach_module) ++ ".tick";
 
-    const encoder = main_window.device.createCommandEncoder(&.{ .label = label });
+    const encoder = window.device.createCommandEncoder(&.{ .label = label });
     defer encoder.release();
 
     // Begin render pass
@@ -131,7 +143,7 @@ pub fn tick(app: *App, core: *mach.Core) void {
     // Submit our commands to the queue
     var command = encoder.finish(&.{ .label = label });
     defer command.release();
-    main_window.queue.submit(&[_]*gpu.CommandBuffer{command});
+    window.queue.submit(&[_]*gpu.CommandBuffer{command});
 
     // update the window title every second
     // if (app.title_timer.read() >= 1.0) {

examples/play-opus/App.zig

@@ -28,6 +28,7 @@ pub const deinit = mach.schedule(.{
     .{ mach.Audio, .deinit },
 });
 
+window: mach.ObjectID,
 /// Tag object we set as a child of mach.Audio objects to indicate they are background music.
 // TODO(object): consider adding a better object 'tagging' system?
 bgm: mach.Objects(.{}, struct {}),
@@ -46,6 +47,10 @@ pub fn init(
     core.on_tick = app_mod.id.tick;
     core.on_exit = app_mod.id.deinit;
 
+    const window = try core.windows.new(.{
+        .title = "play-opus",
+    });
+
     // Configure the audio module to send our app's .audio_state_change event when an entity's sound
     // finishes playing.
     audio.on_state_change = app_mod.id.audioStateChange;
@@ -61,7 +66,7 @@ pub fn init(
     const sfx = try mach.Audio.Opus.decodeStream(allocator, sfx_sound_stream);
 
     // Initialize module state
-    app.* = .{ .sfx = sfx, .bgm = app.bgm };
+    app.* = .{ .sfx = sfx, .bgm = app.bgm, .window = window };
 
     const bgm_buffer = blk: {
         audio.buffers.lock();
@@ -138,16 +143,16 @@ pub fn tick(
         }
     }
 
-    var main_window = core.windows.getValue(core.main_window);
+    var window = core.windows.getValue(app.window);
 
     // Grab the back buffer of the swapchain
     // TODO(Core)
-    const back_buffer_view = main_window.swap_chain.getCurrentTextureView().?;
+    const back_buffer_view = window.swap_chain.getCurrentTextureView().?;
     defer back_buffer_view.release();
 
     // Create a command encoder
     const label = @tagName(mach_module) ++ ".tick";
-    const encoder = main_window.device.createCommandEncoder(&.{ .label = label });
+    const encoder = window.device.createCommandEncoder(&.{ .label = label });
     defer encoder.release();
 
     // Begin render pass
@@ -172,5 +177,5 @@ pub fn tick(
     // Submit our commands to the queue
     var command = encoder.finish(&.{ .label = label });
     defer command.release();
-    main_window.queue.submit(&[_]*gpu.CommandBuffer{command});
+    window.queue.submit(&[_]*gpu.CommandBuffer{command});
 }

src/Core.zig

@@ -106,9 +106,6 @@ on_tick: ?mach.FunctionID = null,
 /// Callback system invoked when application is exiting
 on_exit: ?mach.FunctionID = null,
 
-/// Main window of the application
-main_window: mach.ObjectID,
-
 /// Current state of the application
 state: enum {
     running,
@@ -132,8 +129,6 @@ pub fn init(core: *Core) !void {
     // TODO: fix all leaks and use options.allocator
     try mach.sysgpu.Impl.init(allocator, .{});
 
-    const main_window = try core.windows.new(.{});
-
     var events = EventQueue.init(allocator);
     try events.ensureTotalCapacity(8192);
 
@@ -142,7 +137,6 @@ pub fn init(core: *Core) !void {
         .windows = core.windows,
 
         .allocator = allocator,
-        .main_window = main_window,
         .events = events,
         .input_state = .{},
 
@@ -150,11 +144,6 @@ pub fn init(core: *Core) !void {
         .frame = .{ .target = 1 },
     };
 
-    // Tick the platform so that the platform can grab the newly created window
-    // and perform initialization
-    // TODO: consider removing `main_window` and then this wont be necessary
-    try Platform.tick(core);
-
     try core.frame.start();
     try core.input.start();
 }
@@ -229,6 +218,8 @@ pub fn initWindow(core: *Core, window_id: mach.ObjectID) !void {
     core_window.framebuffer_format = core_window.swap_chain_descriptor.format;
     core_window.framebuffer_width = core_window.swap_chain_descriptor.width;
     core_window.framebuffer_height = core_window.swap_chain_descriptor.height;
+
+    core.pushEvent(.{ .window_open = .{ .window_id = window_id } });
 }
 
 pub fn tick(core: *Core, core_mod: mach.Mod(Core)) !void {
@@ -686,6 +677,9 @@ pub const Event = union(enum) {
         yoffset: f32,
     },
     window_resize: ResizeEvent,
+    window_open: struct {
+        window_id: mach.ObjectID,
+    },
     focus_gained: struct {
         window_id: mach.ObjectID,
     },