runtime hooks

src/nu/ImGui.zig

@@ -6,6 +6,7 @@ const vk = @import("vk");
 const nu = @import("../nu.zig");
 const au = @import("Render/au.zig");
 
+const Hook = @import("hooks.zig").Hook;
 const Render = @import("Render.zig");
 const Window = @import("Window.zig");
 
@@ -14,6 +15,11 @@ pub usingnamespace im;
 
 pub const Options = struct {};
 
+pub const Hooks = struct {
+    pub const Frame = Hook(fn () void);
+    frame: Frame,
+};
+
 pub fn loader_wrapper(procname: [*c]const u8, _: ?*anyopaque) callconv(.C) vk.PfnVoidFunction {
     return au.glfwGetInstanceProcAddress(au.I.handle, procname);
 }
@@ -21,7 +27,9 @@ pub fn loader_wrapper(procname: [*c]const u8, _: ?*anyopaque) callconv(.C) vk.Pf
 var ctx: *im.ImGuiContext = undefined;
 var descriptor_pool: vk.DescriptorPool = undefined;
 
-pub fn init() !void {
+pub var hooks: Hooks = undefined;
+
+pub fn init(alloc: std.mem.Allocator) !void {
     ctx = im.igCreateContext(null) orelse {
         return error.igCreateContextFailed;
     };
@@ -77,6 +85,24 @@ pub fn init() !void {
     if (!im.impl.ImGui_ImplVulkan_CreateFontsTexture()) {
         return error.igVulkanFontTextureFailed;
     }
+
+    hooks = .{
+        .frame = Hooks.Frame.init(alloc),
+    };
+    errdefer hooks.frame.deinit();
+}
+
+pub fn deinit() void {
+    hooks.frame.deinit();
+    im.impl.ImGui_ImplVulkan_Shutdown();
+    au.D.destroyDescriptorPool(descriptor_pool, null);
+    im.impl.ImGui_ImplGlfw_Shutdown();
+    im.igDestroyContext(ctx);
+}
+
+pub fn connect() !void {
+    try nu.hooks.frame.register(nu_frame);
+    try Render.hooks.present.register(nu_render_present);
 }
 
 pub fn nu_frame() !void {
@@ -84,7 +110,7 @@ pub fn nu_frame() !void {
     im.impl.ImGui_ImplVulkan_NewFrame();
     im.igNewFrame();
 
-    try nu.invoke_hook("nu_imgui_frame", .{});
+    hooks.frame.invoke(.{});
 
     im.igEndFrame();
     im.igRender();
@@ -97,10 +123,3 @@ pub fn nu_render_present(cmd: au.CommandBufferProxy) void {
         null,
     );
 }
-
-pub fn deinit() void {
-    im.impl.ImGui_ImplVulkan_Shutdown();
-    au.D.destroyDescriptorPool(descriptor_pool, null);
-    im.impl.ImGui_ImplGlfw_Shutdown();
-    im.igDestroyContext(ctx);
-}

src/nu/Render.zig

@@ -9,6 +9,8 @@ const vk = @import("vk");
 const nu = @import("../nu.zig");
 const au = @import("Render/au.zig");
 
+const Hook = @import("hooks.zig").Hook;
+
 pub const Options = struct {
     app_name: [*:0]const u8 = "nu-au-app",
     app_version: struct {
@@ -27,6 +29,14 @@ pub const Options = struct {
     frames_in_flight: u8 = 3,
 };
 
+pub const Hooks = struct {
+    pub const Present = Hook(fn (au.CommandBufferProxy) void);
+
+    present: Present,
+};
+
+pub var hooks: Hooks = undefined;
+
 var sc: au.SwapChain = undefined;
 var flights: au.Flights = undefined;
 
@@ -40,6 +50,21 @@ pub fn init(alloc: std.mem.Allocator) !void {
 
     flights = try au.Flights.init(alloc, nu.options.render.frames_in_flight);
     errdefer flights.deinit();
+
+    hooks = .{ .present = Hooks.Present.init(alloc) };
+    errdefer hooks.present.deinit();
+}
+
+pub fn deinit() void {
+    hooks.present.deinit();
+    flights.deinit();
+    sc.deinit();
+    au.deinit();
+}
+
+pub fn connect() !void {
+    try nu.hooks.frame.register(nu_frame);
+    try nu.hooks.close.register(nu_close);
 }
 
 pub fn nu_frame() !void {
@@ -70,7 +95,7 @@ pub fn nu_frame() !void {
 
         // todo manage frame in flight state for each hook; pass the current flight in as context.
         // will need some comptime -> anytype mapping.
-        try nu.invoke_hook("nu_render_present", .{cmd});
+        hooks.present.invoke(.{cmd});
 
         target.end_rendering(cmd);
         try cmd.endCommandBuffer();
@@ -102,12 +127,8 @@ pub fn nu_frame() !void {
     }
 }
 
-pub fn nu_close() !void {
-    try au.D.deviceWaitIdle();
-}
-
-pub fn deinit() void {
-    flights.deinit();
-    sc.deinit();
-    au.deinit();
+pub fn nu_close() void {
+    au.D.deviceWaitIdle() catch |err| {
+        std.debug.panic("Device wait failed: {!}", .{err});
+    };
 }

src/nu/Window.zig

@@ -21,7 +21,7 @@ pub const Options = struct {
     x11_instance_name: [*:0]const u8 = "floating_window",
 };
 
-var bus: Bus = undefined;
+var bus: Bus = undefined; // todo bus should probably move to engine.
 pub var handle: *c.GLFWwindow = undefined;
 var unfocused_rate: f32 = 1.0 / 20.0;