comptime topological sort of dependencies

src/nu/Render.zig

@@ -32,21 +32,11 @@ pub const Config = struct {
 };
 const config = nu.config.render;
 
-pub fn module() nu.Module {
-    return nu.Module{
-        .name = "Render",
-        .setup = setup,
-        .teardown = teardown,
-        .frame = frame,
-        .dependencies = &.{nu.Window.driver().module},
-    };
-}
+pub const depends = .{nu.Window};
 
 var sc: au.SwapChain = undefined;
 var flights: au.Flights = undefined;
 
-pub var present: nu.Hook(fn (au.CommandBufferProxy) void) = undefined;
-
 pub fn setup(alloc: std.mem.Allocator) !void {
     // todo pick apart au into helpers; not a sub-module filled with its own globals.
     try au.init(alloc);
@@ -57,20 +47,16 @@ pub fn setup(alloc: std.mem.Allocator) !void {
 
     flights = try au.Flights.init(alloc, config.frames_in_flight);
     errdefer flights.deinit();
-
-    present = @TypeOf(present).init(alloc);
-    errdefer present.deinit();
 }
 
 pub fn teardown() void {
     au.D.deviceWaitIdle() catch |err| std.debug.panic("Device wait failed: {!}", .{err});
-    errdefer present.deinit();
     flights.deinit();
     sc.deinit();
     au.deinit();
 }
 
-pub fn frame() !void {
+pub fn render(engine: anytype) !void {
     const flight: au.Flights.Flight = flights.next();
     try flight.wait();
 
@@ -97,9 +83,8 @@ pub fn frame() !void {
         target.begin_rendering(cmd, render_area);
 
         // todo manage frame in flight state for each hook; pass the current flight in as context.
-        // will need some comptime -> anytype mapping.
 
-        present.invoke(.{cmd});
+        engine.invoke("present", .{cmd});
 
         target.end_rendering(cmd);
         try cmd.endCommandBuffer();