{module,Audio}: ability to store event name and send it later

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>

src/Audio.zig

@@ -18,10 +18,6 @@ pub const local_events = .{
     .audio_tick = .{ .handler = audioTick },
 };
 
-pub const global_events = .{
-    .audio_state_change = .{ .handler = fn (mach.EntityID) void },
-};
-
 const log = std.log.scoped(name);
 
 // The number of milliseconds worth of audio to render ahead of time. The lower this number is, the
@@ -35,6 +31,7 @@ ms_render_ahead: f32 = 16,
 allocator: std.mem.Allocator,
 ctx: sysaudio.Context,
 player: sysaudio.Player,
+on_state_change: mach.AnyEvent,
 output_mu: std.Thread.Mutex = .{},
 output: SampleBuffer,
 mixing_buffer: ?std.ArrayListUnmanaged(f32) = null,
@@ -45,7 +42,7 @@ var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 
 const SampleBuffer = std.fifo.LinearFifo(u8, .Dynamic);
 
-fn init(audio: *Mod) !void {
+fn init(audio: *Mod, on_state_change: mach.AnyEvent) !void {
     const allocator = gpa.allocator();
     const ctx = try sysaudio.Context.init(null, allocator, .{});
     try ctx.refresh();
@@ -71,6 +68,7 @@ fn init(audio: *Mod) !void {
         .allocator = allocator,
         .ctx = ctx,
         .player = player,
+        .on_state_change = on_state_change,
         .output = SampleBuffer.init(allocator),
         .debug = debug,
     });
@@ -133,6 +131,7 @@ fn audioTick(audio: *Mod) !void {
     // not undefined memory.
     @memset(mixing_buffer.items, 0);
 
+    var did_state_change = false;
     var max_samples: usize = 0;
     var archetypes_iter = audio.entities.query(.{ .all = &.{
         .{ .mach_audio = &.{ .samples, .playing, .index } },
@@ -151,7 +150,7 @@ fn audioTick(audio: *Mod) !void {
             max_samples = @max(max_samples, to_read);
             if (index + to_read >= samples.len) {
                 // No longer playing, we've read all samples
-                audio.sendGlobal(.audio_state_change, .{id});
+                did_state_change = true;
                 try audio.set(id, .playing, false);
                 try audio.set(id, .index, 0);
                 continue;
@@ -159,6 +158,7 @@ fn audioTick(audio: *Mod) !void {
             try audio.set(id, .index, index + to_read);
         }
     }
+    if (did_state_change) audio.sendAnyEvent(audio.state().on_state_change);
 
     // Write our rendered samples to the fifo, expanding its size as needed and converting our f32
     // samples to the format the driver expects.

src/main.zig

@@ -32,6 +32,10 @@ pub const Mod = ModSet(modules).Mod;
 pub const EntityID = @import("module/main.zig").EntityID; // TODO: rename to just Entity?
 pub const Archetype = @import("module/main.zig").Archetype;
 
+pub const ModuleID = @import("module/main.zig").ModuleID;
+pub const EventID = @import("module/main.zig").EventID;
+pub const AnyEvent = @import("module/main.zig").AnyEvent;
+
 /// To use experimental sysgpu graphics API, you can write this in your main.zig:
 ///
 /// ```

src/module/main.zig

@@ -7,6 +7,9 @@ pub const Entities = @import("entities.zig").Entities;
 pub const Archetype = @import("Archetype.zig");
 pub const ModSet = @import("module.zig").ModSet;
 pub const Modules = @import("module.zig").Modules;
+pub const ModuleID = @import("module.zig").ModuleID;
+pub const EventID = @import("module.zig").EventID;
+pub const AnyEvent = @import("module.zig").AnyEvent;
 
 test {
     std.testing.refAllDeclsRecursive(@This());

src/module/module.zig

@@ -93,16 +93,21 @@ fn Serializable(comptime T: type) type {
     return T;
 }
 
+// TODO: add runtime module support
+pub const ModuleID = u32;
+pub const EventID = u32;
+
+pub const AnyEvent = struct {
+    module_id: ModuleID,
+    event_id: EventID,
+};
+
 /// Manages comptime .{A, B, C} modules and runtime modules.
 pub fn Modules(comptime modules: anytype) type {
     // Verify that each module is valid.
     inline for (modules) |M| _ = ModuleInterface(M);
 
     return struct {
-        // TODO: add runtime module support
-        pub const ModuleID = u32;
-        pub const EventID = u32;
-
         pub const GlobalEvent = GlobalEventEnum(modules);
         pub const LocalEvent = LocalEventEnum(modules);
 
@@ -593,6 +598,28 @@ pub fn ModSet(comptime modules: anytype) type {
                     const mods = @fieldParentPtr(ModulesT, "mod", mod_ptr);
                     mods.sendGlobal(module_tag, event_name, args);
                 }
+
+                pub inline fn event(_: *@This(), comptime event_name: LocalEventEnumM(M)) AnyEvent {
+                    const module_name_g: ModuleName(modules) = M.name;
+                    const event_name_g: Modules(modules).LocalEvent = comptime Modules(modules).moduleToGlobalEvent(
+                        M,
+                        LocalEventEnumM,
+                        LocalEventEnum,
+                        event_name,
+                    );
+                    return .{
+                        .module_id = @intFromEnum(module_name_g),
+                        .event_id = @intFromEnum(event_name_g),
+                    };
+                }
+
+                pub inline fn sendAnyEvent(m: *@This(), ev: AnyEvent) void {
+                    const ModulesT = Modules(modules);
+                    const MByName = ModsByName(modules);
+                    const mod_ptr: *MByName = @alignCast(@fieldParentPtr(MByName, @tagName(module_tag), m));
+                    const mods = @fieldParentPtr(ModulesT, "mod", mod_ptr);
+                    mods.sendDynamic(ev.module_id, ev.event_id, .{});
+                }
             };
         }
     };