feat: rewrite device ticks

src/core/apu.zig

@@ -169,6 +169,8 @@ pub const Apu = struct {
 
     is_buffer_full: bool,
 
+    pub const Tick = enum { Length, Envelope, Sweep };
+
     pub fn init(sched: *Scheduler) Self {
         const apu: Self = .{
             .ch1 = ToneSweep.init(sched),
@@ -377,12 +379,12 @@ pub const Apu = struct {
         self.fs.tick();
 
         switch (self.fs.step) {
-            7 => self.tickEnvelopes(), // Clock Envelope
-            0, 4 => self.tickLengths(), // Clock Length
+            7 => self.tick(.Envelope), // Clock Envelope
+            0, 4 => self.tick(.Length), // Clock Length
             2, 6 => {
                 // Clock Length and Sweep
-                self.tickLengths();
-                self.ch1.tickSweep();
+                self.tick(.Length);
+                self.tick(.Sweep);
             },
             1, 3, 5 => {},
         }
@@ -390,17 +392,21 @@ pub const Apu = struct {
         self.sched.push(.FrameSequencer, ((1 << 24) / 512) -| late);
     }
 
-    fn tickLengths(self: *Self) void {
-        self.ch1.tickLength();
-        self.ch2.tickLength();
-        self.ch3.tickLength();
-        self.ch4.tickLength();
+    fn tick(self: *Self, comptime kind: Tick) void {
+        switch (kind) {
+            .Length => {
+                self.ch1.tick(kind);
+                self.ch2.tick(kind);
+                self.ch3.tick(kind);
+                self.ch4.tick(kind);
+            },
+            .Envelope => {
+                self.ch1.tick(kind);
+                self.ch2.tick(kind);
+                self.ch4.tick(kind);
+            },
+            .Sweep => self.ch1.tick(kind),
         }
-
-    fn tickEnvelopes(self: *Self) void {
-        self.ch1.tickEnvelope();
-        self.ch2.tickEnvelope();
-        self.ch4.tickEnvelope();
     }
 
     pub fn onDmaAudioSampleRequest(self: *Self, cpu: *Arm7tdmi, tim_id: u3) void {

src/core/apu/Noise.zig

@@ -3,6 +3,7 @@ const util = @import("../../util.zig");
 
 const Scheduler = @import("../scheduler.zig").Scheduler;
 const FrameSequencer = @import("../apu.zig").FrameSequencer;
+const Tick = @import("../apu.zig").Apu.Tick;
 const Envelope = @import("device/Envelope.zig");
 const Length = @import("device/Length.zig");
 const Lfsr = @import("signal/Lfsr.zig");
@@ -57,12 +58,12 @@ pub fn reset(self: *Self) void {
     self.enabled = false;
 }
 
-pub fn tickLength(self: *Self) void {
-    self.len_dev.tick(self.cnt.length_enable.read(), &self.enabled);
-}
-
-pub fn tickEnvelope(self: *Self) void {
-    self.env_dev.tick(self.envelope);
+pub fn tick(self: *Self, comptime kind: Tick) void {
+    switch (kind) {
+        .Length => self.len_dev.tick(self.cnt.length_enable.read(), &self.enabled),
+        .Envelope => self.env_dev.tick(self.envelope),
+        .Sweep => @compileError("Channel 4 does not implement Sweep"),
+    }
 }
 
 /// NR41, NR42

src/core/apu/Tone.zig

@@ -3,6 +3,7 @@ const util = @import("../../util.zig");
 
 const Scheduler = @import("../scheduler.zig").Scheduler;
 const FrameSequencer = @import("../apu.zig").FrameSequencer;
+const Tick = @import("../apu.zig").Apu.Tick;
 const Length = @import("device/Length.zig");
 const Envelope = @import("device/Envelope.zig");
 const Square = @import("signal/Square.zig");
@@ -50,12 +51,12 @@ pub fn reset(self: *Self) void {
     self.enabled = false;
 }
 
-pub fn tickLength(self: *Self) void {
-    self.len_dev.tick(self.freq.length_enable.read(), &self.enabled);
-}
-
-pub fn tickEnvelope(self: *Self) void {
-    self.env_dev.tick(self.envelope);
+pub fn tick(self: *Self, comptime kind: Tick) void {
+    switch (kind) {
+        .Length => self.len_dev.tick(self.freq.length_enable.read(), &self.enabled),
+        .Envelope => self.env_dev.tick(self.envelope),
+        .Sweep => @compileError("Channel 2 does not implement Sweep"),
+    }
 }
 
 pub fn onToneEvent(self: *Self, late: u64) void {

src/core/apu/ToneSweep.zig

@@ -8,6 +8,8 @@ const Envelope = @import("device/Envelope.zig");
 const Sweep = @import("device/Sweep.zig");
 const Square = @import("signal/Square.zig");
 
+const Tick = @import("../apu.zig").Apu.Tick;
+
 const Self = @This();
 
 /// NR10
@@ -59,16 +61,12 @@ pub fn reset(self: *Self) void {
     self.enabled = false;
 }
 
-pub fn tickSweep(self: *Self) void {
-    self.sweep_dev.tick(self);
-}
-
-pub fn tickLength(self: *Self) void {
-    self.len_dev.tick(self.freq.length_enable.read(), &self.enabled);
-}
-
-pub fn tickEnvelope(self: *Self) void {
-    self.env_dev.tick(self.envelope);
+pub fn tick(self: *Self, comptime kind: Tick) void {
+    switch (kind) {
+        .Length => self.len_dev.tick(self.freq.length_enable.read(), &self.enabled),
+        .Envelope => self.env_dev.tick(self.envelope),
+        .Sweep => self.sweep_dev.tick(self),
+    }
 }
 
 pub fn onToneSweepEvent(self: *Self, late: u64) void {

src/core/apu/Wave.zig

@@ -3,6 +3,8 @@ const util = @import("../../util.zig");
 
 const Scheduler = @import("../scheduler.zig").Scheduler;
 const FrameSequencer = @import("../apu.zig").FrameSequencer;
+const Tick = @import("../apu.zig").Apu.Tick;
+
 const Length = @import("device/Length.zig");
 const Wave = @import("signal/Wave.zig");
 
@@ -49,8 +51,12 @@ pub fn reset(self: *Self) void {
     self.enabled = false;
 }
 
-pub fn tickLength(self: *Self) void {
-    self.len_dev.tick(self.freq.length_enable.read(), &self.enabled);
+pub fn tick(self: *Self, comptime kind: Tick) void {
+    switch (kind) {
+        .Length => self.len_dev.tick(self.freq.length_enable.read(), &self.enabled),
+        .Envelope => @compileError("Channel 3 does not implement Envelope"),
+        .Sweep => @compileError("Channel 3 does not implement Sweep"),
+    }
 }
 
 /// NR30, NR31, NR32