src/apu.rs

@@ -468,15 +468,6 @@ impl Channel1 {
 
         // If this bit is set, a trigger event occurs
         if self.freq_hi.initial() {
-            if self.is_dac_enabled() {
-                self.enabled = true;
-            }
-
-            // Length behaviour during trigger event
-            if self.length_timer == 0 {
-                self.length_timer = 64;
-            }
-
             // Envelope Behaviour during trigger event
             self.period_timer = self.envelope.period();
             self.current_volume = self.envelope.init_vol();
@@ -484,15 +475,25 @@ impl Channel1 {
             // Sweep behaviour during trigger event
             let sweep_period = self.sweep.period();
             let sweep_shift = self.sweep.shift_count();
-
             self.shadow_freq = self.frequency();
             self.sweep_timer = if sweep_period == 0 { 8 } else { sweep_period };
 
-            self.sweep_enabled = sweep_period != 0 || sweep_shift != 0;
+            if sweep_period != 0 || sweep_shift != 0 {
+                self.sweep_enabled = true;
+            }
 
             if sweep_shift != 0 {
                 let _ = self.calc_sweep_freq();
             }
+
+            // Length behaviour during trigger event
+            if self.length_timer == 0 {
+                self.length_timer = 64;
+            }
+
+            if self.is_dac_enabled() {
+                self.enabled = true;
+            }
         }
     }
 

src/main.rs

@@ -4,6 +4,7 @@ use gb::{AudioSPSC, Cycle, GB_HEIGHT, GB_WIDTH};
 use gilrs::Gilrs;
 use pixels::{PixelsBuilder, SurfaceTexture};
 use rodio::{OutputStream, Sink};
+use std::time::{Duration, Instant};
 use winit::dpi::LogicalSize;
 use winit::event::{Event, VirtualKeyCode};
 use winit::event_loop::{ControlFlow, EventLoop};
@@ -70,7 +71,6 @@ fn main() -> Result<()> {
         let (prod, cons) = spsc.init();
         let sink = Sink::try_new(&stream_handle)?;
         sink.append(cons);
-        sink.set_volume(0.1); // TODO: Is this the right way to go about this?
         game_boy.apu_mut().attach_producer(prod);
 
         std::thread::spawn(move || {
@@ -78,6 +78,8 @@ fn main() -> Result<()> {
         });
     }
 
+    let mut start = Instant::now();
+    let frame_time = Duration::from_secs_f64(1.0 / 59.73); // 59.73 Hz on Host
     let mut cycle_count: Cycle = Default::default();
 
     event_loop.run(move |event, _, control_flow| {
@@ -102,7 +104,15 @@ fn main() -> Result<()> {
                 pixels.resize_surface(size.width, size.height);
             }
 
+            let mut diff = Instant::now() - start;
+            while diff.subsec_nanos() < frame_time.subsec_nanos() {
+                if cycle_count < gb::emu::CYCLES_IN_FRAME {
                     cycle_count += gb::emu::run_frame(&mut game_boy, &mut gamepad, &input);
+                }
+
+                diff = Instant::now() - start;
+            }
+            start = Instant::now();
 
             if cycle_count >= gb::emu::CYCLES_IN_FRAME {
                 cycle_count %= gb::emu::CYCLES_IN_FRAME;