Reduce popping sounds

README.md

@@ -28,6 +28,7 @@
 - Working audio
 - Auto generated ROM backgrounds in the library
 - Save state preview in the saves menu
+- Gamepad support
 - Supported mappers: [NROM](https://nesdir.github.io/mapper0.html) (0), [MMC1](https://nesdir.github.io/mapper1.html) (1), [UNROM](https://nesdir.github.io/mapper2.html) (2), [MMC3](https://nesdir.github.io/mapper4.html) (4)
 
 ## Settings Menu
@@ -45,7 +46,7 @@ Use the arrow keys to navigate the menus and press enter to validate
 - Use an AudioWorkletNode instead of a scriptProcessor
 - Lock framerate at 60fps even on higher refresh rate displays
 - Support iNes 2.0 roms
-- Support gamepads + Joypad2
+- Support Joypad2
 - Time travel mode (Save states recorded at regular intervals)
 - Replay mode (Replay all inputs from the start)
 - Different color palettes

crate/src/apu/mod.rs

@@ -13,8 +13,7 @@ mod noise;
 mod pulse;
 mod triangle;
 
-const APU_BUFFER_SIZE: usize = 8 * 1024;
-const APU_BUFFER_MASK: u16 = APU_BUFFER_SIZE as u16 - 1;
+const APU_BUFFER_SIZE: usize = 16 * 1024;
 const CPU_FREQ: f64 = 1789772.5;
 
 #[derive(Clone, Copy)]
@@ -45,10 +44,8 @@ impl From<FrameMode> for u8 {
 #[allow(clippy::upper_case_acronyms)]
 pub struct APU {
     cycles_per_sample: f64,
-    samples_per_frame: f64,
     buffer: [f32; APU_BUFFER_SIZE],
     buffer_write_index: u16,
-    buffer_read_index: u16,
     cycle: u32,
     frame_counter: u32,
     frame_interrupt: bool,
@@ -110,10 +107,8 @@ impl APU {
     pub fn new(sound_card_sample_rate: f64) -> APU {
         APU {
             cycles_per_sample: CPU_FREQ / sound_card_sample_rate,
-            samples_per_frame: sound_card_sample_rate / 60.0,
             buffer: [0.0; APU_BUFFER_SIZE],
             buffer_write_index: 0,
-            buffer_read_index: 0,
             cycle: 0,
             frame_counter: 0,
             frame_interrupt: false,
@@ -146,11 +141,16 @@ impl APU {
     }
 
     fn push_sample(&mut self) {
-        self.samples_pushed += 1;
         let sample = self.get_sample();
         self.current_sample = Some(sample);
-        self.buffer[self.buffer_write_index as usize] = sample;
-        self.buffer_write_index = (self.buffer_write_index + 1) & APU_BUFFER_MASK;
+
+        if self.buffer_write_index < APU_BUFFER_SIZE as u16 {
+            self.buffer[self.buffer_write_index as usize] = sample;
+            self.samples_pushed += 1;
+            self.buffer_write_index += 1;
+        } else {
+            self.clear_buffer();
+        }
     }
 
     #[inline]
@@ -306,15 +306,7 @@ impl APU {
     }
 
     pub fn remaining_buffered_samples(&self) -> u16 {
-        if self.buffer_write_index >= self.buffer_read_index {
-            self.buffer_write_index - self.buffer_read_index
-        } else {
-            APU_BUFFER_SIZE as u16 - self.buffer_read_index + self.buffer_write_index
-        }
-    }
-
-    pub fn remaining_samples_in_frame(&self) -> usize {
-        (self.samples_per_frame - (self.samples_pushed as f64 % self.samples_per_frame)) as usize
+        self.buffer_write_index
     }
 
     pub fn fill(&mut self, buffer: &mut [f32]) {
@@ -340,6 +332,11 @@ impl APU {
         };
     }
 
+    pub fn clear_buffer(&mut self) {
+        self.buffer_write_index = 0;
+        self.buffer.fill(0.0);
+    }
+
     #[inline]
     pub fn is_asserting_irq(&mut self) -> bool {
         let irq = self.frame_interrupt || self.dmc.interrupt_flag;
@@ -376,12 +373,11 @@ impl savestate::Save for APU {
     fn save(&self, parent: &mut savestate::Section) {
         let s = parent.create_child("apu");
 
-        // ignore cycles_per_sample and samples_per_frame
-        // as they depend on the sample rate
+        // ignore cycles_per_sample
+        // as it depends on the sample rate
 
         s.data.write_f32_slice(&self.buffer);
         s.data.write_u16(self.buffer_write_index);
-        s.data.write_u16(self.buffer_read_index);
         s.data.write_u32(self.cycle);
         s.data.write_u32(self.frame_counter);
         s.data.write_bool(self.frame_interrupt);
@@ -403,7 +399,6 @@ impl savestate::Save for APU {
 
         s.data.read_f32_slice(&mut self.buffer)?;
         self.buffer_write_index = s.data.read_u16()?;
-        self.buffer_read_index = s.data.read_u16()?;
         self.cycle = s.data.read_u32()?;
         self.frame_counter = s.data.read_u32()?;
         self.frame_interrupt = s.data.read_bool()?;

crate/src/lib.rs

@@ -69,7 +69,7 @@ impl WasmNes {
     #[wasm_bindgen(js_name = nextFrame)]
     pub fn next_frame(&mut self, buffer: &mut [u8]) {
         self.nes.next_frame();
-        buffer.copy_from_slice(self.nes.get_frame())
+        buffer.copy_from_slice(self.nes.get_frame());
     }
 
     #[wasm_bindgen(js_name = nextSamples)]
@@ -106,4 +106,9 @@ impl WasmNes {
     pub fn fill_audio_buffer(&mut self, buffer: &mut [f32], avoid_underruns: bool) {
         self.nes.fill_audio_buffer(buffer, avoid_underruns);
     }
+
+    #[wasm_bindgen(js_name = clearAudioBuffer)]
+    pub fn clear_audio_buffer(&mut self) {
+        self.nes.clear_audio_buffer();
+    }
 }

crate/src/nes.rs

@@ -75,18 +75,19 @@ impl Nes {
                 self.cpu.bus.apu.remaining_buffered_samples() as usize;
 
             // ensure that the buffer is filled with enough samples
-            // wihtout skipping a frame
             if remaining_samples_in_bufffer < buffer.len() {
-                let remaining_samples_in_frame = self.cpu.bus.apu.remaining_samples_in_frame();
-                let remaining_samples = buffer.len() - remaining_samples_in_bufffer;
-                let wait_for = remaining_samples.min(remaining_samples_in_frame - 1);
+                let wait_for = buffer.len() - remaining_samples_in_bufffer + 1;
                 self.wait_for_samples(wait_for);
             }
         }
 
         self.cpu.bus.apu.fill(buffer);
     }
 
+    pub fn clear_audio_buffer(&mut self) {
+        self.cpu.bus.apu.clear_buffer();
+    }
+
     pub fn soft_reset(&mut self) {
         self.cpu.soft_reset();
     }

web/src/main.ts

@@ -29,7 +29,7 @@ async function setup() {
     Nes.initPanicHook();
     const store = await createStore();
     const ui = createUI(store);
-    const syncMode = SYNC_VIDEO;
+    const syncMode = SYNC_BOTH;
     const audioBufferSize = AUDIO_BUFFER_SIZE_MAPPING[syncMode];
     const avoidUnderruns = syncMode === SYNC_BOTH;
     const canvas = document.querySelector<HTMLCanvasElement>('#screen')!;
@@ -82,6 +82,7 @@ async function setup() {
 
         if (!ui.visible) {
             if (nes !== undefined) {
+                nes.clearAudioBuffer();
                 await audioCtx.resume();
             }
         } else {