channel 3 audio

Cargo.lock

@@ -279,6 +279,12 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9ea835d29036a4087793836fa931b08837ad5e957da9e23886b29586fb9b6650"
 
+[[package]]
+name = "either"
+version = "1.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fcaabb2fef8c910e7f4c7ce9f67a1283a1715879a7c230ca9d6d1ae31f16d91"
+
 [[package]]
 name = "errno"
 version = "0.2.8"
@@ -413,6 +419,7 @@ dependencies = [
  "cpal",
  "futures",
  "gilrs",
+ "itertools",
  "minifb",
  "once_cell",
  "rand",
@@ -546,6 +553,15 @@ dependencies = [
  "windows-sys 0.42.0",
 ]
 
+[[package]]
+name = "itertools"
+version = "0.10.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0fd2260e829bddf4cb6ea802289de2f86d6a7a690192fbe91b3f46e0f2c8473"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "jni"
 version = "0.19.0"

Cargo.toml

@@ -17,3 +17,4 @@ ringbuf = "0.3.2"
 async-ringbuf = "0.1.2"
 futures = "0.3.26"
 once_cell = "1.17.1"
+itertools = "0.10.5"

src/processor/memory/mmio/apu.rs

@@ -13,6 +13,7 @@ use cpal::{
     Device, Stream, StreamConfig,
 };
 use futures::executor;
+use itertools::izip;
 use samplerate::{ConverterType, Samplerate};
 
 mod channels;
@@ -27,8 +28,12 @@ const fn reg(a: Address) -> usize {
 
 impl DacSample {
     fn mixed(&self, mixer: &Mixer) -> Vec<f32> {
-        let left = (self.one * mixer.ch1.left.scale()) + (self.two * mixer.ch2.left.scale());
-        let right = (self.one * mixer.ch1.right.scale()) + (self.two * mixer.ch2.right.scale());
+        let left = (self.one * mixer.ch1.left.scale())
+            + (self.two * mixer.ch2.left.scale())
+            + (self.three * mixer.ch3.left.scale());
+        let right = (self.one * mixer.ch1.right.scale())
+            + (self.two * mixer.ch2.right.scale())
+            + (self.three * mixer.ch3.right.scale());
         vec![
             self.mix_channel(left, mixer.vol_left),
             self.mix_channel(right, mixer.vol_right),
@@ -150,18 +155,18 @@ impl Apu {
             // tick sound length timers
             self.channels.one.length_tick();
             self.channels.two.length_tick();
+            self.channels.three.length_tick();
         }
     }
 
     fn tick(&mut self, steps: usize) {
         self.buffer.append(
-            &mut self
-                .channels
-                .one
-                .tick(steps)
-                .into_iter()
-                .zip(self.channels.two.tick(steps).into_iter())
-                .map(|(one, two)| DacSample { one, two })
+            &mut izip!(
+                self.channels.one.tick(steps).into_iter(),
+                self.channels.two.tick(steps).into_iter(),
+                self.channels.three.tick(steps).into_iter()
+            )
+            .map(|(one, two, three)| DacSample { one, two, three })
             .collect(),
         );
         if self.buffer.len() >= CYCLES_PER_FRAME {

src/processor/memory/mmio/apu/channels.rs

@@ -1,6 +1,6 @@
 use crate::{
     processor::memory::Address,
-    util::{get_bit, set_or_clear_bit},
+    util::{get_bit, set_or_clear_bit, Nibbles},
 };
 
 #[derive(Clone, Copy, PartialEq)]
@@ -180,7 +180,7 @@ impl PwmChannel {
     }
 
     pub(super) fn frequency_tick(&mut self) {
-        if self.sweep.slope == 0 || !self.enabled {
+        if self.sweep.slope == 0 || self.sweep.pace == 0 || !self.enabled {
             return;
         }
         self.sweep.counter += 1;
@@ -279,6 +279,7 @@ impl PwmChannel {
     }
 }
 
+#[derive(Debug, PartialEq)]
 enum ShiftVolumePercent {
     Zero,
     TwentyFive,
@@ -286,6 +287,30 @@ enum ShiftVolumePercent {
     OneHundred,
 }
 
+impl ShiftVolumePercent {
+    fn as_shift_amount(&self) -> u8 {
+        match self {
+            ShiftVolumePercent::Zero => 8,
+            ShiftVolumePercent::TwentyFive => 2,
+            ShiftVolumePercent::Fifty => 1,
+            ShiftVolumePercent::OneHundred => 0,
+        }
+    }
+}
+
+struct WaveRam {
+    data: [u8; 16],
+}
+
+impl WaveRam {
+    fn as_samples(&self) -> Vec<u8> {
+        self.data
+            .into_iter()
+            .flat_map(|v| [v.get_high_nibble(), v.get_low_nibble()])
+            .collect()
+    }
+}
+
 pub(super) struct WaveChannel {
     pub(super) enabled: bool,
     dac_enabled: bool,
@@ -295,7 +320,7 @@ pub(super) struct WaveChannel {
     wavelength: u16,
     wave_timer: u16,
     wave_position: usize,
-    wave_ram: [u8; 16],
+    wave_ram: WaveRam,
 }
 
 impl WaveChannel {
@@ -308,9 +333,9 @@ impl WaveChannel {
             length_timer: 0xFF,
             volume: ShiftVolumePercent::Zero,
             wavelength,
-            wave_timer: (2048 - wavelength) * 4,
+            wave_timer: (2048 - wavelength) * 2,
             wave_position: 1,
-            wave_ram: [0; 16],
+            wave_ram: WaveRam { data: [0; 16] },
         }
     }
 
@@ -318,6 +343,41 @@ impl WaveChannel {
         self.enabled = true;
     }
 
+    pub fn tick(&mut self, steps: usize) -> Vec<f32> {
+        if self.enabled {
+            (0..steps)
+                .map(|_| {
+                    let b;
+                    (self.wave_timer, b) = self.wave_timer.overflowing_sub(1);
+                    if b {
+                        self.wave_position = (self.wave_position + 1) % 32;
+                        self.set_wave_timer();
+                    }
+                    self.dac(self.wave_ram.as_samples()[self.wave_position])
+                })
+                .collect()
+        } else {
+            vec![0.; steps]
+        }
+    }
+
+    fn dac(&self, digital: u8) -> f32 {
+        if self.dac_enabled && self.volume != ShiftVolumePercent::Zero {
+            ((((digital >> self.volume.as_shift_amount()) as f32) * (-2.)) + 1.) / 15.
+        } else {
+            0.
+        }
+    }
+
+    pub(super) fn length_tick(&mut self) {
+        if self.length_enable && self.enabled {
+            self.length_timer += 1;
+            if self.length_timer >= 64 {
+                self.enabled = false;
+            }
+        }
+    }
+
     pub(super) fn update_dac(&mut self, data: u8) {
         self.dac_enabled = get_bit(data, 7);
     }
@@ -337,7 +397,7 @@ impl WaveChannel {
             0b10 => ShiftVolumePercent::Fifty,
             0b11 => ShiftVolumePercent::TwentyFive,
             _ => panic!("should be unreachable"),
-        }
+        };
     }
 
     pub(super) fn get_volume(&self) -> u8 {
@@ -370,14 +430,14 @@ impl WaveChannel {
 
     pub(super) fn update_wave_ram(&mut self, addr: Address, data: u8) {
         let real_addr = (addr - 0xFF30) as usize;
-        if real_addr >= self.wave_ram.len() {
+        if real_addr >= self.wave_ram.data.len() {
             panic!("sent the wrong address to update_wave_ram");
         }
-        self.wave_ram[real_addr] = data;
+        self.wave_ram.data[real_addr] = data;
     }
 
     fn set_wave_timer(&mut self) {
-        self.wave_timer = (2048 - self.wavelength) * 4;
+        self.wave_timer = (2048 - self.wavelength) * 2;
     }
 }
 

src/processor/memory/mmio/apu/types.rs

@@ -93,10 +93,15 @@ impl Default for Mixer {
 pub(super) struct DacSample {
     pub(super) one: f32,
     pub(super) two: f32,
+    pub(super) three: f32,
 }
 
 impl Default for DacSample {
     fn default() -> Self {
-        Self { one: 0., two: 0. }
+        Self {
+            one: 0.,
+            two: 0.,
+            three: 0.,
+        }
     }
 }