wave channel memory implemented

src/processor/memory/mmio/apu.rs

@@ -208,6 +208,9 @@ impl Apu {
             0xFF16 => self.channels.two.get_length_timer_and_duty_cycle(),
             0xFF17 => self.channels.two.get_volume_and_envelope(),
             0xFF19 => self.channels.two.get_control(),
+            0xFF1A => self.channels.three.get_dac(),
+            0xFF1C => self.channels.three.get_volume(),
+            0xFF1E => self.channels.three.get_control(),
             0xFF24 => {
                 // NR50 - Master volume + VIN panning
                 let mut v =
@@ -242,6 +245,8 @@ impl Apu {
             0xFF13 | 0xFF18 | 0xFF1B | 0xFF1D | 0xFF20 => 0xFF,
             // not registers
             0xFF15 | 0xFF1F | 0xFF27..0xFF30 => 0xFF,
+            // wave ram
+            0xFF30..0xFF40 => 0xFF,
             0x0..0xFF10 | 0xFF40..=0xFFFF => panic!("non-apu addr in apu"),
             _ => self.mem[reg(addr)],
         }
@@ -258,8 +263,11 @@ impl Apu {
             0xFF17 => self.channels.two.update_volume_and_envelope(data),
             0xFF18 => self.channels.two.update_wavelength_low(data),
             0xFF19 => self.channels.two.update_wavelength_high_and_control(data),
-            0xFF1A => self.masked_io(reg(addr), data, 0b10000000),
+            0xFF1A => self.channels.three.update_dac(data),
-            0xFF1C => self.masked_io(reg(addr), data, 0b1100000),
+            0xFF1B => self.channels.three.update_length(data),
+            0xFF1C => self.channels.three.update_volume(data),
+            0xFF1D => self.channels.three.update_wavelength_low(data),
+            0xFF1E => self.channels.three.update_wavelength_high_and_control(data),
             0xFF20 => self.masked_io(reg(addr), data, 0b111111),
             0xFF23 => {
                 self.mem[reg(addr)] = (self.mem[reg(addr)] & 0b10111111) | (data & 0b01000000)
@@ -281,7 +289,8 @@ impl Apu {
                 self.mixer.ch4.left = Volume::from_bool(get_bit(data, 7));
             }
             0xFF26 => self.apu_enable = (1 << 7) == (data & 0b10000000),
-            0xFF11..0xFF1A | 0xFF1B | 0xFF1D..0xFF23 | 0xFF24..0xFF40 => self.mem[reg(addr)] = data,
+            0xFF30..0xFF40 => self.channels.three.update_wave_ram(addr, data),
+            0xFF11..0xFF1A | 0xFF1D..0xFF23 | 0xFF24..0xFF30 => self.mem[reg(addr)] = data,
             0x0..0xFF10 | 0xFF40..0xFFFF | 0xFFFF => panic!("non-apu addr in apu"),
         }
     }

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

@@ -1,4 +1,7 @@
-use crate::util::{get_bit, set_or_clear_bit};
+use crate::{
+    processor::memory::Address,
+    util::{get_bit, set_or_clear_bit},
+};
 
 #[derive(Clone, Copy, PartialEq)]
 pub(super) enum EnvelopeMode {
@@ -276,13 +279,105 @@ impl PwmChannel {
     }
 }
 
+enum ShiftVolumePercent {
+    Zero,
+    TwentyFive,
+    Fifty,
+    OneHundred,
+}
+
 pub(super) struct WaveChannel {
     pub(super) enabled: bool,
+    dac_enabled: bool,
+    length_enable: bool,
+    length_timer: u8,
+    volume: ShiftVolumePercent,
+    wavelength: u16,
+    wave_timer: u16,
+    wave_position: usize,
+    wave_ram: [u8; 16],
 }
 
 impl WaveChannel {
     pub(super) fn new(enabled: bool) -> Self {
-        Self { enabled }
+        let wavelength = 0x7FF;
+        Self {
+            enabled,
+            dac_enabled: false,
+            length_enable: false,
+            length_timer: 0xFF,
+            volume: ShiftVolumePercent::Zero,
+            wavelength,
+            wave_timer: (2048 - wavelength) * 4,
+            wave_position: 1,
+            wave_ram: [0; 16],
+        }
+    }
+
+    fn trigger(&mut self) {
+        self.enabled = true;
+    }
+
+    pub(super) fn update_dac(&mut self, data: u8) {
+        self.dac_enabled = get_bit(data, 7);
+    }
+
+    pub(super) fn get_dac(&self) -> u8 {
+        set_or_clear_bit(0xFF, 7, self.dac_enabled)
+    }
+
+    pub(super) fn update_length(&mut self, data: u8) {
+        self.length_timer = data;
+    }
+
+    pub(super) fn update_volume(&mut self, data: u8) {
+        self.volume = match (data & 0b1100000) >> 5 {
+            0b00 => ShiftVolumePercent::Zero,
+            0b01 => ShiftVolumePercent::OneHundred,
+            0b10 => ShiftVolumePercent::Fifty,
+            0b11 => ShiftVolumePercent::TwentyFive,
+            _ => panic!("should be unreachable"),
+        }
+    }
+
+    pub(super) fn get_volume(&self) -> u8 {
+        0b10011111
+            & (match self.volume {
+                ShiftVolumePercent::Zero => 0b00,
+                ShiftVolumePercent::TwentyFive => 0b11,
+                ShiftVolumePercent::Fifty => 0b10,
+                ShiftVolumePercent::OneHundred => 0b01,
+            } << 5)
+    }
+
+    pub(super) fn update_wavelength_low(&mut self, data: u8) {
+        self.wavelength = (self.wavelength & 0xFF00) | (data as u16);
+        self.set_wave_timer();
+    }
+
+    pub(super) fn update_wavelength_high_and_control(&mut self, data: u8) {
+        self.length_enable = get_bit(data, 6);
+        self.wavelength = (self.wavelength & 0xFF) | (((data & 0b111) as u16) << 8);
+        self.set_wave_timer();
+        if get_bit(data, 7) {
+            self.trigger();
+        }
+    }
+
+    pub(super) fn get_control(&self) -> u8 {
+        set_or_clear_bit(0xFF, 6, self.length_enable)
+    }
+
+    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() {
+            panic!("sent the wrong address to update_wave_ram");
+        }
+        self.wave_ram[real_addr] = data;
+    }
+
+    fn set_wave_timer(&mut self) {
+        self.wave_timer = (2048 - self.wavelength) * 4;
     }
 }