More work. DMA sound seems to work, but sounds very crappy.

Former-commit-id: cc9f2877f9ccc1b05163af3fd35ff07efa8e3067

src/core/gba.rs

@@ -129,7 +129,7 @@ where
         }
 
         io.intc.request_irqs(irqs);
-
-        io.sound.update(self.cpu.cycles);
+        let mut audio_device = self.audio_device.borrow_mut();
+        io.sound.update(self.cpu.cycles, &mut (*audio_device));
     }
 }

src/core/sound/mod.rs

@@ -3,6 +3,7 @@ use bit::BitIndex;
 use super::dma::DmaController;
 use super::iodev::consts::*;
 use super::iodev::io_reg_string;
+use crate::AudioInterface;
 
 mod fifo;
 use fifo::SoundFifo;
@@ -16,18 +17,20 @@ const DUTY_RATIOS: [f32; 4] = [0.125, 0.25, 0.5, 0.75];
 struct NoiseChannel {}
 
 #[derive(Debug)]
-struct DmaSound {
+struct DmaSoundChannel {
+    value: i8,
     volume: f32,
     enable_right: bool,
     enable_left: bool,
     timer_select: usize,
-    fifo: SoundFifo<i8>,
+    fifo: SoundFifo,
 }
 
-impl Default for DmaSound {
-    fn default() -> DmaSound {
-        DmaSound {
+impl Default for DmaSoundChannel {
+    fn default() -> DmaSoundChannel {
+        DmaSoundChannel {
             volume: DMA_RATIOS[0],
+            value: 0,
             enable_right: false,
             enable_left: false,
             timer_select: 0,
@@ -74,8 +77,9 @@ pub struct SoundController {
 
     sound_bias: u16,
 
-    sound_a: DmaSound,
-    sound_b: DmaSound,
+    dma_sound: [DmaSoundChannel; 2],
+
+    pub output_buffer: Vec<i8>,
 }
 
 impl SoundController {
@@ -104,8 +108,9 @@ impl SoundController {
             sqr1_initial_vol: 0,
             sqr1_cur_vol: 0,
             sound_bias: 0x200,
-            sound_a: Default::default(),
-            sound_b: Default::default(),
+            dma_sound: [Default::default(), Default::default()],
+
+            output_buffer: Vec::with_capacity(32),
         }
     }
 
@@ -132,18 +137,18 @@ impl SoundController {
                     .expect("bad dmg_volume_ratio!") as u16
                     | DMA_RATIOS
                         .iter()
-                        .position(|&f| f == self.sound_a.volume)
+                        .position(|&f| f == self.dma_sound[0].volume)
                         .unwrap() as u16
                     | DMA_RATIOS
                         .iter()
-                        .position(|&f| f == self.sound_b.volume)
+                        .position(|&f| f == self.dma_sound[1].volume)
                         .unwrap() as u16
-                    | cbit(8, self.sound_a.enable_right)
-                    | cbit(9, self.sound_a.enable_left)
-                    | cbit(10, self.sound_a.timer_select != 0)
-                    | cbit(12, self.sound_b.enable_right)
-                    | cbit(13, self.sound_b.enable_left)
-                    | cbit(14, self.sound_b.timer_select != 0)
+                    | cbit(8, self.dma_sound[0].enable_right)
+                    | cbit(9, self.dma_sound[0].enable_left)
+                    | cbit(10, self.dma_sound[0].timer_select != 0)
+                    | cbit(12, self.dma_sound[1].enable_right)
+                    | cbit(13, self.dma_sound[1].enable_left)
+                    | cbit(14, self.dma_sound[1].timer_select != 0)
             }
 
             REG_SOUNDBIAS => self.sound_bias,
@@ -205,20 +210,20 @@ impl SoundController {
 
             REG_SOUNDCNT_H => {
                 self.dmg_volume_ratio = DMG_RATIOS[value.bit_range(0..1) as usize];
-                self.sound_a.volume = DMA_RATIOS[value.bit(2) as usize];
-                self.sound_b.volume = DMA_RATIOS[value.bit(3) as usize];
-                self.sound_a.enable_right = value.bit(8);
-                self.sound_a.enable_left = value.bit(9);
-                self.sound_a.timer_select = DMA_TIMERS[value.bit(10) as usize];
-                self.sound_b.enable_right = value.bit(12);
-                self.sound_b.enable_left = value.bit(13);
-                self.sound_b.timer_select = DMA_TIMERS[value.bit(14) as usize];
+                self.dma_sound[0].volume = DMA_RATIOS[value.bit(2) as usize];
+                self.dma_sound[1].volume = DMA_RATIOS[value.bit(3) as usize];
+                self.dma_sound[0].enable_right = value.bit(8);
+                self.dma_sound[0].enable_left = value.bit(9);
+                self.dma_sound[0].timer_select = DMA_TIMERS[value.bit(10) as usize];
+                self.dma_sound[1].enable_right = value.bit(12);
+                self.dma_sound[1].enable_left = value.bit(13);
+                self.dma_sound[1].timer_select = DMA_TIMERS[value.bit(14) as usize];
 
                 if value.bit(11) {
-                    self.sound_a.fifo.reset();
+                    self.dma_sound[0].fifo.reset();
                 }
                 if value.bit(15) {
-                    self.sound_b.fifo.reset();
+                    self.dma_sound[1].fifo.reset();
                 }
             }
 
@@ -239,13 +244,13 @@ impl SoundController {
             }
 
             REG_FIFO_A_L | REG_FIFO_A_H => {
-                self.sound_a.fifo.write(((value >> 8) & 0xff) as i8);
-                self.sound_a.fifo.write((value & 0xff) as i8);
+                self.dma_sound[0].fifo.write(((value >> 8) & 0xff) as i8);
+                self.dma_sound[0].fifo.write((value & 0xff) as i8);
             }
 
             REG_FIFO_B_L | REG_FIFO_B_H => {
-                self.sound_b.fifo.write(((value >> 8) & 0xff) as i8);
-                self.sound_b.fifo.write((value & 0xff) as i8);
+                self.dma_sound[1].fifo.write(((value >> 8) & 0xff) as i8);
+                self.dma_sound[1].fifo.write((value & 0xff) as i8);
             }
 
             REG_SOUNDBIAS => self.sound_bias = value & 0xc3fe,
@@ -260,23 +265,53 @@ impl SoundController {
         }
     }
 
-    pub fn handle_timer_overflow(&mut self, dmac: &mut DmaController, timer_id: usize) {
+    pub fn handle_timer_overflow(
+        &mut self,
+        dmac: &mut DmaController,
+        timer_id: usize,
+        num_overflows: usize,
+    ) {
         if !self.mse {
             return;
         }
         // TODO - play sound ?
 
-        if timer_id == self.sound_a.timer_select {
-            dmac.notify_sound_fifo(REG_FIFO_A);
-        }
-        if timer_id == self.sound_b.timer_select {
-            dmac.notify_sound_fifo(REG_FIFO_B);
+        const FIFO_INDEX_TO_REG: [u32; 2] = [REG_FIFO_A, REG_FIFO_B];
+        for fifo in 0..2 {
+            let channel = &mut self.dma_sound[fifo];
+
+            if timer_id == channel.timer_select {
+                channel.value = channel.fifo.read();
+                if channel.fifo.count() <= 16 {
+                    dmac.notify_sound_fifo(FIFO_INDEX_TO_REG[fifo]);
+                }
+            }
         }
     }
 
-    pub fn update(&mut self, cycles: usize) {
-        while cycles - self.last_sample_cycles >= self.sample_rate_to_cpu_freq {
-            self.last_sample_cycles += self.sample_rate_to_cpu_freq;
+    fn sample_rate(&self) -> i32 {
+        let resolution = self.sound_bias.bit_range(14..16) as usize;
+        (32768 << resolution) as i32
+    }
+
+    pub fn update(&mut self, cycles: usize, audio_device: &mut dyn AudioInterface) {
+        let resolution = self.sound_bias.bit_range(14..16) as usize;
+        let cycles_per_sample = 512 >> resolution;
+        while cycles - self.last_sample_cycles >= cycles_per_sample {
+            self.last_sample_cycles += cycles_per_sample;
+
+            let mut sample = (0, 0);
+
+            for i in 0..2 {
+                let channel = &self.dma_sound[i];
+                if channel.enable_left {
+                    sample.0 += (channel.value as i16) << 8;
+                }
+                if channel.enable_right {
+                    sample.1 += (channel.value as i16) << 8;
+                }
+            }
+            audio_device.play(&[sample.0, sample.1]);
         }
     }
 }

src/core/timer.rs

@@ -67,7 +67,7 @@ impl Timers {
     pub fn new() -> Timers {
         Timers {
             timers: [Timer::new(0), Timer::new(1), Timer::new(2), Timer::new(3)],
-            trace: true,
+            trace: false,
         }
     }
 
@@ -155,7 +155,9 @@ impl Timers {
                 }
             }
             if id == 0 || id == 1 {
-                sb.io.sound.handle_timer_overflow(&mut sb.io.dmac, id);
+                sb.io
+                    .sound
+                    .handle_timer_overflow(&mut sb.io.dmac, id, num_overflows);
             }
         }
     }

src/lib.rs

@@ -35,7 +35,10 @@ pub trait VideoInterface {
 }
 
 pub trait AudioInterface {
-    fn get_sample_rate(&self) -> u32;
+    fn get_sample_rate(&self) -> i32;
+
+    #[allow(unused_variables)]
+    fn play(&mut self, samples: &[i16]) {}
 }
 
 pub trait InputInterface {

src/plat/minifb/main.rs

@@ -75,7 +75,7 @@ impl InputInterface for MiniFb {
 }
 
 impl AudioInterface for MiniFb {
-    fn get_sample_rate(&self) -> u32 {
+    fn get_sample_rate(&self) -> i32 {
         0
     }
 }

src/plat/sdl2/audio.rs

@@ -1,31 +1,20 @@
 use sdl2;
-use sdl2::audio::{AudioDevice, AudioSpec, AudioSpecDesired};
+use sdl2::audio::{AudioDevice, AudioQueue, AudioSpec, AudioSpecDesired, AudioStatus};
 
 use rustboyadvance_ng::AudioInterface;
 
 pub struct Sdl2AudioPlayer {
-    device: AudioDevice<GbaAudioCallback>,
-    freq: u32,
+    device: AudioQueue<i16>,
+    freq: i32,
 }
 
 impl AudioInterface for Sdl2AudioPlayer {
-    fn get_sample_rate(&self) -> u32 {
+    fn get_sample_rate(&self) -> i32 {
         self.freq
     }
-}
 
-struct GbaAudioCallback {
-    spec: AudioSpec,
-}
-
-impl sdl2::audio::AudioCallback for GbaAudioCallback {
-    type Channel = f32;
-
-    fn callback(&mut self, out: &mut [f32]) {
-        // TODO audio
-        for x in out.iter_mut() {
-            *x = 0.0;
-        }
+    fn play(&mut self, samples: &[i16]) {
+        self.device.queue(&samples);
     }
 }
 
@@ -33,19 +22,26 @@ pub fn create_audio_player(sdl: &sdl2::Sdl) -> Sdl2AudioPlayer {
     let audio_subsystem = sdl.audio().unwrap();
 
     let desired_spec = AudioSpecDesired {
-        freq: Some(44100),
-        channels: Some(1), // stereo
+        freq: Some(44_100),
+        channels: Some(2), // stereo
         samples: None,
     };
 
-    let mut device = audio_subsystem
-        .open_playback(None, &desired_spec, |spec| {
-            println!("Obtained {:?}", spec);
+    // let mut device = audio_subsystem
+    //     .open_playback(None, &desired_spec, |spec| {
+    //         println!("Obtained {:?}", spec);
 
-            GbaAudioCallback { spec: spec }
-        })
+    //         GbaAudioCallback { spec: spec }
+    //     })
+    //     .unwrap();
+
+    let mut device = audio_subsystem
+        .open_queue::<i16, _>(None, &desired_spec)
         .unwrap();
 
-    let freq = (*device.lock()).spec.freq as u32;
+    println!("Found audio device: {:?}", device.spec());
+
+    let freq = device.spec().freq;
+    device.resume();
     Sdl2AudioPlayer { device, freq }
 }