SPU: fix CD ram writeback

Fixes Crash Team Racing

src/psx/spu/mod.rs

@@ -385,6 +385,10 @@ fn run_cycle(psx: &mut Psx) {
 
     let [cd_left, cd_right] = cd::run_audio_cycle(psx);
 
+    // Write CD audio (pre-volume) to the RAM
+    ram_write(psx, psx.spu.capture_index, cd_left as u16);
+    ram_write(psx, psx.spu.capture_index | 0x200, cd_right as u16);
+
     if psx.spu.cd_audio_enabled() {
         let cd_left = (i32::from(cd_left) * i32::from(psx.spu.cd_volume_left)) >> 15;
         let cd_right = (i32::from(cd_right) * i32::from(psx.spu.cd_volume_right)) >> 15;
@@ -674,6 +678,7 @@ fn run_reverb_cycle(psx: &mut Psx, (left_in, right_in): (i16, i16)) -> (i16, i16
                     >> 1,
             );
 
+            // All-pass filter
             let apf_in1 = i32::from(load_reverb_sample(
                 psx,
                 psx.spu.regs[regmap::REVERB_APF_LEFT1]
@@ -798,7 +803,7 @@ fn run_voice_decoder(psx: &mut Psx, voice: u8) {
     // This is important if the IRQ is enabled since it means that it would trigger a bit earlier
     // when the block is read.
     //
-    // This is still not entirely cycle accurate, so we could be improved further with more
+    // This is still not entirely cycle accurate, so it could be further improved with more
     // testing. Mednafen's codebase has a few comments giving hints on what could be done. More
     // testing required.
     if psx.spu[voice].decoder_fifo.len() >= 11 {
@@ -831,7 +836,7 @@ fn run_voice_decoder(psx: &mut Psx, voice: u8) {
         if psx.spu.irq_enabled() {
             // Test current address
             check_for_irq(psx, psx.spu[voice].cur_index);
-            // This is taken from mednafen, not shure why it's necessary
+            // This is taken from mednafen, not sure why it's necessary
             check_for_irq(psx, psx.spu[voice].cur_index & 0x3_fff8);
         }
 
@@ -988,11 +993,12 @@ fn store16(psx: &mut Psx, off: u32, val: u16) {
             regmap::EXT_VOLUME_RIGHT => (),
             // Reverb configuration
             regmap::REVERB_APF_OFFSET1..=regmap::REVERB_INPUT_VOLUME_RIGHT => (),
-            _ => unimplemented!(
+            _ => warn!(
-                "SPU store index {:x} (off = {:x}, abs = {:x})",
+                "SPU store index {:x} (off = {:x}, abs = {:x}): {:x}",
                 index,
                 off,
-                0x1f80_1c00 + off
+                0x1f80_1c00 + off,
+                val
             ),
         }
     } else if index < 0x130 {
@@ -1355,9 +1361,9 @@ impl Voice {
 
 /// Saturating cast from i32 to i16
 fn saturate_to_i16(v: i32) -> i16 {
-    if v < i16::min_value() as i32 {
+    if v < i32::from(i16::min_value()) {
         i16::min_value()
-    } else if v > i16::max_value() as i32 {
+    } else if v > i32::from(i16::max_value()) {
         i16::max_value()
     } else {
         v as i16

src/psx/spu/reverb_resampler.rs

@@ -49,7 +49,8 @@ impl Default for ReverbResampler {
     }
 }
 
-/// FIR coefficients
+/// FIR coefficients. Mednafen and No$ use the same (although Mednafen uses an optimization that
+/// removes zeroes and special-cases the resampling, not sure if it's worth it).
 static FIR_COEFFS: [i16; 39] = [
     -1, 0, 2, 0, -10, 0, 35, 0, -103, 0, 266, 0, -616, 0, 1332, 0, -2960, 0, 10246, 16384, 10246,
     0, -2960, 0, 1332, 0, -616, 0, 266, 0, -103, 0, 35, 0, -10, 0, 2, 0, -1,