Ref #8 PulseSound取得関数を追加

kamiyaowl · Sep 9, 2019 · 80b9df8 · 80b9df8
1 parent cf04bd8
commit 80b9df8
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Showing 2 changed files with 47 additions and 14 deletions.
diff --git a/src/nes/apu.rs b/src/nes/apu.rs
@@ -3,12 +3,12 @@ use super::system::*;
 #[derive(Copy, Clone)]
 pub struct PulseSound {
     // $4000 / $4004
-    /// 0-100でDuty Cycleを設定する
-    pub dutyCycle: u8,
+    /// Duty Cycleを設定する
+    pub dutyCycle: f32,
     /// 再生時間カウンタ有効
-    pub lengthCounterHalt: bool,
+    pub isLengthCounterHalt: bool,
     /// 音響選択
-    pub constantVolume: bool,
+    pub isConstantVolume: bool,
     /// 音量値 4bit
     pub volume: u8,
 
@@ -18,7 +18,7 @@ pub struct PulseSound {
     /// 周波数スイープ値
     pub sweepPeriod: u8,
     /// 周波数スイープの方向(add/sub)
-    pub isSweepPositive: bool,
+    pub isSweepNegative: bool,
     /// 周波数範囲
     pub sweepShift: u8,
 
@@ -31,13 +31,13 @@ pub struct PulseSound {
 impl Default for PulseSound {
     fn default() -> Self {
         Self {
-            dutyCycle: 0,
-            lengthCounterHalt: false,
-            constantVolume: false,
+            dutyCycle: 0.0,
+            isLengthCounterHalt: false,
+            isConstantVolume: false,
             volume: 0,
             isSweepEnable: false,
             sweepPeriod: 0,
-            isSweepPositive: false,
+            isSweepNegative: false,
             sweepShift: 0,
             timerValue: 0,
             lengthCounterLoad: 0,
@@ -49,7 +49,7 @@ impl Default for PulseSound {
 pub struct TriangleSound {
     // $4008
     /// 再生時間カウンタ有効
-    pub lengthCounterHalt: bool,
+    pub isLengthCounterHalt: bool,
     /// 再生時間カウンタ値
     pub counterValue: u8,
     // $400a, $400b
@@ -62,7 +62,7 @@ pub struct TriangleSound {
 impl Default for TriangleSound {
     fn default() -> Self {
         Self {
-            lengthCounterHalt: false,
+            isLengthCounterHalt: false,
             counterValue: 0,
             timerValue: 0,
             lengthCounterLoad: 0,
@@ -76,7 +76,7 @@ pub struct NoiseSound {
     /// 再生時間カウンタ有効
     pub lengthCounterHalt: bool,
     /// 音響選択
-    pub constantVolume: bool,
+    pub isConstantVolume: bool,
     /// 音量値 4bit
     pub volume: u8,
     // $400E
@@ -93,7 +93,7 @@ impl Default for NoiseSound {
     fn default() -> Self {
         Self {
             lengthCounterHalt: false,
-            constantVolume: false,
+            isConstantVolume: false,
             volume: 0,
             isNoiseTypeLoop: false,
             noisePeriod: 0,

diff --git a/src/nes/system_apu_reg.rs b/src/nes/system_apu_reg.rs
@@ -9,7 +9,40 @@ pub const APU_DMC_OFFSET:            usize = 0x10;
 pub const APU_STATUS_OFFSET:         usize = 0x15;
 pub const APU_FRAMECOUNTER_OFFSET:   usize = 0x15;
 
-// APU & I/O(PAD) Register Implement
+/// APU & I/O(PAD) Register Implement
+/// APUのみ(DMAはsystem_ppu_reg.rs, padはレジスタの変数を使わない)
+/// 固定小数点演算が入るものは、別途関数で計算する(定数を返すだけなら構わない)
 impl System {
+    /// Puluse波の設定を取得します
+    /// `index` - 0 or 1
+    pub fn read_apu_pulse_config(&self, index: u8) -> PulseSound {
+        let mut dst = PulseSound::default();
+        debug_assert!(index < 2);
+        let base_offset = if index == 0 { APU_PULSE_1_OFFSET } else { APU_PULSE_2_OFFSET };
+        // 順番に読んで値を決めるだけ
+        dst.dutyCycle = match (self.io_reg[base_offset + 0] >> 6) & 0x03 {
+            0 => 87.5,
+            1 => 75.0,
+            2 => 50.0,
+            3 => 25.0,
+            _ => panic!("invalid pulse dutyCycle: {}", self.io_reg[base_offset + 0]),
+        };
+        // $4000 DDLCVVVV
+        dst.isLengthCounterHalt = (self.io_reg[base_offset + 0] & 0x20) == 0x20;
+        dst.isConstantVolume    = (self.io_reg[base_offset + 0] & 0x10) == 0x10;
+        dst.volume              =  self.io_reg[base_offset + 0] & 0x0f;
+        // $4001 EPPPNSSS
+        dst.isSweepEnable       = (self.io_reg[base_offset + 1] & 0x80) == 0x80;
+        dst.sweepPeriod         = (self.io_reg[base_offset + 1] & 0x70) >> 4;
+        dst.isSweepNegative     = (self.io_reg[base_offset + 1] & 0x04) == 0x04;
+        dst.sweepShift          =  self.io_reg[base_offset + 1] & 0x07;
+        // $4002 TTTTTTTT(timer lower)
+        // $4003 LLLLLTTT(timer Upper)
+        dst.timerValue          = u16::from(self.io_reg[base_offset + 2]) |
+                                 (u16::from(self.io_reg[base_offset + 3] & 0x07) << 8);
+        dst.lengthCounterLoad   = (self.io_reg[base_offset + 3] & 0xf8) >> 3;
+
+        dst
+    }
 
 }