adpcm: Separate panning and clock ratio

negativeExponent · Aug 15, 2024 · 842d04e · 842d04e
1 parent 58cba3c
commit 842d04e
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Showing 3 changed files with 26 additions and 18 deletions.
diff --git a/x68k/adpcm.c b/x68k/adpcm.c
@@ -61,8 +61,9 @@ static uint8_t ADPCM_Playing     = 0;
 static uint8_t ADPCM_Clock       = 0;
 static int32_t ADPCM_PreCounter  = 0;
 static int32_t ADPCM_DifBuf      = 0;
+static uint8_t ADPCM_Ratio       = 0;
+static uint8_t ADPCM_Pan         = 0;
 
-static int32_t ADPCM_Pan = 0x00;
 static int32_t OldR = 0, OldL = 0;
 static int32_t Outs[8];
 static int32_t OutsIp[4];
@@ -332,28 +333,30 @@ void ADPCM_SetVolume(uint8_t vol)
 		ADPCM_VolumeShift = 0;
 }
 
-void ADPCM_SetPan(int n)
+void ADPCM_SetClock(uint8_t clock)
 {
-	if ((ADPCM_Pan & 0x0c) != (n & 0x0c))
-	{
-		ADPCM_Count     = 0;
-		ADPCM_Clock     = (ADPCM_Clock & 4) | ((n >> 2) & 3);
-		ADPCM_ClockRate = ADPCM_Clocks[ADPCM_Clock];
-	}
-
-	ADPCM_Pan = n;
+	ADPCM_Count     = 0;
+	ADPCM_Clock     = clock | (ADPCM_Ratio & 3);
+	ADPCM_ClockRate = ADPCM_Clocks[ADPCM_Clock];
 }
 
-void ADPCM_SetClock(int n)
+void ADPCM_SetRatio(uint8_t ratio)
 {
-	if ((ADPCM_Clock & 4) != n)
+	if (ADPCM_Ratio != ratio)
 	{
+		ADPCM_Ratio     = ratio;
+
 		ADPCM_Count     = 0;
-		ADPCM_Clock     = n | ((ADPCM_Pan >> 2) & 3);
+		ADPCM_Clock     = (ADPCM_Clock & 4) | ratio;
 		ADPCM_ClockRate = ADPCM_Clocks[ADPCM_Clock];
 	}
 }
 
+void ADPCM_SetPan(uint8_t pan)
+{
+	ADPCM_Pan = 0;
+}
+
 void ADPCM_Init(uint32_t samplerate)
 {
 	ADPCM_WrPtr      = 0;
@@ -373,7 +376,9 @@ void ADPCM_Init(uint32_t samplerate)
 
 	OldL = OldR = 0;
 
-	ADPCM_SetPan(0x0b);
+	ADPCM_SetPan(0x03);
+	ADPCM_SetRatio(0x02);
+
 	ADPCM_InitTable();
 }
 
@@ -396,6 +401,7 @@ int ADPCM_StateContext(void *f, int writing) {
 	state_context_f(&ADPCM_DifBuf, sizeof(ADPCM_DifBuf));
 
 	state_context_f(&ADPCM_Pan, sizeof(ADPCM_Pan));
+	state_context_f(&ADPCM_Ratio, sizeof(ADPCM_Ratio));
 	state_context_f(&OldR, sizeof(OldR));
 	state_context_f(&OldL, sizeof(OldL));
 	state_context_f(Outs, sizeof(Outs));

diff --git a/x68k/adpcm.h b/x68k/adpcm.h
@@ -4,8 +4,9 @@
 void FASTCALL ADPCM_PreUpdate(int32_t clock);
 void FASTCALL ADPCM_Update(int16_t *buffer, int32_t length, int16_t *pbsp, int16_t *pbep);
 void ADPCM_SetVolume(uint8_t vol);
-void ADPCM_SetPan(int n);
-void ADPCM_SetClock(int n);
+void ADPCM_SetPan(uint8_t pan);
+void ADPCM_SetClock(uint8_t clock);
+void ADPCM_SetRatio(uint8_t ratio);
 void ADPCM_Init(uint32_t samplerate);
 int  ADPCM_IsReady(void);
 

diff --git a/x68k/pia.c b/x68k/pia.c
@@ -33,8 +33,9 @@ static void PIA_SetPortC(uint32_t data)
 	portc = pia.PortC;
 	pia.PortC = data;
 
-	if ((portc & 0x0f) != (pia.PortC & 0x0f))
-		ADPCM_SetPan(pia.PortC & 0x0f);
+	ADPCM_SetPan(data & 3);
+
+	ADPCM_SetRatio((data >> 2) & 3);
 
 	if ((portc & 0x10) != (pia.PortC & 0x10))
 		Joystick_Write(0, (uint8_t)((data & 0x10) ? 0xff : 0x00));