Implemented proper VRC6 audio emulation for mappers 24 and 26

Fixes DS-Homebrew#15, related to sound in these titles: - Esper Dream 2. - Mouryou Senki Madara. - Mega Man RushJet VRC6 edition. - Mega Man II RushJet VRC6 edition. - super Mario Bros VRC6 expanded.
Dartz150 · Jun 5, 2024 · 77a89b7 · 77a89b7
1 parent 8f2bc2f
commit 77a89b7
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Showing 6 changed files with 435 additions and 226 deletions.
diff --git a/arm7/include/s_vrc6.h b/arm7/include/s_vrc6.h
@@ -5,13 +5,76 @@
 extern "C" {
 #endif
 
-void VRC6SoundInstall(void);
-Int32 VRC6SoundRender1(void);
-Int32 VRC6SoundRender2(void);
-Int32 VRC6SoundRender3(void);
-void VRC6SoundWrite9000(Uint address, Uint value);
-void VRC6SoundWriteA000(Uint address, Uint value);
-void VRC6SoundWriteB000(Uint address, Uint value);
+#include <string.h>
+#include "nestypes.h"
+#include "audiosys.h"
+#include "handler.h"
+#include "nsf6502.h"
+#include "nsdout.h"
+
+#define NES_BASECYCLES (21477270)
+#define CPS_SHIFT 16
+
+typedef struct 
+{
+    Uint32 cps;
+    Int32 cycles;
+    Uint32 spd;
+    Uint8 regs[3];
+    Uint8 update;
+    Uint8 adr;
+    Uint8 mute;
+} VRC6_SQUARE;
+
+typedef struct 
+{
+    Uint32 cps;
+    Int32 cycles;
+    Uint32 spd;
+    Uint32 output;
+    Uint8 regs[3];
+    Uint8 update;
+    Uint8 adr;
+    Uint8 mute;
+} VRC6_SAW;
+
+typedef struct 
+{
+    VRC6_SQUARE square[2];
+    VRC6_SAW saw;
+    Uint32 mastervolume;
+} VRC6SOUND;
+
+extern VRC6SOUND vrc6s;
+
+//TODO: Move DivFix to a common header file
+Uint32 DivFix(Uint32 p1, Uint32 p2, Uint32 fix);
+
+void VRC6SoundSquareReset(VRC6_SQUARE *ch);
+void VRC6SoundSawReset(VRC6_SAW *ch);
+void VRC6SoundReset(void);
+
+// VRC6 Mapper 24 Install and Render
+void VRC6SoundInstall_24(void);
+Int32 VRC6SoundRender1_24(void);
+Int32 VRC6SoundRender2_24(void);
+Int32 VRC6SoundRender3_24(void);
+
+// VRC6 Mapper 26 Install and Render
+void VRC6SoundInstall_26(void);
+Int32 VRC6SoundRender1_26(void);
+Int32 VRC6SoundRender2_26(void);
+Int32 VRC6SoundRender3_26(void);
+
+// VRC6 Mapper 24 Write functions
+void VRC6SoundWrite9000_24(Uint address, Uint value);
+void VRC6SoundWriteA000_24(Uint address, Uint value);
+void VRC6SoundWriteB000_24(Uint address, Uint value);
+
+// VRC6 Mapper 26 Write functions
+void VRC6SoundWrite9000_26(Uint address, Uint value);
+void VRC6SoundWriteA000_26(Uint address, Uint value);
+void VRC6SoundWriteB000_26(Uint address, Uint value);
 
 #ifdef __cplusplus
 }

diff --git a/arm7/source/arm7main.c b/arm7/source/arm7main.c
@@ -7,6 +7,8 @@
 #include "calc_lut.h"
 #include "mixer.h"
 #include "audio_capture.h"
+#include "s_vrc6.h"
+
 
 s16 buffer [MIXBUFSIZE * 20]; // Sound Samples Buffer Size, adjust size if necessary
 
@@ -333,7 +335,8 @@ int32_t VRC6SoundRender2();
 int32_t VRC6SoundRender3();
 
 // VRC must be inited to get raw pcm data from ARM9
-void VRC6SoundInstall();
+void VRC6SoundInstall_24();
+void VRC6SoundInstall_26();
 void FDSSoundInstall();
 void readAPU();
 
@@ -422,6 +425,25 @@ static short int accum;
 void mix(int chan)
 {
     int mapper = IPC_MAPPER;
+
+	int32_t (*VRC6SoundRender1)();
+    int32_t (*VRC6SoundRender2)();
+    int32_t (*VRC6SoundRender3)();
+
+    if (mapper == 24) {
+        VRC6SoundRender1 = VRC6SoundRender1_24;
+        VRC6SoundRender2 = VRC6SoundRender2_24;
+        VRC6SoundRender3 = VRC6SoundRender3_24;
+    } else if (mapper == 26) {
+        VRC6SoundRender1 = VRC6SoundRender1_26;
+        VRC6SoundRender2 = VRC6SoundRender2_26;
+        VRC6SoundRender3 = VRC6SoundRender3_26;
+    } else {
+        VRC6SoundRender1 = NULL;
+        VRC6SoundRender2 = NULL;
+        VRC6SoundRender3 = NULL;
+    }
+
     if (!APU_paused) 
 	{
         int i;
@@ -482,7 +504,7 @@ void mix(int chan)
 			}
 
 		//pcmBuffer+=MIXBUFSIZE;	
-        if (mapper == 24 || mapper == 26 || mapper == 256)
+        if (VRC6SoundRender1 && VRC6SoundRender2 && VRC6SoundRender3)
 		{
 			pcmBuffer+=MIXBUFSIZE;
             for (i = 0; i < MIXBUFSIZE; i++)
@@ -717,7 +739,8 @@ void nesmain()
 	// Change func name to "DPCMSoundInstall();"
 	APUSoundInstall();
 	FDSSoundInstall();
-	VRC6SoundInstall();
+	VRC6SoundInstall_24();
+	VRC6SoundInstall_26();
 
 	resetAPU();
 	NESVolume(0);

diff --git a/arm7/source/s_apu.c b/arm7/source/s_apu.c
@@ -809,15 +809,31 @@ void APUSoundWrite(Uint address, Uint value)
 	{
 		if(0x9000 <= address && address <= 0x9002) 
 		{
-			VRC6SoundWrite9000(address, value);
+			VRC6SoundWrite9000_24(address, value);
 		}
 		else if(0xA000 <= address && address <= 0xA002) 
 		{
-			VRC6SoundWriteA000(address, value);
+			VRC6SoundWriteA000_24(address, value);
 		}
 		else if(0xB000 <= address && address <= 0xB002) 
 		{
-			VRC6SoundWriteB000(address, value);
+			VRC6SoundWriteB000_24(address, value);
+		}
+	}
+
+	else if(0x8000 <= address && address < 0xffff) 
+	{
+		if(0x9000 <= address && address <= 0x9002) 
+		{
+			VRC6SoundWrite9000_26(address, value);
+		}
+		else if(0xA000 <= address && address <= 0xA002) 
+		{
+			VRC6SoundWriteA000_26(address, value);
+		}
+		else if(0xB000 <= address && address <= 0xB002) 
+		{
+			VRC6SoundWriteB000_26(address, value);
 		}
 	}
 }
@@ -881,23 +897,23 @@ void __fastcall APU4015Reg()
 	}
 }
 
-static Uint32 DivFix(Uint32 p1, Uint32 p2, Uint32 fix)
-{
-	Uint32 ret;
-	ret = p1 / p2;
-	p1  = p1 % p2;/* p1 = p1 - p2 * ret; */
-	while (fix--)
-	{
-		p1 += p1;
-		ret += ret;
-		if (p1 >= p2)
-		{
-			p1 -= p2;
-			ret++;
-		}
-	}
-	return ret;
-}
+// Uint32 DivFix(Uint32 p1, Uint32 p2, Uint32 fix)
+// {
+// 	Uint32 ret;
+// 	ret = p1 / p2;
+// 	p1  = p1 % p2;/* p1 = p1 - p2 * ret; */
+// 	while (fix--)
+// 	{
+// 		p1 += p1;
+// 		ret += ret;
+// 		if (p1 >= p2)
+// 		{
+// 			p1 -= p2;
+// 			ret++;
+// 		}
+// 	}
+// 	return ret;
+// }
 
 static void NESAPUSoundSquareReset(NESAPU_SQUARE *ch)
 {