naomi: emulate midi ffb drive board response

needed for driving simulator

core/hw/aica/aica.cpp

@@ -18,6 +18,7 @@ InterruptInfo* MCIRE;
 InterruptInfo* SCIEB;
 InterruptInfo* SCIPD;
 InterruptInfo* SCIRE;
+std::deque<u8> midiSendBuffer;
 
 //Interrupts
 //arm side
@@ -235,6 +236,15 @@ template void WriteAicaReg<>(u32 reg, u8 data);
 template void WriteAicaReg<>(u32 reg, u16 data);
 template void WriteAicaReg<>(u32 reg, u32 data);
 
+void aica_midiSend(u8 data)
+{
+	midiSendBuffer.push_back(data);
+	SCIPD->MIDI_IN = 1;
+	update_arm_interrupts();
+	MCIPD->MIDI_IN = 1;
+	UpdateSh4Ints();
+}
+
 //misc :p
 s32 libAICA_Init()
 {

core/hw/aica/aica.h

@@ -1,5 +1,6 @@
 #pragma once
 #include "types.h"
+#include <deque>
 
 #define SCIEB_addr 0x289C
 #define SCIPD_addr (0x289C+4)
@@ -299,6 +300,7 @@ extern InterruptInfo* MCIRE;
 extern InterruptInfo* SCIEB;
 extern InterruptInfo* SCIPD;
 extern InterruptInfo* SCIRE;
+extern std::deque<u8> midiSendBuffer;
 
 extern CommonData_struct* CommonData;
 extern DSPData_struct*	  DSPData;

core/hw/aica/aica_if.h

@@ -14,6 +14,7 @@ void aica_Init();
 void aica_Reset(bool hard);
 void aica_Term();
 void aica_setMidiReceiver(void (*handler)(u8 data));
+void aica_midiSend(u8 data);
 
 void aica_sb_Init();
 void aica_sb_Reset(bool hard);

core/hw/aica/sgc_if.cpp

@@ -1338,10 +1338,23 @@ void ReadCommonReg(u32 reg,bool byte)
 	{
 	case 0x2808:
 	case 0x2809:
-		CommonData->MIEMP = 1;
-		CommonData->MOEMP = 1;
+		if (!midiSendBuffer.empty())
+		{
+			if (!byte || reg == 0x2808)
+			{
+				CommonData->MIBUF = midiSendBuffer.front();
+				midiSendBuffer.pop_front();
+			}
+			CommonData->MIEMP = 0;
+			CommonData->MIFUL = 1;
+		}
+		else
+		{
+			CommonData->MIEMP = 1;
+			CommonData->MIFUL = 0;
+		}
 		CommonData->MIOVF = 0;
-		CommonData->MIFUL = 0;
+		CommonData->MOEMP = 1;
 		CommonData->MOFUL = 0;
 		break;
 	case 0x2810: // EG, SGC, LP
@@ -1627,6 +1640,9 @@ void channel_serialize(Serializer& ser)
 	ser << beepCounter;
 	ser << cdda_sector;
 	ser << cdda_index;
+	ser << (u32)midiSendBuffer.size();
+	for (u8 b : midiSendBuffer)
+		ser << b;
 }
 
 void channel_deserialize(Deserializer& deser)
@@ -1761,4 +1777,16 @@ void channel_deserialize(Deserializer& deser)
 		deser.skip(4 * 64); 		// mxlr
 		deser.skip(4);			// samples_gen
 	}
+	midiSendBuffer.clear();
+	if (deser.version() >= Deserializer::V28)
+	{
+		u32 size;
+		deser >> size;
+		for (u32 i = 0; i < size; i++)
+		{
+			u8 b;
+			deser >> b;
+			midiSendBuffer.push_back(b);
+		}
+	}
 }

core/hw/naomi/naomi.cpp

@@ -748,13 +748,34 @@ void naomi_Deserialize(Deserializer& deser)
 	}
 }
 
-static void initFFBMidiReceiver(u8 data)
+static void midiSend(u8 b1, u8 b2, u8 b3)
 {
+	aica_midiSend(b1);
+	aica_midiSend(b2);
+	aica_midiSend(b3);
+	aica_midiSend((b1 ^ b2 ^ b3) & 0x7f);
+}
+
+static void forceFeedbackMidiReceiver(u8 data)
+{
+	static float position = 8192.f;
+	static float torque;
+	position = std::min(16383.f, std::max(0.f, position + torque));
 	if (data & 0x80)
 		midiTxBufIndex = 0;
 	midiTxBuf[midiTxBufIndex] = data;
 	if (midiTxBufIndex == 3 && ((midiTxBuf[0] ^ midiTxBuf[1] ^ midiTxBuf[2]) & 0x7f) == midiTxBuf[3])
 	{
+		if (midiTxBuf[0] == 0x84)
+			torque = ((midiTxBuf[1] << 7) | midiTxBuf[2]) - 0x80;
+		else if (midiTxBuf[0] == 0xff)
+		{
+			torque = 0;
+			position = 8192;
+		}
+		// required: b1 & 0x1f == 0x10 && b1 & 0x40 == 0
+		midiSend(0x90, ((int)position >> 7) & 0x7f, (int)position & 0x7f);
+
 		// decoding from FFB Arcade Plugin (by Boomslangnz)
 		// https://github.com/Boomslangnz/FFBArcadePlugin/blob/master/Game%20Files/Demul.cpp
 		if (midiTxBuf[0] == 0x85 && midiTxBuf[1] == 0x3f)
@@ -763,7 +784,7 @@ static void initFFBMidiReceiver(u8 data)
 	midiTxBufIndex = (midiTxBufIndex + 1) % ARRAY_SIZE(midiTxBuf);
 }
 
-void initdFFBInit()
+void initMidiForceFeedback()
 {
-	aica_setMidiReceiver(initFFBMidiReceiver);
+	aica_setMidiReceiver(forceFeedbackMidiReceiver);
 }

core/hw/naomi/naomi.h

@@ -26,7 +26,7 @@ extern u32 reg_dimm_parameterl;
 extern u32 reg_dimm_parameterh;
 extern u32 reg_dimm_status;
 
-void initdFFBInit();
+void initMidiForceFeedback();
 
 u32  libExtDevice_ReadMem_A0_006(u32 addr, u32 size);
 void libExtDevice_WriteMem_A0_006(u32 addr, u32 data, u32 size);

core/hw/naomi/naomi_cart.cpp

@@ -587,13 +587,17 @@ void naomi_cart_LoadRom(const char* file, LoadProgress *progress)
 				|| gameId == "INITIAL D CYCRAFT")
 		{
 			card_reader::initialDCardReader.init();
-			initdFFBInit();
+			initMidiForceFeedback();
 		}
 		else if (gameId == "MAXIMUM SPEED")
 		{
 			maxSpeedNetPipe.init();
 			configure_maxspeed_flash(config::NetworkEnable, config::ActAsServer);
 		}
+		else if (gameId == "SAMPLE GAME MAX LONG NAME-") // Driving Simulator
+		{
+			initMidiForceFeedback();
+		}
 	}
 	else
 		NOTICE_LOG(NAOMI, "NAOMI GAME ID [%s]", naomi_game_id);

core/serialize.h

@@ -41,29 +41,30 @@ public:
 		VLAST_LIBRETRO = V13_LIBRETRO,
 
 		V5 = 800,
-		V6 = 801,
-		V7 = 802,
-		V8 = 803,
-		V9 = 804,
-		V10 = 805,
-		V11 = 806,
-		V12 = 807,
-		V13 = 808,
-		V14 = 809,
-		V15 = 810,
-		V16 = 811,
-		V17 = 812,
-		V18 = 813,
-		V19 = 814,
-		V20 = 815,
-		V21 = 816,
-		V22 = 817,
-		V23 = 818,
-		V24 = 819,
-		V25 = 820,
-		V26 = 821,
-		V27 = 822,
-		Current = V27,
+		V6,
+		V7,
+		V8,
+		V9,
+		V10,
+		V11,
+		V12,
+		V13,
+		V14,
+		V15,
+		V16,
+		V17,
+		V18,
+		V19,
+		V20,
+		V21,
+		V22,
+		V23,
+		V24,
+		V25,
+		V26,
+		V27,
+		V28,
+		Current = V28,
 
 		Next = Current + 1,
 	};

tests/src/serialize_test.cpp

@@ -31,7 +31,7 @@ TEST_F(SerializeTest, SizeTest)
 	std::vector<char> data(30000000);
 	Serializer ser(data.data(), data.size());
 	dc_serialize(ser);
-	ASSERT_EQ(28191595u, ser.size());
+	ASSERT_EQ(28191599u, ser.size());
 }