Modularized APU

.gitignore

@@ -4,4 +4,8 @@ build/
 cmake-build-debug/
 .idea/
 src/.vscode/
-src/dmg_boot.gb
+src/dmg_boot.gb
+tests/*
+.vscode/*
+run.sh
+output.txt

.vscode/settings.json

@@ -54,6 +54,35 @@
         "ios": "cpp",
         "queue": "cpp",
         "semaphore": "cpp",
-        "cinttypes": "cpp"
+        "cinttypes": "cpp",
+        "any": "cpp",
+        "hash_map": "cpp",
+        "strstream": "cpp",
+        "charconv": "cpp",
+        "codecvt": "cpp",
+        "complex": "cpp",
+        "condition_variable": "cpp",
+        "list": "cpp",
+        "map": "cpp",
+        "set": "cpp",
+        "unordered_set": "cpp",
+        "optional": "cpp",
+        "source_location": "cpp",
+        "format": "cpp",
+        "fstream": "cpp",
+        "future": "cpp",
+        "iomanip": "cpp",
+        "iostream": "cpp",
+        "istream": "cpp",
+        "mutex": "cpp",
+        "shared_mutex": "cpp",
+        "span": "cpp",
+        "sstream": "cpp",
+        "stdfloat": "cpp",
+        "text_encoding": "cpp",
+        "cfenv": "cpp",
+        "typeindex": "cpp",
+        "valarray": "cpp",
+        "variant": "cpp"
     }
 }

run.sh

@@ -22,14 +22,14 @@ elif [[ $last_keyword == "gbemu" ]]; then
         echo "making new build directory"
         mkdir build
         cd build
-        cmake ..
+        cmake  ..
         cmake --build . -j8
         ./gbemu
     else 
         echo "making new build directory"
         mkdir build
         cd build
-        cmake ..
+        cmake -DDEBUG=on ..
         cmake --build . -j8
         ./gbemu
     fi

src/audio.cpp

@@ -1,5 +1,4 @@
 #include "audio.h"
-#include "types.h"
 
 APU::APU()
 {
@@ -16,7 +15,7 @@ APU::APU()
 	enableVINRight = false;
 	volumeLeft = 0;
 	volumeRight = 0;
-
+	mMap = nullptr;
 	channel1 = new PulseChannel(CH1);
 	channel2 = new PulseChannel(CH2);
 	channel3 = new WaveChannel();
@@ -47,6 +46,7 @@ bool APU::init()
 	channel2->setFrameSequencer(frameSequencer);
 	channel3->setFrameSequencer(frameSequencer);
 	channel4->setFrameSequencer(frameSequencer);
+
 	return true;
 }
 
@@ -55,9 +55,16 @@ void APU::test()
 	printf("APU test\n");
 }
 
+// initialize the writehandler of memorymap
+void APU::initializeWriteHandler()
+{
+	if (mMap)
+		mMap->setAudioWriteHandler([this](Word address) { this->onMemoryWrite(address); });
+}
+
 void APU::writeByte(Word address, Byte value)
 {
-	printf("APU Address: %X, Value: %X\n", address, value);
+	printf("APU Address: %04X, Value: %02X\n", address, value);
 	if (address == 0xFF26)
 	{
 		bool enable = (value & 0x80) >> 7;
@@ -125,6 +132,7 @@ void APU::writeByte(Word address, Byte value)
 
 Byte APU::readByte(Word address)
 {
+	printf("Address: %04X\n", address);
 	if (address >= 0xFF10 && address <= 0xFF14)
 	{
 		return channel1->readByte(address);
@@ -158,7 +166,7 @@ Byte APU::readByte(Word address)
 
 	case 0xFF26:
 		val = (enabled ? 0x80 : 0) | (channel1->isEnabled() ? 0x01 : 0) | (channel2->isEnabled() ? 0x02 : 0) | (channel3->isEnabled() ? 0x04 : 0) | (channel4->isEnabled() ? 0x08 : 0) | 0x70;
-		printf("APU Read 0xFF26: %X\n", val);
+		// printf("APU Read 0xFF26: %04X\n", val);
 		return val;
 
 	default:
@@ -175,8 +183,8 @@ void APU::stepAPU(int cycles)
 
 	if (frameSequencerCounter >= 8192)
 	{
+		printf("FrameSquencer start\n");
 		// update envelope clocks and length timers
-
 		channel1->run();
 		channel2->run();
 		channel3->run();
@@ -189,6 +197,14 @@ void APU::stepAPU(int cycles)
 		channel2->setFrameSequencer(frameSequencer);
 		channel3->setFrameSequencer(frameSequencer);
 		channel4->setFrameSequencer(frameSequencer);
+
+		// Read and write back after updating
+		Word address[] = { 0xFF19, 0xFF1E, 0xFF23, 0xFF26 };
+		for (auto addr : address)
+		{
+			audioRegisterUpdate(addr, AudioWrite);
+		}
+		printf("FramerSequencer ends\n");
 	}
 }
 
@@ -205,6 +221,33 @@ void APU::clearRegisters()
 	channel2->powerOff();
 	channel3->powerOff();
 	channel4->powerOff();
+	// Could be done by simply writing 0s but for checking's sake done as such
+	for (int address = 0xFF10; address <= 0xFF3F; address++)
+	{
+		audioRegisterUpdate(address, AudioWrite);
+	}
+}
+
+// Updates APU registers on write in MemoryMap
+void APU::onMemoryWrite(Word address)
+{
+	// address where write has occurred
+	audioRegisterUpdate(address, AudioMemoryWrite);
+	// Update the audio channel controller register
+	audioRegisterUpdate(AUDIO_MASTER_CONTROL_REGISTER, AudioWrite);
+}
+
+// Write Update
+void APU::audioRegisterUpdate(Word address, audioWriteFlag flag)
+{
+	Byte value = 0xFF;
+	if (flag)
+	{
+		value = mMap->readMemory(address);
+		writeByte(address, value);
+	}
+	value = readByte(address);
+	mMap->MemoryWriteBack(address, value);
 }
 
 // PulseChannel
@@ -246,6 +289,7 @@ void PulseChannel::writeByte(Word address, Byte value)
 		// Sound length/Wave pattern duty
 		waveDuty = (value & 0xC0) >> 6;
 		lengthTimer = maxLengthTimer - (value & 0x3F);
+		printf("PC: lengthTimer\n");
 		return;
 	case 0xFF12:
 	case 0xFF17:
@@ -276,6 +320,7 @@ void PulseChannel::writeByte(Word address, Byte value)
 		}
 		if (value & 0x80)
 		{
+			printf("WC triggered\n");
 			trigger();
 		}
 		return;
@@ -431,6 +476,7 @@ void WaveChannel::writeByte(Word address, Byte value)
 		// NR31
 		// Sound length
 		lengthTimer = maxLengthTimer - value;
+		printf("WC: lengthTimer\n");
 		return;
 	case 0xFF1C:
 		// NR32
@@ -453,6 +499,7 @@ void WaveChannel::writeByte(Word address, Byte value)
 		}
 		if (value & 0x80)
 		{
+			printf("WC triggered\n");
 			trigger();
 		}
 		return;
@@ -590,6 +637,7 @@ void NoiseChannel::writeByte(Word address, Byte value)
 		// NR41
 		// Sound length
 		lengthTimer = maxLengthTimer - (value & 0x3F);
+		printf("NC: lengthtimer\n");
 		return;
 	case 0xFF21:
 		// NR42
@@ -618,6 +666,7 @@ void NoiseChannel::writeByte(Word address, Byte value)
 		}
 		if (value & 0x80)
 		{
+			printf("NC Triggered...\n");
 			trigger();
 		}
 		return;
@@ -728,4 +777,4 @@ void NoiseChannel::trigger()
 {
 	LFSR = 0x7FFF;
 	enabled = dacEnabled;
-}
+}

src/audio.h

@@ -1,7 +1,10 @@
 #pragma once
 #include "types.h"
+#include "mmap.h"
 #include <stdio.h>
-#include <SDL.h>
+#include <SDL.h> // SDL Audio
+
+#define AUDIO_MASTER_CONTROL_REGISTER 0xFF26
 
 enum Channel
 {
@@ -11,13 +14,21 @@ enum Channel
 	CH4 = 3
 };
 
+// For checking whether Write is due to memory or APU itself
+enum audioWriteFlag
+{
+	AudioWrite = 0,
+	AudioMemoryWrite = 1
+
+};
+
 class PulseChannel
 {
 private:
 	Channel channel;
-    bool enabled;
-    bool dacEnabled;
-    int frameSequencer;
+	bool enabled;
+	bool dacEnabled;
+	int frameSequencer;
 
 	Byte sweepPeriod;
 	bool sweepNegate;
@@ -26,7 +37,7 @@ class PulseChannel
 	// NRx1
 	Byte waveDuty;
 	int lengthTimer;
-    int maxLengthTimer = 64;
+	int maxLengthTimer = 64;
 
 	Byte envelopeInitialVolume;
 	bool envelopeIncrease;
@@ -41,25 +52,24 @@ class PulseChannel
 	void test();
 	void writeByte(Word address, Byte value);
 	Byte readByte(Word address);
-    bool isEnabled();
-    void powerOff();
-    void run();
-    void set_NRx4(Byte value);
-    void setFrameSequencer(int frameSequencer);
-    void trigger();
+	bool isEnabled();
+	void powerOff();
+	void run();
+	void set_NRx4(Byte value);
+	void setFrameSequencer(int frameSequencer);
+	void trigger();
 };
 
 class WaveChannel
 {
 private:
-
 	Byte waveRAM[16];
 	bool dacEnabled;
 	bool enabled;
 
 	int lengthTimer;
 	int maxLengthTimer = 256;
-    int frameSequencer;
+	int frameSequencer;
 
 	Byte outputLevel;
 
@@ -73,22 +83,22 @@ class WaveChannel
 	void writeByte(Word address, Byte value);
 	Byte readByte(Word address);
 	void trigger();
-    bool isEnabled();
-    void powerOff();
-    void set_NRx4(Byte value);
-    void run();
-    void setFrameSequencer(int frameSequencer);
+	bool isEnabled();
+	void powerOff();
+	void set_NRx4(Byte value);
+	void run();
+	void setFrameSequencer(int frameSequencer);
 };
 
 class NoiseChannel
 {
 private:
-    bool enabled;
-    bool dacEnabled;
+	bool enabled;
+	bool dacEnabled;
 
 	int lengthTimer;
 	int maxLengthTimer = 64;
-    int frameSequencer;
+	int frameSequencer;
 
 	Byte envelopeInitialVolume;
 	bool envelopeIncrease;
@@ -112,11 +122,11 @@ class NoiseChannel
 	void writeByte(Word address, Byte value);
 	Byte readByte(Word address);
 	void trigger();
-    bool isEnabled();
-    void powerOff();
-    void set_NRx4(Byte value);
-    void run();
-    void setFrameSequencer(int frameSequencer);
+	bool isEnabled();
+	void powerOff();
+	void set_NRx4(Byte value);
+	void run();
+	void setFrameSequencer(int frameSequencer);
 };
 
 class APU
@@ -160,12 +170,22 @@ class APU
 	WaveChannel* channel3;
 	NoiseChannel* channel4;
 
+	// Memory Map
+	MemoryMap* mMap;
+
 public:
 	APU();
 	void test();
-    bool init();
+	bool init();
 	void writeByte(Word address, Byte value);
 	Byte readByte(Word address);
 	void stepAPU(int cycles);
 	void clearRegisters();
+	void setMemoryMap(MemoryMap* map) { mMap = map; }
+	// Writes back on  Memory Write
+	void onMemoryWrite(Word address);
+	// Write update
+	void audioRegisterUpdate(Word address, audioWriteFlag flag);
+	// initializes the audioWriteHandler of MemoryMap
+	void initializeWriteHandler();
 };