Wire audio frame counter (tbc)

Signed-off-by: Adrian.Conlon <adrian.conlon@arup.com>

LR35902/inc/Audio.h

@@ -7,6 +7,8 @@
 
 #include <Processor.h>
 
+#include "AudioFrame.h"
+
 namespace EightBit {
 	namespace GameBoy {
 
@@ -110,7 +112,8 @@ namespace EightBit {
 
 		class WaveVoice : public AudioVoice {
 		public:
-			WaveVoice() {}
+			WaveVoice(int cyclesPerSecond)
+			: m_cyclesPerSecond(cyclesPerSecond) {}
 
 			virtual void reset() override {
 				AudioVoice::reset();
@@ -141,9 +144,8 @@ namespace EightBit {
 
 			int hertz() const {
 				// f = 4194304 / (4 x 8 x (2048 - X)) Hz
-				auto clock = 4 * 1024 * 1024;
 				auto division = 4 * 8 * (2048 - frequency());
-				return clock / division;
+				return m_cyclesPerSecond / division;
 			}
 
 			void setFrequency(int value) {
@@ -158,13 +160,15 @@ namespace EightBit {
 			}
 
 		private:
+			const int m_cyclesPerSecond;
 			int m_frequencyLowOrder;	// 8 bits
 			int m_frequencyHighOrder;	// 3 bits
 		};
 
 		class RectangularVoice : public WaveVoice {
 		public:
-			RectangularVoice() {}
+			RectangularVoice(int cyclesPerSecond)
+			: WaveVoice(cyclesPerSecond) {}
 
 			virtual void reset() override {
 				WaveVoice::reset();
@@ -194,7 +198,8 @@ namespace EightBit {
 		// NR2X
 		class EnvelopedRectangularVoice : public RectangularVoice {
 		public:
-			EnvelopedRectangularVoice() {}
+			EnvelopedRectangularVoice(int cyclesPerSecond)
+			: RectangularVoice(cyclesPerSecond) {}
 
 			virtual void reset() override {
 				RectangularVoice::reset();
@@ -219,7 +224,8 @@ namespace EightBit {
 		// NR1X
 		class SweptEnvelopedRectangularVoice : public EnvelopedRectangularVoice {
 		public:
-			SweptEnvelopedRectangularVoice() {}
+			SweptEnvelopedRectangularVoice(int cyclesPerSecond)
+			: EnvelopedRectangularVoice(cyclesPerSecond) {}
 
 			virtual void reset() override {
 				EnvelopedRectangularVoice::reset();
@@ -244,7 +250,8 @@ namespace EightBit {
 		// NR3X
 		class UserDefinedWaveVoice : public WaveVoice {
 		public:
-			UserDefinedWaveVoice() {}
+			UserDefinedWaveVoice(int cyclesPerSecond)
+			: WaveVoice(cyclesPerSecond) {}
 
 			virtual void reset() override {
 				WaveVoice::reset();
@@ -391,12 +398,19 @@ namespace EightBit {
 
 		class Audio final {
 		public:
-			Audio()
+			Audio(int cyclesPerSecond)
-			: m_enabled(false) {
+			: m_frameSequencer(cyclesPerSecond),
-				m_voices[0] = std::make_shared<SweptEnvelopedRectangularVoice>();
+			  m_enabled(false) {
-				m_voices[1] = std::make_shared<EnvelopedRectangularVoice>();
+
-				m_voices[2] = std::make_shared<UserDefinedWaveVoice>();
+				m_voices[0] = std::make_shared<SweptEnvelopedRectangularVoice>(cyclesPerSecond);
+				m_voices[1] = std::make_shared<EnvelopedRectangularVoice>(cyclesPerSecond);
+				m_voices[2] = std::make_shared<UserDefinedWaveVoice>(cyclesPerSecond);
 				m_voices[3] = std::make_shared<WhiteNoiseWaveVoice>();
+
+				m_frameSequencer.FrameStep.connect(std::bind(&Audio::Sequencer_FrameStep, this, std::placeholders::_1));
+				m_frameSequencer.LengthStep.connect(std::bind(&Audio::Sequencer_LengthStep, this, std::placeholders::_1));
+				m_frameSequencer.VolumeStep.connect(std::bind(&Audio::Sequencer_VolumeStep, this, std::placeholders::_1));
+				m_frameSequencer.SweepStep.connect(std::bind(&Audio::Sequencer_SweepStep, this, std::placeholders::_1));
 			}
 
 			std::shared_ptr<AudioVoice> voice(int i) { return m_voices[i]; }
@@ -759,7 +773,25 @@ namespace EightBit {
 				return voice3()->packedWaveDatum(i);
 			}
 
+			void stepFrame(int cycles) {
+				m_frameSequencer.step(cycles);
+			}
+
+			void Sequencer_FrameStep(const int step) {
+			}
+
+			void Sequencer_LengthStep(const int step) {
+			}
+
+			void Sequencer_VolumeStep(const int step) {
+			}
+
+			void Sequencer_SweepStep(const int step) {
+			}
+
 		private:
+			AudioFrame m_frameSequencer;
+
 			std::array<std::shared_ptr<AudioVoice>, 4> m_voices;
 			std::array<OutputChannel, 2> m_channels;
 			bool m_enabled;

LR35902/inc/AudioFrame.h

@@ -0,0 +1,47 @@
+#pragma once
+
+#include <Signal.h>
+
+namespace EightBit {
+	namespace GameBoy {
+		class AudioFrame final {
+		private:
+			enum { StepCycle = 7, Frequency = 512 };
+
+			int m_cyclesPerTick;
+			int m_currentStep;
+			int m_currentCycles;
+
+		public:
+			AudioFrame(int cyclesPerSecond)
+			: m_cyclesPerTick(cyclesPerSecond / Frequency),
+			  m_currentStep(0),
+			  m_currentCycles(m_cyclesPerTick) {
+			}
+
+			Signal<int> FrameStep;
+			Signal<int> LengthStep;
+			Signal<int> VolumeStep;
+			Signal<int> SweepStep;
+
+			void step() {
+				m_currentStep = (m_currentStep + 1) % StepCycle;
+				FrameStep.fire(m_currentStep);
+				if ((m_currentStep % 2) == 0)
+					LengthStep.fire(m_currentStep);
+				if (m_currentStep == 7)
+					VolumeStep.fire(m_currentStep);
+				if ((m_currentStep == 2) || (m_currentStep == 6))
+					SweepStep.fire(m_currentStep);
+			}
+
+			void step(int cycles) {
+				m_currentCycles -= cycles;
+				if (m_currentCycles < 0) {
+					step();
+					m_currentCycles += m_cyclesPerTick;
+				}
+			}
+		};
+	}
+}

LR35902/src/GameBoyBus.cpp

@@ -30,7 +30,8 @@ EightBit::GameBoy::Bus::Bus()
   m_p13(true),
   m_p12(true),
   m_p11(true),
-  m_p10(true) {
+  m_p10(true),
+  m_audio(CyclesPerSecond) {
 	ReadingByte.connect(std::bind(&GameBoy::Bus::Bus_ReadingByte, this, std::placeholders::_1));
 	WrittenByte.connect(std::bind(&GameBoy::Bus::Bus_WrittenByte, this, std::placeholders::_1));
 	m_divCounter.word = 0xabcc;

LR35902/src/LR35902.vcxproj

@@ -141,6 +141,7 @@
   <ItemGroup>
     <ClInclude Include="..\inc\AbstractColourPalette.h" />
     <ClInclude Include="..\inc\Audio.h" />
+    <ClInclude Include="..\inc\AudioFrame.h" />
     <ClInclude Include="..\inc\GameBoyBus.h" />
     <ClInclude Include="..\inc\CharacterDefinition.h" />
     <ClInclude Include="..\inc\Disassembler.h" />

LR35902/src/LR35902.vcxproj.filters

@@ -41,6 +41,9 @@
     <ClInclude Include="..\inc\Audio.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\inc\AudioFrame.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="stdafx.cpp">