From 6ac6e48b9535474dea2cd2d6b0b20187fd0e8e69 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sat, 13 Apr 2024 21:54:50 -0400
Subject: [PATCH] Attempt audio output.

---
 Machines/Acorn/Archimedes/Archimedes.cpp      |  6 ++++
 .../Acorn/Archimedes/MemoryController.hpp     |  5 +++
 Machines/Acorn/Archimedes/Sound.hpp           | 31 +++++++++++++++++--
 .../xcschemes/Clock Signal.xcscheme           |  2 +-
 4 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/Machines/Acorn/Archimedes/Archimedes.cpp b/Machines/Acorn/Archimedes/Archimedes.cpp
index 5e9016c2d..fb18453b5 100644
--- a/Machines/Acorn/Archimedes/Archimedes.cpp
+++ b/Machines/Acorn/Archimedes/Archimedes.cpp
@@ -321,6 +321,7 @@ struct HackyDebugger {
 
 class ConcreteMachine:
 	public Machine,
+	public MachineTypes::AudioProducer,
 	public MachineTypes::MappedKeyboardMachine,
 	public MachineTypes::MediaTarget,
 	public MachineTypes::MouseMachine,
@@ -480,6 +481,11 @@ class ConcreteMachine:
 			return true;
 		}
 
+		// MARK: - AudioProducer
+		Outputs::Speaker::Speaker *get_speaker() override {
+			return executor_.bus.speaker();
+		}
+
 		// MARK: - Activity::Source.
 		void set_activity_observer(Activity::Observer *observer) final {
 			executor_.bus.set_activity_observer(observer);
diff --git a/Machines/Acorn/Archimedes/MemoryController.hpp b/Machines/Acorn/Archimedes/MemoryController.hpp
index dbb91c511..f76b6c91c 100644
--- a/Machines/Acorn/Archimedes/MemoryController.hpp
+++ b/Machines/Acorn/Archimedes/MemoryController.hpp
@@ -96,6 +96,7 @@ struct MemoryController {
 					case 0b111:
 						os_mode_ = address & (1 << 12);
 						sound_dma_enable_ = address & (1 << 11);
+						ioc_.sound().set_dma_enabled(sound_dma_enable_);
 						video_dma_enable_ = address & (1 << 10);
 						switch((address >> 8) & 3) {
 							default:
@@ -203,6 +204,10 @@ struct MemoryController {
 		ioc_.set_disk(disk, drive);
 	}
 
+	Outputs::Speaker::Speaker *speaker() {
+		return ioc_.sound().speaker();
+	}
+
 	auto &sound() 					{	return ioc_.sound();	}
 	const auto &sound() const	 	{	return ioc_.sound();	}
 	auto &video()					{	return ioc_.video();	}
diff --git a/Machines/Acorn/Archimedes/Sound.hpp b/Machines/Acorn/Archimedes/Sound.hpp
index 29de60267..6864534c4 100644
--- a/Machines/Acorn/Archimedes/Sound.hpp
+++ b/Machines/Acorn/Archimedes/Sound.hpp
@@ -61,6 +61,9 @@ struct Sound: private SoundLevels {
 	void set_next_start(uint32_t value) {
 		next_.start = value;
 		set_buffer_valid(true);	// My guess: this is triggered on next buffer start write.
+
+		// Definitely wrong; testing.
+//		set_halted(false);
 	}
 
 	bool interrupt() const {
@@ -89,9 +92,20 @@ struct Sound: private SoundLevels {
 		positions_[channel].left = 6 - positions_[channel].right;
 	}
 
+	void set_dma_enabled(bool enabled) {
+		dma_enabled_ = enabled;
+	}
+
 	void tick() {
-		// Do nothing if not currently outputting.
-		if(halted_) {
+		// Write silence if not currently outputting.
+		if(halted_ || !dma_enabled_) {
+			samples_[byte_].left = samples_[byte_].right = 0;
+			++byte_;
+			if(byte_ == 16) {
+				speaker_.push(reinterpret_cast<int16_t *>(samples_.data()), 16);
+				byte_ = 0;
+			}
+
 			return;
 		}
 
@@ -101,11 +115,15 @@ struct Sound: private SoundLevels {
 		divider_ = reload_;
 
 		// Grab a single byte from the FIFO.
-		// TODO: and convert to a linear value, apply stereo image, output.
+		const uint8_t raw = ram_[current_.start + byte_];
+		// TODO: volume, pan.
+		samples_[byte_].left = levels[raw];
+		samples_[byte_].right = 0;
 		++byte_;
 
 		// If the FIFO is exhausted, consider triggering a DMA request.
 		if(byte_ == 16) {
+			speaker_.push(reinterpret_cast<int16_t *>(samples_.data()), 16);
 			byte_ = 0;
 
 			current_.start += 16;
@@ -119,6 +137,10 @@ struct Sound: private SoundLevels {
 		}
 	}
 
+	Outputs::Speaker::Speaker *speaker() {
+		return &speaker_;
+	}
+
 private:
 	const uint8_t *ram_ = nullptr;
 
@@ -132,6 +154,7 @@ private:
 
 	void set_halted(bool halted) {
 		if(halted_ != halted && !halted) {
+			speaker_.push(reinterpret_cast<int16_t *>(samples_.data()), byte_);
 			byte_ = 0;
 			divider_ = reload_;
 		}
@@ -140,6 +163,7 @@ private:
 
 	bool next_buffer_valid_ = false;
 	bool halted_ = true;				// This is a bit of a guess.
+	bool dma_enabled_ = false;
 
 	struct Buffer {
 		uint32_t start = 0, end = 0;
@@ -154,6 +178,7 @@ private:
 	InterruptObserverT &observer_;
 	Outputs::Speaker::PushLowpass<true> speaker_;
 	Concurrency::AsyncTaskQueue<true> queue_;
+	std::array<Outputs::Speaker::StereoSample, 16> samples_;
 };
 
 }
diff --git a/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme b/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme
index 474fa352e..19b54b90e 100644
--- a/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme	
+++ b/OSBindings/Mac/Clock Signal.xcodeproj/xcshareddata/xcschemes/Clock Signal.xcscheme	
@@ -62,7 +62,7 @@
       </Testables>
    </TestAction>
    <LaunchAction
-      buildConfiguration = "Debug"
+      buildConfiguration = "Release"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       enableASanStackUseAfterReturn = "YES"