Introduces the MSX keyboard toggle sample source.

In support of which, it also introduces a means of sample source composition.

Machines/MSX/MSX.cpp

@@ -21,10 +21,46 @@
 #include "../ConfigurationTarget.hpp"
 #include "../KeyboardMachine.hpp"
 
+#include "../../Outputs/Speaker/Implementation/CompoundSource.hpp"
 #include "../../Outputs/Speaker/Implementation/LowpassSpeaker.hpp"
+#include "../../Outputs/Speaker/Implementation/SampleSource.hpp"
 
 namespace MSX {
 
+/*!
+	Provides a sample source that can programmatically be set to one of two values.
+*/
+class AudioToggle: public Outputs::Speaker::SampleSource {
+	public:
+		AudioToggle(Concurrency::DeferringAsyncTaskQueue &audio_queue) :
+			audio_queue_(audio_queue) {}
+
+		void get_samples(std::size_t number_of_samples, std::int16_t *target) {
+			for(std::size_t sample = 0; sample < number_of_samples; ++sample) {
+				target[sample] = level_;
+			}
+		}
+
+		void skip_samples(const std::size_t number_of_samples) {}
+
+		void set_output(bool enabled) {
+			if(is_enabled_ == enabled) return;
+			is_enabled_ = enabled;
+			audio_queue_.defer([=] {
+				level_ = enabled ? 4096 : 0;
+			});
+		}
+
+		bool get_output() {
+			return is_enabled_;
+		}
+
+	private:
+		bool is_enabled_ = false;
+		int16_t level_ = 0;
+		Concurrency::DeferringAsyncTaskQueue &audio_queue_;
+};
+
 struct AYPortHandler: public GI::AY38910::PortHandler {
 	void set_port_output(bool port_b, uint8_t value) {
 //		printf("AY port %c output: %02x\n", port_b ? 'b' : 'a', value);
@@ -47,8 +83,10 @@ class ConcreteMachine:
 			z80_(*this),
 			i8255_(i8255_port_handler_),
 			ay_(audio_queue_),
-			speaker_(ay_),
+			audio_toggle_(audio_queue_),
-			i8255_port_handler_(*this) {
+			mixer_(ay_, audio_toggle_),
+			speaker_(mixer_),
+			i8255_port_handler_(*this, audio_toggle_) {
 			set_clock_rate(3579545);
 			std::memset(unpopulated_, 0xff, sizeof(unpopulated_));
 			clear_all_keys();
@@ -96,7 +134,6 @@ class ConcreteMachine:
 		}
 
 		void page_memory(uint8_t value) {
-//			printf("Page: %02x\n", value);
 			for(size_t c = 0; c < 4; ++c) {
 				read_pointers_[c] = memory_slots_[value & 3].read_pointers[c];
 				write_pointers_[c] = memory_slots_[value & 3].write_pointers[c];
@@ -133,7 +170,7 @@ class ConcreteMachine:
 						break;
 
 						case 0xa2:
-							speaker_.run_for(audio_queue_, time_since_ay_update_.divide_cycles(Cycles(2)));
+							update_audio();
 							ay_.set_control_lines(static_cast<GI::AY38910::ControlLines>(GI::AY38910::BC2 | GI::AY38910::BC1));
 							*cycle.value = ay_.get_data_output();
 							ay_.set_control_lines(static_cast<GI::AY38910::ControlLines>(0));
@@ -161,7 +198,7 @@ class ConcreteMachine:
 						break;
 
 						case 0xa0:	case 0xa1:
-							speaker_.run_for(audio_queue_, time_since_ay_update_.divide_cycles(Cycles(2)));
+							update_audio();
 							ay_.set_control_lines(static_cast<GI::AY38910::ControlLines>(GI::AY38910::BDIR | GI::AY38910::BC2 | ((port == 0xa0) ? GI::AY38910::BC1 : 0)));
 							ay_.set_data_input(*cycle.value);
 							ay_.set_control_lines(static_cast<GI::AY38910::ControlLines>(0));
@@ -195,7 +232,7 @@ class ConcreteMachine:
 
 		void flush() {
 			vdp_->run_for(time_since_vdp_update_.flush());
-			speaker_.run_for(audio_queue_, time_since_ay_update_.divide_cycles(Cycles(2)));
+			update_audio();
 			audio_queue_.perform();
 		}
 
@@ -256,21 +293,34 @@ class ConcreteMachine:
 		}
 
 	private:
+		void update_audio() {
+			speaker_.run_for(audio_queue_, time_since_ay_update_.divide_cycles(Cycles(2)));
+		}
+
 		class i8255PortHandler: public Intel::i8255::PortHandler {
 			public:
-				i8255PortHandler(ConcreteMachine &machine) : machine_(machine) {}
+				i8255PortHandler(ConcreteMachine &machine, AudioToggle &audio_toggle) :
+					machine_(machine), audio_toggle_(audio_toggle) {}
 
 				void set_value(int port, uint8_t value) {
 					switch(port) {
 						case 0:	machine_.page_memory(value);	break;
-						case 2:
+						case 2: {
 							// TODO:
-							//	b7	keyboard click
 							//	b6	caps lock LED
 							//	b5 	audio output
 							//	b4	cassette motor relay
+
+							//	b7: keyboard click
+							bool new_audio_level = !!(value & 0x80);
+							if(audio_toggle_.get_output() != new_audio_level) {
+								machine_.update_audio();
+								audio_toggle_.set_output(new_audio_level);
+							}
+
+							// b0–b3: keyboard line
 							machine_.set_keyboard_line(value & 0xf);
-						break;
+						} break;
 						default: printf("What what what what?\n"); break;
 					}
 				}
@@ -284,6 +334,7 @@ class ConcreteMachine:
 
 			private:
 				ConcreteMachine &machine_;
+				AudioToggle &audio_toggle_;
 		};
 
 		CPU::Z80::Processor<ConcreteMachine, false, false> z80_;
@@ -292,7 +343,9 @@ class ConcreteMachine:
 
 		Concurrency::DeferringAsyncTaskQueue audio_queue_;
 		GI::AY38910::AY38910 ay_;
-		Outputs::Speaker::LowpassSpeaker<GI::AY38910::AY38910> speaker_;
+		AudioToggle audio_toggle_;
+		Outputs::Speaker::CompoundSource<GI::AY38910::AY38910, AudioToggle> mixer_;
+		Outputs::Speaker::LowpassSpeaker<Outputs::Speaker::CompoundSource<GI::AY38910::AY38910, AudioToggle>> speaker_;
 
 		i8255PortHandler i8255_port_handler_;
 		AYPortHandler ay_port_handler_;

OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj

@@ -840,6 +840,7 @@
 		4B71368F1F789C93008B8ED9 /* SegmentParser.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = SegmentParser.cpp; sourceTree = "<group>"; };
 		4B7136901F789C93008B8ED9 /* SegmentParser.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = SegmentParser.hpp; sourceTree = "<group>"; };
 		4B77069C1EC904570053B588 /* Z80.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; name = Z80.hpp; path = Z80/Z80.hpp; sourceTree = "<group>"; };
+		4B770A961FE9EE770026DC70 /* CompoundSource.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = CompoundSource.hpp; sourceTree = "<group>"; };
 		4B7913CA1DFCD80E00175A82 /* Video.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = Video.cpp; path = Electron/Video.cpp; sourceTree = "<group>"; };
 		4B7913CB1DFCD80E00175A82 /* Video.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; name = Video.hpp; path = Electron/Video.hpp; sourceTree = "<group>"; };
 		4B79A4FE1FC9082300EEDAD5 /* TypedDynamicMachine.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = TypedDynamicMachine.hpp; sourceTree = "<group>"; };
@@ -2023,6 +2024,7 @@
 			children = (
 				4B8EF6071FE5AF830076CCDD /* LowpassSpeaker.hpp */,
 				4B698D1A1FE768A100696C91 /* SampleSource.hpp */,
+				4B770A961FE9EE770026DC70 /* CompoundSource.hpp */,
 			);
 			path = Implementation;
 			sourceTree = "<group>";

Outputs/Speaker/Implementation/CompoundSource.hpp

@@ -0,0 +1,63 @@
+//
+//  CompoundSource.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 19/12/2017.
+//  Copyright © 2017 Thomas Harte. All rights reserved.
+//
+
+#ifndef CompoundSource_h
+#define CompoundSource_h
+
+#include "SampleSource.hpp"
+
+#include <cstring>
+
+namespace Outputs {
+namespace Speaker {
+
+/*!
+	A CompoundSource adds together the sound generated by multiple individual SampleSources.
+	It's an instance of template metaprogramming; this is the base case.
+*/
+template <typename... T> class CompoundSource: public Outputs::Speaker::SampleSource {
+	public:
+		void get_samples(std::size_t number_of_samples, std::int16_t *target) {
+			std::memset(target, 0, sizeof(std::int16_t) * number_of_samples);
+		}
+};
+
+/*!
+	A CompoundSource adds together the sound generated by multiple individual SampleSources.
+	It's an instance of template metaprogramming; this is the recursive case.
+*/
+template <typename T, typename... R> class CompoundSource<T, R...>: public Outputs::Speaker::SampleSource {
+	public:
+		CompoundSource(T &source, R &...next) : source_(source), next_source_(next...) {}
+
+		void get_samples(std::size_t number_of_samples, std::int16_t *target) {
+			// This is an ugly solution: get whatever the next source supplies and add the local
+			// results to it, with the degenerate case performing a memset to supply an array of 0.
+			// TODO: do better. Might need some alteration of SampleSource.
+			int16_t next_samples[number_of_samples];
+			next_source_.get_samples(number_of_samples, next_samples);
+			source_.get_samples(number_of_samples, target);
+			while(number_of_samples--) {
+				target[number_of_samples] += next_samples[number_of_samples];
+			}
+		}
+
+		void skip_samples(const std::size_t number_of_samples) {
+			source_.skip_samples(number_of_samples);
+			next_source_.skip_samples(number_of_samples);
+		}
+
+	private:
+		T &source_;
+		CompoundSource<R...> next_source_;
+};
+
+}
+}
+
+#endif /* CompoundSource_h */