Adds new hook for watching audio output rate changes.

Analyser/Dynamic/MultiMachine/Implementation/MultiSpeaker.cpp

@@ -54,7 +54,17 @@ void MultiSpeaker::speaker_did_complete_samples(Speaker *speaker, const std::vec
 	}
 }
 
+void MultiSpeaker::speaker_did_change_input_clock(Speaker *speaker) {
+	std::lock_guard<std::mutex> lock_guard(front_speaker_mutex_);
+	if(delegate_ && speaker == front_speaker_) {
+		delegate_->speaker_did_change_input_clock(this);
+	}
+}
+
 void MultiSpeaker::set_new_front_machine(::Machine::DynamicMachine *machine) {
 	std::lock_guard<std::mutex> lock_guard(front_speaker_mutex_);
 	front_speaker_ = machine->crt_machine()->get_speaker();
+	if(delegate_) {
+		delegate_->speaker_did_change_input_clock(this);
+	}
 }

Analyser/Dynamic/MultiMachine/Implementation/MultiSpeaker.hpp

@@ -38,12 +38,13 @@ class MultiSpeaker: public Outputs::Speaker::Speaker, Outputs::Speaker::Speaker:
 		void set_new_front_machine(::Machine::DynamicMachine *machine);
 
 		// Below is the standard Outputs::Speaker::Speaker interface; see there for documentation.
-		float get_ideal_clock_rate_in_range(float minimum, float maximum);
+		float get_ideal_clock_rate_in_range(float minimum, float maximum) override;
-		void set_output_rate(float cycles_per_second, int buffer_size);
+		void set_output_rate(float cycles_per_second, int buffer_size) override;
-		void set_delegate(Outputs::Speaker::Speaker::Delegate *delegate);
+		void set_delegate(Outputs::Speaker::Speaker::Delegate *delegate) override;
 
 	private:
-		void speaker_did_complete_samples(Speaker *speaker, const std::vector<int16_t> &buffer);
+		void speaker_did_complete_samples(Speaker *speaker, const std::vector<int16_t> &buffer) override;
+		void speaker_did_change_input_clock(Speaker *speaker) override;
 		MultiSpeaker(const std::vector<Outputs::Speaker::Speaker *> &speakers);
 
 		std::vector<Outputs::Speaker::Speaker *> speakers_;

OSBindings/Mac/Clock Signal/Machine/CSMachine.h

@@ -43,9 +43,6 @@
 @property (nonatomic, strong) CSAudioQueue *audioQueue;
 @property (nonatomic, readonly) CSOpenGLView *view;
 
-@property (nonatomic, readonly) double clockRate;
-@property (nonatomic, readonly) BOOL clockIsUnlimited;
-
 @property (nonatomic, readonly) NSString *userDefaultsPrefix;
 
 - (void)paste:(NSString *)string;

OSBindings/Mac/Clock Signal/Machine/CSMachine.mm

@@ -25,6 +25,7 @@
 
 @interface CSMachine() <CSFastLoading>
 - (void)speaker:(Outputs::Speaker::Speaker *)speaker didCompleteSamples:(const int16_t *)samples length:(int)length;
+- (void)speakerDidChangeInputClock:(Outputs::Speaker::Speaker *)speaker;
 @end
 
 struct LockProtectedDelegate {
@@ -35,11 +36,16 @@ struct LockProtectedDelegate {
 };
 
 struct SpeakerDelegate: public Outputs::Speaker::Speaker::Delegate, public LockProtectedDelegate {
-	void speaker_did_complete_samples(Outputs::Speaker::Speaker *speaker, const std::vector<int16_t> &buffer) {
+	void speaker_did_complete_samples(Outputs::Speaker::Speaker *speaker, const std::vector<int16_t> &buffer) override {
 		[machineAccessLock lock];
 		[machine speaker:speaker didCompleteSamples:buffer.data() length:(int)buffer.size()];
 		[machineAccessLock unlock];
 	}
+	void speaker_did_change_input_clock(Outputs::Speaker::Speaker *speaker) override {
+		[machineAccessLock lock];
+		[machine speakerDidChangeInputClock:speaker];
+		[machineAccessLock unlock];
+	}
 };
 
 @implementation CSMachine {
@@ -71,6 +77,10 @@ struct SpeakerDelegate: public Outputs::Speaker::Speaker::Delegate, public LockP
 	[self.audioQueue enqueueAudioBuffer:samples numberOfSamples:(unsigned int)length];
 }
 
+- (void)speakerDidChangeInputClock:(Outputs::Speaker::Speaker *)speaker {
+	// TODO: consider changing output audio queue rate.
+}
+
 - (void)dealloc {
 	// The two delegate's references to this machine are nilled out here because close_output may result
 	// in a data flush, which might cause an audio callback, which could cause the audio queue to decide
@@ -142,10 +152,6 @@ struct SpeakerDelegate: public Outputs::Speaker::Speaker::Delegate, public LockP
 	_machine->crt_machine()->get_crt()->draw_frame((unsigned int)pixelSize.width, (unsigned int)pixelSize.height, onlyIfDirty ? true : false);
 }
 
-- (double)clockRate {
-	return _machine->crt_machine()->get_clock_rate();
-}
-
 - (void)paste:(NSString *)paste {
 	KeyboardMachine::Machine *keyboardMachine = _machine->keyboard_machine();
 	if(keyboardMachine)

Outputs/Speaker/Implementation/LowpassSpeaker.hpp

@@ -15,6 +15,7 @@
 #include "../../../ClockReceiver/ClockReceiver.hpp"
 #include "../../../Concurrency/AsyncTaskQueue.hpp"
 
+#include <mutex>
 #include <cstring>
 
 namespace Outputs {
@@ -34,6 +35,8 @@ template <typename T> class LowpassSpeaker: public Speaker {
 
 		// Implemented as per Speaker.
 		float get_ideal_clock_rate_in_range(float minimum, float maximum) {
+			std::lock_guard<std::recursive_mutex> lock_guard(filter_parameters_mutex_);
+
 			// return twice the cut off, if applicable
 			if(	filter_parameters_.high_frequency_cutoff > 0.0f &&
 				filter_parameters_.input_cycles_per_second >= filter_parameters_.high_frequency_cutoff * 3.0f &&
@@ -55,6 +58,7 @@ template <typename T> class LowpassSpeaker: public Speaker {
 
 		// Implemented as per Speaker.
 		void set_output_rate(float cycles_per_second, int buffer_size) {
+			std::lock_guard<std::recursive_mutex> lock_guard(filter_parameters_mutex_);
 			filter_parameters_.output_cycles_per_second = cycles_per_second;
 			filter_parameters_.parameters_are_dirty = true;
 			output_buffer_.resize(static_cast<std::size_t>(buffer_size));
@@ -64,8 +68,10 @@ template <typename T> class LowpassSpeaker: public Speaker {
 			Sets the clock rate of the input audio.
 		*/
 		void set_input_rate(float cycles_per_second) {
+			std::lock_guard<std::recursive_mutex> lock_guard(filter_parameters_mutex_);
 			filter_parameters_.input_cycles_per_second = cycles_per_second;
 			filter_parameters_.parameters_are_dirty = true;
+			filter_parameters_.input_rate_changed = true;
 		}
 
 		/*!
@@ -75,6 +81,7 @@ template <typename T> class LowpassSpeaker: public Speaker {
 			path to be explicit about its effect, and get that simulation for free.
 		*/
 		void set_high_frequency_cutoff(float high_frequency) {
+			std::lock_guard<std::recursive_mutex> lock_guard(filter_parameters_mutex_);
 			filter_parameters_.high_frequency_cutoff = high_frequency;
 			filter_parameters_.parameters_are_dirty = true;
 		}
@@ -88,7 +95,13 @@ template <typename T> class LowpassSpeaker: public Speaker {
 
 			std::size_t cycles_remaining = static_cast<size_t>(cycles.as_int());
 			if(!cycles_remaining) return;
+
+			std::lock_guard<std::recursive_mutex> lock_guard(filter_parameters_mutex_);
 			if(filter_parameters_.parameters_are_dirty) update_filter_coefficients();
+			if(filter_parameters_.input_rate_changed) {
+				delegate_->speaker_did_change_input_clock(this);
+				filter_parameters_.input_rate_changed = false;
+			}
 
 			// If input and output rates exactly match, and no additional cut-off has been specified,
 			// just accumulate results and pass on.
@@ -175,12 +188,14 @@ template <typename T> class LowpassSpeaker: public Speaker {
 		std::unique_ptr<SignalProcessing::Stepper> stepper_;
 		std::unique_ptr<SignalProcessing::FIRFilter> filter_;
 
+		std::recursive_mutex filter_parameters_mutex_;
 		struct FilterParameters {
 			float input_cycles_per_second = 0.0f;
 			float output_cycles_per_second = 0.0f;
 			float high_frequency_cutoff = -1.0;
 
 			bool parameters_are_dirty = true;
+			bool input_rate_changed = false;
 		} filter_parameters_;
 
 		void update_filter_coefficients() {

Outputs/Speaker/Speaker.hpp

@@ -28,6 +28,7 @@ class Speaker {
 
 		struct Delegate {
 			virtual void speaker_did_complete_samples(Speaker *speaker, const std::vector<int16_t> &buffer) = 0;
+			virtual void speaker_did_change_input_clock(Speaker *speaker) {}
 		};
 		virtual void set_delegate(Delegate *delegate) {
 			delegate_ = delegate;