Started sketching out an interface for sound generation. Which made me realise that the CRT in CRTDelegate was redundant, since C++ has namespaces.

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

@@ -12,6 +12,7 @@
 		4B14145E1B5887AA00E04248 /* CPU6502AllRAM.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B1414591B58879D00E04248 /* CPU6502AllRAM.cpp */; };
 		4B1414601B58885000E04248 /* WolfgangLorenzTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4B14145F1B58885000E04248 /* WolfgangLorenzTests.swift */; };
 		4B1414621B58888700E04248 /* KlausDormannTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4B1414611B58888700E04248 /* KlausDormannTests.swift */; };
+		4B2409551C45AB05004DA684 /* Speaker.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B2409531C45AB05004DA684 /* Speaker.cpp */; };
 		4B2E2D951C399D1200138695 /* ElectronDocument.xib in Resources */ = {isa = PBXBuildFile; fileRef = 4B2E2D931C399D1200138695 /* ElectronDocument.xib */; };
 		4B2E2D9A1C3A06EC00138695 /* Atari2600.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B2E2D971C3A06EC00138695 /* Atari2600.cpp */; };
 		4B2E2D9D1C3A070400138695 /* Electron.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B2E2D9B1C3A070400138695 /* Electron.cpp */; };
@@ -327,6 +328,8 @@
 		4B14145A1B58879D00E04248 /* CPU6502AllRAM.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = CPU6502AllRAM.hpp; sourceTree = "<group>"; };
 		4B14145F1B58885000E04248 /* WolfgangLorenzTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = WolfgangLorenzTests.swift; sourceTree = "<group>"; };
 		4B1414611B58888700E04248 /* KlausDormannTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = KlausDormannTests.swift; sourceTree = "<group>"; };
+		4B2409531C45AB05004DA684 /* Speaker.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = Speaker.cpp; path = ../../Outputs/Speaker.cpp; sourceTree = "<group>"; };
+		4B2409541C45AB05004DA684 /* Speaker.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; name = Speaker.hpp; path = ../../Outputs/Speaker.hpp; sourceTree = "<group>"; };
 		4B2632551B631A510082A461 /* CRTFrame.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; name = CRTFrame.h; path = ../../Outputs/CRTFrame.h; sourceTree = "<group>"; };
 		4B2E2D941C399D1200138695 /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.xib; name = Base; path = Base.lproj/ElectronDocument.xib; sourceTree = "<group>"; };
 		4B2E2D971C3A06EC00138695 /* Atari2600.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = Atari2600.cpp; sourceTree = "<group>"; };
@@ -708,6 +711,8 @@
 				4B366DFA1B5C165A0026627B /* CRT.cpp */,
 				4B366DFB1B5C165A0026627B /* CRT.hpp */,
 				4B2632551B631A510082A461 /* CRTFrame.h */,
+				4B2409531C45AB05004DA684 /* Speaker.cpp */,
+				4B2409541C45AB05004DA684 /* Speaker.hpp */,
 			);
 			name = Outputs;
 			sourceTree = "<group>";
@@ -1532,6 +1537,7 @@
 				4B55CE4B1C3B3B0C0093A61B /* CSAtari2600.mm in Sources */,
 				4B55CE581C3B7D360093A61B /* Atari2600Document.swift in Sources */,
 				4B55CE5F1C3B7D960093A61B /* MachineDocument.swift in Sources */,
+				4B2409551C45AB05004DA684 /* Speaker.cpp in Sources */,
 				4B55CE4E1C3B3BDA0093A61B /* CSMachine.mm in Sources */,
 				4B2E2D9D1C3A070400138695 /* Electron.cpp in Sources */,
 				4B55CE5D1C3B7D6F0093A61B /* CSCathodeRayView.m in Sources */,

OSBindings/Mac/Clock Signal/Wrappers/CSAtari2600.mm

@@ -70,7 +70,7 @@
 	[view setSignalDecoder:[NSString stringWithUTF8String:_atari2600.get_signal_decoder()] type:CSCathodeRayViewSignalTypeNTSC];
 }
 
-- (void)setCRTDelegate:(Outputs::CRT::CRTDelegate *)delegate{
+- (void)setCRTDelegate:(Outputs::CRT::Delegate *)delegate{
 	_atari2600.get_crt()->set_delegate(delegate);
 }
 

OSBindings/Mac/Clock Signal/Wrappers/CSElectron.mm

@@ -27,7 +27,7 @@
 	_electron.set_rom(Electron::ROMSlotBASIC, rom.length, (const uint8_t *)rom.bytes);
 }
 
-- (void)setCRTDelegate:(Outputs::CRT::CRTDelegate *)delegate{
+- (void)setCRTDelegate:(Outputs::CRT::Delegate *)delegate{
 	_electron.get_crt()->set_delegate(delegate);
 }
 

OSBindings/Mac/Clock Signal/Wrappers/CSMachine+Subclassing.h

@@ -11,7 +11,7 @@
 
 @interface CSMachine (Subclassing)
 
-- (void)setCRTDelegate:(Outputs::CRT::CRTDelegate *)delegate;
+- (void)setCRTDelegate:(Outputs::CRT::Delegate *)delegate;
 - (void)doRunForNumberOfCycles:(int)numberOfCycles;
 - (void)crt:(Outputs::CRT *)crt didEndFrame:(CRTFrame *)frame didDetectVSync:(BOOL)didDetectVSync;
 

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

@@ -9,7 +9,7 @@
 #import "CSMachine.h"
 #import "CSMachine+Subclassing.h"
 
-struct CRTDelegate: public Outputs::CRT::CRTDelegate {
+struct CRTDelegate: public Outputs::CRT::Delegate {
 	__weak CSMachine *machine;
 	void crt_did_end_frame(Outputs::CRT *crt, CRTFrame *frame, bool did_detect_vsync) {
 		[machine crt:crt didEndFrame:frame didDetectVSync:did_detect_vsync];
@@ -60,7 +60,7 @@ typedef NS_ENUM(NSInteger, CSAtari2600RunningState) {
 	return self;
 }
 
-- (void)setCRTDelegate:(Outputs::CRT::CRTDelegate *)delegate {}
+- (void)setCRTDelegate:(Outputs::CRT::Delegate *)delegate {}
 - (void)doRunForNumberOfCycles:(int)numberOfCycles {}
 
 @end

Outputs/CRT.cpp

@@ -335,7 +335,7 @@ void CRT::return_frame()
 
 #pragma mark - delegate
 
-void CRT::set_delegate(CRTDelegate *delegate)
+void CRT::set_delegate(Delegate *delegate)
 {
 	_delegate = delegate;
 }

Outputs/CRT.hpp

@@ -58,11 +58,11 @@ class CRT {
 		void output_level(unsigned int number_of_cycles);
 		void output_data(unsigned int number_of_cycles);
 
-		class CRTDelegate {
+		class Delegate {
 			public:
 				virtual void crt_did_end_frame(CRT *crt, CRTFrame *frame, bool did_detect_vsync) = 0;
 		};
-		void set_delegate(CRTDelegate *delegate);
+		void set_delegate(Delegate *delegate);
 		void return_frame();
 
 		void allocate_write_area(int required_length);
@@ -90,7 +90,7 @@ class CRT {
 		CRTFrameBuilder *_current_frame_builder;
 		int _frames_with_delegate;
 		int _frame_read_pointer;
-		CRTDelegate *_delegate;
+		Delegate *_delegate;
 
 		// outer elements of sync separation
 		bool _is_receiving_sync;				// true if the CRT is currently receiving sync (i.e. this is for edge triggering of horizontal sync)

Outputs/Speaker.cpp

@@ -0,0 +1,9 @@
+//
+//  Speaker.cpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 12/01/2016.
+//  Copyright © 2016 Thomas Harte. All rights reserved.
+//
+
+#include "Speaker.hpp"

Outputs/Speaker.hpp

@@ -0,0 +1,32 @@
+//
+//  Speaker.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 12/01/2016.
+//  Copyright © 2016 Thomas Harte. All rights reserved.
+//
+
+#ifndef Speaker_hpp
+#define Speaker_hpp
+
+#include <stdint.h>
+
+namespace Speaker {
+
+class Delegate {
+	public:
+		virtual void speaker_did_complete_samples(uint8_t *buffer);
+};
+
+template <class T> class Filter {
+	public:
+		void set_output_rate(int cycles_per_second);
+		void set_delegate(Delegate *delegate);
+
+		void set_input_rate(int cycles_per_second);
+		void run_for_cycles(int input_cycles);
+};
+
+}
+
+#endif /* Speaker_hpp */