Possibly adds enough for the Electron and ZX80 to start outputting dummy lines.

Let's see!

Components/6560/6560.hpp

@@ -64,7 +64,7 @@ template <class BusHandler> class MOS6560 {
 	public:
 		MOS6560(BusHandler &bus_handler) :
 				bus_handler_(bus_handler),
-				crt_(new Outputs::CRT::CRT(65*4, 4, Outputs::Display::Type::NTSC60, 2)),
+//				crt_(new Outputs::CRT::CRT(65*4, 4, Outputs::Display::Type::NTSC60, 2)),
 				audio_generator_(audio_queue_),
 				speaker_(audio_generator_)
 		{

Components/9918/9918.cpp

@@ -49,8 +49,9 @@ struct ReverseTable {
 }
 
 Base::Base(Personality p) :
-	personality_(p),
-	crt_(new Outputs::CRT::CRT(CRTCyclesPerLine, CRTCyclesDivider, Outputs::Display::Type::NTSC60, 4)) {
+	personality_(p)//,
+//	crt_(new Outputs::CRT::CRT(CRTCyclesPerLine, CRTCyclesDivider, Outputs::Display::Type::NTSC60, 4))
+	{
 
 	switch(p) {
 		case TI::TMS::TMS9918A:

Machines/AmstradCPC/AmstradCPC.cpp

@@ -326,7 +326,7 @@ class CRTCBusHandler {
 
 		/// Constructs an appropriate CRT for video output.
 		void setup_output(Outputs::Display::ScanTarget *scan_target) {
-			crt_.reset(new Outputs::CRT::CRT(1024, 16, Outputs::Display::Type::PAL50, 1));
+//			crt_.reset(new Outputs::CRT::CRT(1024, 16, Outputs::Display::Type::PAL50, 1));
 //			crt_->set_rgb_sampling_function(
 //				"vec3 rgb_sample(usampler2D sampler, vec2 coordinate)"
 //				"{"

Machines/AppleII/Video.cpp

@@ -11,7 +11,7 @@
 using namespace AppleII::Video;
 
 VideoBase::VideoBase(bool is_iie, std::function<void(Cycles)> &&target) :
-	crt_(new Outputs::CRT::CRT(910, 1, Outputs::Display::Type::NTSC60, 1)),
+//	crt_(new Outputs::CRT::CRT(910, 1, Outputs::Display::Type::NTSC60, 1)),
 	is_iie_(is_iie),
 	deferrer_(std::move(target)) {
 

Machines/Atari2600/TIA.cpp

@@ -24,7 +24,7 @@ namespace {
 
 TIA::TIA(bool create_crt) {
 	if(create_crt) {
-		crt_.reset(new Outputs::CRT::CRT(cycles_per_line * 2 - 1, 1, Outputs::Display::Type::NTSC60, 1));
+//		crt_.reset(new Outputs::CRT::CRT(cycles_per_line * 2 - 1, 1, Outputs::Display::Type::NTSC60, 1));
 //		crt_->set_video_signal(Outputs::Display::VideoSignal::Composite);
 		set_output_mode(OutputMode::NTSC);
 	}

Machines/Electron/Electron.cpp

@@ -374,17 +374,9 @@ class ConcreteMachine:
 		}
 
 		void setup_output(Outputs::Display::ScanTarget *scan_target) override final {
-			video_output_.reset(new VideoOutput(ram_));
+			video_output_.reset(new VideoOutput(ram_, scan_target));
 		}
 
-//		void close_output() override final {
-//			video_output_.reset();
-//		}
-//
-//		Outputs::CRT::CRT *get_crt() override final {
-//			return video_output_->get_crt();
-//		}
-
 		Outputs::Speaker::Speaker *get_speaker() override final {
 			return &speaker_;
 		}

Machines/Electron/Video.cpp

@@ -38,12 +38,18 @@ namespace {
 
 // MARK: - Lifecycle
 
-VideoOutput::VideoOutput(uint8_t *memory) : ram_(memory) {
+VideoOutput::VideoOutput(uint8_t *memory, Outputs::Display::ScanTarget *scan_target) : ram_(memory) {
 	memset(palette_, 0xf, sizeof(palette_));
 	setup_screen_map();
 	setup_base_address();
 
-	crt_.reset(new Outputs::CRT::CRT(crt_cycles_per_line, 8, Outputs::Display::Type::PAL50, 1));
+	crt_.reset(new Outputs::CRT::CRT(
+		crt_cycles_per_line,
+		1024,
+		Outputs::Display::Type::PAL50,
+		Outputs::Display::ScanTarget::Modals::DataType::Red1Green1Blue1,
+		scan_target));
+
 //	crt_->set_rgb_sampling_function(
 //		"vec3 rgb_sample(usampler2D sampler, vec2 coordinate)"
 //		"{"

Machines/Electron/Video.hpp

@@ -27,10 +27,12 @@ namespace Electron {
 class VideoOutput {
 	public:
 		/*!
-			Instantiates a VideoOutput that will read its pixels from @c memory. The pointer supplied
-			should be to address 0 in the unexpanded Electron's memory map.
+			Instantiates a VideoOutput that will read its pixels from @c memory and output video
+			to @c scan_target.
+
+			The pointer supplied should be to address 0 in the unexpanded Electron's memory map.
 		*/
-		VideoOutput(uint8_t *memory);
+		VideoOutput(uint8_t *memory, Outputs::Display::ScanTarget *scan_target);
 
 		/// @returns the CRT to which output is being painted.
 		Outputs::CRT::CRT *get_crt();

Machines/Oric/Video.cpp

@@ -23,7 +23,7 @@ namespace {
 
 VideoOutput::VideoOutput(uint8_t *memory) :
 		ram_(memory),
-		crt_(new Outputs::CRT::CRT(64*6, 6, Outputs::Display::Type::PAL50, 2)),
+//		crt_(new Outputs::CRT::CRT(64*6, 6, Outputs::Display::Type::PAL50, 2)),
 		v_sync_start_position_(PAL50VSyncStartPosition), v_sync_end_position_(PAL50VSyncEndPosition),
 		counter_period_(PAL50Period) {
 //	crt_->set_rgb_sampling_function(

Machines/ZX8081/Video.cpp

@@ -22,8 +22,9 @@ const std::size_t StandardAllocationSize = 320;
 
 }
 
-Video::Video() :
-	crt_(new Outputs::CRT::CRT(207 * 2, 1, Outputs::Display::Type::PAL50, 1)) {
+Video::Video(Outputs::Display::ScanTarget *scan_target) :
+	crt_(new Outputs::CRT::CRT(207 * 2, 414, Outputs::Display::Type::PAL50, Outputs::Display::ScanTarget::Modals::DataType::Luminance1, scan_target))
+	{
 
 	// Set a composite sampling function that assumes two-level input; either a byte is 0, which is black,
 	// or it is non-zero, which is white.

Machines/ZX8081/Video.hpp

@@ -27,7 +27,7 @@ namespace ZX8081 {
 class Video {
 	public:
 		/// Constructs an instance of the video feed; a CRT is also created.
-		Video();
+		Video(Outputs::Display::ScanTarget *scan_target);
 		/// @returns The CRT this video feed is feeding.
 		Outputs::CRT::CRT *get_crt();
 

Machines/ZX8081/ZX8081.cpp

@@ -311,7 +311,7 @@ template<bool is_zx81> class ConcreteMachine:
 		}
 
 		void setup_output(Outputs::Display::ScanTarget *scan_target) override final {
-			video_.reset(new Video);
+			video_.reset(new Video(scan_target));
 		}
 
 		Outputs::Speaker::Speaker *get_speaker() override final {

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

@@ -29,6 +29,8 @@
 #import <OpenGL/OpenGL.h>
 #include <OpenGL/gl3.h>
 
+#include "ScanTarget.hpp"
+
 @interface CSMachine() <CSFastLoading>
 - (void)speaker:(Outputs::Speaker::Speaker *)speaker didCompleteSamples:(const int16_t *)samples length:(int)length;
 - (void)speakerDidChangeInputClock:(Outputs::Speaker::Speaker *)speaker;
@@ -71,6 +73,27 @@ struct ActivityObserver: public Activity::Observer {
 	__unsafe_unretained CSMachine *machine;
 };
 
+class ScanTarget: public Outputs::Display::ScanTarget {
+	public:
+		void set_modals(Modals) {}
+
+		Scan *get_scan() {
+			return &scan_;
+		}
+
+		uint8_t *allocate_write_area(size_t required_length, size_t required_alignment) {
+			write_area_.resize(required_length);
+			return write_area_.data();
+		}
+
+		void submit(bool only_if_no_allocation_failures) {
+		}
+
+	private:
+		Scan scan_;
+		std::vector<uint8_t> write_area_;
+};
+
 @implementation CSMachine {
 	SpeakerDelegate _speakerDelegate;
 	ActivityObserver _activityObserver;
@@ -83,6 +106,8 @@ struct ActivityObserver: public Activity::Observer {
 	CSJoystickManager *_joystickManager;
 	std::bitset<65536> _depressedKeys;
 	NSMutableArray<NSString *> *_leds;
+
+	ScanTarget _scanTarget;
 }
 
 - (instancetype)initWithAnalyser:(CSStaticAnalyser *)result {
@@ -231,7 +256,7 @@ struct ActivityObserver: public Activity::Observer {
 }
 
 - (void)setupOutputWithAspectRatio:(float)aspectRatio {
-//	_machine->crt_machine()->setup_output(aspectRatio);
+	_machine->crt_machine()->setup_output(&_scanTarget);
 
 	// Since OS X v10.6, Macs have had a gamma of 2.2.
 //	_machine->crt_machine()->get_crt()->set_output_gamma(2.2f);

Outputs/CRT/CRT.cpp

@@ -56,12 +56,14 @@ void CRT::set_new_timing(int cycles_per_line, int height_of_display, Outputs::Di
 	vertical_flywheel_.reset(new Flywheel(multiplied_cycles_per_line * height_of_display, scanlinesVerticalRetraceTime * multiplied_cycles_per_line, (multiplied_cycles_per_line * height_of_display) >> 3));
 
 	// figure out the divisor necessary to get the horizontal flywheel into a 16-bit range
-	const int real_clock_scan_period = (multiplied_cycles_per_line * height_of_display) / (time_multiplier_ * common_output_divisor_);
-	vertical_flywheel_output_divider_ = static_cast<uint16_t>(ceilf(real_clock_scan_period / 65536.0f) * (time_multiplier_ * common_output_divisor_));
+//	const int real_clock_scan_period = (multiplied_cycles_per_line * height_of_display) / (time_multiplier_);
+//	vertical_flywheel_output_divider_ = static_cast<uint16_t>(ceilf(real_clock_scan_period / 65536.0f) * (time_multiplier_));
 
 //	openGL_output_builder_.set_timing(cycles_per_line, multiplied_cycles_per_line, height_of_display, horizontal_flywheel_->get_scan_period(), vertical_flywheel_->get_scan_period(), vertical_flywheel_output_divider_);
 
-	// TODO: set scan_target modals.
+	scan_target_modals_.expected_vertical_lines = height_of_display;
+	scan_target_modals_.composite_colour_space = colour_space;
+	scan_target_->set_modals(scan_target_modals_);
 }
 
 void CRT::set_new_display_type(int cycles_per_line, Outputs::Display::Type displayType) {
@@ -91,24 +93,30 @@ void CRT::set_input_gamma(float gamma) {
 //	update_gamma();
 }
 
-CRT::CRT(int common_output_divisor, int buffer_depth) :
-	common_output_divisor_(common_output_divisor) {}
-
 CRT::CRT(	int cycles_per_line,
-			int common_output_divisor,
+			int pixel_clock_least_common_multiple,
 			int height_of_display,
 			Outputs::Display::ColourSpace colour_space,
 			int colour_cycle_numerator, int colour_cycle_denominator,
 			int vertical_sync_half_lines,
 			bool should_alternate,
-			int buffer_depth) :
-		CRT(common_output_divisor, buffer_depth) {
+			Outputs::Display::ScanTarget::Modals::DataType data_type,
+			Outputs::Display::ScanTarget *scan_target) {
+	scan_target_ = scan_target;
+	scan_target_modals_.source_data_type = data_type;
+	scan_target_modals_.pixel_clock_least_common_multiple = pixel_clock_least_common_multiple;
 	set_new_timing(cycles_per_line, height_of_display, colour_space, colour_cycle_numerator, colour_cycle_denominator, vertical_sync_half_lines, should_alternate);
 }
 
-CRT::CRT(int cycles_per_line, int common_output_divisor, Outputs::Display::Type displayType, int buffer_depth) :
-		CRT(common_output_divisor, buffer_depth) {
-	set_new_display_type(cycles_per_line, displayType);
+CRT::CRT(	int cycles_per_line,
+			int pixel_clock_least_common_multiple,
+			Outputs::Display::Type display_type,
+			Outputs::Display::ScanTarget::Modals::DataType data_type,
+			Outputs::Display::ScanTarget *scan_target) {
+	scan_target_ = scan_target;
+	scan_target_modals_.source_data_type = data_type;
+	scan_target_modals_.pixel_clock_least_common_multiple = pixel_clock_least_common_multiple;
+	set_new_display_type(cycles_per_line, display_type);
 }
 
 // MARK: - Sync loop
@@ -193,6 +201,8 @@ void CRT::advance_cycles(int number_of_cycles, bool hsync_requested, bool vsync_
 			}
 		}
 	}
+
+	scan_target_->submit();
 }
 
 // MARK: - stream feeding methods

Outputs/CRT/CRT.hpp

@@ -27,12 +27,9 @@ class Delegate {
 
 class CRT {
 	private:
-		CRT(int common_output_divisor, int buffer_depth);
-
 		// the incoming clock lengths will be multiplied by something to give at least 1000
 		// sample points per line
 		int time_multiplier_ = 1;
-		const int common_output_divisor_ = 1;
 
 		// the two flywheels regulating scanning
 		std::unique_ptr<Flywheel> horizontal_flywheel_, vertical_flywheel_;
@@ -82,6 +79,7 @@ class CRT {
 		int cycles_per_line_ = 1;
 
 		Outputs::Display::ScanTarget *scan_target_ = nullptr;
+		Outputs::Display::ScanTarget::Modals scan_target_modals_;
 
 	public:
 		/*!	Constructs the CRT with a specified clock rate, height and colour subcarrier frequency.
@@ -91,10 +89,7 @@ class CRT {
 			@param cycles_per_line The clock rate at which this CRT will be driven, specified as the number
 			of cycles expected to take up one whole scanline of the display.
 
-			@param common_output_divisor The greatest a priori common divisor of all cycle counts that will be
-			supplied to @c output_sync, @c output_data, etc; supply 1 if no greater divisor is known. For many
-			machines output will run at a fixed multiple of the clock rate; knowing this divisor can improve
-			internal precision.
+			@param pixel_clock_least_common_multiple TODO.
 
 			@param height_of_display The number of lines that nominally form one field of the display, rounded
 			up to the next whole integer.
@@ -107,22 +102,22 @@ class CRT {
 			@param vertical_sync_half_lines The expected length of vertical synchronisation (equalisation pulses aside),
 			in multiples of half a line.
 
-			@param buffer_depth The depth per pixel of source data buffers to create for this machine. Machines
-			may provide per-clock-cycle data in the depth that they consider convenient, supplying a sampling
-			function to convert between their data format and either a composite or RGB signal, allowing that
-			work to be offloaded onto the GPU and allowing the output signal to be sampled at a rate appropriate
-			to the display size.
+			@param data_type TODO.
+
+			@param scan_target TODO.
 
 			@see @c set_rgb_sampling_function , @c set_composite_sampling_function
 		*/
 		CRT(int cycles_per_line,
-			int common_output_divisor,
+			int pixel_clock_least_common_multiple,
 			int height_of_display,
 			Outputs::Display::ColourSpace colour_space,
-			int colour_cycle_numerator, int colour_cycle_denominator,
+			int colour_cycle_numerator,
+			int colour_cycle_denominator,
 			int vertical_sync_half_lines,
 			bool should_alternate,
-			int buffer_depth);
+			Outputs::Display::ScanTarget::Modals::DataType data_type,
+			Outputs::Display::ScanTarget *scan_target);
 
 		/*!	Constructs the CRT with the specified clock rate, with the display height and colour
 			subcarrier frequency dictated by a standard display type and with the requested number of
@@ -132,9 +127,10 @@ class CRT {
 			looked up by display type.
 		*/
 		CRT(int cycles_per_line,
-			int common_output_divisor,
+			int pixel_clock_least_common_multiple,
 			Outputs::Display::Type display_type,
-			int buffer_depth);
+			Outputs::Display::ScanTarget::Modals::DataType data_type,
+			Outputs::Display::ScanTarget *scan_target);
 
 		/*!	Resets the CRT with new timing information. The CRT then continues as though the new timing had
 			been provided at construction. */
@@ -149,7 +145,12 @@ class CRT {
 
 		/*!	Resets the CRT with new timing information derived from a new display type. The CRT then continues
 			as though the new timing had been provided at construction. */
-		void set_new_display_type(int cycles_per_line, Outputs::Display::Type display_type);
+		void set_new_display_type(
+			int cycles_per_line,
+			Outputs::Display::Type display_type);
+
+		// TODO.
+		void set_new_data_type(Outputs::Display::ScanTarget::Modals::DataType data_type);
 
 		/*!	Output at the sync level.
 

Outputs/ScanTarget.hpp

@@ -34,7 +34,7 @@ struct Rect {
 		float width, height;
 	} size;
 
-	Rect() {}
+	Rect() : origin({0.0f, 0.0f}), size({1.0f, 1.0f}) {}
 	Rect(float x, float y, float width, float height) :
 		origin({x, y}), size({width, height}) {}
 };
@@ -178,7 +178,7 @@ struct ScanTarget {
 
 		/// Announces that the owner is finished with the region created by the most recent @c allocate_write_area
 		/// and indicates that its actual final size was @c actual_length.
-		virtual void reduce_previous_allocation_to(size_t actual_length) = 0;
+		virtual void reduce_previous_allocation_to(size_t actual_length) {};
 
 		/// Announces that all endpoint pairs and write areas obtained since the last @c submit have now been
 		/// populated with appropriate data.
@@ -187,15 +187,10 @@ struct ScanTarget {
 		/// as long as it feels is appropriate subject to an @c flush.
 		virtual void submit(bool only_if_no_allocation_failures = true) = 0;
 
-		/// Discards all data and endpoints supplied since the last @c submit. This is generally used when
-		/// failures in either get_endpoing_pair of allocate_write_area mean that proceeding would produce
-		/// a faulty total output.
-		virtual void reset() = 0;
-
 		/// Announces that any submitted data not yet output should be output now, but needn't block while
 		/// doing so. This generally communicates that processing is now otherwise 'up to date', so no
 		/// further delay should be allowed.
-		virtual void flush() = 0;
+//		virtual void flush() = 0;
 
 
 	/*