Makes first, faltering steps towards video display.

Machines/Apple/AppleIIgs/AppleIIgs.cpp

@@ -102,11 +102,24 @@ class ConcreteMachine:
 			m65816_.run_for(cycles);
 		}
 
-		void set_scan_target(Outputs::Display::ScanTarget *) override {
+		void flush() {
+			video_.flush();
+		}
+
+		void set_scan_target(Outputs::Display::ScanTarget *target) override {
+			video_->set_scan_target(target);
 		}
 
 		Outputs::Display::ScanStatus get_scaled_scan_status() const override {
-			return Outputs::Display::ScanStatus();
+			return video_->get_scaled_scan_status() * 2.0f;	// TODO: expose multiplier and divider via the JustInTime template?
+		}
+
+		void set_display_type(Outputs::Display::DisplayType display_type) final {
+			video_->set_display_type(display_type);
+		}
+
+		Outputs::Display::DisplayType get_display_type() const final {
+			return video_->get_display_type();
 		}
 
 		forceinline Cycles perform_bus_operation(const CPU::WDC65816::BusOperation operation, const uint32_t address, uint8_t *const value) {
@@ -544,7 +557,7 @@ class ConcreteMachine:
 		// MARK: - Other components.
 
 		Apple::Clock::ParallelClock clock_;
-		JustInTimeActor<Apple::IIgs::Video::Video, 1, 7, Cycles> video_;	// i.e. run video at twice the 1Mhz clock.
+		JustInTimeActor<Apple::IIgs::Video::Video, 1, 2, Cycles> video_;	// i.e. run video at twice the 1Mhz clock.
 		Apple::IIgs::ADB::GLU adb_glu_;
 		Apple::IIgs::Sound::GLU sound_glu_;
  		Zilog::SCC::z8530 scc_;

Machines/Apple/AppleIIgs/Video.cpp

@@ -12,14 +12,35 @@ using namespace Apple::IIgs::Video;
 
 namespace {
 
-constexpr int CyclesPerLine = 910;
+constexpr int CyclesPerTick = 7;	// One 'tick' being the non-stretched length of a cycle on the old Apple II 1Mhz clock.
+constexpr int CyclesPerLine = 456;	// Each of the Mega II's cycles lasts 7 cycles, making 455/line except for the
+									// final on on a line which lasts an additional 1 (i.e. is 1/7th longer).
 constexpr int Lines = 263;
 constexpr int FinalPixelLine = 192;
 
+constexpr auto FinalColumn = CyclesPerLine / CyclesPerTick;
+
 }
 
 VideoBase::VideoBase() :
-	VideoSwitches<Cycles>(true, Cycles(2), [this] (Cycles cycles) { advance(cycles); }) {
+	VideoSwitches<Cycles>(true, Cycles(2), [this] (Cycles cycles) { advance(cycles); }),
+	crt_(130, 1, Outputs::Display::Type::NTSC60, Outputs::Display::InputDataType::Red4Green4Blue4) {
+}
+
+void VideoBase::set_scan_target(Outputs::Display::ScanTarget *scan_target) {
+	crt_.set_scan_target(scan_target);
+}
+
+Outputs::Display::ScanStatus VideoBase::get_scaled_scan_status() const {
+	return crt_.get_scaled_scan_status();
+}
+
+void VideoBase::set_display_type(Outputs::Display::DisplayType display_type) {
+	crt_.set_display_type(display_type);
+}
+
+Outputs::Display::DisplayType VideoBase::get_display_type() const {
+	return crt_.get_display_type();
 }
 
 void VideoBase::set_internal_ram(const uint8_t *ram) {
@@ -27,25 +48,111 @@ void VideoBase::set_internal_ram(const uint8_t *ram) {
 }
 
 void VideoBase::advance(Cycles cycles) {
-	// TODO: everything else!
+	const int column_start = (cycles_into_frame_ % CyclesPerLine) / CyclesPerTick;
-	const auto old = cycles_into_frame_;
+	const int row_start = cycles_into_frame_ / CyclesPerLine;
+
 	cycles_into_frame_ = (cycles_into_frame_ + cycles.as<int>()) % (CyclesPerLine * Lines);
 
-	// DEBUGGING HACK!!
+	const int column_end = (cycles_into_frame_ % CyclesPerLine) / CyclesPerTick;
-	// Scan the output buffer, assuming this is 40-column text mode, and print anything found.
+	const int row_end = cycles_into_frame_ / CyclesPerLine;
-	if(cycles_into_frame_ < old) {
-		for(int line = 0; line < 192; line += 8) {
-			const uint16_t address = get_row_address(line);
 
-			bool did_print_line = false;
+	if(row_end == row_start) {
-			for(int column = 0; column < 40; column++) {
+		output_row(row_start, column_start, column_end);
-				const char c = char(ram_[address + column]);
+	} else {
-				if(c > 0) {
+		output_row(row_start, column_start, FinalColumn);
-					printf("%c", c);
+		for(int row = row_start+1; row < row_end; row++) {
-					did_print_line = true;
+			output_row(row, 0, FinalColumn);
-				}
+		}
-			}
+		if(column_end) {
-			if(did_print_line) printf("\n");
+			output_row(row_end, 0, column_end);
+		}
+	}
+}
+
+void VideoBase::output_row(int row, int start, int end) {
+	// Reasoned guesswork ahoy!
+	//
+	// The IIgs VGC can fetch four bytes per column — I'm unclear physically how, but that's definitely true
+	// since the IIgs modes packs 160 bytes work of graphics into the Apple II's usual 40-cycle fetch area;
+	// it's possible that if I understood the meaning of the linear video bit in the new video flag I'd know more.
+	//
+	// Super Hi-Res also fetches 16*2 = 32 bytes of palette and a control byte sometime before each row.
+	// So it needs five windows for that.
+	//
+	// Guessing four cycles of sync, I've chosen to arrange one output row for this emulator as:
+	//
+	//	5 cycles of back porch;
+	//	8 windows left border, the final five of which fetch palette and control if in IIgs mode;
+	//	40 windows of pixel output;
+	//	8 cycles of right border;
+	//	4 cycles of sync (including the extra 1/7th window, as it has to go _somewhere_).
+	//
+	// Otherwise, the first 200 rows may be pixels and the 192 in the middle of those are the II set.
+	constexpr int first_sync_line = 220;	// A complete guess. Information needed.
+
+	constexpr int blank_ticks = 5;
+	constexpr int left_border_ticks = 8;
+	constexpr int pixel_ticks = 40;
+	constexpr int right_border_ticks = 8;
+
+	constexpr int start_of_left_border = blank_ticks;
+	constexpr int start_of_pixels = start_of_left_border + left_border_ticks;
+	constexpr int start_of_right_border = start_of_pixels + pixel_ticks;
+	constexpr int start_of_sync = start_of_right_border + right_border_ticks;
+	constexpr int sync_period = CyclesPerLine - start_of_sync*CyclesPerTick;
+
+	// Deal with vertical sync.
+	if(row >= first_sync_line && row < first_sync_line + 3) {
+		// Simplification: just output the whole line at line's end.
+		if(end == FinalColumn) {
+			crt_.output_sync(CyclesPerLine - sync_period);
+			crt_.output_blank(sync_period);
+		}
+
+		return;
+	}
+
+	// Deal with the pixel area.
+	if(row < Lines) {	// TODO: use real test here.
+
+		// Output blank only at the end of its window.
+		if(start < blank_ticks && end >= blank_ticks) {
+			crt_.output_blank(blank_ticks * CyclesPerTick);
+			start = blank_ticks;
+		}
+
+		// Output left border as far as currently known.
+		if(start >= start_of_left_border && start < start_of_pixels) {
+			const int duration = std::max(left_border_ticks, end - start_of_left_border);
+			start += duration;
+
+			// TODO: output real border colour.
+			crt_.output_blank(duration * CyclesPerTick);
+		}
+
+		// Output left border as far as currently known.
+		if(start >= start_of_pixels && start < start_of_right_border) {
+			const int duration = std::max(pixel_ticks, end - start_of_pixels);
+			start += duration;
+
+			// TODO: output real pixels.
+			uint16_t *const pixel = reinterpret_cast<uint16_t *>(crt_.begin_data(2, 2));
+			if(pixel) *pixel = 0xffff;
+			crt_.output_data(duration * CyclesPerTick, 1);
+		}
+
+		// Output left border as far as currently known.
+		if(start >= start_of_right_border && start < start_of_sync) {
+			const int duration = std::max(right_border_ticks, end - start_of_right_border);
+			start += duration;
+
+			// TODO: output real border colour.
+			crt_.output_blank(duration * CyclesPerTick);
+		}
+
+		// Output sync if the moment has arrived.
+		if(end == FinalColumn) {
+			crt_.output_sync(sync_period);
 		}
 	}
 }

Machines/Apple/AppleIIgs/Video.hpp

@@ -10,6 +10,7 @@
 #define Apple_IIgs_Video_hpp
 
 #include "../AppleII/VideoSwitches.hpp"
+#include "../../../Outputs/CRT/CRT.hpp"
 #include "../../../ClockReceiver/ClockReceiver.hpp"
 
 namespace Apple {
@@ -37,7 +38,21 @@ class VideoBase: public Apple::II::VideoSwitches<Cycles> {
 
 		void notify_clock_tick();
 
+		/// Sets the scan target.
+		void set_scan_target(Outputs::Display::ScanTarget *scan_target);
+
+		/// Gets the current scan status.
+		Outputs::Display::ScanStatus get_scaled_scan_status() const;
+
+		/// Sets the type of output.
+		void set_display_type(Outputs::Display::DisplayType);
+
+		/// Gets the type of output.
+		Outputs::Display::DisplayType get_display_type() const;
+
 	private:
+		Outputs::CRT::CRT crt_;
+
 		void advance(Cycles);
 
 		uint8_t new_video_ = 0x01;
@@ -46,6 +61,8 @@ class VideoBase: public Apple::II::VideoSwitches<Cycles> {
 
 		int cycles_into_frame_ = 0;
 		const uint8_t *ram_ = nullptr;
+
+		void output_row(int row, int start, int end);
 };
 
 class Video: public VideoBase {