From e511261b04b1231e71d90c8b4501cff857d493d0 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 21 Sep 2018 22:13:07 -0400
Subject: [PATCH] Adds a Master System class, so that SMSs can end up
 somewhere.

---
 Machines/MasterSystem/MasterSystem.cpp | 109 +++++++++++++++++++++++++
 Machines/MasterSystem/MasterSystem.hpp |  15 +++-
 Machines/Utility/MachineForTarget.cpp  |   2 +
 3 files changed, 125 insertions(+), 1 deletion(-)

diff --git a/Machines/MasterSystem/MasterSystem.cpp b/Machines/MasterSystem/MasterSystem.cpp
index d9b93a5c3..0a48f4308 100644
--- a/Machines/MasterSystem/MasterSystem.cpp
+++ b/Machines/MasterSystem/MasterSystem.cpp
@@ -7,3 +7,112 @@
 //
 
 #include "MasterSystem.hpp"
+
+#include "../../Processors/Z80/Z80.hpp"
+
+#include "../../Components/9918/9918.hpp"
+#include "../../Components/SN76489/SN76489.hpp"
+
+#include "../CRTMachine.hpp"
+#include "../JoystickMachine.hpp"
+
+#include "../../ClockReceiver/ForceInline.hpp"
+
+#include "../../Outputs/Speaker/Implementation/LowpassSpeaker.hpp"
+
+namespace {
+const int sn76489_divider = 2;
+}
+
+namespace Sega {
+namespace MasterSystem {
+
+class ConcreteMachine:
+	public Machine,
+	public CPU::Z80::BusHandler,
+	public CRTMachine::Machine {
+
+	public:
+		ConcreteMachine(const Analyser::Static::Target &target, const ROMMachine::ROMFetcher &rom_fetcher) :
+			z80_(*this),
+			sn76489_(TI::SN76489::Personality::SN76489, audio_queue_, sn76489_divider),
+			speaker_(sn76489_) {
+			speaker_.set_input_rate(3579545.0f / static_cast<float>(sn76489_divider));
+			set_clock_rate(3579545);
+		}
+
+		~ConcreteMachine() {
+			audio_queue_.flush();
+		}
+
+		void setup_output(float aspect_ratio) override {
+			vdp_.reset(new TI::TMS::TMS9918(TI::TMS::TMS9918A));
+			get_crt()->set_video_signal(Outputs::CRT::VideoSignal::Composite);
+		}
+
+		void close_output() override {
+			vdp_.reset();
+		}
+
+		Outputs::CRT::CRT *get_crt() override {
+			return vdp_->get_crt();
+		}
+
+		Outputs::Speaker::Speaker *get_speaker() override {
+			return &speaker_;
+		}
+
+		void run_for(const Cycles cycles) override {
+			z80_.run_for(cycles);
+		}
+
+		forceinline HalfCycles perform_machine_cycle(const CPU::Z80::PartialMachineCycle &cycle) {
+			time_since_vdp_update_ += cycle.length;
+			time_since_sn76489_update_ += cycle.length;
+
+			if(time_until_interrupt_ > 0) {
+				time_until_interrupt_ -= cycle.length;
+				if(time_until_interrupt_ <= HalfCycles(0)) {
+					z80_.set_non_maskable_interrupt_line(true, time_until_interrupt_);
+				}
+			}
+
+			return HalfCycles(0);
+		}
+
+		void flush() {
+			update_video();
+			update_audio();
+			audio_queue_.perform();
+		}
+
+	private:
+		inline void update_audio() {
+			speaker_.run_for(audio_queue_, time_since_sn76489_update_.divide_cycles(Cycles(sn76489_divider)));
+		}
+		inline void update_video() {
+			vdp_->run_for(time_since_vdp_update_.flush());
+		}
+
+		CPU::Z80::Processor<ConcreteMachine, false, false> z80_;
+		std::unique_ptr<TI::TMS::TMS9918> vdp_;
+
+		Concurrency::DeferringAsyncTaskQueue audio_queue_;
+		TI::SN76489 sn76489_;
+		Outputs::Speaker::LowpassSpeaker<TI::SN76489> speaker_;
+
+		HalfCycles time_since_vdp_update_;
+		HalfCycles time_since_sn76489_update_;
+		HalfCycles time_until_interrupt_;
+};
+
+}
+}
+
+using namespace Sega::MasterSystem;
+
+Machine *Machine::MasterSystem(const Analyser::Static::Target *target, const ROMMachine::ROMFetcher &rom_fetcher) {
+	return new ConcreteMachine(*target, rom_fetcher);
+}
+
+Machine::~Machine() {}
diff --git a/Machines/MasterSystem/MasterSystem.hpp b/Machines/MasterSystem/MasterSystem.hpp
index 80eecc3f6..e6cfae681 100644
--- a/Machines/MasterSystem/MasterSystem.hpp
+++ b/Machines/MasterSystem/MasterSystem.hpp
@@ -9,6 +9,19 @@
 #ifndef MasterSystem_hpp
 #define MasterSystem_hpp
 
-#include <stdio.h>
+#include "../../Analyser/Static/StaticAnalyser.hpp"
+#include "../ROMMachine.hpp"
+
+namespace Sega {
+namespace MasterSystem {
+
+class Machine {
+	public:
+		virtual ~Machine();
+		static Machine *MasterSystem(const Analyser::Static::Target *target, const ROMMachine::ROMFetcher &rom_fetcher);
+};
+
+}
+}
 
 #endif /* MasterSystem_hpp */
diff --git a/Machines/Utility/MachineForTarget.cpp b/Machines/Utility/MachineForTarget.cpp
index 4d61e701e..44f0c43db 100644
--- a/Machines/Utility/MachineForTarget.cpp
+++ b/Machines/Utility/MachineForTarget.cpp
@@ -14,6 +14,7 @@
 #include "../ColecoVision/ColecoVision.hpp"
 #include "../Commodore/Vic-20/Vic20.hpp"
 #include "../Electron/Electron.hpp"
+#include "../MasterSystem/MasterSystem.hpp"
 #include "../MSX/MSX.hpp"
 #include "../Oric/Oric.hpp"
 #include "../ZX8081/ZX8081.hpp"
@@ -36,6 +37,7 @@ namespace {
 			Bind(Atari2600)
 			BindD(Coleco::Vision, ColecoVision)
 			Bind(Electron)
+			BindD(Sega::MasterSystem, MasterSystem)
 			Bind(MSX)
 			Bind(Oric)
 			BindD(Commodore::Vic20, Vic20)