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◆ main openmsx / src / Autofire.hh
2.3 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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#ifndef AUTOFIRE_HH
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#define AUTOFIRE_HH
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#include "DynamicClock.hh"
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#include "EmuTime.hh"
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#include "IntegerSetting.hh"
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#include "Observer.hh"
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#include "StateChange.hh"
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#include "StateChangeListener.hh"
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#include <cstdint>
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namespace openmsx {
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class MSXMotherBoard;
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class Scheduler;
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class StateChangeDistributor;
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/**
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 * Autofire is a device that is between two other devices and outside
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 * the bus. For example, between the keyboard and the PPI
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 * or between a joyPort connecter and the PSG.
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 *
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 * There can be multiple autofire circuits. For example, one used
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 * by the Ren-Sha Turbo and another one built into a joystick.
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 */
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class Autofire final : private Observer<Setting>, private StateChangeListener
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{
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public:
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	Autofire(MSXMotherBoard& motherBoard,
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	         unsigned newMinInts, unsigned newMaxInts,
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	         AutofireID id);
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	~Autofire();
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	/** Get the output signal in negative logic.
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	  * @result When auto-fire is on, result will alternate between true
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	  *         and false. When auto-fire if off result is false.
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	  */
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	[[nodiscard]] bool getSignal(EmuTime time) const;
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	template<typename Archive>
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	void serialize(Archive& ar, unsigned version);
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private:
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	void setSpeed(EmuTime time);
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	/** Sets the clock frequency according to the current value of the speed
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	  * settings.
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	  */
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	void setClock(int speed);
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	// Observer<Setting>
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	void update(const Setting& setting) noexcept override;
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	// StateChangeListener
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	void signalStateChange(const StateChange& event) override;
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	void stopReplay(EmuTime time) noexcept override;
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private:
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	Scheduler& scheduler;
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	StateChangeDistributor& stateChangeDistributor;
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	// Following two values specify the range of the autofire
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	// as measured by the test program:
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	/** Number of interrupts at fastest setting (>=1).
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	  * The number of interrupts for 50 periods, measured
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	  * in ntsc mode (which gives 60 interrupts per second).
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	  */
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	const unsigned min_ints;
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	/** Number of interrupts at slowest setting (>=min_ints+1).
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	  * The number of interrupts for 50 periods, measured
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	  * in ntsc mode (which gives 60 interrupts per second).
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	  */
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	const unsigned max_ints;
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	/** The currently selected speed. */
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	IntegerSetting speedSetting;
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	/** Each tick of this clock, the signal changes.
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	  * Frequency is derived from speed, min_ints and max_ints.
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	  */
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	DynamicClock clock;
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	const AutofireID id;
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};
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} // namespace openmsx
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#endif