OXYGENHUB
◆ main openmsx / src / input / SG1000JoystickIO.cc
1.3 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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#include "SG1000JoystickIO.hh"
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#include "JoystickPort.hh"
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#include "MSXMotherBoard.hh"
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#include "serialize.hh"
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#include "narrow.hh"
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namespace openmsx {
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// MSXDevice
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SG1000JoystickIO::SG1000JoystickIO(const DeviceConfig& config)
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	: MSXDevice(config)
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{
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	MSXMotherBoard& motherBoard = getMotherBoard();
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	auto time = getCurrentTime();
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	for (unsigned i = 0; i < 2; i++) {
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		ports[i] = &motherBoard.getJoystickPort(i);
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		// Clear strobe bit, or MSX joysticks will stay silent.
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		ports[i]->write(0xFB, time);
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	}
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}
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byte SG1000JoystickIO::readIO(uint16_t port, EmuTime time)
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{
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	return peekIO(port, time);
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}
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byte SG1000JoystickIO::peekIO(uint16_t port, EmuTime time) const
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{
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	// Joystick hardware cannot detect when it's being read, so using the
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	// read() method for peeking should be safe.
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	if (port & 1) {
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		byte joy2 = ports[1]->read(time) & 0x3F;
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		return 0xF0 | (joy2 >> 2);
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	} else {
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		byte joy1 = ports[0]->read(time) & 0x3F;
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		byte joy2 = ports[1]->read(time) & 0x3F;
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		return narrow_cast<byte>(joy1 | (joy2 << 6));
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	}
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}
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template<typename Archive>
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void SG1000JoystickIO::serialize(Archive& ar, unsigned /*version*/)
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{
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	ar.template serializeBase<MSXDevice>(*this);
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}
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INSTANTIATE_SERIALIZE_METHODS(SG1000JoystickIO);
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REGISTER_MSXDEVICE(SG1000JoystickIO, "SG1000Joystick");
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} // namespace openmsx