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◆ main openmsx / src / sound / DACSound16S.cc
2.0 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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#include "DACSound16S.hh"
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#include "DeviceConfig.hh"
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#include "DynamicClock.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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static constexpr unsigned DUMMY_INPUT_RATE = 44100; // actual rate depends on frequency setting
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DACSound16S::DACSound16S(std::string_view name_, static_string_view desc,
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                         const DeviceConfig& config)
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	: SoundDevice(config.getMotherBoard().getMSXMixer(), name_, desc, 1, DUMMY_INPUT_RATE, false)
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{
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	registerSound(config);
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}
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DACSound16S::~DACSound16S()
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{
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	unregisterSound();
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}
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void DACSound16S::setOutputRate(unsigned hostSampleRate, double /*speed*/)
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{
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	setInputRate(hostSampleRate);
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}
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void DACSound16S::reset(EmuTime time)
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{
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	writeDAC(0, time);
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}
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void DACSound16S::writeDAC(int16_t value, EmuTime time)
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{
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	int delta = value - lastWrittenValue;
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	if (delta == 0) return;
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	lastWrittenValue = value;
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	BlipBuffer::TimeIndex t;
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	getHostSampleClock().getTicksTill(time, t);
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	blip.addDelta(t, narrow<float>(delta));
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}
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void DACSound16S::generateChannels(std::span<float*> bufs, unsigned num)
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{
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	// Note: readSamples() replaces the values in the buffer (it doesn't
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	// add the new values to the existing values in the buffer). That's OK
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	// because this is a single-channel SoundDevice.
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	assert(bufs.size() == 1);
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	if (!blip.readSamples<1>(bufs[0], num)) {
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		bufs[0] = nullptr;
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	}
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}
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bool DACSound16S::updateBuffer(size_t length, float* buffer,
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                               EmuTime /*time*/)
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{
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	return mixChannels(buffer, length);
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}
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template<typename Archive>
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void DACSound16S::serialize(Archive& ar, unsigned /*version*/)
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{
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	// Note: It's ok to NOT serialize a DAC object if you call the
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	//       writeDAC() method in some other way during de-serialization.
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	//       This is for example done in MSXPPI/KeyClick.
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	int16_t lastValue = lastWrittenValue;
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	ar.serialize("lastValue", lastValue);
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	if constexpr (Archive::IS_LOADER) {
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		writeDAC(lastValue, getHostSampleClock().getTime());
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	}
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}
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INSTANTIATE_SERIALIZE_METHODS(DACSound16S);
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} // namespace openmsx