OXYGENHUB
◆ main openmsx / src / sound / DACSound16S.cc
2.0 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
e8555c89 Andy McCall 1 
#include "DACSound16S.hh"
2
3 
#include "DeviceConfig.hh"
4 
#include "DynamicClock.hh"
5 
#include "MSXMotherBoard.hh"
6 
#include "serialize.hh"
7
8 
#include "narrow.hh"
9
10 
namespace openmsx {
11
12 
static constexpr unsigned DUMMY_INPUT_RATE = 44100; // actual rate depends on frequency setting
13
14 
DACSound16S::DACSound16S(std::string_view name_, static_string_view desc,
15 
                         const DeviceConfig& config)
16 
	: SoundDevice(config.getMotherBoard().getMSXMixer(), name_, desc, 1, DUMMY_INPUT_RATE, false)
17 
{
18 
	registerSound(config);
19 
}
20
21 
DACSound16S::~DACSound16S()
22 
{
23 
	unregisterSound();
24 
}
25
26 
void DACSound16S::setOutputRate(unsigned hostSampleRate, double /*speed*/)
27 
{
28 
	setInputRate(hostSampleRate);
29 
}
30
31 
void DACSound16S::reset(EmuTime time)
32 
{
33 
	writeDAC(0, time);
34 
}
35
36 
void DACSound16S::writeDAC(int16_t value, EmuTime time)
37 
{
38 
	int delta = value - lastWrittenValue;
39 
	if (delta == 0) return;
40 
	lastWrittenValue = value;
41
42 
	BlipBuffer::TimeIndex t;
43 
	getHostSampleClock().getTicksTill(time, t);
44 
	blip.addDelta(t, narrow<float>(delta));
45 
}
46
47 
void DACSound16S::generateChannels(std::span<float*> bufs, unsigned num)
48 
{
49 
	// Note: readSamples() replaces the values in the buffer (it doesn't
50 
	// add the new values to the existing values in the buffer). That's OK
51 
	// because this is a single-channel SoundDevice.
52 
	assert(bufs.size() == 1);
53 
	if (!blip.readSamples<1>(bufs[0], num)) {
54 
		bufs[0] = nullptr;
55 
	}
56 
}
57
58 
bool DACSound16S::updateBuffer(size_t length, float* buffer,
59 
                               EmuTime /*time*/)
60 
{
61 
	return mixChannels(buffer, length);
62 
}
63
64 
template<typename Archive>
65 
void DACSound16S::serialize(Archive& ar, unsigned /*version*/)
66 
{
67 
	// Note: It's ok to NOT serialize a DAC object if you call the
68 
	//       writeDAC() method in some other way during de-serialization.
69 
	//       This is for example done in MSXPPI/KeyClick.
70 
	int16_t lastValue = lastWrittenValue;
71 
	ar.serialize("lastValue", lastValue);
72 
	if constexpr (Archive::IS_LOADER) {
73 
		writeDAC(lastValue, getHostSampleClock().getTime());
74 
	}
75 
}
76 
INSTANTIATE_SERIALIZE_METHODS(DACSound16S);
77
78 
} // namespace openmsx