OXYGENHUB
◆ main openmsx / src / sound / YM2413OriginalNukeYKT.cc
2.8 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
e8555c89 Andy McCall 1 
#include "YM2413OriginalNukeYKT.hh"
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#include "narrow.hh"
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#include "ranges.hh"
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#include "serialize.hh"
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#include "xrange.hh"
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#include <algorithm>
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#include <array>
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#include <cassert>
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namespace openmsx {
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namespace YM2413OriginalNukeYKT {
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YM2413::YM2413()
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{
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	reset();
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}
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void YM2413::reset()
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{
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	OPLL_Reset(&opll, opll_type_ym2413b);
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	std::ranges::fill(regs, 0);
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}
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void YM2413::generateChannels(std::span<float*, 9 + 5> out_, uint32_t n)
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{
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	std::array<float*, 9 + 5> out;
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	copy_to_range(out_, out);
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	auto f = [&] {
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		std::array<int32_t, 2> buf;
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		OPLL_Clock(&opll, buf.data());
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		switch (opll.cycles) {
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			case  0: *out[ 9]++ += narrow_cast<float>(buf[1] * 2); break;
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			case  1: *out[10]++ += narrow_cast<float>(buf[1] * 2); break;
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			case  2: *out[ 6]++ += narrow_cast<float>(buf[0]);
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				 *out[11]++ += narrow_cast<float>(buf[1] * 2); break;
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			case  3: *out[ 7]++ += narrow_cast<float>(buf[0]);
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				 *out[12]++ += narrow_cast<float>(buf[1] * 2); break;
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			case  4: *out[ 8]++ += narrow_cast<float>(buf[0]);
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				 *out[13]++ += narrow_cast<float>(buf[1] * 2); break;
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			case  8: *out[ 0]++ += narrow_cast<float>(buf[0]);     break;
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			case  9: *out[ 1]++ += narrow_cast<float>(buf[0]);     break;
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			case 10: *out[ 2]++ += narrow_cast<float>(buf[0]);     break;
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			case 14: *out[ 3]++ += narrow_cast<float>(buf[0]);     break;
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			case 15: *out[ 4]++ += narrow_cast<float>(buf[0]);     break;
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			case 16: *out[ 5]++ += narrow_cast<float>(buf[0]);     break;
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		}
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	};
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	assert(n != 0);
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	for (auto& write : writes) {
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		if (write.port != uint8_t(-1)) {
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			OPLL_Write(&opll, write.port, write.value);
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			write.port = uint8_t(-1);
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		}
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		f();
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	}
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	repeat((n - 1) * 18, f);
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	allowed_offset = std::max<int>(0, allowed_offset - 18); // see writePort()
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}
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void YM2413::writePort(bool port, uint8_t value, int cycle_offset)
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{
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	// see comments in YM2413NukeYKT.cc
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	if (speedUpHack) [[unlikely]] {
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		while (cycle_offset < allowed_offset) [[unlikely]] {
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			float d = 0.0f;
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			std::array<float*, 9 + 5> dummy;
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			std::ranges::fill(dummy, &d);
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			generateChannels(dummy, 1);
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		}
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		allowed_offset = ((port ? 84 : 12) / 4) + cycle_offset;
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	}
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	writes[cycle_offset] = {.port = port, .value = value};
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	// only needed for peekReg()
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	if (port == 0) {
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		latch = value & 63;
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	} else {
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		regs[latch] = value;
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	}
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}
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void YM2413::pokeReg(uint8_t /*reg*/, uint8_t /*value*/)
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{
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	// not supported
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}
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std::span<const uint8_t, 64> YM2413::peekRegs() const
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{
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	return regs;
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}
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float YM2413::getAmplificationFactor() const
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{
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	return 1.0f / 256.0f;
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}
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void YM2413::setSpeed(double speed)
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{
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	speedUpHack = speed > 1.0;
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}
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template<typename Archive>
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void YM2413::serialize(Archive& /*ar*/, unsigned /*version*/)
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{
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	// Not implemented
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}
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} // namespace OriginalNuke
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using YM2413OriginalNukeYKT::YM2413;
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INSTANTIATE_SERIALIZE_METHODS(YM2413);
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REGISTER_POLYMORPHIC_INITIALIZER(YM2413Core, YM2413, "YM2413-Original-NukeYKT");
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} // namespace openmsx