Mesen2/Core/NES/OpnInterface.h
Sour 1affcd14ce NES: Fixed EPSM sound quality issues
The 500kHz to ~48kHz downsampling was causing problems
2024-10-02 17:14:16 +09:00

116 lines
2.3 KiB
C++

#pragma once
#include "NES/NesConsole.h"
#include "NES/NesCpu.h"
#include "Utilities/Audio/ymfm/ymfm_opn.h"
#include "Utilities/ISerializable.h"
#include "Utilities/Serializer.h"
class OpnInterface : public ymfm::ymfm_interface, public ISerializable
{
public:
static constexpr uint32_t ClockRate = 8000000;
private:
ymfm::ymf288 _opn;
NesConsole* _console = nullptr;
vector<uint8_t> _adpcmRom;
uint32_t _timers[2] = {};
uint32_t _busyCounter = 0;
public:
OpnInterface(NesConsole* console, vector<uint8_t>& adpcmRom) : _opn(*this)
{
_adpcmRom = adpcmRom;
//Ensure the size is 8kb
_adpcmRom.resize(0x2000);
_console = console;
_opn.set_fidelity(ymfm::OPN_FIDELITY_MED);
_opn.reset();
}
void ymfm_set_busy_end(uint32_t clocks) override
{
_busyCounter = clocks;
}
uint8_t ymfm_external_read(ymfm::access_class type, uint32_t address) override
{
if(type == ymfm::access_class::ACCESS_ADPCM_A) {
return _adpcmRom[address];
} else {
return 0;
}
}
bool ymfm_is_busy() override
{
return _busyCounter != 0;
}
void ymfm_set_timer(uint32_t timerId, int32_t duration) override
{
_timers[timerId] = duration < 0 ? 0 : (uint32_t)duration;
}
void ymfm_update_irq(bool irqEnabled) override
{
if(irqEnabled) {
_console->GetCpu()->SetIrqSource(IRQSource::Epsm);
} else {
_console->GetCpu()->ClearIrqSource(IRQSource::Epsm);
}
}
void Exec()
{
if(_busyCounter) {
_busyCounter--;
}
if(_timers[0] && --_timers[0] == 0) {
m_engine->engine_timer_expired(0);
}
if(_timers[1] && --_timers[1] == 0) {
m_engine->engine_timer_expired(1);
}
}
void Write(uint8_t addr, uint8_t value)
{
_opn.write(addr, value);
}
uint32_t GetSampleRate()
{
return _opn.sample_rate(OpnInterface::ClockRate);
}
void GenerateSamples(vector<int16_t>& samples)
{
ymfm::ymf288::output_data output;
_opn.generate(&output, 1);
samples.push_back(output.data[0] + (output.data[2] >> 2));
samples.push_back(output.data[1] + (output.data[2] >> 2));
}
void Serialize(Serializer& s) override
{
vector<uint8_t> opnData;
ymfm::ymfm_saved_state state = ymfm::ymfm_saved_state(opnData, s.IsSaving());
SVArray(_timers, 2);
SV(_busyCounter);
if(s.IsSaving()) {
_opn.save_restore(state);
SVVector(opnData);
} else {
SVVector(opnData);
_opn.save_restore(state);
}
}
};