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Update to use Opal OPL3 emulator
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@a740g
a740g committed Jun 23, 2024
1 parent 8c5d57d commit fb0a9ce
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Showing 3 changed files with 67 additions and 97 deletions.
67 changes: 38 additions & 29 deletions OPL3.bas
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Original file line number Diff line number Diff line change
Expand Up @@ -10,35 +10,35 @@ $INCLUDEONCE
'-----------------------------------------------------------------------------------------------------------------------
' Test code for debugging the library
'-----------------------------------------------------------------------------------------------------------------------
'IF OPL3_Initialize THEN
' OPL3_WriteRegister 1, 0
' OPL3_WriteRegister &H23, &H21
' OPL3_WriteRegister &H43, 0
' OPL3_WriteRegister &H63, &HFF
' OPL3_WriteRegister &H83, &H05
' OPL3_WriteRegister &H20, &H20
' OPL3_WriteRegister &H40, &H3F
' OPL3_WriteRegister &H60, &H44
' OPL3_WriteRegister &H80, &H5
' OPL3_WriteRegister &HA0, &H41
' OPL3_WriteRegister &HB0, &H32

' PRINT "Playing sine wave @ 440Hz"

' DO
' OPL3_Update OPL3_SOUND_BUFFER_TIME_DEFAULT
' _LIMIT 60
' LOOP UNTIL _KEYHIT = 27

' PRINT "Key off"

' OPL3_WriteRegister &HB0, &H12
' OPL3_Update OPL3_SOUND_BUFFER_TIME_DEFAULT

' OPL3_Finalize
'END IF

'END
IF OPL3_Initialize THEN
OPL3_WriteRegister 1, 0
OPL3_WriteRegister &H23, &H21
OPL3_WriteRegister &H43, 0
OPL3_WriteRegister &H63, &HFF
OPL3_WriteRegister &H83, &H05
OPL3_WriteRegister &H20, &H20
OPL3_WriteRegister &H40, &H3F
OPL3_WriteRegister &H60, &H44
OPL3_WriteRegister &H80, &H5
OPL3_WriteRegister &HA0, &H41
OPL3_WriteRegister &HB0, &H32

PRINT "Playing sine wave @ 440Hz"

DO
OPL3_Update OPL3_SOUND_BUFFER_TIME_DEFAULT
_LIMIT 60
LOOP UNTIL _KEYHIT = 27

PRINT "Key off"

OPL3_WriteRegister &HB0, &H12
OPL3_Update OPL3_SOUND_BUFFER_TIME_DEFAULT

OPL3_Finalize
END IF

END
'-----------------------------------------------------------------------------------------------------------------------

FUNCTION OPL3_Initialize%%
Expand Down Expand Up @@ -80,6 +80,15 @@ SUB OPL3_Finalize
END SUB


SUB OPL3_SetVolume (volume AS SINGLE)
SHARED __OPL3 AS __OPL3Type

IF OPL3_IsInitialized THEN
_SNDVOL __OPL3.soundHandle, volume
END IF
END SUB


' This handles playback and keeps track of the render buffer
' You can call this as frequenctly as you want. The routine will simply exit if nothing is to be done
SUB OPL3_Update (bufferTimeSecs AS SINGLE)
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1 change: 0 additions & 1 deletion OPL3.bi
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Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,6 @@ DECLARE LIBRARY "OPL3"
SUB __OPL3_Finalize
FUNCTION OPL3_IsInitialized%%
SUB OPL3_Reset
SUB OPL3_SetGain (BYVAL gain AS SINGLE)
SUB OPL3_WriteRegister (BYVAL address AS _UNSIGNED INTEGER, BYVAL value AS _UNSIGNED _BYTE)
SUB __OPL3_GenerateSamples (buffer AS SINGLE, BYVAL frames AS _UNSIGNED LONG)
END DECLARE
Expand Down
96 changes: 29 additions & 67 deletions OPL3.h
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Original file line number Diff line number Diff line change
@@ -1,99 +1,70 @@
//----------------------------------------------------------------------------------------------------------------------
// OPL3 emulation for QB64-PE using ymfm
// OPL3 emulation for QB64-PE using Opal
// Copyright (c) 2024 Samuel Gomes
//----------------------------------------------------------------------------------------------------------------------

#pragma once

#include "Types.h"
#include "external/ymfm/ymfm_adpcm.cpp"
#include "external/ymfm/ymfm_pcm.cpp"
#include "external/ymfm/ymfm_opl.cpp"
#include "external/opal.h"
#include <memory>

class OPL3 : public ymfm::ymfm_interface
class OPL3
{
private:
static const auto MASTER_CLOCK = 14318181;
static const auto RSM_FRAC = 10;

ymfm::ymf262 *chip;
uint32_t chipSampleRate;
std::unique_ptr<Opal> chip;
uint32_t sampleRate;
int32_t rateRatio;
int32_t sampleCnt;
ymfm::ymf262::output_data outputFrame;
ymfm::ymf262::output_data oldOutputFrame;
float gain;

public:
OPL3(uint32_t sampleRate) : ymfm::ymfm_interface()
OPL3(uint32_t sampleRate)
{
chip = new ymfm::ymf262(*this);
chipSampleRate = chip->sample_rate(MASTER_CLOCK);
this->sampleRate = sampleRate;
rateRatio = (sampleRate << RSM_FRAC) / chipSampleRate;
sampleCnt = 0;
outputFrame.clear();
oldOutputFrame.clear();
SetGain(1.0f);
Reset();
}

~OPL3()
{
delete chip;
chip.reset();
}

void Reset()
{
chip->reset();
chip.reset();
chip = std::make_unique<Opal>(sampleRate);
}

void SetGain(float gain)
{
this->gain = gain;
}
uint32_t GetSampleRate() const { return sampleRate; }

void WriteRegister(uint16_t address, uint8_t data)
{
if (address < 0x100)
chip->write_address((uint8_t)address);
else
chip->write_address_hi((uint8_t)address);

chip->write_data(data);
chip->Port(address, data);
}

void GenerateSamples(float *buffer, uint32_t frames)
{
for (uint32_t i = 0; i < frames; i++)
{
while (sampleCnt >= rateRatio)
{
oldOutputFrame.data[0] = outputFrame.data[0];
oldOutputFrame.data[1] = outputFrame.data[1];
oldOutputFrame.data[2] = outputFrame.data[2];
oldOutputFrame.data[3] = outputFrame.data[3];

chip->generate(&outputFrame);
static constexpr float normalization_factor = 1.0f / 32768.0f;

sampleCnt -= rateRatio;
}
std::pair<int16_t, int16_t> output;
uint32_t sample = 0;

auto buf0 = (int16_t)((oldOutputFrame.data[0] * (rateRatio - sampleCnt) + outputFrame.data[0] * sampleCnt) / rateRatio);
auto buf1 = (int16_t)((oldOutputFrame.data[1] * (rateRatio - sampleCnt) + outputFrame.data[1] * sampleCnt) / rateRatio);
auto buf2 = (int16_t)((oldOutputFrame.data[2] * (rateRatio - sampleCnt) + outputFrame.data[2] * sampleCnt) / rateRatio);
auto buf3 = (int16_t)((oldOutputFrame.data[3] * (rateRatio - sampleCnt) + outputFrame.data[3] * sampleCnt) / rateRatio);

*buffer++ = ((float)(buf0 + buf2) / 32768.0f) * gain;
*buffer++ = ((float)(buf1 + buf3) / 32768.0f) * gain;
while (sample < frames * 2)
{
chip->Sample(&output.first, &output.second);
buffer[sample] = output.first * normalization_factor;
buffer[sample + 1] = output.second * normalization_factor;

sampleCnt += 1 << RSM_FRAC;
sample += 2;
}
}

OPL3() = delete;
OPL3(const OPL3 &) = delete;
OPL3(OPL3 &&) = delete;
OPL3 &operator=(const OPL3 &) = delete;
OPL3 &operator=(OPL3 &&) = delete;
};

static OPL3 *g_OPL3Chip = nullptr;
static std::unique_ptr<OPL3> g_OPL3Chip;

inline qb_bool __OPL3_Initialize(uint32_t sampleRate)
{
Expand All @@ -103,7 +74,7 @@ inline qb_bool __OPL3_Initialize(uint32_t sampleRate)
if (!sampleRate)
return QB_FALSE;

g_OPL3Chip = new OPL3(sampleRate);
g_OPL3Chip = std::make_unique<OPL3>(sampleRate);

return TO_QB_BOOL(g_OPL3Chip != nullptr);
}
Expand All @@ -113,8 +84,7 @@ inline void __OPL3_Finalize()
if (!g_OPL3Chip)
return;

delete g_OPL3Chip;
g_OPL3Chip = nullptr;
g_OPL3Chip.reset();
}

inline qb_bool OPL3_IsInitialized()
Expand All @@ -130,14 +100,6 @@ inline void OPL3_Reset()
g_OPL3Chip->Reset();
}

inline void OPL3_SetGain(float gain)
{
if (!g_OPL3Chip)
return;

g_OPL3Chip->SetGain(gain);
}

inline void OPL3_WriteRegister(uint16_t address, uint8_t data)
{
if (!g_OPL3Chip)
Expand Down

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