zmusic/thirdparty/opnmidi/chips/gens_opn2.cpp
Wohlstand faa997b986 Updated libOPNMIDI to 1.5.1
Changelog:
 * Added an ability to disable the automatical arpeggio
 * Updated the GENS chip emulator from the 2.10 into GS/II (thanks to @freq-mod for the help)
 * Added an ability to set number of loops
 * Added an ability to disable/enable playing of selected MIDI channels
 * Fixed memory damages and crashes while playing XMI files
 * Added the chip channels allocation mode option
 * Fixed the playback of multi-song XMI files
 * Added an ability to switch the XMI song on the fly

And also:
 * Fixed the work on big endian processors
 * Fixed ARM64 build on some platforms
 * Improved support of the EA-MUS files (Thanks to [dashodanger](https://github.com/dashodanger))
 * Fixed crash on attempt to change the volume of a blank note
2023-01-02 08:11:31 +01:00

110 lines
2.8 KiB
C++

/*
* Interfaces over Yamaha OPN2 (YM2612) chip emulators
*
* Copyright (c) 2017-2022 Vitaly Novichkov (Wohlstand)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "gens_opn2.h"
#include <cstdio>
#include <cstring>
#include <cassert>
#include "gens/Ym2612.hpp"
#ifndef INT16_MIN
#define INT16_MIN (-0x7fff - 1)
#endif
#ifndef INT16_MAX
#define INT16_MAX 0x7fff
#endif
GensOPN2::GensOPN2(OPNFamily f)
: OPNChipBaseBufferedT(f),
chip(new LibGens::Ym2612())
{
setRate(m_rate, m_clock);
}
GensOPN2::~GensOPN2()
{
delete chip;
}
void GensOPN2::setRate(uint32_t rate, uint32_t clock)
{
OPNChipBaseBufferedT::setRate(rate, clock);
uint32_t chipRate = isRunningAtPcmRate() ? rate : nativeRate();
chip->reInit(clock, chipRate); // implies reset()
}
void GensOPN2::reset()
{
OPNChipBaseBufferedT::reset();
chip->reset();
}
void GensOPN2::writeReg(uint32_t port, uint16_t addr, uint8_t data)
{
LibGens::Ym2612 *chip = this->chip;
switch (port)
{
case 0:
chip->write(0, addr);
chip->write(1, data);
break;
case 1:
chip->write(2, addr);
chip->write(3, data);
break;
}
}
void GensOPN2::writePan(uint16_t chan, uint8_t data)
{
chip->write_pan(static_cast<int>(chan), static_cast<int>(data));
}
void GensOPN2::nativeGenerateN(int16_t *output, size_t frames)
{
enum { maxFrames = 256 };
assert(frames <= maxFrames);
LibGens::Ym2612 *chip = this->chip;
int32_t bufLR[2 * maxFrames] = {};
int32_t *bufL = &bufLR[0];
int32_t *bufR = &bufLR[maxFrames];
chip->resetBufferPtrs(bufL, bufR);
chip->addWriteLen((int)frames);
chip->specialUpdate();
//TODO
// chip->updateDacAndTimers(bufL, bufR, frames);
for (size_t i = 0; i < 2 * frames; ++i) {
int32_t sample = ((i & 1) ? bufR : bufL)[i / 2];
sample /= 4; // has too high volume, attenuation needed
sample = (sample < INT16_MIN) ? INT16_MIN : sample;
sample = (sample > INT16_MAX) ? INT16_MAX : sample;
output[i] = (int16_t)sample;
}
}
const char *GensOPN2::emulatorName()
{
return "GENS/GS II OPN2";
}