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Update internal MUNT to version 2.7.0

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This commit is contained in:
Alexander Babikov
2022-07-24 07:50:54 +05:00
parent 1bc4ae5337
commit be8784b17c
87 changed files with 3292 additions and 994 deletions
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44
src/sound/munt/TVP.cpp
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@@ -1,5 +1,5 @@
/* Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009 Dean Beeler, Jerome Fisher
* Copyright (C) 2011-2020 Dean Beeler, Jerome Fisher, Sergey V. Mikayev
* Copyright (C) 2011-2022 Dean Beeler, Jerome Fisher, Sergey V. Mikayev
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
@@ -54,13 +54,32 @@ static Bit16u keyToPitchTable[] = {
// We want to do processing 4000 times per second. FIXME: This is pretty arbitrary.
static const int NOMINAL_PROCESS_TIMER_PERIOD_SAMPLES = SAMPLE_RATE / 4000;
// The timer runs at 500kHz. This is how much to increment it after 8 samples passes.
// We multiply by 8 to get rid of the fraction and deal with just integers.
static const int PROCESS_TIMER_INCREMENT_x8 = 8 * 500000 / SAMPLE_RATE;
// In all hardware units we emulate, the main clock frequency of the MCU is 12MHz.
// However, the MCU used in the 3rd-gen sound modules (like CM-500 and LAPC-N)
// is significantly faster. Importantly, the software timer also works faster,
// yet this fact has been seemingly missed. To be more specific, the software timer
// ticks each 8 "state times", and 1 state time equals to 3 clock periods
// for 8095 and 8098 but 2 clock periods for 80C198. That is, on MT-32 and CM-32L,
// the software timer tick rate is 12,000,000 / 3 / 8 = 500kHz, but on the 3rd-gen
// devices it's 12,000,000 / 2 / 8 = 750kHz instead.
// For 1st- and 2nd-gen devices, the timer ticks at 500kHz. This is how much to increment
// timeElapsed once 16 samples passes. We multiply by 16 to get rid of the fraction
// and deal with just integers.
static const int PROCESS_TIMER_TICKS_PER_SAMPLE_X16_1N2_GEN = (500000 << 4) / SAMPLE_RATE;
// For 3rd-gen devices, the timer ticks at 750kHz. This is how much to increment
// timeElapsed once 16 samples passes. We multiply by 16 to get rid of the fraction
// and deal with just integers.
static const int PROCESS_TIMER_TICKS_PER_SAMPLE_X16_3_GEN = (750000 << 4) / SAMPLE_RATE;
TVP::TVP(const Partial *usePartial) :
partial(usePartial), system(&usePartial->getSynth()->mt32ram.system) {
}
partial(usePartial),
system(&usePartial->getSynth()->mt32ram.system),
processTimerTicksPerSampleX16(
partial->getSynth()->controlROMFeatures->quirkFastPitchChanges
? PROCESS_TIMER_TICKS_PER_SAMPLE_X16_3_GEN
: PROCESS_TIMER_TICKS_PER_SAMPLE_X16_1N2_GEN)
{}
static Bit16s keyToPitch(unsigned int key) {
// We're using a table to do: return round_to_nearest_or_even((key - 60) * (4096.0 / 12.0))
@@ -270,7 +289,7 @@ void TVP::setupPitchChange(int targetPitchOffset, Bit8u changeDuration) {
pitchOffsetDelta = -pitchOffsetDelta;
}
// We want to maximise the number of bits of the Bit16s "pitchOffsetChangePerBigTick" we use in order to get the best possible precision later
Bit32u absPitchOffsetDelta = pitchOffsetDelta << 16;
Bit32u absPitchOffsetDelta = (pitchOffsetDelta & 0xFFFF) << 16;
Bit8u normalisationShifts = normalise(absPitchOffsetDelta); // FIXME: Double-check: normalisationShifts is usually between 0 and 15 here, unless the delta is 0, in which case it's 31
absPitchOffsetDelta = absPitchOffsetDelta >> 1; // Make room for the sign bit
@@ -301,7 +320,7 @@ void TVP::startDecay() {
Bit16u TVP::nextPitch() {
// We emulate MCU software timer using these counter and processTimerIncrement variables.
// The value of nominalProcessTimerPeriod approximates the period in samples
// The value of NOMINAL_PROCESS_TIMER_PERIOD_SAMPLES approximates the period in samples
// between subsequent firings of the timer that normally occur.
// However, accurate emulation is quite complicated because the timer is not guaranteed to fire in time.
// This makes pitch variations on real unit non-deterministic and dependent on various factors.
@@ -309,7 +328,7 @@ Bit16u TVP::nextPitch() {
timeElapsed = (timeElapsed + processTimerIncrement) & 0x00FFFFFF;
// This roughly emulates pitch deviations observed on real units when playing a single partial that uses TVP/LFO.
counter = NOMINAL_PROCESS_TIMER_PERIOD_SAMPLES + (rand() & 3);
processTimerIncrement = (PROCESS_TIMER_INCREMENT_x8 * counter) >> 3;
processTimerIncrement = (processTimerTicksPerSampleX16 * counter) >> 4;
process();
}
counter--;
@@ -337,13 +356,16 @@ void TVP::process() {
return;
}
// FIXME: Write explanation for this stuff
// NOTE: Value of shifts may happily exceed the maximum of 31 specified for the 8095 MCU.
// We assume the device performs a shift with the rightmost 5 bits of the counter regardless of argument size,
// since shift instructions of any size have the same maximum.
int rightShifts = shifts;
if (rightShifts > 13) {
rightShifts -= 13;
negativeBigTicksRemaining = negativeBigTicksRemaining >> rightShifts; // PORTABILITY NOTE: Assumes arithmetic shift
negativeBigTicksRemaining = negativeBigTicksRemaining >> (rightShifts & 0x1F); // PORTABILITY NOTE: Assumes arithmetic shift
rightShifts = 13;
}
int newResult = (negativeBigTicksRemaining * pitchOffsetChangePerBigTick) >> rightShifts; // PORTABILITY NOTE: Assumes arithmetic shift
int newResult = (negativeBigTicksRemaining * pitchOffsetChangePerBigTick) >> (rightShifts & 0x1F); // PORTABILITY NOTE: Assumes arithmetic shift
newResult += targetPitchOffsetWithoutLFO + lfoPitchOffset;
currentPitchOffset = newResult;
updatePitch();