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Attempts to voice the current attenuation (and, therefore, the ADSR output), even if linearly rather than logarithmically.

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This commit is contained in:
Thomas Harte 2020-04-13 22:12:55 -04:00
parent a1f80b5142
commit 09d1aed3a5
2 changed files with 29 additions and 19 deletions
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30
Components/OPL2/OPL2.cpp
View File

@ -141,10 +141,10 @@ OPLL::OPLL(Concurrency::DeferringAsyncTaskQueue &task_queue, int audio_divider,
}
bool OPLL::is_zero_level() {
for(int c = 0; c < 9; ++c) {
if(channels_[c].is_audible()) return false;
}
return true;
// for(int c = 0; c < 9; ++c) {
// if(channels_[c].is_audible()) return false;
// }
return false;
}
void OPLL::get_samples(std::size_t number_of_samples, std::int16_t *target) {
@ -402,7 +402,7 @@ void Operator::update(OperatorState &state, bool key_on, int channel_frequency,
};
// Update the raw phase.
const int octave_divider = 32 << channel_octave;
const int octave_divider = 64 << channel_octave;
state.divider_ %= octave_divider;
state.divider_ += multipliers[frequency_multiple] * channel_frequency;
state.raw_phase_ += state.divider_ / octave_divider;
@ -449,7 +449,7 @@ void Operator::update(OperatorState &state, bool key_on, int channel_frequency,
} else {
const int sample_length = 1 << (14 - (attack_rate >> 2)); // TODO: don't throw away KSR bits.
if(!(state.time_in_phase_ & (sample_length - 1))) {
state.adsr_attenuation_ = state.adsr_attenuation_ - (state.adsr_attenuation_ / 8) - 1;
state.adsr_attenuation_ = state.adsr_attenuation_ - (state.adsr_attenuation_ >> 3) - 1;
}
}
@ -460,8 +460,9 @@ void Operator::update(OperatorState &state, bool key_on, int channel_frequency,
}
} break;
case OperatorState::ADSRPhase::Release:
case OperatorState::ADSRPhase::Decay:
case OperatorState::ADSRPhase::Release: {
{
// Rules:
//
// (relative to a 511 scale)
@ -480,7 +481,7 @@ void Operator::update(OperatorState &state, bool key_on, int channel_frequency,
case 1: state.adsr_attenuation_ += 4; break;
case 2: state.adsr_attenuation_ += 2; break;
default: {
const int sample_length = 1 << ((decrease_rate >> 2) - 3);
const int sample_length = 1 << ((decrease_rate >> 2) - 4);
if(!(state.time_in_phase_ & (sample_length - 1))) {
++state.adsr_attenuation_;
}
@ -492,8 +493,9 @@ void Operator::update(OperatorState &state, bool key_on, int channel_frequency,
state.adsr_attenuation_ = std::min(state.adsr_attenuation_, 511);
// Check for the decay exit condition.
if(state.adsr_phase_ == OperatorState::ADSRPhase::Decay && state.adsr_attenuation_ > (sustain_level_ << 5)) {
state.adsr_phase_ = hold_sustain_level ? OperatorState::ADSRPhase::Sustain : OperatorState::ADSRPhase::Release;
if(state.adsr_phase_ == OperatorState::ADSRPhase::Decay && state.adsr_attenuation_ >= (sustain_level_ << 5)) {
state.adsr_attenuation_ = sustain_level_ << 5;
state.adsr_phase_ = ((overrides && overrides->hold_sustain_level) || hold_sustain_level) ? OperatorState::ADSRPhase::Sustain : OperatorState::ADSRPhase::Release;
}
} break;
@ -507,7 +509,11 @@ void Operator::update(OperatorState &state, bool key_on, int channel_frequency,
state.time_in_phase_ = 0;
}
// TODO: calculate attenuation properly. Need to factor in channel attenuation, but presumably not through multiplication?
state.attenuation = state.adsr_attenuation_;
// TODO: probably there's no multiply here?
if(overrides) {
state.attenuation = (state.adsr_attenuation_ * overrides->attenuation) >> 4;
} else {
state.attenuation = (state.adsr_attenuation_ * attenuation_) >> 6;
}
}

18
Components/OPL2/OPL2.hpp
View File

@ -107,10 +107,12 @@ class Operator {
void update(OperatorState &state, bool key_on, int channel_frequency, int channel_octave, OperatorOverrides *overrides = nullptr);
bool is_audible(OperatorState &state, OperatorOverrides *overrides = nullptr) {
if(overrides) {
if(overrides->attenuation == 0xf) return false;
} else {
if(attenuation_ == 0x3f) return false;
if(state.adsr_phase_ == OperatorState::ADSRPhase::Release) {
if(overrides) {
if(overrides->attenuation == 0xf) return false;
} else {
if(attenuation_ == 0x3f) return false;
}
}
return state.adsr_attenuation_ != 511;
}
@ -196,12 +198,14 @@ class Channel {
/// This should be called at a rate of around 49,716 Hz; it returns the current output level
/// level for this channel.
int update(Operator *modulator, Operator *carrier, OperatorOverrides *modulator_overrides = nullptr, OperatorOverrides *carrier_overrides = nullptr) {
modulator->update(modulator_state_, key_on, frequency << frequency_shift, octave, modulator_overrides);
// modulator->update(modulator_state_, key_on, frequency << frequency_shift, octave, modulator_overrides);
carrier->update(carrier_state_, key_on, frequency << frequency_shift, octave, carrier_overrides);
// TODO: almost everything else. This is a quick test.
if(!key_on) return 0;
return int(sin(float(carrier_state_.phase) / 1024.0) * 20000.0);
// Specifically: use lookup tables, apply attenuation properly.
if(carrier_state_.attenuation == 511) return 0;
const float volume = 1.0f - float(carrier_state_.attenuation) / 511.0f;
return int(volume * sin(float(carrier_state_.phase) / 1024.0) * 20000.0);
}
/// @returns @c true if this channel is currently producing any audio; @c false otherwise;