void PeakController::updateValueBuffer()
{
if( m_peakEffect )
{
float targetSample = m_peakEffect->lastSample();
if( m_currentSample != targetSample )
{
const f_cnt_t frames = engine::mixer()->framesPerPeriod();
float * values = m_valueBuffer.values();
const float ratio = ( 44100.0 / 256.0 ) / engine::mixer()->processingSampleRate();
const float v = m_currentSample >= targetSample
? m_peakEffect->decayModel()->value()
: m_peakEffect->attackModel()->value();
const float diff = ( targetSample - m_currentSample ) * ratio;
const float a = ( 1.0f - sqrt_neg( sqrt_neg( v ) ) ) * diff;
const bool att = m_currentSample < targetSample;
for( f_cnt_t f = 0; f < frames; ++f )
{
if( att ) // going up...
{
m_currentSample = qMin( targetSample, m_currentSample + a ); // qmin prevents overshoot
}
else
{
m_currentSample = qMax( targetSample, m_currentSample + a ); // qmax prevents overshoot
}
values[f] = m_currentSample;
}
}
else
{
m_valueBuffer.fill( m_currentSample );
}
}
else
{
m_valueBuffer.fill( 0 );
}
m_bufferLastUpdated = s_periods;
}
bool PeakControllerEffect::processAudioBuffer( sampleFrame * _buf,
const fpp_t _frames )
{
PeakControllerEffectControls & c = m_peakControls;
// This appears to be used for determining whether or not to continue processing
// audio with this effect
if( !isEnabled() || !isRunning() )
{
return false;
}
// RMS:
double sum = 0;
if( c.m_absModel.value() )
{
for( int i = 0; i < _frames; ++i )
{
// absolute value is achieved because the squares are > 0
sum += _buf[i][0]*_buf[i][0] + _buf[i][1]*_buf[i][1];
}
}
else
{
for( int i = 0; i < _frames; ++i )
{
// the value is absolute because of squaring,
// so we need to correct it
sum += _buf[i][0] * _buf[i][0] * sign( _buf[i][0] )
+ _buf[i][1] * _buf[i][1] * sign( _buf[i][1] );
}
}
// TODO: flipping this might cause clipping
// this will mute the output after the values were measured
if( c.m_muteModel.value() )
{
for( int i = 0; i < _frames; ++i )
{
_buf[i][0] = _buf[i][1] = 0.0f;
}
}
float curRMS = sqrt_neg( sum / _frames );
const float tres = c.m_tresholdModel.value();
const float amount = c.m_amountModel.value() * c.m_amountMultModel.value();
curRMS = qAbs( curRMS ) < tres ? 0.0f : curRMS;
m_lastSample = qBound( 0.0f, c.m_baseModel.value() + amount * curRMS, 1.0f );
return isRunning();
}