float EqEffect::peakBand( float minF, float maxF, EqAnalyser *fft, int sr )
{
float peak = -60;
float * b = fft->m_bands;
float h = 0;
for(int x = 0; x < MAX_BANDS; x++, b++)
{
if( bandToFreq( x ,sr) >= minF && bandToFreq( x,sr ) <= maxF )
{
h = 20*( log10( *b / fft->m_energy ) );
peak = h > peak ? h : peak;
}
}
return (peak+100)/100;
}
void EqSpectrumView::paintEvent(QPaintEvent *event)
{
//only analyse if the view is visible
m_analyser->setActive( isVisible() );
const float energy = m_analyser->getEnergy();
if( energy <= 0 && m_peakSum <= 0 )
{
//dont draw anything
return;
}
const int fh = height();
const int LOWER_Y = -36; // dB
QPainter painter( this );
painter.setPen( QPen( m_color, 1, Qt::SolidLine, Qt::RoundCap, Qt::BevelJoin ) );
if( m_analyser->getInProgress() || m_periodicalUpdate == false )
{
//only paint the cached path
painter.fillPath( m_path, QBrush( m_color ) );
return;
}
m_periodicalUpdate = false;
//Now we calculate the path
m_path = QPainterPath();
float *bands = m_analyser->m_bands;
float peak;
m_path.moveTo( 0, height() );
m_peakSum = 0;
float fallOff = 1.2;
for( int x = 0; x < MAX_BANDS; ++x, ++bands )
{
peak = ( fh * 2.0 / 3.0 * ( 20 * ( log10( *bands / energy ) ) - LOWER_Y ) / ( - LOWER_Y ) );
if( peak < 0 )
{
peak = 0;
}
else if( peak >= fh )
{
continue;
}
if ( peak > m_bandHeight[x] )
{
m_bandHeight[x] = peak;
}
else
{
m_bandHeight[x] = m_bandHeight[x] / fallOff;
}
if( m_bandHeight[x] < 0 )
{
m_bandHeight[x] = 0;
}
m_path.lineTo( EqHandle::freqToXPixel( bandToFreq( x ), width() ), fh - m_bandHeight[x] );
m_peakSum += m_bandHeight[x];
}
m_path.lineTo( width(), height() );
m_path.closeSubpath();
painter.fillPath( m_path, QBrush( m_color ) );
painter.drawPath( m_path );
}
