Method visualize

src/core/SampleBuffer.cpp:949–984

void SampleBuffer::visualize( QPainter & _p, const QRect & _dr,
							const QRect & _clip, f_cnt_t _from_frame, f_cnt_t _to_frame )
{
	if( m_frames == 0 ) return;

	const bool focus_on_range = _to_frame <= m_frames
					&& 0 <= _from_frame && _from_frame < _to_frame;
	//_p.setClipRect( _clip );
	const int w = _dr.width();
	const int h = _dr.height();

	const int yb = h / 2 + _dr.y();
	const float y_space = h*0.5f;
	const int nb_frames = focus_on_range ? _to_frame - _from_frame : m_frames;

	const int fpp = tLimit<int>( nb_frames / w, 1, 20 );
	QPointF * l = new QPointF[nb_frames / fpp + 1];
	QPointF * r = new QPointF[nb_frames / fpp + 1];
	int n = 0;
	const int xb = _dr.x();
	const int first = focus_on_range ? _from_frame : 0;
	const int last = focus_on_range ? _to_frame : m_frames;
	for( int frame = first; frame < last; frame += fpp )
	{
		l[n] = QPointF( xb + ( (frame - first) * double( w ) / nb_frames ),
			( yb - ( m_data[frame][0] * y_space * m_amplification ) ) );
		r[n] = QPointF( xb + ( (frame - first) * double( w ) / nb_frames ),
			( yb - ( m_data[frame][1] * y_space * m_amplification ) ) );
		++n;
	}
	_p.setRenderHint( QPainter::Antialiasing );
	_p.drawPolyline( l, nb_frames / fpp );
	_p.drawPolyline( r, nb_frames / fpp );
	delete[] l;
	delete[] r;
}