// Make a single zoom step on the X axis.
void CPlotter::zoomStepX(float step, int x)
{
// calculate new range shown on FFT
float new_range = qBound(10.0f,
(float)(m_Span) * step,
(float)(m_SampleFreq) * 10.0f);
// Frequency where event occured is kept fixed under mouse
float ratio = (float)x / (float)m_OverlayPixmap.width();
float fixed_hz = freqFromX(x);
float f_max = fixed_hz + (1.0 - ratio) * new_range;
float f_min = f_max - new_range;
qint64 fc = (qint64)(f_min + (f_max - f_min) / 2.0);
setFftCenterFreq(fc - m_CenterFreq);
setSpanFreq((quint32)new_range);
float factor = (float)m_SampleFreq / (float)m_Span;
qDebug() << QString("Spectrum zoom: %1x").arg(factor, 0, 'f', 1);
m_PeakHoldValid = false;
}
//////////////////////////////////////////////////////////////////////
// Called when a mouse wheel is turned
//////////////////////////////////////////////////////////////////////
void CPlotter::wheelEvent(QWheelEvent * event)
{
QPoint pt = event->pos();
int numDegrees = event->delta() / 8;
int numSteps = numDegrees / 15; /** FIXME: Only used for direction **/
/** FIXME: zooming could use some optimisation **/
if (m_CursorCaptured == YAXIS)
{
// Vertical zoom. Wheel down: zoom out, wheel up: zoom in
// During zoom we try to keep the point (dB or kHz) under the cursor fixed
float zoom_fac = event->delta() < 0 ? 1.1 : 0.9;
float ratio = (float)pt.y() / (float)m_OverlayPixmap.height();
float db_range = (float)(m_MaxdB - m_MindB);
float y_range = (float)m_OverlayPixmap.height();
float db_per_pix = db_range / y_range;
float fixed_db = m_MaxdB - pt.y() * db_per_pix;
db_range = qBound(1.0f, db_range * zoom_fac, 2000.0f);
m_MaxdB = fixed_db + ratio*db_range;
m_MindB = m_MaxdB - db_range;
}
else if (m_CursorCaptured == XAXIS)
{
// calculate new range shown on FFT
float zoom_factor = event->delta() < 0 ? 1.1 : 0.9;
float new_range = qBound(10.0f,
(float)(m_Span) * zoom_factor,
(float)(m_SampleFreq) * 10.0f);
// Frequency where event occured is kept fixed under mouse
float ratio = (float)pt.x() / (float)m_OverlayPixmap.width();
float fixed_hz = freqFromX(pt.x());
float f_max = fixed_hz + (1.0 - ratio) * new_range;
float f_min = f_max - new_range;
qint64 fc = (qint64)(f_min + (f_max - f_min) / 2.0);
setFftCenterFreq(fc-m_CenterFreq);
setSpanFreq((quint32)new_range);
zoom_factor = (float)m_SampleFreq/(float)m_Span;
qDebug() << QString("Spectrum zoom: %1x").arg(zoom_factor, 0, 'f', 1);
}
else if (event->modifiers() & Qt::ControlModifier)
{
// filter width
m_DemodLowCutFreq -= numSteps*m_ClickResolution;
m_DemodHiCutFreq += numSteps*m_ClickResolution;
clampDemodParameters();
emit newFilterFreq(m_DemodLowCutFreq, m_DemodHiCutFreq);
}
else if (event->modifiers() & Qt::ShiftModifier)
{
// filter shift
m_DemodLowCutFreq += numSteps*m_ClickResolution;
m_DemodHiCutFreq += numSteps*m_ClickResolution;
clampDemodParameters();
emit newFilterFreq(m_DemodLowCutFreq, m_DemodHiCutFreq);
}
else
{
// inc/dec demod frequency
m_DemodCenterFreq += (numSteps*m_ClickResolution);
m_DemodCenterFreq = roundFreq(m_DemodCenterFreq, m_ClickResolution );
emit newDemodFreq(m_DemodCenterFreq, m_DemodCenterFreq-m_CenterFreq);
}
if (m_Running)
m_DrawOverlay = true;
else
drawOverlay();
}
/*! \brief Reset horizontal zoom to 100% and centered around 0. */
void CPlotter::resetHorizontalZoom(void)
{
setFftCenterFreq(0);
setSpanFreq((qint32)m_SampleFreq);
}
