Files
oscilloscope/osciwidget.cpp
T

156 lines
2.9 KiB
C++

#include "osciwidget.h"
#include <cmath>
#include <QLine>
namespace {
template<typename T>
auto pythagoras(const T &dx, const T &dy)
{
return std::sqrt(dx * dx + dy * dy);
}
auto pythagoras(const QLine &line)
{
return pythagoras(line.dx(), line.dy());
}
}
OsciWidget::OsciWidget(QWidget *parent) :
QWidget(parent)
{
restartTimer();
resizePixmap();
createBlendPixmap();
}
int OsciWidget::framerate() const
{
return m_framerate;
}
int OsciWidget::blend() const
{
return m_blend;
}
float OsciWidget::factor() const
{
return m_factor;
}
void OsciWidget::setFramerate(int framerate)
{
if (framerate == m_framerate)
return;
qDebug() << "change framerate to" << framerate;
m_framerate = framerate;
restartTimer();
}
void OsciWidget::setBlend(int blend)
{
if (blend == m_blend)
return;
qDebug() << "change blend to" << blend;
m_blend = blend;
createBlendPixmap();
}
void OsciWidget::setFactor(float factor)
{
m_factor = factor;
}
void OsciWidget::renderSamples(const SamplePair *begin, const SamplePair *end)
{
QPainter painter;
painter.begin(&m_pixmap);
painter.setCompositionMode(QPainter::CompositionMode_Plus);
QPen pen;
pen.setWidth(2);
for (auto i = begin; i < end; i++)
{
const qint32 x = (float(i->x) / std::numeric_limits<qint16>::max() / 2 * width() / 2 * m_factor) + (width() / 2);
const qint32 y = (float(-i->y) / std::numeric_limits<qint16>::max() / 2 * height() / 2 * m_factor) + (height() / 2);
const QPoint p{x,y};
if (Q_LIKELY(m_lastPoint.has_value()))
{
auto dist = pythagoras(QLine(*m_lastPoint, p));
if (dist < 1)
dist = 1;
pen.setColor(QColor(0, 1./dist*255, 0));
painter.setPen(pen);
painter.drawLine(*m_lastPoint, p);
}
m_lastPoint = p;
}
painter.end();
}
void OsciWidget::paintEvent(QPaintEvent *event)
{
Q_UNUSED(event)
QPainter painter;
painter.begin(this);
painter.drawPixmap(0, 0, m_pixmap);
painter.end();
painter.begin(&m_pixmap);
painter.setCompositionMode(QPainter::CompositionMode_Multiply);
painter.drawPixmap(0, 0, m_fadeoutPixmap);
painter.end();
}
void OsciWidget::timerEvent(QTimerEvent *event)
{
if (event->timerId() == m_timerId)
{
repaint();
}
else
QWidget::timerEvent(event);
}
void OsciWidget::resizeEvent(QResizeEvent *event)
{
Q_UNUSED(event)
resizePixmap();
createBlendPixmap();
}
void OsciWidget::restartTimer()
{
if (m_timerId != -1)
killTimer(m_timerId);
m_timerId = startTimer(1000/m_framerate);
}
void OsciWidget::resizePixmap()
{
m_pixmap = QPixmap(size());
m_pixmap.fill(QColor());
}
void OsciWidget::createBlendPixmap()
{
m_fadeoutPixmap = QPixmap(size());
m_fadeoutPixmap.fill(QColor(m_blend, m_blend, m_blend));
}