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Replaces QPoint with QPointF, Uses .length instead of pythagoras, Uses setOpacity instead of pen.setColor

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Gitea
2019-08-30 13:38:36 +02:00
parent b0ee466c32
commit 5f0687ca48
2 changed files with 14 additions and 23 deletions
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35
osciwidget.cpp
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@@ -4,19 +4,6 @@
#include <QLine> #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) : OsciWidget::OsciWidget(QWidget *parent) :
QWidget(parent) QWidget(parent)
{ {
@@ -74,22 +61,26 @@ void OsciWidget::renderSamples(const SamplePair *begin, const SamplePair *end)
QPen pen; QPen pen;
pen.setWidth(2); pen.setWidth(2);
pen.setColor(QColor(0, 255, 0));
painter.setPen(pen);
// Paint from center
painter.translate(width()/2, height()/2);
for (auto i = begin; i < end; i++) 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 qreal x = (qreal(i->x) / std::numeric_limits<qint16>::max() / 2 * width() / 2 * m_factor);
const qint32 y = (float(-i->y) / std::numeric_limits<qint16>::max() / 2 * height() / 2 * m_factor) + (height() / 2); const qreal y = (qreal(i->y) / std::numeric_limits<qint16>::max() / 2 * height() / 2 * m_factor);
const QPoint p{x,y}; const QPointF p{x, y};
if (Q_LIKELY(m_lastPoint.has_value())) if (Q_LIKELY(m_lastPoint.has_value()))
{ {
auto dist = pythagoras(QLine(*m_lastPoint, p)); auto speed = QLineF(*m_lastPoint, p).length();
if (dist < 1) if (speed < 1)
dist = 1; speed = 1;
auto brightness = 1./speed;
pen.setColor(QColor(0, 1./dist*255, 0));
painter.setPen(pen);
painter.setOpacity(brightness);
painter.drawLine(*m_lastPoint, p); painter.drawLine(*m_lastPoint, p);
} }

2
osciwidget.h
View File

@@ -49,5 +49,5 @@ private:
QPixmap m_pixmap; QPixmap m_pixmap;
std::optional<QPoint> m_lastPoint; std::optional<QPointF> m_lastPoint;
}; };