feedc0de/oscilloscope
1
0
Fork 0
Code Issues Pull Requests 1 Actions Packages Projects Releases Wiki Activity

Scales using QPainter::scale

Browse Source
This commit is contained in:
Gitea
2019-09-18 00:04:50 +02:00
parent 7d26cf4387
commit 1481a33326
1 changed files with 6 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
osciwidget.cpp
View File

@@ -90,20 +90,15 @@ void OsciWidget::updateFrameBuffer()
painter.drawRect(m_pixmap.rect());
// drawing new lines ontop
painter.translate(m_pixmap.width()/2, m_pixmap.height()/2);
painter.scale(m_factor * m_pixmap.width() / 2.0, m_factor * m_pixmap.height() / 2.0);
painter.setCompositionMode(QPainter::CompositionMode_SourceOver);
QPen pen;
pen.setCosmetic(true); // let pen be scale invariant
pen.setWidth(2);
pen.setColor(QColor(0, 255, 0));
painter.setPen(pen);
painter.translate(m_pixmap.width()/2, m_pixmap.height()/2);
painter.setCompositionMode(QPainter::CompositionMode_Plus);
const auto pointToCoordinates = [width=m_pixmap.width()/2,height=m_pixmap.height()/2,factor=m_factor](const QPointF &point)
{
return QPoint{
int(point.x() * factor * width),
int(point.y() * factor * height)
};
};
for (const auto &i : m_buffer)
{
@@ -116,7 +111,7 @@ void OsciWidget::updateFrameBuffer()
painter.setOpacity(std::min(1.0, 1. / ((line.length() * m_lightspeed) + 1)));
painter.drawLine(pointToCoordinates(m_lastPoint), pointToCoordinates(p));
painter.drawLine(m_lastPoint, p);
m_lastPoint = p;
}