Improved plot graphics

* Ignoring the aspect ratio during auto-fit stretches/compresses the curve strokes
* Keep aspect ratio and use manual scaling to avoid that
* Increased pen sizes and set nicer styles
* y-Axis ("stretcher") isn't needed anymore as we now retain the y-scaling with fixed ratio

src/pulsescopewidget.cpp

@@ -49,17 +49,15 @@ PulseScopeWidget::PulseScopeWidget(QWidget *parent) : QGraphicsView(parent),
     }
 
     m_scopeSizeH = 360.0 * PERIODS;
-    // vertical axes range
     m_scopeSizeV = 10.0;
+    m_scaling = 1.0;
 
     m_pathLHO = NULL;
     m_pathLLO = NULL;
     m_pathVirgo = NULL;
 
-    m_xAxis = m_scene.addLine(0.0, m_scopeSizeV/2.0, m_scopeSizeH, m_scopeSizeV/2.0, QPen(QColor("white"), 0.1));
+    m_xAxis = m_scene.addLine(0.0, m_scopeSizeV/2.0, m_scopeSizeH, m_scopeSizeV/2.0, QPen(QBrush(QColor("white")), 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
     m_xAxis->setZValue(1);
-    m_yAxis = m_scene.addLine(0.0, 0.0, 0.0, m_scopeSizeV);
-    m_yAxis->setZValue(1);
 
     setScene(&m_scene);
 }
@@ -73,24 +71,32 @@ void PulseScopeWidget::resizeEvent(QResizeEvent *event)
 {
     Q_UNUSED(event);
 
-    fitInView(m_scene.itemsBoundingRect(), Qt::IgnoreAspectRatio);
+    // custom scaling to avoid ugly auto-fitting artefacts
+    m_scaling = (height() * 1.0 / width()) * 110;
+    plot(*m_data);
+
+    // custom scaling allows us to retain the aspect ratio during auto-fit (much nicer curves!)
+    fitInView(m_scene.itemsBoundingRect(), Qt::KeepAspectRatio);
 }
 
 void PulseScopeWidget::plot(const PlotData& data)
 {
-    QPainterPath pulsePathLHO(QPointF(0.0, m_scopeSizeV - data.m_dataLHO.at(0) - m_scopeSizeV/2.0));
-    QPainterPath pulsePathLLO(QPointF(0.0, m_scopeSizeV - data.m_dataLLO.at(0) - m_scopeSizeV/2.0));
-    QPainterPath pulsePathVirgo(QPointF(0.0, m_scopeSizeV - data.m_dataVirgo.at(0) - m_scopeSizeV/2.0));
+    // save data for resize-only events
+    m_data = &data;
+
+    QPainterPath pulsePathLHO(QPointF(0.0, m_scopeSizeV - data.m_dataLHO.at(0)*m_scaling - m_scopeSizeV/2.0));
+    QPainterPath pulsePathLLO(QPointF(0.0, m_scopeSizeV - data.m_dataLLO.at(0)*m_scaling - m_scopeSizeV/2.0));
+    QPainterPath pulsePathVirgo(QPointF(0.0, m_scopeSizeV - data.m_dataVirgo.at(0)*m_scaling - m_scopeSizeV/2.0));
 
     for(int i = 1; i < m_scopeSizeH; ++i) {
-        pulsePathLHO.lineTo(i, m_scopeSizeV - data.m_dataLHO.at(i) - m_scopeSizeV/2.0);
-        pulsePathLLO.lineTo(i, m_scopeSizeV - data.m_dataLLO.at(i) - m_scopeSizeV/2.0);
-        pulsePathVirgo.lineTo(i, m_scopeSizeV - data.m_dataVirgo.at(i) - m_scopeSizeV/2.0);
+        pulsePathLHO.lineTo(i, m_scopeSizeV - data.m_dataLHO.at(i)*m_scaling - m_scopeSizeV/2.0);
+        pulsePathLLO.lineTo(i, m_scopeSizeV - data.m_dataLLO.at(i)*m_scaling - m_scopeSizeV/2.0);
+        pulsePathVirgo.lineTo(i, m_scopeSizeV - data.m_dataVirgo.at(i)*m_scaling - m_scopeSizeV/2.0);
     }
     if(m_pathLHO == NULL) {
-        m_pathLHO = m_scene.addPath(pulsePathLHO, QPen(QColor(data.m_colorLHO), 0.2));
-        m_pathLLO = m_scene.addPath(pulsePathLLO, QPen(QColor(data.m_colorLLO), 0.2));
-        m_pathVirgo = m_scene.addPath(pulsePathVirgo, QPen(QColor(data.m_colorVirgo), 0.2));
+        m_pathLHO = m_scene.addPath(pulsePathLHO, QPen(QBrush(QColor(data.m_colorLHO)), 3, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
+        m_pathLLO = m_scene.addPath(pulsePathLLO, QPen(QBrush(QColor(data.m_colorLLO)), 3, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
+        m_pathVirgo = m_scene.addPath(pulsePathVirgo, QPen(QBrush(QColor(data.m_colorVirgo)), 3, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
     }
     else {
         m_pathLHO->setPath(pulsePathLHO);

src/pulsescopewidget.h

@@ -53,10 +53,12 @@ private:
     QGraphicsPathItem *m_pathLLO;
     QGraphicsPathItem *m_pathVirgo;
     QGraphicsLineItem *m_xAxis;
-    QGraphicsLineItem *m_yAxis;
 
     double m_scopeSizeH;
     double m_scopeSizeV;
+    double m_scaling;
+
+    const PlotData* m_data;
 };
 
 #endif /* PULSESCOPEWIDGET_H_ */