Performance improvements

basedevice.h

@@ -2,12 +2,7 @@
 
 #include <QObject>
 
-template<typename T>
+#include "oscicommon.h"
-struct SamplePairT {
-    T x, y;
-};
-
-typedef SamplePairT<qint16> SamplePair;
 
 class BaseDevice : public QObject
 {

fakedevice.cpp

@@ -34,8 +34,8 @@ void FakeDevice::timerEvent(QTimerEvent *event)
              pair != m_buffer.get() + m_bufferSize;
              pair++)
         {
-            pair->x = std::sin(m_dingsDesHaltHochZaehlt) * std::numeric_limits<qint16>::max();
+            pair->first = std::sin(m_dingsDesHaltHochZaehlt) * std::numeric_limits<qint16>::max();
-            pair->y = std::cos(m_dingsDesHaltHochZaehlt) * std::numeric_limits<qint16>::max();
+            pair->second = std::cos(m_dingsDesHaltHochZaehlt) * std::numeric_limits<qint16>::max();
             m_dingsDesHaltHochZaehlt += 0.05;
         }
 

mainwindow.cpp

@@ -46,14 +46,6 @@ MainWindow::MainWindow(QWidget *parent) :
         m_ui->widget->setFps(m_ui->comboBoxFps->currentData().toInt());
     });
 
-    m_ui->spinBoxBlend->setValue(m_ui->widget->blend());
-
-    connect(m_ui->spinBoxBlend, qOverload<int>(&QSpinBox::valueChanged), m_ui->widget, &OsciWidget::setBlend);
-
-    m_ui->spinBoxGlow->setValue(m_ui->widget->glow());
-
-    connect(m_ui->spinBoxGlow, qOverload<int>(&QSpinBox::valueChanged), m_ui->widget, &OsciWidget::setGlow);
-
     auto buttonGroup = new QButtonGroup;
     buttonGroup->setExclusive(true);
     for (auto factor : { .5f, 1.f, 2.f, 4.f, 8.f })

mainwindow.ui

@@ -52,39 +52,6 @@
         </property>
        </widget>
       </item>
-      <item>
-       <spacer name="horizontalSpacer">
-        <property name="orientation">
-         <enum>Qt::Horizontal</enum>
-        </property>
-        <property name="sizeHint" stdset="0">
-         <size>
-          <width>40</width>
-          <height>20</height>
-         </size>
-        </property>
-       </spacer>
-      </item>
-      <item>
-       <widget class="QSpinBox" name="spinBoxBlend">
-        <property name="suffix">
-         <string> blend</string>
-        </property>
-        <property name="maximum">
-         <number>255</number>
-        </property>
-       </widget>
-      </item>
-      <item>
-       <widget class="QSpinBox" name="spinBoxGlow">
-        <property name="suffix">
-         <string> glow</string>
-        </property>
-        <property name="maximum">
-         <number>65535</number>
-        </property>
-       </widget>
-      </item>
       <item>
        <spacer name="horizontalSpacer_2">
         <property name="orientation">

oscicommon.h

@@ -0,0 +1,11 @@
+#pragma once
+
+// Qt includes
+#include <QtGlobal>
+
+template<typename T>
+struct SamplePairT {
+    T first, second;
+};
+
+using SamplePair = SamplePairT<qint16>;

oscilloscope.pro

@@ -16,6 +16,7 @@ HEADERS += \
     basedevice.h \
     fakedevice.h \
     mainwindow.h \
+    oscicommon.h \
     osciwidget.h
 
 OTHER_FILES += \

osciwidget.cpp

@@ -8,110 +8,26 @@
 #include <QTimerEvent>
 
 OsciWidget::OsciWidget(QWidget *parent) :
-    QWidget{parent},
+    QOpenGLWidget{parent},
     m_redrawTimerId(startTimer(1000/m_fps))
 {
-    resizePixmap();
     m_fpsTimer.start();
 }
 
-int OsciWidget::blend() const
-{
-    return m_blend;
-}
-
-float OsciWidget::factor() const
-{
-    return m_factor;
-}
-
-float OsciWidget::glow() const
-{
-    return m_glow;
-}
-
-int OsciWidget::fps() const
-{
-    return m_fps;
-}
-
-void OsciWidget::setBlend(int blend)
-{
-    if (blend == m_blend)
-        return;
-
-    qDebug() << blend;
-
-    m_blend = blend;
-}
-
-void OsciWidget::setFactor(float factor)
-{
-    qDebug() << factor;
-    m_factor = factor;
-}
-
-void OsciWidget::setGlow(float glow)
-{
-    qDebug() << glow;
-    m_glow = glow;
-}
-
 void OsciWidget::setFps(int fps)
 {
-    qDebug() << fps;
     killTimer(m_redrawTimerId);
+
     m_fps = fps;
+
     m_redrawTimerId = startTimer(1000/m_fps);
 }
 
 void OsciWidget::renderSamples(const SamplePair *begin, const SamplePair *end)
 {
-    QPainter painter;
+    m_callbacksCounter++;
-    painter.begin(&m_pixmap);
-    painter.setCompositionMode(QPainter::CompositionMode_Plus);
 
-    QPen pen;
+    m_buffer.insert(m_buffer.end(), begin, end);
-    pen.setWidth(2);
-    pen.setColor(QColor(0, 255, 0));
-    painter.setPen(pen);
-
-    // Paint from center
-    painter.translate(m_pixmap.width()/2, m_pixmap.height()/2);
-
-    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 (auto i = begin; i < end; i++)
-    {
-        const QPointF p{
-            float(i->x) / std::numeric_limits<qint16>::max(),
-            float(-i->y) / std::numeric_limits<qint16>::max()
-        };
-
-        const QLineF line(m_lastPoint, p);
-
-        auto brightness = 1.f / line.length() / m_glow;
-        if (line.length() == 0.f || brightness > 255.f)
-            brightness = 255.f;
-
-        painter.setOpacity(brightness);
-
-        painter.drawLine(pointToCoordinates(m_lastPoint), pointToCoordinates(p));
-
-        m_lastPoint = p;
-    }
-
-    painter.resetTransform();
-    painter.setCompositionMode(QPainter::CompositionMode_Multiply);
-    painter.fillRect(m_pixmap.rect(), QColor(m_blend,m_blend,m_blend));
-
-    painter.end();
 }
 
 void OsciWidget::paintEvent(QPaintEvent *event)
@@ -121,25 +37,64 @@ void OsciWidget::paintEvent(QPaintEvent *event)
     m_frameCounter++;
     if (m_fpsTimer.hasExpired(1000))
     {
-        m_displayFrameCounter = m_frameCounter;
+        m_statsDisplay = QString("%0FPS (%1 callbacks)").arg(m_frameCounter).arg(m_callbacksCounter);
         m_frameCounter = 0;
+        m_callbacksCounter = 0;
         m_fpsTimer.restart();
     }
 
     QPainter painter;
     painter.begin(this);
-    painter.drawPixmap(0, 0, m_pixmap);
 
+    // draw background
+    painter.setBrush(Qt::black);
+    painter.drawRect(rect());
+
+    // drawing new lines ontop
+    QPen pen;
+    pen.setWidth(2);
+    pen.setColor(QColor(0, 255, 0));
+    painter.setPen(pen);
+    painter.translate(width()/2, height()/2);
+    painter.setCompositionMode(QPainter::CompositionMode_Plus);
+
+    const auto pointToCoordinates = [width=width()/2,height=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)
+    {
+        const QPointF p{
+            float(i.first) / std::numeric_limits<qint16>::max(),
+            float(-i.second) / std::numeric_limits<qint16>::max()
+        };
+
+        const QLineF line(m_lastPoint, p);
+
+        painter.setOpacity(std::min(1.0, 1. / ((line.length() * 100) + 1)));
+
+        painter.drawLine(pointToCoordinates(m_lastPoint), pointToCoordinates(p));
+
+        m_lastPoint = p;
+    }
+
+    painter.resetTransform();
+    painter.setOpacity(1);
+
+    m_buffer.clear();
+
+    // draw stats
     painter.setPen(Qt::white);
     painter.setBrush(Qt::white);
     QFont font;
     font.setPixelSize(24);
-    painter.drawText(20, 20, QString("%0FPS").arg(m_displayFrameCounter));
+    painter.drawText(20, 20, m_statsDisplay);
 
     painter.end();
-
-    if (m_pixmap.rect() != rect())
-        qDebug() << m_pixmap.rect() << rect();
 }
 
 void OsciWidget::timerEvent(QTimerEvent *event)
@@ -148,15 +103,3 @@ void OsciWidget::timerEvent(QTimerEvent *event)
     if (event->timerId() == m_redrawTimerId)
         repaint();
 }
-
-void OsciWidget::resizeEvent(QResizeEvent *event)
-{
-    QWidget::resizeEvent(event);
-    resizePixmap();
-}
-
-void OsciWidget::resizePixmap()
-{
-    m_pixmap = QPixmap(size());
-    m_pixmap.fill(QColor{});
-}

osciwidget.h

@@ -1,52 +1,48 @@
 #pragma once
 
-#include <QWidget>
+// Qt includes
+#include <QOpenGLWidget>
 #include <QPixmap>
 #include <QPointF>
 #include <QElapsedTimer>
 
-#include "audiodevice.h"
+// system includes
+#include <vector>
 
-class OsciWidget : public QWidget
+// local includes
+#include "oscicommon.h"
+
+class OsciWidget : public QOpenGLWidget
 {
     Q_OBJECT
 
 public:
     explicit OsciWidget(QWidget *parent = nullptr);
 
-    int blend() const;
+    float factor() const { return m_factor; }
-    float factor() const;
+    int fps() const { return m_fps; }
-    float glow() const;
-    int fps() const;
 
 public slots:
-    void setBlend(int blend);
+    void setFactor(float factor) { m_factor = factor; }
-    void setFactor(float factor);
-    void setGlow(float glow);
     void setFps(int fps);
 
     void renderSamples(const SamplePair *begin, const SamplePair *end);
 
 protected:
     void paintEvent(QPaintEvent *event) override;
-    void resizeEvent(QResizeEvent *event) override;
     void timerEvent(QTimerEvent *event) override;
 
 private:
-    void resizePixmap();
+    float m_factor{2.f};
-    void createBlendPixmap();
-
-    int m_blend{150};
-    float m_factor{4.f};
-    float m_glow{512.f};
-
-    QPixmap m_pixmap;
 
     QPointF m_lastPoint;
 
-    int m_frameCounter{0}, m_displayFrameCounter{0};
+    int m_frameCounter{0}, m_callbacksCounter{0};
+    QString m_statsDisplay;
     QElapsedTimer m_fpsTimer;
 
     int m_fps{15};
     int m_redrawTimerId;
+
+    std::vector<SamplePair> m_buffer;
 };