LibreVNA/Software/PC_Application/Traces/tracesmithchart.cpp

#include "tracesmithchart.h"
#include <QPainter>
#include <array>
#include <math.h>
#include "tracemarker.h"
#include <QDebug>
#include "preferences.h"

using namespace std;

TraceSmithChart::TraceSmithChart(TraceModel &model, QWidget *parent)
    : TracePlot(parent)
{
    chartLinesPen = QPen(palette().windowText(), 0.75);
    thinPen = QPen(palette().windowText(), 0.25);
    textPen = QPen(palette().windowText(), 0.25);
    pointDataPen = QPen(QColor("red"), 4.0, Qt::SolidLine, Qt::RoundCap);
    lineDataPen = QPen(QColor("blue"), 1.0);
    initializeTraceInfo(model);
}

QPoint TraceSmithChart::plotToPixel(std::complex<double> S)
{
    QPoint ret;
    ret.setX(S.real() * plotToPixelXScale + plotToPixelXOffset);
    ret.setY(S.imag() * plotToPixelYScale + plotToPixelYOffset);
    return ret;
}

std::complex<double> TraceSmithChart::pixelToPlot(const QPoint &pos)
{
    return complex<double>((pos.x() - plotToPixelXOffset) / plotToPixelXScale, (pos.y() - plotToPixelYOffset) / plotToPixelYScale);
}

void TraceSmithChart::mousePressEvent(QMouseEvent *event)
{
    auto clickPoint = event->pos();
    unsigned int closestDistance = numeric_limits<unsigned int>::max();
    TraceMarker *closestMarker = nullptr;
    for(auto t : traces) {
        auto markers = t.first->getMarkers();
        for(auto m : markers) {
            auto S = m->getData();
            auto markerPoint = plotToPixel(S);
            auto yDiff = abs(markerPoint.y() - clickPoint.y());
            auto xDiff = abs(markerPoint.x() - clickPoint.x());
            unsigned int distance = xDiff * xDiff + yDiff * yDiff;
            if(distance < closestDistance) {
                closestDistance = distance;
                closestMarker = m;
            }
        }
    }
    if(closestDistance <= 400) {
        selectedMarker = closestMarker;
    } else {
        selectedMarker = nullptr;
    }
}

void TraceSmithChart::mouseMoveEvent(QMouseEvent *event)
{
    if(selectedMarker) {
        auto t = selectedMarker->trace();
        auto mouseS = pixelToPlot(event->pos());
        auto samples = t->size();
        if(!samples) {
            return;
        }
        double closestDistance = numeric_limits<double>::max();
        unsigned int closestIndex = 0;
        for(unsigned int i=0;i<samples;i++) {
            auto data = t->sample(i);
            auto distance = norm(data.S - mouseS);
            if(distance < closestDistance) {
                closestDistance = distance;
                closestIndex = i;
            }
        }
        selectedMarker->setFrequency(t->sample(closestIndex).frequency);
    }
}

void TraceSmithChart::draw(QPainter * painter, double width_factor) {
    painter->setPen(QPen(1.0 * width_factor));
    painter->setBrush(palette().windowText());
    painter->setRenderHint(QPainter::Antialiasing);

//    // Display parameter name
//    QFont font = painter->font();
//    font.setPixelSize(48);
//    font.setBold(true);
//    painter->setFont(font);
//    painter->drawText(-512, -512, title);

    auto pref = Preferences::getInstance();

    // Outer circle
    painter->setPen(QPen(pref.General.graphColors.axis, 1.5 * width_factor));
    QRectF rectangle(-smithCoordMax, -smithCoordMax, 2*smithCoordMax, 2*smithCoordMax);
    painter->drawArc(rectangle, 0, 5760);

    constexpr int Circles = 6;
    painter->setPen(QPen(pref.General.graphColors.divisions, 0.5 * width_factor, Qt::DashLine));
    for(int i=1;i<Circles;i++) {
        rectangle.adjust(2*smithCoordMax/Circles, smithCoordMax/Circles, 0, -smithCoordMax/Circles);
        painter->drawArc(rectangle, 0, 5760);
    }

    painter->drawLine(-smithCoordMax, 0, smithCoordMax, 0);
    constexpr std::array<double, 5> impedanceLines = {10, 25, 50, 100, 250};
    for(auto z : impedanceLines) {
        z /= ReferenceImpedance;
        auto radius = smithCoordMax * 1.0/z;
        double span = M_PI - 2 * atan(radius/smithCoordMax);
        span *= 5760 / (2 * M_PI);
        QRectF rectangle(smithCoordMax - radius, -2*radius, 2 * radius, 2 * radius);
        painter->drawArc(rectangle, 4320 - span, span);
        rectangle = QRectF(smithCoordMax - radius, 0, 2 * radius, 2 * radius);
        painter->drawArc(rectangle, 1440, span);
    }

    for(auto t : traces) {
        if(!t.second) {
            // trace not enabled in plot
            continue;
        }
        auto trace = t.first;
        if(!trace->isVisible()) {
            // trace marked invisible
            continue;
        }
        painter->setPen(QPen(trace->color(), 1.5 * width_factor));
        int nPoints = trace->size();
        for(int i=1;i<nPoints;i++) {
            auto last = trace->sample(i-1).S;
            auto now = trace->sample(i).S;
            if(isnan(now.real())) {
                break;
            }
            // scale to size of smith diagram
            last *= smithCoordMax;
            now *= smithCoordMax;
            // draw line
            painter->drawLine(std::real(last), -std::imag(last), std::real(now), -std::imag(now));
        }
        if(trace->size() > 0) {
            // only draw markers if the trace has at least one point
            auto markers = t.first->getMarkers();
            for(auto m : markers) {
                auto coords = m->getData();
                coords *= smithCoordMax;
                auto symbol = m->getSymbol();
                symbol = symbol.scaled(symbol.width()*width_factor, symbol.height()*width_factor);
                painter->drawPixmap(coords.real() - symbol.width()/2, -coords.imag() - symbol.height(), symbol);
            }
        }
    }
}

void TraceSmithChart::replot()
{
    update();
}

void TraceSmithChart::paintEvent(QPaintEvent * /* the event */)
{
    auto pref = Preferences::getInstance();
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);
    painter.setBackground(QBrush(pref.General.graphColors.background));
    painter.fillRect(0, 0, width(), height(), QBrush(pref.General.graphColors.background));

    double side = qMin(width(), height()) * screenUsage;

    painter.setViewport((width()-side)/2, (height()-side)/2, side, side);
    painter.setWindow(-smithCoordMax, -smithCoordMax, 2*smithCoordMax, 2*smithCoordMax);

    plotToPixelXOffset = width()/2;
    plotToPixelYOffset = height()/2;
    plotToPixelXScale = side/2;
    plotToPixelYScale = -side/2;

    draw(&painter, 2*smithCoordMax/side);
}

bool TraceSmithChart::supported(Trace *t)
{
    if(t->isReflection()) {
        return true;
    } else {
        return false;
    }
}