expocurve.cpp

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/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, see <http://www.gnu.org/licenses/>
 */

#include "qwt/src/qwt_painter.h"
#include "expocurve.h"

#include <QFrame>

ExpoCurve::ExpoCurve(QWidget *parent)
    : QwtPlot(parent)
{
    QPalette palette = parent->palette();

    palette.setColor(QPalette::Foreground, palette.color(QPalette::Dark));
    palette.setColor(QPalette::Background, palette.color(QPalette::Light));

    QwtPainter::setPolylineSplitting(false);
    QwtPainter::setRoundingAlignment(false);
    setMouseTracking(true);

    setMinimumSize(64, 64);
    setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::MinimumExpanding);
    setContentsMargins(6, 0, 0, 0);

    QFrame *f = qobject_cast<QFrame *>(canvas());
    if (f) {
        f->setFrameStyle(QFrame::Box | QFrame::Plain);
        f->setLineWidth(1);
        f->setPalette(palette);
    }

    // Add grid lines
    QwtPlotGrid *grid = new QwtPlotGrid;
    grid->setMajorPen(QPen(Qt::gray, 0, Qt::DashLine));
    grid->setMinorPen(QPen(Qt::lightGray, 0, Qt::DotLine));
    grid->setPen(QPen(Qt::darkGray, 1, Qt::DotLine));
    grid->attach(this);

    roll_elements.Curve.setRenderHint(QwtPlotCurve::RenderAntialiased);
    roll_elements.Curve.setPen(QPen(QColor(41, 128, 185), 1.25, Qt::SolidLine, Qt::FlatCap));
    roll_elements.Curve.attach(this);

    pitch_elements.Curve.setRenderHint(QwtPlotCurve::RenderAntialiased);
    pitch_elements.Curve.setPen(QPen(QColor(192, 57, 43), 1.25, Qt::SolidLine, Qt::FlatCap));
    pitch_elements.Curve.attach(this);

    yaw_elements.Curve.setRenderHint(QwtPlotCurve::RenderAntialiased);
    yaw_elements.Curve.setPen(QPen(QColor(39, 174, 96), 1.25, Qt::SolidLine, Qt::FlatCap));
    yaw_elements.Curve.attach(this);

    // legend
    // Show a legend at the top
    QwtLegend *m_legend = new QwtLegend(this);
    m_legend->setDefaultItemMode(QwtLegendData::Checkable);
    // m_legend->setFrameStyle(QFrame::Box | QFrame::Sunken);
    m_legend->setToolTip(tr("Click legend to show/hide expo curve"));

    // connect signal when clicked on legend entry to function that shows/hides the curve
    connect(m_legend, &QwtLegend::checked, this, &ExpoCurve::showCurve);

    QPalette pal = m_legend->palette();
    pal.setColor(m_legend->backgroundRole(), QColor(100, 100, 100)); // background colour
    pal.setColor(QPalette::Text, QColor(0, 0, 0)); // text colour
    m_legend->setPalette(pal);
    m_legend->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Expanding);

    insertLegend(m_legend, QwtPlot::RightLegend);

    steps = 150;
    x_data = new double[steps];
    y_data = new double[steps];

    // double step = 2 * 1.0 / (steps - 1);
    double step = 1.0 / (steps - 1);
    for (int i = 0; i < steps; i++) {
        // x_data[i] = (i * step) - 1.0;
        x_data[i] = (i * step);
    }

    //  setup of the axis title
    QwtText axis_title;

    // get the default font
    QFont axis_title_font = this->axisTitle(yLeft).font();
    // and only change the font size
    axis_title_font.setPointSize(10);
    axis_title.setFont(axis_title_font);

    axis_title.setText(tr("normalized stick input"));
    this->setAxisTitle(QwtPlot::xBottom, axis_title);

    roll_elements.Curve.setTitle(tr("Roll"));
    pitch_elements.Curve.setTitle(tr("Pitch"));
    yaw_elements.Curve.setTitle(tr("Yaw"));

    axis_title.setText(tr("rate (deg/s)"));
    this->setAxisTitle(QwtPlot::yLeft, axis_title);

    this->axisWidget(QwtPlot::xBottom)->setPalette(palette);
    this->axisWidget(QwtPlot::yLeft)->setPalette(palette);

    plotDataRoll(50, 720, 50);
    plotDataPitch(50, 720, 50);
    plotDataYaw(50, 720, 30);
}

void ExpoCurve::plotData(int value, int max, int exponent, ExpoPlotElements_t &plot_elements)
{
    for (int i = 0; i < steps; i++) {
        y_data[i] = max * (x_data[i] * ((100 - value) / 100.0)
                           + pow(x_data[i], exponent / 10.0f) * (value / 100.0));
    }

    plot_elements.Curve.setSamples(x_data, y_data, steps);
    plot_elements.Curve.show();

    // Surely there is a less costly way to do this!
    setAxisAutoScale(yLeft, true);
    updateAxes();
    const QwtScaleDiv &div = axisScaleDiv(yLeft);
    setAxisScale(yLeft, 0, div.upperBound(), 180);

    this->replot();
}

void ExpoCurve::plotDataRoll(int value, int max, int exponent)
{
    plotData(value, max, exponent, this->roll_elements);
}

void ExpoCurve::plotDataPitch(int value, int max, int exponent)
{
    plotData(value, max, exponent, this->pitch_elements);
}

void ExpoCurve::plotDataYaw(int value, int max, int exponent)
{
    plotData(value, max, exponent, this->yaw_elements);
}

void ExpoCurve::showCurve(const QVariant &itemInfo, bool on, int index)
{
    Q_UNUSED(index);
    QwtPlotItem *item = QwtPlot::infoToItem(itemInfo);
    if (item) {
        item->setVisible(!on);
    }

    replot();
}