LibrePilot/ground/openpilotgcs/src/plugins/scope/plotdata.cpp

/**
 ******************************************************************************
 *
 * @file       plotdata.cpp
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @addtogroup GCSPlugins GCS Plugins
 * @{
 * @addtogroup ScopePlugin Scope Gadget Plugin
 * @{
 * @brief The scope Gadget, graphically plots the states of UAVObjects
 *****************************************************************************/
/*
 * 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, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */


#include "plotdata.h"
#include <math.h>
#include <QDebug>

PlotData::PlotData(UAVObject *object, UAVObjectField *field, int element,
                   int scaleOrderFactor, int meanSamples, QString mathFunction,
                   double plotDataSize, QPen pen, bool antialiased) :
    m_scalePower(scaleOrderFactor), m_meanSamples(meanSamples),
    m_meanSum(0.0f), m_mathFunction(mathFunction), m_correctionSum(0.0f),
    m_correctionCount(0), m_plotDataSize(plotDataSize),
    m_object(object), m_field(field), m_element(element),
    m_plotCurve(NULL), m_isVisible(true), m_pen(pen), m_isEnumPlot(false)
{
    if (!m_field->getNumElements() > 1) {
        m_elementName = m_field->getElementNames().at(m_element);
    }

    m_plotName.append(QString("%1.%2").arg(m_object->getName()).arg(m_field->getName()));
    if (!m_elementName.isEmpty()) {
        m_plotName.append(QString(".%1").arg(m_elementName));
    }

    if (m_scalePower == 0) {
        m_plotName.append(QString(" (%1)").arg(m_field->getUnits()));
    } else {
        m_plotName.append(QString(" (x10^%1 %2)").arg(m_scalePower).arg(m_field->getUnits()));
    }

    // Create the curve
    m_plotCurve = new QwtPlotCurve(m_plotName);

    if (antialiased) {
        m_plotCurve->setRenderHint(QwtPlotCurve::RenderAntialiased);
    }

    m_plotCurve->setPen(m_pen);
    m_plotCurve->setSamples(m_xDataEntries, m_yDataEntries);
    m_isEnumPlot = m_field->getType() == UAVObjectField::ENUM;
}

PlotData::~PlotData()
{
    while (!m_enumMarkerList.isEmpty()) {
        QwtPlotMarker *marker = m_enumMarkerList.takeFirst();
        marker->detach();
        delete marker;
    }
    m_plotCurve->detach();
    delete m_plotCurve;
}

bool PlotData::isVisible() const
{
    return m_plotCurve->isVisible();
}

void PlotData::setVisible(bool visible)
{
    m_plotCurve->setVisible(visible);
    visibilityChanged(m_plotCurve);
}

void PlotData::updatePlotData()
{
    m_plotCurve->setSamples(m_xDataEntries, m_yDataEntries);
}

bool PlotData::hasData() const
{
    if (!m_isEnumPlot) {
        return !m_xDataEntries.isEmpty();
    } else {
        return !m_enumMarkerList.isEmpty();
    }
}

QString PlotData::lastDataAsString()
{
    if (!m_isEnumPlot) {
        return QString().sprintf("%3.10g", m_yDataEntries.last());
    } else {
        return m_enumMarkerList.last()->title().text();
    }
}

void PlotData::attach(QwtPlot *plot)
{
    m_plotCurve->attach(plot);
}

void PlotData::visibilityChanged(QwtPlotItem *item)
{
    if (m_plotCurve == item) {
        foreach(QwtPlotMarker * marker, m_enumMarkerList) {
            m_plotCurve->isVisible() ? marker->attach(m_plotCurve->plot()) : marker->detach();
        }
    }
}

void PlotData::calcMathFunction(double currentValue)
{
    // Put the new value at the back
    m_yDataHistory.append(currentValue);

    // calculate average value
    m_meanSum += currentValue;
    if (m_yDataHistory.size() > m_meanSamples) {
        m_meanSum -= m_yDataHistory.first();
        m_yDataHistory.pop_front();
    }
    // make sure to correct the sum every meanSamples steps to prevent it
    // from running away due to floating point rounding errors
    m_correctionSum += currentValue;
    if (++m_correctionCount >= m_meanSamples) {
        m_meanSum = m_correctionSum;
        m_correctionSum = 0.0f;
        m_correctionCount = 0;
    }

    double boxcarAvg = m_meanSum / m_yDataHistory.size();
    if (m_mathFunction == "Standard deviation") {
        // Calculate square of sample standard deviation, with Bessel's correction
        double stdSum = 0;
        for (int i = 0; i < m_yDataHistory.size(); i++) {
            stdSum += pow(m_yDataHistory.at(i) - boxcarAvg, 2) / (m_meanSamples - 1);
        }
        m_yDataEntries.append(sqrt(stdSum));
    } else {
        m_yDataEntries.append(boxcarAvg);
    }
}

QwtPlotMarker *PlotData::createMarker(QString value)
{
    QwtPlotMarker *marker = new QwtPlotMarker(value);

    marker->setZ(10);
    QwtText label(QString(" %1 ").arg(value));
    label.setColor(QColor(Qt::black));
    label.setBorderPen(QPen(m_pen.color(), 1));
    label.setBorderRadius(2);
    QColor labelBackColor = QColor(Qt::white);
    labelBackColor.setAlpha(200);
    label.setBackgroundBrush(labelBackColor);
    QFont fnt(label.font());
    fnt.setPointSize(8);
    label.setFont(fnt);
    marker->setLabel(label);
    marker->setTitle(value);
    marker->setLabelOrientation(Qt::Vertical);
    marker->setLabelAlignment(Qt::AlignBottom);
    marker->setLineStyle(QwtPlotMarker::VLine);
    marker->setLinePen(QPen(m_pen.color(), 1, Qt::DashDotLine));
    return marker;
}

bool SequentialPlotData::append(UAVObject *obj)
{
    if (m_object == obj && m_field) {
        if (!m_isEnumPlot) {
            double currentValue = m_field->getValue(m_element).toDouble() * pow(10, m_scalePower);

            // Perform scope math, if necessary
            if (m_mathFunction == "Boxcar average" || m_mathFunction == "Standard deviation") {
                calcMathFunction(currentValue);
            } else {
                m_yDataEntries.append(currentValue);
            }

            if (m_yDataEntries.size() > m_plotDataSize) {
                // If new data overflows the window, remove old data...
                m_yDataEntries.pop_front();
            } else {
                // ...otherwise, add a new y point at position xData
                m_xDataEntries.insert(m_xDataEntries.size(), m_xDataEntries.size());
            }
            return true;
        } else {
            // Enum markers
            QString value = m_field->getValue(m_element).toString();

            QwtPlotMarker *marker = m_enumMarkerList.isEmpty() ? NULL : m_enumMarkerList.last();
            if (!marker || marker->title() != value) {
                marker = createMarker(value);
                marker->setXValue(m_enumMarkerList.size());

                if (m_plotCurve->isVisible()) {
                    marker->attach(m_plotCurve->plot());
                }
                m_enumMarkerList.append(marker);
            }
        }
    }
    return false;
}

bool ChronoPlotData::append(UAVObject *obj)
{
    if (m_object == obj && m_field) {
        // Get the field of interest
        // THINK ABOUT REIMPLEMENTING THIS TO SHOW UAVO TIME, NOT SYSTEM TIME
        QDateTime NOW = QDateTime::currentDateTime();

        double xValue = NOW.toTime_t() + NOW.time().msec() / 1000.0;
        if (!m_isEnumPlot) {
            double currentValue = m_field->getValue(m_element).toDouble() * pow(10, m_scalePower);

            // Perform scope math, if necessary
            if (m_mathFunction == "Boxcar average" || m_mathFunction == "Standard deviation") {
                calcMathFunction(currentValue);
            } else {
                m_yDataEntries.append(currentValue);
            }

            m_xDataEntries.append(xValue);
        } else {
            // Enum markers
            QString value = m_field->getValue(m_element).toString();

            QwtPlotMarker *marker = m_enumMarkerList.isEmpty() ? NULL : m_enumMarkerList.last();
            if (!marker || marker->title() != value) {
                marker = createMarker(value);
                marker->setXValue(xValue);

                if (m_plotCurve->isVisible()) {
                    marker->attach(m_plotCurve->plot());
                }
                m_enumMarkerList.append(marker);
            }
        }
        removeStaleData();
        return true;
    }
    return false;
}

void ChronoPlotData::removeStaleData()
{
    while (!m_xDataEntries.isEmpty() &&
           (m_xDataEntries.last() - m_xDataEntries.first()) > m_plotDataSize) {
        m_yDataEntries.pop_front();
        m_xDataEntries.pop_front();
    }
    while (!m_enumMarkerList.isEmpty() &&
           (m_enumMarkerList.last()->xValue() - m_enumMarkerList.first()->xValue()) > m_plotDataSize) {
        QwtPlotMarker *marker = m_enumMarkerList.takeFirst();
        marker->detach();
        delete marker;
    }
}