File indexing completed on 2024-12-22 04:14:49

 /*
  *  SPDX-FileCopyrightText: 2016 Eugene Ingerman <geneing at gmail dot com>
  *
  *  SPDX-License-Identifier: LGPL-2.0-or-later
  */
 
 #include "histogramdockerwidget.h"
 
 #include <QThread>
 #include <QVector>
 #include <limits>
 #include <algorithm>
 #include <QTime>
 #include <QPainter>
 #include <QPainterPath>
 #include <functional>
 
 #include "KoChannelInfo.h"
 #include "KisViewManager.h"
 #include "kis_canvas2.h"
 
 
 
 HistogramDockerWidget::HistogramDockerWidget(QWidget *parent, const char *name, Qt::WindowFlags f)
     : KisWidgetWithIdleTask<QLabel>(parent, f)
 {
     setObjectName(name);
     qRegisterMetaType<HistogramData>();
 }
 
 HistogramDockerWidget::~HistogramDockerWidget()
 {
 }
 
 void HistogramDockerWidget::receiveNewHistogram(HistogramData data)
 {
     m_histogramData = data.bins;
     m_colorSpace = data.colorSpace;
     update();
 }
 
 KisIdleTasksManager::TaskGuard HistogramDockerWidget::registerIdleTask(KisCanvas2 *canvas)
 {
     KIS_SAFE_ASSERT_RECOVER_RETURN_VALUE(canvas, KisIdleTasksManager::TaskGuard());
 
     return
         canvas->viewManager()->idleTasksManager()->
         addIdleTaskWithGuard([this](KisImageSP image) {
             HistogramComputationStrokeStrategy* strategy =
                 new HistogramComputationStrokeStrategy(image);
 
             connect(strategy, SIGNAL(computationResultReady(HistogramData)), this, SLOT(receiveNewHistogram(HistogramData)));
 
             return strategy;
         });
 }
 
 void HistogramDockerWidget::clearCachedState()
 {
     m_colorSpace = 0;
     m_histogramData.clear();
 }
 
 void HistogramDockerWidget::paintEvent(QPaintEvent *event)
 {
     if (m_colorSpace && !m_histogramData.empty()) {
         int nBins = m_histogramData.at(0).size();
         const KoColorSpace* cs = m_colorSpace;
 
         QLabel::paintEvent(event);
         QPainter painter(this);
         painter.fillRect(0, 0, this->width(), this->height(), this->palette().dark().color());
         painter.setPen(this->palette().light().color());
 
         const int NGRID = 4;
         for (int i = 0; i <= NGRID; ++i) {
             painter.drawLine(this->width()*i / NGRID, 0., this->width()*i / NGRID, this->height());
             painter.drawLine(0., this->height()*i / NGRID, this->width(), this->height()*i / NGRID);
         }
 
         unsigned int nChannels = cs->channelCount();
         const QList<KoChannelInfo *> channels = cs->channels();
         unsigned int highest = 0;
         //find the most populous bin in the histogram to scale it properly
         for (int chan = 0; chan < channels.size(); chan++) {
             if (channels.at(chan)->channelType() != KoChannelInfo::ALPHA) {
                 std::vector<quint32> histogramTemp = m_histogramData.at(chan);
                 //use 98th percentile, rather than max for better visual appearance
                 int nthPercentile = 2 * histogramTemp.size() / 100;
                 //unsigned int max = *std::max_element(m_histogramData.at(chan).begin(),m_histogramData.at(chan).end());
                 std::nth_element(histogramTemp.begin(),
                                  histogramTemp.begin() + nthPercentile, histogramTemp.end(), std::greater<int>());
                 unsigned int max = *(histogramTemp.begin() + nthPercentile);
 
                 highest = std::max(max, highest);
             }
         }
 
         painter.setWindow(QRect(-1, 0, nBins + 1, highest));
         painter.setCompositionMode(QPainter::CompositionMode_Plus);
 
         for (int chan = 0; chan < (int)nChannels; chan++) {
             if (channels.at(chan)->channelType() != KoChannelInfo::ALPHA) {
                 QColor color = channels.at(chan)->color();
 
                 //special handling of grayscale color spaces. can't use color returned above.
                 if(cs->colorChannelCount()==1){
                     color = QColor(Qt::gray);
                 }
 
                 QColor fill_color = color;
                 fill_color.setAlphaF(.25);
                 painter.setBrush(fill_color);
                 QPen pen = QPen(color);
                 pen.setWidth(0);
                 painter.setPen(pen);
 
                 if (m_smoothHistogram) {
                     QPainterPath path;
                     path.moveTo(QPointF(-1, highest));
                     for (qint32 i = 0; i < nBins; ++i) {
                         float v = std::max((float)highest - m_histogramData[chan][i], 0.f);
                         path.lineTo(QPointF(i, v));
 
                     }
                     path.lineTo(QPointF(nBins + 1, highest));
                     path.closeSubpath();
                     painter.drawPath(path);
                 } else {
                     pen.setWidth(1);
                     painter.setPen(pen);
                     for (qint32 i = 0; i < nBins; ++i) {
                         float v = std::max((float)highest - m_histogramData[chan][i], 0.f);
                         painter.drawLine(QPointF(i, highest), QPointF(i, v));
                     }
                 }
             }
         }
     }
 }