File indexing completed on 2024-05-12 04:33:22

 /*
  * SPDX-FileCopyrightText: 2007-2008 Kare Sars <kare.sars@iki .fi>
  * SPDX-FileCopyrightText: 2014 Gregor Mitsch : port to KDE5 frameworks
  *
  * SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
  */
 
 // Local includes
 #include "gammadisp.h"
 
 // Qt includes
 #include <QPainter>
 
 #include <cmath>
 
 namespace KSaneIface
 {
 
 GammaDisp::GammaDisp(QWidget *parent, int *brightness, int *contrast, int *gamma, int maxValue)
 : QWidget(parent)
 , m_brightness(brightness)
 , m_contrast(contrast)
 , m_gamma(gamma)
 , m_gammaColor(QColor::fromRgb(0,0,0))
 , m_maxValue(maxValue)
 {}
 
 QSize GammaDisp::minimumSizeHint() const
 {
     return QSize(75, 75);
 }
 
 QSize GammaDisp::sizeHint() const
 {
     return QSize(75, 75);
 }
 
 void GammaDisp::setColor(const QColor &color)
 {
     m_gammaColor = color;
 }
 
 void GammaDisp::resizeEvent(QResizeEvent *)
 {
     repaint();
 }
 
 void GammaDisp::paintEvent(QPaintEvent *)
 {
     /*    QMemArray<QRect> rects = event->region().rects();
         for (int i = 0; i < (int)rects.size(); i++) {
             bitBlt(this, rects[i].topLeft(), &pixmap, rects[i]);
         }*/
     QPointF p1, p2;
     QPainter painter(this);
     painter.fillRect(rect(), QBrush(Qt::white));
 
     const int xResolution = 100;
     double max = static_cast<double>(m_maxValue);
     double xscale = static_cast<double>(size().width() - 1)  / static_cast<double>(xResolution);
     double yscale = static_cast<double>(size().height() - 1) / max;
 
     painter.setPen(m_gammaColor);
 
     double gamma    = 100.0 / *m_gamma;
     double contrast = (200.0 / (100.0 - *m_contrast)) - 1;
     double halfMax  = max / 2.0;
     double brightness  = (*m_brightness / halfMax) * max;
 
     double xPrevious = 0;
     double xNext = 0;
 
     // gamma is zero for first one, start with contrast
     xPrevious = (contrast * (xPrevious - halfMax)) + halfMax;
     // apply brightness + rounding
     xPrevious += brightness + 0.5;
     // ensure correct value
     if (xPrevious > max) {
         xPrevious = max;
     }
     if (xPrevious < 0) {
         xPrevious = 0;
     }
 
     for (int i = 0; i < xResolution - 1; i++) {
         xNext = std::pow(static_cast<double>(i+1) / xResolution, gamma) * max;
         // apply contrast
         xNext = (contrast * (xNext - halfMax)) + halfMax;
         // apply brightness + rounding
         xNext += brightness + 0.5;
 
         // ensure correct value
         if (xNext > max) {
             xNext = max;
         }
         if (xNext < 0) {
             xNext = 0;
         }
 
         p1.setX(i * xscale);
         p1.setY(size().height() - 1 - (xPrevious * yscale));
 
         p2.setX((i + 1)*xscale);
         p2.setY(size().height() - 1 - (xNext * yscale));
 
         painter.drawLine(p1, p2);
         xPrevious = xNext;
     }
 }
 
 }  // NameSpace KSaneIface
 
 #include "moc_gammadisp.cpp"