diff --git a/src/kcmodule/pressurecurvewidget.cpp b/src/kcmodule/pressurecurvewidget.cpp
index e15ae46..2737fd0 100644
--- a/src/kcmodule/pressurecurvewidget.cpp
+++ b/src/kcmodule/pressurecurvewidget.cpp
@@ -1,213 +1,215 @@
 /*
  * This file is part of the KDE wacomtablet project. For copyright
  * information and license terms see the AUTHORS and COPYING files
  * in the top-level directory of this distribution.
  *
  * 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 2 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 "pressurecurvewidget.h"
 
 //Qt includes
+#include <QDebug>
 #include <QPainter>
 #include <QMouseEvent>
 #include <QResizeEvent>
 #include <QTabletEvent>
 
 using namespace Wacom;
 
 PressureCurveWidget::PressureCurveWidget(QWidget *parent) :
         QWidget(parent)
 {
     setBackgroundRole(QPalette::Base);
     setAutoFillBackground(true);
 }
 
 void PressureCurveWidget::setControlPoints(qreal p1, qreal p2, qreal p3, qreal p4)
 {
     // change y values upside down (xsetwacom has 0,0 in the lower left QWidget in the upper left)
     p2 = 100 - p2;
     p4 = 100 - p4;
     m_cP1 = QPointF((p1 / 100.0) * width() , (p2 / 100.0) * height());
     m_cP2 = QPointF((p3 / 100.0) * width() , (p4 / 100.0) * height());
 }
 
 void PressureCurveWidget::mousePressEvent(QMouseEvent * event)
 {
     setNearestPoint(event->localPos());
 }
 
 void PressureCurveWidget::mouseMoveEvent(QMouseEvent * event)
 {
     moveControlPoint(event->localPos());
     update();
 }
 
 void PressureCurveWidget::mouseReleaseEvent(QMouseEvent * event)
 {
     Q_UNUSED(event);
     m_activePoint = 0;
 }
 
 void PressureCurveWidget::resizeEvent(QResizeEvent * event)
 {
     // avoid unpredictable ratio on first initialisation
-    if (event->oldSize().width() == -1) {
+    if (event->oldSize().width() == -1
+            || event->oldSize().width() == 0
+            || event->oldSize().height() == 0) {
         return;
     }
 
-    qreal xRatio = (qreal)event->size().width() / (qreal)event->oldSize().width();
-    qreal yRatio = (qreal)event->size().height() / (qreal)event->oldSize().height();
+    const qreal xRatio = static_cast<qreal>(event->size().width())  / event->oldSize().width();
+    const qreal yRatio = static_cast<qreal>(event->size().height()) / event->oldSize().height();
 
     m_cP1.setX(m_cP1.x() * xRatio);
     m_cP1.setY(m_cP1.y() * yRatio);
     m_cP2.setX(m_cP2.x() * xRatio);
     m_cP2.setY(m_cP2.y() * yRatio);
 }
 
 void PressureCurveWidget::tabletEvent(QTabletEvent * event)
 {
     event->accept();
     m_presssure = event->pressure();
 
-    if (event->pressure() == 0) {
+    constexpr qreal threshold = 0.001;
+    if (m_presssure <= threshold) {
         m_activePoint = 0;
     }
 
     if (m_activePoint > 0) {
         moveControlPoint(event->pos());
-    }
-
-    else if (event->pressure() > 0) {
+    } else if (m_presssure > threshold) {
         setNearestPoint(event->pos());
     }
 
     update();
 }
 
 void PressureCurveWidget::setNearestPoint(const QPointF & pos)
 {
     qreal d1 = QLineF(pos, m_cP1).length();
     qreal d2 = QLineF(pos, m_cP2).length();
 
     if (d1 <  m_pointSize) {
         m_activePoint = 1;
     } else if (d2 < m_pointSize) {
         m_activePoint = 2;
     }
 }
 
 void PressureCurveWidget::moveControlPoint(const QPointF & pos)
 {
     int x;
     int y;
 
     if (pos.x() > width()) {
         x = width();
     } else if (pos.x() < 0) {
         x = 0;
     } else {
-        x = pos.x();
+        x = qRound(pos.x());
     }
 
     if (pos.y() > height()) {
         y = height();
     } else if (pos.y() < 0) {
         y = 0;
     } else {
-        y = pos.y();
+        y = qRound(pos.y());
     }
 
     switch (m_activePoint) {
     case 1:
         m_cP1 = QPoint(x, y);
         m_cP2 = QPoint(y, x);   // seems xsetwacom is expecting to be both controllpoints the same with switches xy values
         // makes no sense to me, but otherwise the wacom driver complains
         // the wacom_utility does it the same way though
         break;
     case 2:
         m_cP2 = QPoint(x, y);
         m_cP1 = QPoint(y, x);   // see above
         break;
     }
 
     // build string with controlpoints as used in xsetwacom settings
-    int p1 = (m_cP1.x() / width()) * 100.0;
-    int p2 = (m_cP1.y() / height()) * 100.0;
-    int p3 = (m_cP2.x() / width()) * 100.0;
-    int p4 = (m_cP2.y() / height()) * 100.0;
+    int p1 = qRound((m_cP1.x() / width())  * 100.0);
+    int p2 = qRound((m_cP1.y() / height()) * 100.0);
+    int p3 = qRound((m_cP2.x() / width())  * 100.0);
+    int p4 = qRound((m_cP2.y() / height()) * 100.0);
 
     //change y values upside down
     p2 = 100 - p2;
     p4 = 100 - p4;
     QString pointsString = QString::fromLatin1("%1 %2 %3 %4").arg(p1).arg(p2).arg(p3).arg(p4);
 
     emit controlPointsChanged(pointsString);
 }
 
 void PressureCurveWidget::paintEvent(QPaintEvent * event)
 {
     Q_UNUSED(event);
 
     QPainter painter(this);
     painter.setRenderHint(QPainter::Antialiasing, true);
     painter.translate( + 0.5, + 0.5);
 
     // draw the background grid
     int yStep = height() / 10;
     int xStep = width() / 10;
     painter.setPen(QColor(Qt::gray));
 
     for (int i = 1; i < 10;i++) {
         painter.drawLine(i * xStep, 0, i * xStep, height());
         painter.drawLine(0, i * yStep, width(), i * yStep);
     }
 
     // draw controllpoint lines
     painter.setPen(QColor(Qt::gray));
     painter.drawLine(m_cP1, QPoint(0, height()));
     painter.drawLine(m_cP2, QPoint(width(), 0));
 
     // create presscurve
     QPainterPath curvePath;
     curvePath.moveTo(0, height());
     curvePath.cubicTo(m_cP1, m_cP2, QPoint(width(), 0));
 
     //create polygon for the area below the curve
     QPainterPath areaBelowCurve(curvePath);
     areaBelowCurve.lineTo(width(), height());
     areaBelowCurve.lineTo(0, height());
     QRectF clearRect(m_presssure * width(), 0, width(), height());
     QPainterPath subtract;
     subtract.addRect(clearRect);
 
     //draw below curve area
     painter.setPen(QPen());
     painter.setBrush(QColor(0, 102, 255));
     painter.drawPath(areaBelowCurve.subtracted(subtract));
 
     // draw presscurve
     QPen curvePen;
     curvePen.setWidth(2);
     curvePen.setColor(m_curveColor);
     painter.setPen(curvePen);
     painter.setBrush(QBrush());
     painter.drawPath(curvePath);
 
     // draw controllpoints
     painter.setPen(QColor(226, 8, 0));
     painter.setBrush(QColor(226, 8, 0));
     painter.drawEllipse(m_cP1, m_pointSize, m_pointSize);
     painter.drawEllipse(m_cP2, m_pointSize, m_pointSize);
 }