File indexing completed on 2024-12-22 04:13:00

 /*
  *  SPDX-FileCopyrightText: 2011 Dmitry Kazakov <dimula73@gmail.com>
  *
  *  SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #include "kis_tool_freehand_helper.h"
 
 #include <QTimer>
 #include <QElapsedTimer>
 #include <QQueue>
 
 #include <klocalizedstring.h>
 
 #include <KoPointerEvent.h>
 #include <KoCanvasResourceProvider.h>
 
 #include "kis_algebra_2d.h"
 #include "kis_distance_information.h"
 #include "kis_painting_information_builder.h"
 #include "kis_image.h"
 #include "kis_painter.h"
 #include <brushengine/kis_paintop_preset.h>
 #include <brushengine/kis_paintop_utils.h>
 
 #include "kis_update_time_monitor.h"
 #include "kis_stabilized_events_sampler.h"
 #include "KisStabilizerDelayedPaintHelper.h"
 #include "kis_config.h"
 
 #include "kis_random_source.h"
 #include "KisPerStrokeRandomSource.h"
 
 #include "strokes/freehand_stroke.h"
 #include "strokes/KisFreehandStrokeInfo.h"
 #include "KisAsynchronousStrokeUpdateHelper.h"
 #include "kis_canvas_resource_provider.h"
 #include <KisOptimizedBrushOutline.h>
 
 #include <math.h>
 
 //#define DEBUG_BEZIER_CURVES
 
 // Factor by which to scale the airbrush timer's interval, relative to the actual airbrushing rate.
 // Setting this less than 1 makes the timer-generated pseudo-events happen faster than the desired
 // airbrush rate, which can improve responsiveness.
 const qreal AIRBRUSH_INTERVAL_FACTOR = 0.5;
 
 // The amount of time, in milliseconds, to allow between updates of the spacing information. Only
 // used when spacing updates between dabs are enabled.
 const qreal SPACING_UPDATE_INTERVAL = 50.0;
 
 // The amount of time, in milliseconds, to allow between updates of the timing information. Only
 // used when airbrushing.
 const qreal TIMING_UPDATE_INTERVAL = 50.0;
 
 struct KisToolFreehandHelper::Private
 {
     KoCanvasResourceProvider *resourceManager;
     KisPaintingInformationBuilder *infoBuilder;
     KisStrokesFacade *strokesFacade;
     KisAsynchronousStrokeUpdateHelper asyncUpdateHelper;
 
     KUndo2MagicString transactionText;
 
     bool haveTangent;
     QPointF previousTangent;
 
     bool hasPaintAtLeastOnce;
 
     QElapsedTimer strokeTime;
     QTimer strokeTimeoutTimer;
 
     QVector<KisFreehandStrokeInfo*> strokeInfos;
     KisResourcesSnapshotSP resources;
     KisStrokeId strokeId;
 
     KisPaintInformation previousPaintInformation;
     KisPaintInformation olderPaintInformation;
 
     KisSmoothingOptionsSP smoothingOptions;
 
     // fake random sources for hovering outline *only*
     KisRandomSourceSP fakeDabRandomSource;
     KisPerStrokeRandomSourceSP fakeStrokeRandomSource;
 
     // Timer used to generate paint updates periodically even without input events. This is only
     // used for paintops that depend on timely updates even when the cursor is not moving, e.g. for
     // airbrushing effects.
     QTimer airbrushingTimer;
 
     QList<KisPaintInformation> history;
     QList<qreal> distanceHistory;
 
     // Keeps track of past cursor positions. This is used to determine the drawing angle when
     // drawing the brush outline or starting a stroke.
     KisPaintOpUtils::PositionHistory lastCursorPos;
 
     // Stabilizer data
     bool usingStabilizer;
     QQueue<KisPaintInformation> stabilizerDeque;
     QTimer stabilizerPollTimer;
     KisStabilizedEventsSampler stabilizedSampler;
     KisStabilizerDelayedPaintHelper stabilizerDelayedPaintHelper;
 
     qreal effectiveSmoothnessDistance() const;
 };
 
 
 KisToolFreehandHelper::KisToolFreehandHelper(KisPaintingInformationBuilder *infoBuilder,
                                              KoCanvasResourceProvider *resourceManager,
                                              const KUndo2MagicString &transactionText,
                                              KisSmoothingOptions *smoothingOptions)
     : m_d(new Private())
 {
     m_d->resourceManager = resourceManager;
     m_d->infoBuilder = infoBuilder;
     m_d->transactionText = transactionText;
     m_d->smoothingOptions = KisSmoothingOptionsSP(
                 smoothingOptions ? smoothingOptions : new KisSmoothingOptions());
 
     m_d->fakeDabRandomSource = new KisRandomSource();
     m_d->fakeStrokeRandomSource = new KisPerStrokeRandomSource();
 
     m_d->strokeTimeoutTimer.setSingleShot(true);
     connect(&m_d->strokeTimeoutTimer, SIGNAL(timeout()), SLOT(finishStroke()));
     connect(&m_d->airbrushingTimer, SIGNAL(timeout()), SLOT(doAirbrushing()));
     connect(&m_d->stabilizerPollTimer, SIGNAL(timeout()), SLOT(stabilizerPollAndPaint()));
     connect(m_d->smoothingOptions.data(), SIGNAL(sigSmoothingTypeChanged()), SLOT(slotSmoothingTypeChanged()));
 
     m_d->stabilizerDelayedPaintHelper.setPaintLineCallback(
                 [this](const KisPaintInformation &pi1, const KisPaintInformation &pi2) {
                     paintLine(pi1, pi2);
                 });
     m_d->stabilizerDelayedPaintHelper.setUpdateOutlineCallback(
                 [this]() {
                     emit requestExplicitUpdateOutline();
                 });
 }
 
 KisToolFreehandHelper::~KisToolFreehandHelper()
 {
     delete m_d;
 }
 
 void KisToolFreehandHelper::setSmoothness(KisSmoothingOptionsSP smoothingOptions)
 {
     m_d->smoothingOptions = smoothingOptions;
 }
 
 KisSmoothingOptionsSP KisToolFreehandHelper::smoothingOptions() const
 {
     return m_d->smoothingOptions;
 }
 
 KisOptimizedBrushOutline KisToolFreehandHelper::paintOpOutline(const QPointF &savedCursorPos,
                                                                const KoPointerEvent *event,
                                                                const KisPaintOpSettingsSP globalSettings,
                                                                KisPaintOpSettings::OutlineMode mode) const
 {
     KisPaintOpSettingsSP settings = globalSettings;
     QPointF prevPoint = m_d->lastCursorPos.pushThroughHistory(savedCursorPos, currentZoom());
     qreal startAngle = KisAlgebra2D::directionBetweenPoints(prevPoint, savedCursorPos, 0);
     KisDistanceInformation distanceInfo(prevPoint, startAngle);
 
     KisPaintInformation info;
 
     if (!m_d->strokeInfos.isEmpty()) {
         settings = m_d->resources->currentPaintOpPreset()->settings();
         if (m_d->stabilizerDelayedPaintHelper.running() &&
                 m_d->stabilizerDelayedPaintHelper.hasLastPaintInformation()) {
             info = m_d->stabilizerDelayedPaintHelper.lastPaintInformation();
         } else {
             info = m_d->previousPaintInformation;
         }
 
         /**
          * When LoD mode is active it may happen that the helper has
          * already started a stroke, but it painted noting, because
          * all the work is being calculated by the scaled-down LodN
          * stroke. So at first we try to fetch the data from the lodN
          * stroke ("buddy") and then check if there is at least
          * something has been painted with this distance information
          * object.
          */
         KisDistanceInformation *buddyDistance =
             m_d->strokeInfos.first()->buddyDragDistance();
 
         if (buddyDistance) {
             /**
              * Tiny hack alert: here we fetch the distance information
              * directly from the LodN stroke. Ideally, we should
              * upscale its data, but here we just override it with our
              * local copy of the coordinates.
              */
             distanceInfo = *buddyDistance;
             distanceInfo.overrideLastValues(prevPoint, startAngle);
 
         } else if (m_d->strokeInfos.first()->dragDistance->isStarted()) {
             distanceInfo = *m_d->strokeInfos.first()->dragDistance;
         }
     } else {
         info = m_d->infoBuilder->hover(savedCursorPos, event, !m_d->strokeInfos.isEmpty());
     }
 
     KisPaintInformation::DistanceInformationRegistrar registrar =
         info.registerDistanceInformation(&distanceInfo);
 
     info.setRandomSource(m_d->fakeDabRandomSource);
     info.setPerStrokeRandomSource(m_d->fakeStrokeRandomSource);
 
     KisOptimizedBrushOutline outline = settings->brushOutline(info, mode, currentPhysicalZoom());
 
     if (m_d->resources &&
         m_d->smoothingOptions->smoothingType() == KisSmoothingOptions::STABILIZER &&
         m_d->smoothingOptions->useDelayDistance()) {
 
         const qreal R = m_d->smoothingOptions->delayDistance() /
             m_d->resources->effectiveZoom();
 
         outline.addEllipse(info.pos(), R, R);
     }
 
     return outline;
 }
 
 void KisToolFreehandHelper::cursorMoved(const QPointF &cursorPos)
 {
     m_d->lastCursorPos.pushThroughHistory(cursorPos, currentZoom());
 }
 
 void KisToolFreehandHelper::initPaint(KoPointerEvent *event,
                                       const QPointF &pixelCoords,
                                       KisImageWSP image, KisNodeSP currentNode,
                                       KisStrokesFacade *strokesFacade,
                                       KisNodeSP overrideNode,
                                       KisDefaultBoundsBaseSP bounds)
 {
     QPointF prevPoint = m_d->lastCursorPos.pushThroughHistory(pixelCoords, currentZoom());
     m_d->strokeTime.start();
     KisPaintInformation pi =
         m_d->infoBuilder->startStroke(event, elapsedStrokeTime(), m_d->resourceManager);
     qreal startAngle = KisAlgebra2D::directionBetweenPoints(prevPoint, pixelCoords, 0.0);
 
     initPaintImpl(startAngle,
                   pi,
                   m_d->resourceManager,
                   image,
                   currentNode,
                   strokesFacade,
                   overrideNode,
                   bounds);
 }
 
 bool KisToolFreehandHelper::isRunning() const
 {
     return m_d->strokeId;
 }
 
 void KisToolFreehandHelper::initPaintImpl(qreal startAngle,
                                           const KisPaintInformation &pi,
                                           KoCanvasResourceProvider *resourceManager,
                                           KisImageWSP image,
                                           KisNodeSP currentNode,
                                           KisStrokesFacade *strokesFacade,
                                           KisNodeSP overrideNode,
                                           KisDefaultBoundsBaseSP bounds)
 {
     m_d->strokesFacade = strokesFacade;
 
     m_d->haveTangent = false;
     m_d->previousTangent = QPointF();
 
     m_d->hasPaintAtLeastOnce = false;
 
     m_d->previousPaintInformation = pi;
 
     m_d->resources = new KisResourcesSnapshot(image,
                                               currentNode,
                                               resourceManager,
                                               bounds);
     if(overrideNode) {
         m_d->resources->setCurrentNode(overrideNode);
     }
 
     const bool airbrushing = m_d->resources->needsAirbrushing();
     const bool useSpacingUpdates = m_d->resources->needsSpacingUpdates();
 
     KisDistanceInitInfo startDistInfo(m_d->previousPaintInformation.pos(),
                                       startAngle,
                                       useSpacingUpdates ? SPACING_UPDATE_INTERVAL : LONG_TIME,
                                       airbrushing ? TIMING_UPDATE_INTERVAL : LONG_TIME,
                                       0);
     KisDistanceInformation startDist = startDistInfo.makeDistInfo();
 
     createPainters(m_d->strokeInfos,
                    startDist);
 
     KisStrokeStrategy *stroke =
         new FreehandStrokeStrategy(m_d->resources,
                                    m_d->strokeInfos,
                                    m_d->transactionText,
                                    FreehandStrokeStrategy::SupportsContinuedInterstrokeData |
                                    FreehandStrokeStrategy::SupportsTimedMergeId);
 
     m_d->strokeId = m_d->strokesFacade->startStroke(stroke);
 
     m_d->history.clear();
     m_d->distanceHistory.clear();
 
     if (airbrushing) {
         m_d->airbrushingTimer.setInterval(computeAirbrushTimerInterval());
         m_d->airbrushingTimer.start();
     } else if (m_d->resources->presetNeedsAsynchronousUpdates()) {
         m_d->asyncUpdateHelper.startUpdateStream(m_d->strokesFacade, m_d->strokeId);
     }
 
     if (m_d->smoothingOptions->smoothingType() == KisSmoothingOptions::STABILIZER) {
         stabilizerStart(m_d->previousPaintInformation);
     }
 
     // If airbrushing, paint an initial dab immediately. This is a workaround for an issue where
     // some paintops (Dyna, Particle, Sketch) might never initialize their spacing/timing
     // information until paintAt is called.
     if (airbrushing) {
         paintAt(pi);
     }
 }
 
 KoCanvasResourceProvider *KisToolFreehandHelper::resourceManager() const
 {
     return m_d->resourceManager;
 }
 
 void KisToolFreehandHelper::paintBezierSegment(KisPaintInformation pi1, KisPaintInformation pi2,
                                                QPointF tangent1, QPointF tangent2)
 {
     if (tangent1.isNull() || tangent2.isNull()) return;
 
     const qreal maxSanePoint = 1e6;
 
     QPointF controlTarget1;
     QPointF controlTarget2;
 
     // Shows the direction in which control points go
     QPointF controlDirection1 = pi1.pos() + tangent1;
     QPointF controlDirection2 = pi2.pos() - tangent2;
 
     // Lines in the direction of the control points
     QLineF line1(pi1.pos(), controlDirection1);
     QLineF line2(pi2.pos(), controlDirection2);
 
     // Lines to check whether the control points lay on the opposite
     // side of the line
     QLineF line3(controlDirection1, controlDirection2);
     QLineF line4(pi1.pos(), pi2.pos());
 
     QPointF intersection;
     if (line3.intersect(line4, &intersection) == QLineF::BoundedIntersection) {
         qreal controlLength = line4.length() / 2;
 
         line1.setLength(controlLength);
         line2.setLength(controlLength);
 
         controlTarget1 = line1.p2();
         controlTarget2 = line2.p2();
     } else {
         QLineF::IntersectType type = line1.intersect(line2, &intersection);
 
         if (type == QLineF::NoIntersection ||
             intersection.manhattanLength() > maxSanePoint) {
 
             intersection = 0.5 * (pi1.pos() + pi2.pos());
 //            dbgKrita << "WARNING: there is no intersection point "
 //                     << "in the basic smoothing algorithms";
         }
 
         controlTarget1 = intersection;
         controlTarget2 = intersection;
     }
 
     // shows how near to the controlTarget the value raises
     qreal coeff = 0.8;
 
     qreal velocity1 = QLineF(QPointF(), tangent1).length();
     qreal velocity2 = QLineF(QPointF(), tangent2).length();
 
     if (velocity1 == 0.0 || velocity2 == 0.0) {
         velocity1 = 1e-6;
         velocity2 = 1e-6;
         warnKrita << "WARNING: Basic Smoothing: Velocity is Zero! Please report a bug:" << ppVar(velocity1) << ppVar(velocity2);
     }
 
     qreal similarity = qMin(velocity1/velocity2, velocity2/velocity1);
 
     // the controls should not differ more than 50%
     similarity = qMax(similarity, qreal(0.5));
 
     // when the controls are symmetric, their size should be smaller
     // to avoid corner-like curves
     coeff *= 1 - qMax(qreal(0.0), similarity - qreal(0.8));
 
     Q_ASSERT(coeff > 0);
 
 
     QPointF control1;
     QPointF control2;
 
     if (velocity1 > velocity2) {
         control1 = pi1.pos() * (1.0 - coeff) + coeff * controlTarget1;
         coeff *= similarity;
         control2 = pi2.pos() * (1.0 - coeff) + coeff * controlTarget2;
     } else {
         control2 = pi2.pos() * (1.0 - coeff) + coeff * controlTarget2;
         coeff *= similarity;
         control1 = pi1.pos() * (1.0 - coeff) + coeff * controlTarget1;
     }
 
     paintBezierCurve(pi1,
                      control1,
                      control2,
                      pi2);
 }
 
 qreal KisToolFreehandHelper::Private::effectiveSmoothnessDistance() const
 {
     qreal zoomingCoeff = 1.0;
 
     /// stabilizer has inverted meaning of the "scalable distance", because
     /// it measures "samples", but not "distance"
 
     if ((smoothingOptions->smoothingType() == KisSmoothingOptions::STABILIZER) ^
          smoothingOptions->useScalableDistance()) {
 
         zoomingCoeff = 1.0 / resources->effectiveZoom();
     }
 
     return smoothingOptions->smoothnessDistance() * zoomingCoeff;
 }
 
 void KisToolFreehandHelper::paintEvent(KoPointerEvent *event)
 {
     KisPaintInformation info =
             m_d->infoBuilder->continueStroke(event,
                                              elapsedStrokeTime());
     KisUpdateTimeMonitor::instance()->reportMouseMove(info.pos());
 
     paint(info);
 }
 
 void KisToolFreehandHelper::paint(KisPaintInformation &info)
 {
     /**
      * Smooth the coordinates out using the history and the
      * distance. This is a heavily modified version of an algo used in
      * Gimp and described in https://bugs.kde.org/show_bug.cgi?id=281267 and
      * https://w.atwiki.jp/sigetch_2007/pages/17.html.  The main
      * differences are:
      *
      * 1) It uses 'distance' instead of 'velocity', since time
      *    measurements are too unstable in realworld environment
      *
      * 2) There is no 'Quality' parameter, since the number of samples
      *    is calculated automatically
      *
      * 3) 'Tail Aggressiveness' is used for controlling the end of the
      *    stroke
      *
      * 4) The formula is a little bit different: 'Distance' parameter
      *    stands for $3 \Sigma$
      */
     if (m_d->smoothingOptions->smoothingType() == KisSmoothingOptions::WEIGHTED_SMOOTHING
         && m_d->smoothingOptions->smoothnessDistance() > 0.0) {
 
         { // initialize current distance
             QPointF prevPos;
 
             if (!m_d->history.isEmpty()) {
                 const KisPaintInformation &prevPi = m_d->history.last();
                 prevPos = prevPi.pos();
             } else {
                 prevPos = m_d->previousPaintInformation.pos();
             }
 
             qreal currentDistance = QVector2D(info.pos() - prevPos).length();
             m_d->distanceHistory.append(currentDistance);
         }
 
         m_d->history.append(info);
 
         qreal x = 0.0;
         qreal y = 0.0;
 
         if (m_d->history.size() > 3) {
             const qreal sigma = m_d->effectiveSmoothnessDistance() / 3.0; // '3.0' for (3 * sigma) range
 
             qreal gaussianWeight = 1 / (sqrt(2 * M_PI) * sigma);
             qreal gaussianWeight2 = sigma * sigma;
             qreal distanceSum = 0.0;
             qreal scaleSum = 0.0;
             qreal pressure = 0.0;
             qreal baseRate = 0.0;
 
             Q_ASSERT(m_d->history.size() == m_d->distanceHistory.size());
 
             for (int i = m_d->history.size() - 1; i >= 0; i--) {
                 qreal rate = 0.0;
 
                 const KisPaintInformation nextInfo = m_d->history.at(i);
                 double distance = m_d->distanceHistory.at(i);
                 Q_ASSERT(distance >= 0.0);
 
                 qreal pressureGrad = 0.0;
                 if (i < m_d->history.size() - 1) {
                     pressureGrad = nextInfo.pressure() - m_d->history.at(i + 1).pressure();
 
                     const qreal tailAggressiveness = 40.0 * m_d->smoothingOptions->tailAggressiveness();
 
                     if (pressureGrad > 0.0 ) {
                         pressureGrad *= tailAggressiveness * (1.0 - nextInfo.pressure());
                         distance += pressureGrad * 3.0 * sigma; // (3 * sigma) --- holds > 90% of the region
                     }
                 }
 
                 if (gaussianWeight2 != 0.0) {
                     distanceSum += distance;
                     rate = gaussianWeight * exp(-distanceSum * distanceSum / (2 * gaussianWeight2));
                 }
 
                 if (m_d->history.size() - i == 1) {
                     baseRate = rate;
                 } else if (baseRate / rate > 100) {
                     break;
                 }
 
                 scaleSum += rate;
                 x += rate * nextInfo.pos().x();
                 y += rate * nextInfo.pos().y();
 
                 if (m_d->smoothingOptions->smoothPressure()) {
                     pressure += rate * nextInfo.pressure();
                 }
             }
 
             if (scaleSum != 0.0) {
                 x /= scaleSum;
                 y /= scaleSum;
 
                 if (m_d->smoothingOptions->smoothPressure()) {
                     pressure /= scaleSum;
                 }
             }
 
             if ((x != 0.0 && y != 0.0) || (x == info.pos().x() && y == info.pos().y())) {
                 info.setPos(QPointF(x, y));
                 if (m_d->smoothingOptions->smoothPressure()) {
                     info.setPressure(pressure);
                 }
                 m_d->history.last() = info;
             }
         }
     }
 
     if (m_d->smoothingOptions->smoothingType() == KisSmoothingOptions::SIMPLE_SMOOTHING
         || m_d->smoothingOptions->smoothingType() == KisSmoothingOptions::WEIGHTED_SMOOTHING)
     {
         // Now paint between the coordinates, using the bezier curve interpolation
         if (!m_d->haveTangent) {
             m_d->haveTangent = true;
             m_d->previousTangent =
                 (info.pos() - m_d->previousPaintInformation.pos()) /
                 qMax(qreal(1.0), info.currentTime() - m_d->previousPaintInformation.currentTime());
         } else {
             QPointF newTangent = (info.pos() - m_d->olderPaintInformation.pos()) /
                 qMax(qreal(1.0), info.currentTime() - m_d->olderPaintInformation.currentTime());
 
             if (newTangent.isNull() || m_d->previousTangent.isNull())
             {
                 paintLine(m_d->previousPaintInformation, info);
             } else {
                 paintBezierSegment(m_d->olderPaintInformation, m_d->previousPaintInformation,
                                    m_d->previousTangent, newTangent);
             }
 
             m_d->previousTangent = newTangent;
         }
         m_d->olderPaintInformation = m_d->previousPaintInformation;
 
         // Enable stroke timeout only when not airbrushing.
         if (!m_d->airbrushingTimer.isActive()) {
             m_d->strokeTimeoutTimer.start(100);
         }
     }
     else if (m_d->smoothingOptions->smoothingType() == KisSmoothingOptions::NO_SMOOTHING){
         paintLine(m_d->previousPaintInformation, info);
     }
 
     if (m_d->smoothingOptions->smoothingType() == KisSmoothingOptions::STABILIZER) {
         m_d->stabilizedSampler.addEvent(info);
         if (m_d->stabilizerDelayedPaintHelper.running()) {
             // Paint here so we don't have to rely on the timer
             // This is just a tricky source for a relatively stable 7ms "timer"
             m_d->stabilizerDelayedPaintHelper.paintSome();
         }
     } else {
         m_d->previousPaintInformation = info;
     }
 
     if(m_d->airbrushingTimer.isActive()) {
         m_d->airbrushingTimer.start();
     }
 }
 
 void KisToolFreehandHelper::endPaint()
 {
     if (!m_d->hasPaintAtLeastOnce) {
         paintAt(m_d->previousPaintInformation);
     } else if (m_d->smoothingOptions->smoothingType() != KisSmoothingOptions::NO_SMOOTHING) {
         finishStroke();
     }
     m_d->strokeTimeoutTimer.stop();
 
     if(m_d->airbrushingTimer.isActive()) {
         m_d->airbrushingTimer.stop();
     }
 
     if (m_d->smoothingOptions->smoothingType() == KisSmoothingOptions::STABILIZER) {
         stabilizerEnd();
     }
 
     if (m_d->asyncUpdateHelper.isActive()) {
         m_d->asyncUpdateHelper.endUpdateStream();
     }
 
     /**
      * There might be some timer events still pending, so
      * we should cancel them. Use this flag for the purpose.
      * Please note that we are not in MT here, so no mutex
      * is needed
      */
     m_d->strokeInfos.clear();
 
     // last update to complete rendering if there is still something pending
     m_d->strokesFacade->addJob(m_d->strokeId,
        new KisAsynchronousStrokeUpdateHelper::UpdateData(true));
 
     m_d->strokesFacade->endStroke(m_d->strokeId);
     m_d->strokeId.clear();
     m_d->infoBuilder->reset();
 }
 
 void KisToolFreehandHelper::cancelPaint()
 {
     if (!m_d->strokeId) return;
 
     m_d->strokeTimeoutTimer.stop();
 
     if (m_d->airbrushingTimer.isActive()) {
         m_d->airbrushingTimer.stop();
     }
 
     if (m_d->asyncUpdateHelper.isActive()) {
         m_d->asyncUpdateHelper.cancelUpdateStream();
     }
 
     if (m_d->stabilizerPollTimer.isActive()) {
         m_d->stabilizerPollTimer.stop();
     }
 
     if (m_d->stabilizerDelayedPaintHelper.running()) {
         m_d->stabilizerDelayedPaintHelper.cancel();
     }
 
     // see a comment in endPaint()
     m_d->strokeInfos.clear();
 
     m_d->strokesFacade->cancelStroke(m_d->strokeId);
     m_d->strokeId.clear();
 
 }
 
 int KisToolFreehandHelper::elapsedStrokeTime() const
 {
     return m_d->strokeTime.elapsed();
 }
 
 void KisToolFreehandHelper::stabilizerStart(KisPaintInformation firstPaintInfo)
 {
     m_d->usingStabilizer = true;
     // FIXME: Ugly hack, this is no a "distance" in any way
     int sampleSize = qRound(m_d->effectiveSmoothnessDistance());
     sampleSize = qMax(3, sampleSize);
 
     // Fill the deque with the current value repeated until filling the sample
     m_d->stabilizerDeque.clear();
     for (int i = sampleSize; i > 0; i--) {
         m_d->stabilizerDeque.enqueue(firstPaintInfo);
     }
 
     // Poll and draw regularly
     KisConfig cfg(true);
     int stabilizerSampleSize = cfg.stabilizerSampleSize();
     m_d->stabilizerPollTimer.setInterval(stabilizerSampleSize);
     m_d->stabilizerPollTimer.start();
 
     bool delayedPaintEnabled = cfg.stabilizerDelayedPaint();
     if (delayedPaintEnabled) {
         m_d->stabilizerDelayedPaintHelper.start(firstPaintInfo);
     }
 
     m_d->stabilizedSampler.clear();
     m_d->stabilizedSampler.addEvent(firstPaintInfo);
 }
 
 KisPaintInformation
 KisToolFreehandHelper::getStabilizedPaintInfo(const QQueue<KisPaintInformation> &queue,
                                               const KisPaintInformation &lastPaintInfo)
 {
     KisPaintInformation result(lastPaintInfo.pos(),
                                lastPaintInfo.pressure(),
                                lastPaintInfo.xTilt(),
                                lastPaintInfo.yTilt(),
                                lastPaintInfo.rotation(),
                                lastPaintInfo.tangentialPressure(),
                                lastPaintInfo.perspective(),
                                elapsedStrokeTime(),
                                lastPaintInfo.drawingSpeed());
 
     result.setCanvasRotation(lastPaintInfo.canvasRotation());
     result.setCanvasMirroredH(lastPaintInfo.canvasMirroredH());
     result.setCanvasMirroredV(lastPaintInfo.canvasMirroredV());
 
     if (queue.size() > 1) {
         QQueue<KisPaintInformation>::const_iterator it = queue.constBegin();
         QQueue<KisPaintInformation>::const_iterator end = queue.constEnd();
 
         /**
          * The first point is going to be overridden by lastPaintInfo, skip it.
          */
         it++;
         int i = 2;
 
         if (m_d->smoothingOptions->stabilizeSensors()) {
             while (it != end) {
                 qreal k = qreal(i - 1) / i; // coeff for uniform averaging
                 result.KisPaintInformation::mixOtherWithoutTime(k, *it);
                 it++;
                 i++;
             }
         } else{
             while (it != end) {
                 qreal k = qreal(i - 1) / i; // coeff for uniform averaging
                 result.KisPaintInformation::mixOtherOnlyPosition(k, *it);
                 it++;
                 i++;
             }
         }
     }
 
     return result;
 }
 
 void KisToolFreehandHelper::stabilizerPollAndPaint()
 {
     KisStabilizedEventsSampler::iterator it;
     KisStabilizedEventsSampler::iterator end;
     std::tie(it, end) = m_d->stabilizedSampler.range();
     QVector<KisPaintInformation> delayedPaintTodoItems;
 
     for (; it != end; ++it) {
         KisPaintInformation sampledInfo = *it;
 
         bool canPaint = true;
 
         if (m_d->smoothingOptions->useDelayDistance()) {
             const qreal R = m_d->smoothingOptions->delayDistance() /
                     m_d->resources->effectiveZoom();
 
             QPointF diff = sampledInfo.pos() - m_d->previousPaintInformation.pos();
             qreal dx = sqrt(pow2(diff.x()) + pow2(diff.y()));
 
             if (!(dx > R)) {
                 if (m_d->resources->needsAirbrushing()) {
                     sampledInfo.setPos(m_d->previousPaintInformation.pos());
                 }
                 else {
                     canPaint = false;
                 }
             }
         }
 
         if (canPaint) {
             KisPaintInformation newInfo = getStabilizedPaintInfo(m_d->stabilizerDeque, sampledInfo);
 
             if (m_d->stabilizerDelayedPaintHelper.running()) {
                 delayedPaintTodoItems.append(newInfo);
             } else {
                 paintLine(m_d->previousPaintInformation, newInfo);
             }
             m_d->previousPaintInformation = newInfo;
 
             // Push the new entry through the queue
             m_d->stabilizerDeque.dequeue();
             m_d->stabilizerDeque.enqueue(sampledInfo);
         } else if (m_d->stabilizerDeque.head().pos() != m_d->previousPaintInformation.pos()) {
 
             QQueue<KisPaintInformation>::iterator it = m_d->stabilizerDeque.begin();
             QQueue<KisPaintInformation>::iterator end = m_d->stabilizerDeque.end();
 
             while (it != end) {
                 *it = m_d->previousPaintInformation;
                 ++it;
             }
         }
     }
 
     m_d->stabilizedSampler.clear();
 
     if (m_d->stabilizerDelayedPaintHelper.running()) {
         m_d->stabilizerDelayedPaintHelper.update(delayedPaintTodoItems);
     } else {
         emit requestExplicitUpdateOutline();
     }
 }
 
 void KisToolFreehandHelper::stabilizerEnd()
 {
     // Stop the timer
     m_d->stabilizerPollTimer.stop();
 
     // Finish the line
     if (m_d->smoothingOptions->finishStabilizedCurve()) {
         // Process all the existing events first
         stabilizerPollAndPaint();
 
         // Draw the finish line with pending events and a time override
         m_d->stabilizedSampler.addFinishingEvent(m_d->stabilizerDeque.size());
         stabilizerPollAndPaint();
     }
 
     if (m_d->stabilizerDelayedPaintHelper.running()) {
         m_d->stabilizerDelayedPaintHelper.end();
     }
     m_d->usingStabilizer = false;
 }
 
 void KisToolFreehandHelper::slotSmoothingTypeChanged()
 {
     if (!isRunning()) {
         return;
     }
     KisSmoothingOptions::SmoothingType currentSmoothingType =
             m_d->smoothingOptions->smoothingType();
     if (m_d->usingStabilizer
             && (currentSmoothingType != KisSmoothingOptions::STABILIZER)) {
         stabilizerEnd();
     } else if (!m_d->usingStabilizer
             && (currentSmoothingType == KisSmoothingOptions::STABILIZER)) {
         stabilizerStart(m_d->previousPaintInformation);
     }
 }
 
 void KisToolFreehandHelper::finishStroke()
 {
     if (m_d->haveTangent) {
         m_d->haveTangent = false;
 
         QPointF newTangent = (m_d->previousPaintInformation.pos() - m_d->olderPaintInformation.pos()) /
             (m_d->previousPaintInformation.currentTime() - m_d->olderPaintInformation.currentTime());
 
         paintBezierSegment(m_d->olderPaintInformation,
                            m_d->previousPaintInformation,
                            m_d->previousTangent,
                            newTangent);
     }
 }
 
 void KisToolFreehandHelper::doAirbrushing()
 {
     // Check that the stroke hasn't ended.
     if (!m_d->strokeInfos.isEmpty()) {
 
         // Add a new painting update at a point identical to the previous one, except for the time
         // and speed information.
         const KisPaintInformation &prevPaint = m_d->previousPaintInformation;
         KisPaintInformation nextPaint(prevPaint.pos(),
                                       prevPaint.pressure(),
                                       prevPaint.xTilt(),
                                       prevPaint.yTilt(),
                                       prevPaint.rotation(),
                                       prevPaint.tangentialPressure(),
                                       prevPaint.perspective(),
                                       elapsedStrokeTime(),
                                       0.0);
         nextPaint.setCanvasRotation(prevPaint.canvasRotation());
         nextPaint.setCanvasMirroredH(prevPaint.canvasMirroredH());
         nextPaint.setCanvasMirroredV(prevPaint.canvasMirroredV());
         paint(nextPaint);
     }
 }
 
 int KisToolFreehandHelper::computeAirbrushTimerInterval() const
 {
     qreal realInterval = m_d->resources->airbrushingInterval() * AIRBRUSH_INTERVAL_FACTOR;
     return qMax(1, qFloor(realInterval));
 }
 
 qreal KisToolFreehandHelper::currentZoom() const
 {
     return m_d->resourceManager ? m_d->resourceManager->resource(KoCanvasResource::EffectiveZoom).toReal() : 1.0;
 }
 
 qreal KisToolFreehandHelper::currentPhysicalZoom() const
 {
     return m_d->resourceManager ? m_d->resourceManager->resource(KoCanvasResource::EffectivePhysicalZoom).toReal() : 1.0;
 }
 
 void KisToolFreehandHelper::paintAt(int strokeInfoId,
                                     const KisPaintInformation &pi)
 {
     m_d->hasPaintAtLeastOnce = true;
     m_d->strokesFacade->addJob(m_d->strokeId,
                                new FreehandStrokeStrategy::Data(strokeInfoId, pi));
 
 }
 
 void KisToolFreehandHelper::paintLine(int strokeInfoId,
                                       const KisPaintInformation &pi1,
                                       const KisPaintInformation &pi2)
 {
     m_d->hasPaintAtLeastOnce = true;
     m_d->strokesFacade->addJob(m_d->strokeId,
                                new FreehandStrokeStrategy::Data(strokeInfoId, pi1, pi2));
 
 }
 
 void KisToolFreehandHelper::paintBezierCurve(int strokeInfoId,
                                              const KisPaintInformation &pi1,
                                              const QPointF &control1,
                                              const QPointF &control2,
                                              const KisPaintInformation &pi2)
 {
 #ifdef DEBUG_BEZIER_CURVES
     KisPaintInformation tpi1;
     KisPaintInformation tpi2;
 
     tpi1 = pi1;
     tpi2 = pi2;
 
     tpi1.setPressure(0.3);
     tpi2.setPressure(0.3);
 
     paintLine(tpi1, tpi2);
 
     tpi1.setPressure(0.6);
     tpi2.setPressure(0.3);
 
     tpi1.setPos(pi1.pos());
     tpi2.setPos(control1);
     paintLine(tpi1, tpi2);
 
     tpi1.setPos(pi2.pos());
     tpi2.setPos(control2);
     paintLine(tpi1, tpi2);
 #endif
 
     m_d->hasPaintAtLeastOnce = true;
     m_d->strokesFacade->addJob(m_d->strokeId,
                                new FreehandStrokeStrategy::Data(strokeInfoId,
                                                                 pi1, control1, control2, pi2));
 
 }
 
 void KisToolFreehandHelper::createPainters(QVector<KisFreehandStrokeInfo*> &strokeInfos,
                                            const KisDistanceInformation &startDist)
 {
     strokeInfos << new KisFreehandStrokeInfo(startDist);
 }
 
 void KisToolFreehandHelper::paintAt(const KisPaintInformation &pi)
 {
     paintAt(0, pi);
 }
 
 void KisToolFreehandHelper::paintLine(const KisPaintInformation &pi1,
                                       const KisPaintInformation &pi2)
 {
     paintLine(0, pi1, pi2);
 }
 
 void KisToolFreehandHelper::paintBezierCurve(const KisPaintInformation &pi1,
                                              const QPointF &control1,
                                              const QPointF &control2,
                                              const KisPaintInformation &pi2)
 {
     paintBezierCurve(0, pi1, control1, control2, pi2);
 }