KisSpeedSmoother Class Reference

#include <kis_speed_smoother.h>

Classes
struct	Private

Public Member Functions
void	clear ()
qreal	getNextSpeed (const QPointF &pt, ulong timestamp)
	KisSpeedSmoother ()
qreal	lastSpeed () const
void	updateSettings ()
	~KisSpeedSmoother ()

Private Member Functions
qreal	getNextSpeedImpl (const QPointF &pt, qreal time)

Private Attributes
const QScopedPointer< Private >	m_d

Detailed Description

Definition at line 15 of file kis_speed_smoother.h.

Constructor & Destructor Documentation

KisSpeedSmoother()

KisSpeedSmoother::KisSpeedSmoother

(

)

Definition at line 66 of file kis_speed_smoother.cpp.

    : m_d(new Private(MAX_SMOOTH_HISTORY))
{
    updateSettings();
}

References updateSettings().

~KisSpeedSmoother()

KisSpeedSmoother::~KisSpeedSmoother

(

)

Definition at line 72 of file kis_speed_smoother.cpp.

{
}

Member Function Documentation

clear()

void KisSpeedSmoother::clear

(

)

Definition at line 90 of file kis_speed_smoother.cpp.

{
    m_d->timer.restart();
    m_d->distances.clear();
    m_d->distances.push_back(Private::DistancePoint(0.0, 0.0));
    m_d->lastPoint = QPointF();
    m_d->lastSpeed = 0.0;
}

References m_d.

getNextSpeed()

qreal KisSpeedSmoother::getNextSpeed	(	const QPointF &	pt,
		ulong	timestamp )

Definition at line 81 of file kis_speed_smoother.cpp.

{
    const qreal time = m_d->useTimestamps ?
        qreal(timestamp) :
        qreal(m_d->timer.nsecsElapsed()) / 1000000;
 
    return getNextSpeedImpl(pt, time);
}

References getNextSpeedImpl(), and m_d.

getNextSpeedImpl()

qreal KisSpeedSmoother::getNextSpeedImpl ( const QPointF & pt, qreal time )

private

Mind you, we don't care about the specific timestamps of the tablet events! They are not reliable. Instead, we are trying to estimate the sample rate of the tablet itself using the filtered mean accumulator. It works in an assumption that all the tablets generate events at a fixed sample rate.

Definition at line 107 of file kis_speed_smoother.cpp.

{
    if (m_d->lastPoint.isNull()) {
        m_d->lastPoint = pt;
        m_d->lastTime = time;
        m_d->lastSpeed = 0.0;
        return 0.0;
    }
 
    const qreal dist = kisDistance(pt, m_d->lastPoint);
    // Getting the exact same position is bogus, it is probably just a previous
    // point reported again. On Android, this happens all the time. Skip them.
    if (qFuzzyIsNull(dist)) {
        return m_d->lastSpeed;
    }
 
    const qreal timeDiff = time - m_d->lastTime;
 
    m_d->timeDiffsMean.addValue(timeDiff);
    const qreal avgTimeDiff = m_d->timeDiffsMean.filteredMean();
 
    m_d->lastPoint = pt;
    m_d->lastTime = time;
 
    m_d->distances.push_back(Private::DistancePoint(dist, time));
 
    Private::DistanceBuffer::const_reverse_iterator it = m_d->distances.rbegin();
    Private::DistanceBuffer::const_reverse_iterator end = m_d->distances.rend();
 
    qreal totalDistance = 0;
    qreal totalTime = 0.0;
    int itemsSearched = 0;
 
    for (; it != end; ++it) {
        itemsSearched++;
        totalDistance += it->distance;
 
        totalTime += avgTimeDiff;
 
        if (itemsSearched > m_d->numSmoothingSamples &&
            totalDistance > MIN_TRACKING_DISTANCE) {
 
            break;
        }
    }
 
    if (totalTime > 0 && totalDistance > MIN_TRACKING_DISTANCE) {
        m_d->lastSpeed = totalDistance / totalTime;
    }
 
    return m_d->lastSpeed;
}

References kisDistance(), m_d, MIN_TRACKING_DISTANCE, and qFuzzyIsNull().

lastSpeed()

qreal KisSpeedSmoother::lastSpeed

(

)

const

Definition at line 76 of file kis_speed_smoother.cpp.

{
    return m_d->lastSpeed;
}

References m_d.

updateSettings()

void KisSpeedSmoother::updateSettings

(

)

Definition at line 99 of file kis_speed_smoother.cpp.

{
 
    KisConfig cfg(true);
    m_d->useTimestamps = cfg.readEntry("useTimestampsForBrushSpeed", false);
    m_d->numSmoothingSamples = cfg.readEntry("speedValueSmoothing", 3);
}

References m_d, and KisConfig::readEntry().

Member Data Documentation

m_d

const QScopedPointer<Private> KisSpeedSmoother::m_d

private

Definition at line 31 of file kis_speed_smoother.h.

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The documentation for this class was generated from the following files:

• libs/ui/tool/kis_speed_smoother.h
• libs/ui/tool/kis_speed_smoother.cpp