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#include "qquickspritesequence_p.h"
#include "qquickspritesequence_p_p.h"
#include "qquicksprite_p.h"
#include "qquickspriteengine_p.h"
#include <QtQuick/private/qsgcontext_p.h>
#include <private/qsgadaptationlayer_p.h>
#include <QtQuick/qsgnode.h>
#include <QtQuick/qsgtexturematerial.h>
#include <QtQuick/qsgtexture.h>
#include <QtQuick/qquickwindow.h>
#include <QtQml/qqmlinfo.h>
#include <QFile>
#include <cmath>
#include <qmath.h>
#include <QDebug>

QT_BEGIN_NAMESPACE

/*!
    \qmltype SpriteSequence
    \instantiates QQuickSpriteSequence
    \inqmlmodule QtQuick
    \ingroup qtquick-visual-utility
    \inherits Item
    \brief Draws a sprite animation.

    SpriteSequence renders and controls a list of animations defined
    by \l Sprite types.

    For full details, see the \l{Sprite Animations} overview.
    \sa {Sprite animations with SpriteSequence}
*/
/*!
    \qmlproperty bool QtQuick::SpriteSequence::running

    Whether the sprite is animating or not.

    Default is \c true.
*/
/*!
    \qmlproperty bool QtQuick::SpriteSequence::interpolate

    If \c true, interpolation will occur between sprite frames to make the
    animation appear smoother.

    Default is \c true.
*/
/*!
    \qmlproperty string QtQuick::SpriteSequence::currentSprite

    The name of the \l Sprite that is currently animating.
*/
/*!
    \qmlproperty string QtQuick::SpriteSequence::goalSprite

    The name of the \l Sprite that the animation should move to.

    Sprite states have defined durations and transitions between them; setting \c goalSprite
    will cause it to disregard any path weightings (including \c 0) and head down the path
    that will reach the \c goalSprite quickest (fewest animations). It will pass through
    intermediate states on that path, and animate them for their duration.

    If it is possible to return to the \c goalSprite from the starting point of the \c goalSprite,
    it will continue to do so until \c goalSprite is set to \c "" or an unreachable state.
*/
/*! \qmlmethod QtQuick::SpriteSequence::jumpTo(string sprite)

    This function causes the SpriteSequence to jump to the specified \a sprite immediately;
    intermediate sprites are not played.
*/
/*!
    \qmlproperty list<Sprite> QtQuick::SpriteSequence::sprites

    The sprite or sprites to draw. Sprites will be scaled to the size of this item.
*/

//TODO: Implicitly size element to size of first sprite?
QQuickSpriteSequence::QQuickSpriteSequence(QQuickItem *parent) :
    QQuickItem(*(new QQuickSpriteSequencePrivate), parent)
{
    setFlag(ItemHasContents);
    connect(this, SIGNAL(runningChanged(bool)),
            this, SLOT(update()));
}

void QQuickSpriteSequence::jumpTo(const QString &sprite)
{
    Q_D(QQuickSpriteSequence);
    if (!d->m_spriteEngine)
        return;
    d->m_spriteEngine->setGoal(d->m_spriteEngine->stateIndex(sprite), 0, true);
}

void QQuickSpriteSequence::setGoalSprite(const QString &sprite)
{
    Q_D(QQuickSpriteSequence);
    if (d->m_goalState != sprite){
        d->m_goalState = sprite;
        emit goalSpriteChanged(sprite);
        if (d->m_spriteEngine)
            d->m_spriteEngine->setGoal(d->m_spriteEngine->stateIndex(sprite));
    }
}

void QQuickSpriteSequence::setRunning(bool arg)
{
    Q_D(QQuickSpriteSequence);
    if (d->m_running != arg) {
        d->m_running = arg;
        Q_EMIT runningChanged(arg);
    }
}

void QQuickSpriteSequence::setInterpolate(bool arg)
{
    Q_D(QQuickSpriteSequence);
    if (d->m_interpolate != arg) {
        d->m_interpolate = arg;
        Q_EMIT interpolateChanged(arg);
    }
}

QQmlListProperty<QQuickSprite> QQuickSpriteSequence::sprites()
{
    Q_D(QQuickSpriteSequence);
    return QQmlListProperty<QQuickSprite>(this, &d->m_sprites,
                                          spriteAppend, spriteCount, spriteAt,
                                          spriteClear, spriteReplace, spriteRemoveLast);
}

bool QQuickSpriteSequence::running() const
{
    Q_D(const QQuickSpriteSequence);
    return d->m_running;
}

bool QQuickSpriteSequence::interpolate() const
{
    Q_D(const QQuickSpriteSequence);
    return d->m_interpolate;
}

QString QQuickSpriteSequence::goalSprite() const
{
    Q_D(const QQuickSpriteSequence);
    return d->m_goalState;
}

QString QQuickSpriteSequence::currentSprite() const
{
    Q_D(const QQuickSpriteSequence);
    return d->m_curState;
}

void QQuickSpriteSequence::createEngine()
{
    Q_D(QQuickSpriteSequence);
    //TODO: delay until component complete
    if (d->m_spriteEngine)
        delete d->m_spriteEngine;
    if (d->m_sprites.count()) {
        d->m_spriteEngine = new QQuickSpriteEngine(d->m_sprites, this);
        if (!d->m_goalState.isEmpty())
            d->m_spriteEngine->setGoal(d->m_spriteEngine->stateIndex(d->m_goalState));
    } else {
        d->m_spriteEngine = nullptr;
    }
    reset();
}

QSGSpriteNode *QQuickSpriteSequence::initNode()
{
    Q_D(QQuickSpriteSequence);

    if (!d->m_spriteEngine) {
        qmlWarning(this) << "No sprite engine...";
        return nullptr;
    } else if (d->m_spriteEngine->status() == QQuickPixmap::Null) {
        d->m_spriteEngine->startAssemblingImage();
        update();//Schedule another update, where we will check again
        return nullptr;
    } else if (d->m_spriteEngine->status() == QQuickPixmap::Loading) {
        update();//Schedule another update, where we will check again
        return nullptr;
    }

    QImage image = d->m_spriteEngine->assembledImage(d->sceneGraphRenderContext()->maxTextureSize());
    if (image.isNull())
        return nullptr;

    QSGSpriteNode *node = d->sceneGraphContext()->createSpriteNode();

    d->m_sheetSize = QSize(image.size() / image.devicePixelRatio());
    node->setTexture(window()->createTextureFromImage(image));
    d->m_spriteEngine->start(0);
    node->setTime(0.0f);
    node->setSourceA(QPoint(d->m_spriteEngine->spriteX(), d->m_spriteEngine->spriteY()));
    node->setSourceB(QPoint(d->m_spriteEngine->spriteX(), d->m_spriteEngine->spriteY()));
    node->setSpriteSize(QSize(d->m_spriteEngine->spriteWidth(), d->m_spriteEngine->spriteHeight()));
    node->setSheetSize(d->m_sheetSize);
    node->setSize(QSizeF(width(), height()));

    d->m_curState = d->m_spriteEngine->state(d->m_spriteEngine->curState())->name();
    emit currentSpriteChanged(d->m_curState);
    d->m_timestamp.start();
    return node;
}

void QQuickSpriteSequence::reset()
{
    Q_D(QQuickSpriteSequence);
    d->m_pleaseReset = true;
}

QSGNode *QQuickSpriteSequence::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
{
    Q_D(QQuickSpriteSequence);

    if (d->m_pleaseReset) {
        delete oldNode;

        oldNode = nullptr;
        d->m_pleaseReset = false;
    }

    QSGSpriteNode *node = static_cast<QSGSpriteNode *>(oldNode);
    if (!node)
        node = initNode();

    if (node)
        prepareNextFrame(node);

    if (d->m_running) {
        update();
    }

    return node;
}

void QQuickSpriteSequence::prepareNextFrame(QSGSpriteNode *node)
{
    Q_D(QQuickSpriteSequence);

    uint timeInt = d->m_timestamp.elapsed();
    qreal time =  timeInt / 1000.;

    //Advance State
    d->m_spriteEngine->updateSprites(timeInt);
    if (d->m_curStateIdx != d->m_spriteEngine->curState()) {
        d->m_curStateIdx = d->m_spriteEngine->curState();
        d->m_curState = d->m_spriteEngine->state(d->m_spriteEngine->curState())->name();
        emit currentSpriteChanged(d->m_curState);
        d->m_curFrame= -1;
    }

    //Advance Sprite
    qreal animT = d->m_spriteEngine->spriteStart()/1000.0;
    qreal frameCount = d->m_spriteEngine->spriteFrames();
    qreal frameDuration = d->m_spriteEngine->spriteDuration()/frameCount;
    double frameAt;
    qreal progress;
    if (frameDuration > 0) {
        qreal frame = (time - animT)/(frameDuration / 1000.0);
        frame = qBound(qreal(0.0), frame, frameCount - qreal(1.0));//Stop at count-1 frames until we have between anim interpolation
        progress = std::modf(frame,&frameAt);
    } else {
        d->m_curFrame++;
        if (d->m_curFrame >= frameCount){
            d->m_curFrame = 0;
            d->m_spriteEngine->advance();
        }
        frameAt = d->m_curFrame;
        progress = 0;
    }
    if (d->m_spriteEngine->sprite()->reverse())
        frameAt = (d->m_spriteEngine->spriteFrames() - 1) - frameAt;
    int y = d->m_spriteEngine->spriteY();
    int w = d->m_spriteEngine->spriteWidth();
    int h = d->m_spriteEngine->spriteHeight();
    int x1 = d->m_spriteEngine->spriteX();
    x1 += frameAt * w;
    int x2 = x1;
    if (frameAt < (frameCount-1))
        x2 += w;

    node->setSourceA(QPoint(x1, y));
    node->setSourceB(QPoint(x2, y));
    node->setSpriteSize(QSize(w, h));
    node->setTime(d->m_interpolate ? progress : 0.0);
    node->setSize(QSizeF(width(), height()));
    node->setFiltering(smooth() ? QSGTexture::Linear : QSGTexture::Nearest);
    node->update();
}

QT_END_NAMESPACE

#include "moc_qquickspritesequence_p.cpp"