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#include "qtextureimage.h"
#include "qtextureimage_p.h"
#include "qtexture_p.h"
#include "qabstracttextureimage_p.h"
#include <Qt3DCore/qpropertyupdatedchange.h>
#include <QtCore/QFileInfo>
#include <QtCore/QDateTime>

QT_BEGIN_NAMESPACE

namespace Qt3DRender {

/*!
    \class Qt3DRender::QTextureImage
    \inmodule Qt3DRender
    \since 5.5
    \brief Encapsulates the necessary information to create an OpenGL texture
    image from an image source.

    It contains the necessary information mipmap level, layer, cube face and
    source URL to load at the proper place data into an OpenGL texture.
 */

/*!
    \qmltype TextureImage
    \instantiates Qt3DRender::QTextureImage
    \inherits AbstractTextureImage
    \inqmlmodule Qt3D.Render
    \since 5.5
    \brief Encapsulates the necessary information to create an OpenGL texture
    image from an image source.
*/

/*!
    \enum QTextureImage::Status

    This  enumeration specifies the status values for texture image loading.

    \value None The texture image loading has not been started yet.
    \value Loading The texture image loading has started, but not finised.
    \value Ready The texture image loading has finished.
    \value Error The texture image loading confronted an error.
*/

/*!
    \qmlproperty url TextureImage::source

    This property holds the source url from which data for the texture
    image will be loaded.
*/

/*!
    \qmlproperty enumeration TextureImage::status

    This property holds the status of the texture image loading.

    \list
    \li TextureImage.None
    \li TextureImage.Loading
    \li TextureImage.Ready
    \li TextureImage.Error
    \endlist
    \readonly
*/

/*!
    \property QTextureImage::source

    This property holds the source url from which data for the texture
    image will be loaded.
*/

/*!
    \property QTextureImage::status

    This property holds the status of the texture image loading.

    \list
    \li TextureImage.None
    \li TextureImage.Loading
    \li TextureImage.Ready
    \li TextureImage.Error
    \endlist
    \readonly
*/

/*!
    Constructs a new Qt3DRender::QTextureImage instance with \a parent as parent.
 */
QTextureImage::QTextureImage(QNode *parent)
    : QAbstractTextureImage(*new QTextureImagePrivate, parent)
{
}

/*! \internal */
QTextureImage::~QTextureImage()
{
}

/*!
    \return the source url from which data for the texture image will be loaded.
 */
QUrl QTextureImage::source() const
{
    Q_D(const QTextureImage);
    return d->m_source;
}

/*!
    \return the current status.
 */
QTextureImage::Status QTextureImage::status() const
{
    Q_D(const QTextureImage);
    return d->m_status;
}

/*!
    Sets the source url of the texture image to \a source.
    \note This triggers a call to update()
 */
void QTextureImage::setSource(const QUrl &source)
{
    Q_D(QTextureImage);
    if (source != d->m_source) {
        d->m_source = source;
        emit sourceChanged(source);
        notifyDataGeneratorChanged();
    }
}

/*!
    Sets the status to \a status.
    \param status
 */
void QTextureImage::setStatus(Status status)
{
    Q_D(QTextureImage);
    if (status != d->m_status) {
        d->m_status = status;
        emit statusChanged(status);
    }
}

/*!
    \return the Qt3DRender::QTextureImageDataGeneratorPtr functor to be used by the
    backend to load the texture image data into an OpenGL texture object.
 */
QTextureImageDataGeneratorPtr QTextureImage::dataGenerator() const
{
    return QTextureImageDataGeneratorPtr(new QImageTextureDataFunctor(source()));
}

/*!
    Sets the scene change event to \a change.
    \param change
 */
void QTextureImage::sceneChangeEvent(const Qt3DCore::QSceneChangePtr &change)
{
    Qt3DCore::QPropertyUpdatedChangePtr e = qSharedPointerCast<Qt3DCore::QPropertyUpdatedChange>(change);

    if (e->propertyName() == QByteArrayLiteral("status"))
        setStatus(static_cast<QTextureImage::Status>(e->value().toInt()));
}

/*!
    The constructor creates a new QImageTextureDataFunctor::QImageTextureDataFunctor
    instance with the specified \a url.
 */
QImageTextureDataFunctor::QImageTextureDataFunctor(const QUrl &url)
    : QTextureImageDataGenerator()
    , m_url(url)
    , m_status(QTextureImage::None)
{
    if (url.isLocalFile()) {
        QFileInfo info(url.toLocalFile());
        m_lastModified = info.lastModified();
    }
}

QTextureImageDataPtr QImageTextureDataFunctor::operator ()()
{
    // We assume that a texture image is going to contain a single image data
    // For compressed dds or ktx textures a warning should be issued if
    // there are layers or 3D textures
    return TextureLoadingHelper::loadTextureData(m_url, false);
}

bool QImageTextureDataFunctor::operator ==(const QTextureImageDataGenerator &other) const
{
    const QImageTextureDataFunctor *otherFunctor = functor_cast<QImageTextureDataFunctor>(&other);

    // if its the same URL, but different modification times, its not the same image.
    return (otherFunctor != Q_NULLPTR && otherFunctor->m_url == m_url && otherFunctor->m_lastModified == m_lastModified);
}

} // namespace Qt3DRender

QT_END_NAMESPACE

