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#include "qmesh.h"
#include "qmesh_p.h"

#include <QtCore/private/qfactoryloader_p.h>
#include <QDebug>
#include <QFile>
#include <QFileInfo>
#include <QScopedPointer>
#include <Qt3DRender/private/qgeometryloaderinterface_p.h>
#include <Qt3DCore/qpropertyupdatedchange.h>
#include <Qt3DRender/private/renderlogging_p.h>
#include <Qt3DRender/private/qurlhelper_p.h>
#include <Qt3DRender/private/qgeometryloaderfactory_p.h>

QT_BEGIN_NAMESPACE

namespace Qt3DRender {

Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, geometryLoader, (QGeometryLoaderFactory_iid, QLatin1String("/geometryloaders"), Qt::CaseInsensitive))

QMeshPrivate::QMeshPrivate()
    : QGeometryRendererPrivate()
{
}

/*!
 * \qmltype Mesh
 * \instantiates Qt3DRender::QMesh
 * \inqmlmodule Qt3D.Render
 * \brief A custom mesh loader.
 *
 * Loads mesh data from external files in a variety of formats.
 *
 * In Qt3D 5.9, Mesh supports the following formats:
 *
 * \list
 * \li Wavefront OBJ
 * \li Stanford Triangle Format PLY
 * \li STL (STereoLithography)
 * \endlist
 *
 * QMesh will also support the following format if the SDK is installed and the fbx geometry loader plugin is built and found.
 * \list
 * \li Autodesk FBX
 * \endlist
 */

/*!
 * \qmlproperty url Mesh::source
 *
 * Holds the source url to the file containing the custom mesh.
 */

/*!
 * \qmlproperty string Mesh::meshName
 *
 * Filter indicating which part of the mesh should be loaded.
 *
 * If meshName is empty (the default), then the entire mesh is loaded.
 *
 * If meshName is a plain string, then only the sub-mesh matching that name, if present, will be loaded.
 *
 * If meshName is a regular expression, than all sub-meshes matching the expression will be loaded.
 *
 * \note Only Wavefront OBJ files support sub-meshes.
 *
 * \sa QRegularExpression
 */

/*!
 * \class Qt3DRender::QMesh
 * \inheaderfile Qt3DRender/QMesh
 * \inmodule Qt3DRender
 *
 * \inherits Qt3DRender::QGeometryRenderer
 *
 * \brief A custom mesh loader.
 *
 * Loads mesh data from external files in a variety of formats.
 * Qt3DRender::QMesh loads data into a single mesh.
 *
 * In Qt3D 5.9, QMesh supports the following formats:
 *
 * \list
 * \li Wavefront OBJ
 * \li Stanford Triangle Format PLY
 * \li STL (STereoLithography)
 * \endlist
 *
 * QMesh will also support the following format if the SDK is installed and the fbx geometry loader plugin is built and found:
 * \list
 * \li Autodesk FBX
 * \endlist
 *
 * If you wish to load an entire scene made of several objects, you should rather use the Qt3DRender::QSceneLoader instead.
 *
 * \sa Qt3DRender::QSceneLoader
 */

/*!
 * Constructs a new QMesh with \a parent.
 */
QMesh::QMesh(QNode *parent)
    : QGeometryRenderer(*new QMeshPrivate, parent)
{
}

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

/*! \internal */
QMesh::QMesh(QMeshPrivate &dd, QNode *parent)
    : QGeometryRenderer(dd, parent)
{
}

void QMesh::setSource(const QUrl& source)
{
    Q_D(QMesh);
    if (d->m_source == source)
        return;
    d->m_source = source;
    // update the functor
    QGeometryRenderer::setGeometryFactory(QGeometryFactoryPtr(new MeshFunctor(d->m_source, d->m_meshName)));
    const bool blocked = blockNotifications(true);
    emit sourceChanged(source);
    blockNotifications(blocked);
}

/*!
 * \property QMesh::source
 *
 * Holds the \a source url to the file containing the custom mesh.
 */
QUrl QMesh::source() const
{
    Q_D(const QMesh);
    return d->m_source;
}

void QMesh::setMeshName(const QString &meshName)
{
    Q_D(QMesh);
    if (d->m_meshName == meshName)
        return;
    d->m_meshName = meshName;
    // update the functor
    QGeometryRenderer::setGeometryFactory(QGeometryFactoryPtr(new MeshFunctor(d->m_source, d->m_meshName)));
    const bool blocked = blockNotifications(true);
    emit meshNameChanged(meshName);
    blockNotifications(blocked);
}

/*!
 * \property QMesh::meshName
 *
 * Holds the name of the mesh.
 */
QString QMesh::meshName() const
{
    Q_D(const QMesh);
    return d->m_meshName;
}

/*!
 * \internal
 */
MeshFunctor::MeshFunctor(const QUrl &sourcePath, const QString& meshName)
    : QGeometryFactory()
    , m_sourcePath(sourcePath)
    , m_meshName(meshName)
{
}

/*!
 * \internal
 */
QGeometry *MeshFunctor::operator()()
{
    if (m_sourcePath.isEmpty()) {
        qCWarning(Render::Jobs) << Q_FUNC_INFO << "Mesh is empty, nothing to load";
        return nullptr;
    }

    // TO DO: Handle file download if remote url
    QString filePath = Qt3DRender::QUrlHelper::urlToLocalFileOrQrc(m_sourcePath);

    QFileInfo finfo(filePath);
    auto ext = finfo.suffix();
    if (ext.isEmpty())
        ext = QLatin1String("obj");

    QScopedPointer<QGeometryLoaderInterface> loader;

    loader.reset(qLoadPlugin<QGeometryLoaderInterface, QGeometryLoaderFactory>(geometryLoader(), ext));
    if (!loader) {
        qCWarning(Render::Jobs, "unsupported format encountered (%s)", qPrintable(ext));
        return nullptr;
    }

    QFile file(filePath);
    if (!file.open(QIODevice::ReadOnly)) {
        qCDebug(Render::Jobs) << "Could not open file" << filePath << "for reading";
        return nullptr;
    }

    qCDebug(Render::Jobs) << Q_FUNC_INFO << "Loading mesh from" << m_sourcePath << " part:" << m_meshName;

    if (loader->load(&file, m_meshName))
        return loader->geometry();

    qCWarning(Render::Jobs) << Q_FUNC_INFO << "Mesh loading failure for:" << filePath;

    return nullptr;
}

/*!
 * \internal
 */
bool MeshFunctor::operator ==(const QGeometryFactory &other) const
{
    const MeshFunctor *otherFunctor = functor_cast<MeshFunctor>(&other);
    if (otherFunctor != nullptr) {
        return (otherFunctor->m_sourcePath == m_sourcePath
                && otherFunctor->m_meshName == m_meshName);
    }
    return false;
}

} // namespace Qt3DRender

QT_END_NAMESPACE