qquick3dinstancing.cpp

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// Copyright (C) 2020 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
#include "qquick3dinstancing_p.h"
#include "qquick3dscenemanager_p.h"
#include <QtQuick3DRuntimeRender/private/qssgrenderinstancetable_p.h>
#include <QtQuick3DUtils/private/qssgutils_p.h>
#include <QXmlStreamReader>
#include <QtQml/QQmlFile>
 
QT_BEGIN_NAMESPACE
 
QQuick3DInstancingPrivate::QQuick3DInstancingPrivate()
    : QQuick3DObjectPrivate(QQuick3DObjectPrivate::Type::ModelInstance)
{
}
 
QQuick3DInstancing::QQuick3DInstancing(QQuick3DObject *parent)
    : QQuick3DObject(*new QQuick3DInstancingPrivate, parent)
{
}
 
QQuick3DInstancing::~QQuick3DInstancing()
{
}
 
QByteArray QQuick3DInstancing::instanceBuffer(int *instanceCount)
{
    Q_D(QQuick3DInstancing);
    QByteArray retval = getInstanceBuffer(instanceCount);
    if (instanceCount && d->m_instanceCountOverride >= 0)
        *instanceCount = qMin(d->m_instanceCountOverride, *instanceCount);
    return retval;
}
 
int QQuick3DInstancing::instanceCountOverride() const
{
    Q_D(const QQuick3DInstancing);
    return d->m_instanceCountOverride;
}
 
bool QQuick3DInstancing::hasTransparency() const
{
    Q_D(const QQuick3DInstancing);
    return d->m_hasTransparency;
}
 
bool QQuick3DInstancing::depthSortingEnabled() const
{
    Q_D(const QQuick3DInstancing);
    return d->m_depthSortingEnabled;
}
 
const QQuick3DInstancing::InstanceTableEntry *QQuick3DInstancing::getInstanceEntry(int index)
{
    const QByteArray data = getInstanceBuffer(nullptr);
    if (index >= int(data.size() / sizeof(InstanceTableEntry)))
        return nullptr;
    return reinterpret_cast<const QQuick3DInstancing::InstanceTableEntry*>(data.constData()) + index;
}
 
QVector3D QQuick3DInstancing::InstanceTableEntry::getPosition() const
{
    return QVector3D{ row0[3], row1[3], row2[3] };
}
 
QVector3D QQuick3DInstancing::InstanceTableEntry::getScale() const
{
    const QVector3D col0{row0[0], row1[0], row2[0]};
    const QVector3D col1{row0[1], row1[1], row2[1]};
    const QVector3D col2{row0[2], row1[2], row2[2]};
    const float scaleX = col0.length();
    const float scaleY = col1.length();
    const float scaleZ = col2.length();
    return QVector3D(scaleX, scaleY, scaleZ);
}
 
QQuaternion QQuick3DInstancing::InstanceTableEntry::getRotation() const
{
    const QVector3D col0 = QVector3D(row0[0], row1[0], row2[0]).normalized();
    const QVector3D col1 = QVector3D(row0[1], row1[1], row2[1]).normalized();
    const QVector3D col2 = QVector3D(row0[2], row1[2], row2[2]).normalized();
 
    const float data3x3[3*3] { // row-major order
        col0[0], col1[0], col2[0],
        col0[1], col1[1], col2[1],
        col0[2], col1[2], col2[2],
    };
    QMatrix3x3 rot(data3x3);
    return QQuaternion::fromRotationMatrix(rot).normalized();
}
 
QColor QQuick3DInstancing::InstanceTableEntry::getColor() const
{
    return QColor::fromRgbF(color[0], color[1], color[2], color[3]);
}
 
QVector3D QQuick3DInstancing::instancePosition(int index)
{
    auto *entry = getInstanceEntry(index);
    if (!entry)
        return {};
 
    return QVector3D{ entry->row0[3], entry->row1[3], entry->row2[3] };
}
 
QVector3D QQuick3DInstancing::instanceScale(int index)
{
    auto *entry = getInstanceEntry(index);
    if (!entry)
        return {};
    return entry->getScale();
}
 
QQuaternion QQuick3DInstancing::instanceRotation(int index)
{
    const auto *entry = getInstanceEntry(index);
    if (!entry)
        return {};
    return entry->getRotation();
}
 
QColor QQuick3DInstancing::instanceColor(int index)
{
    const auto *entry = getInstanceEntry(index);
    if (!entry)
        return {};
    return entry->getColor();
}
 
QVector4D QQuick3DInstancing::instanceCustomData(int index)
{
    const auto *entry = getInstanceEntry(index);
    if (!entry)
        return {};
    return entry->instanceData;
}
 
void QQuick3DInstancing::setInstanceCountOverride(int instanceCountOverride)
{
    Q_D(QQuick3DInstancing);
    if (d->m_instanceCountOverride == instanceCountOverride)
        return;
 
    d->m_instanceCountOverride = instanceCountOverride;
    d->m_instanceCountOverrideChanged = true;
    d->dirty(QQuick3DObjectPrivate::DirtyType::Content);
    emit instanceCountOverrideChanged();
}
 
void QQuick3DInstancing::setHasTransparency(bool hasTransparency)
{
    Q_D(QQuick3DInstancing);
    if (d->m_hasTransparency == hasTransparency)
        return;
 
    d->m_hasTransparency = hasTransparency;
    d->dirty(QQuick3DObjectPrivate::DirtyType::Content);
    emit hasTransparencyChanged();
}
 
void QQuick3DInstancing::setDepthSortingEnabled(bool enabled)
{
    Q_D(QQuick3DInstancing);
    if (d->m_depthSortingEnabled == enabled)
        return;
 
    d->m_depthSortingEnabled = enabled;
    d->dirty(QQuick3DObjectPrivate::DirtyType::Content);
    emit depthSortingEnabledChanged();
}
 
void QQuick3DInstancing::markDirty()
{
    Q_D(QQuick3DInstancing);
    d->dirty(QQuick3DObjectPrivate::DirtyType::Content);
    d->m_instanceDataChanged = true;
    emit instanceTableChanged();
}
 
QSSGRenderGraphObject *QQuick3DInstancing::updateSpatialNode(QSSGRenderGraphObject *node)
{
    Q_D(QQuick3DInstancing);
    if (!node) {
        markAllDirty();
        node = new QSSGRenderInstanceTable();
        emit instanceNodeDirty();
        d->m_instanceDataChanged = true;
    }
    QQuick3DObject::updateSpatialNode(node);
    auto effectiveInstanceCount = [d]() {
        if (d->m_instanceCountOverride >= 0)
            return qMin(d->m_instanceCount, d->m_instanceCountOverride);
        return d->m_instanceCount;
    };
    auto *instanceTable = static_cast<QSSGRenderInstanceTable *>(node);
    if (d->m_instanceDataChanged) {
        QByteArray buffer = getInstanceBuffer(&d->m_instanceCount);
        instanceTable->setData(buffer, effectiveInstanceCount(), sizeof(InstanceTableEntry));
        d->m_instanceDataChanged = false;
    } else if (d->m_instanceCountOverrideChanged) {
        instanceTable->setInstanceCountOverride(effectiveInstanceCount());
    }
    d->m_instanceCountOverrideChanged = false;
    instanceTable->setHasTransparency(d->m_hasTransparency);
    instanceTable->setDepthSorting(d->m_depthSortingEnabled);
    return node;
}
 
static inline QQuick3DInstancing::InstanceTableEntry calculate(const QVector3D &position, const QVector3D &scale,
                                                                         const QVector3D &eulerRotation, const QColor &color,
                                                                         const QVector4D &customData)
{
    QMatrix4x4 xform;
 
    xform(0, 0) = scale[0];
    xform(1, 1) = scale[1];
    xform(2, 2) = scale[2];
 
    QQuaternion quaternion = QQuaternion::fromEulerAngles(eulerRotation);
    xform = QMatrix4x4(quaternion.toRotationMatrix()) * xform;
 
    xform(0, 3) += position[0];
    xform(1, 3) += position[1];
    xform(2, 3) += position[2];
 
    auto linearColor = QSSGUtils::color::sRGBToLinear(color);
 
    return {
        xform.row(0),
        xform.row(1),
        xform.row(2),
        linearColor,
        customData
    };
}
 
QQuick3DInstancing::InstanceTableEntry QQuick3DInstancing::calculateTableEntry(const QVector3D &position, const QVector3D &scale,
                                   const QVector3D &eulerRotation, const QColor &color, const QVector4D &customData)
{
    return calculate(position, scale, eulerRotation, color, customData);
}
 
QQuick3DInstancing::InstanceTableEntry QQuick3DInstancing::calculateTableEntryFromQuaternion(const QVector3D &position, const QVector3D &scale, const QQuaternion &rotation, const QColor &color, const QVector4D &customData)
{
    QMatrix4x4 xform;
 
    xform(0, 0) = scale[0];
    xform(1, 1) = scale[1];
    xform(2, 2) = scale[2];
 
    xform = QMatrix4x4(rotation.toRotationMatrix()) * xform;
 
    xform(0, 3) += position[0];
    xform(1, 3) += position[1];
    xform(2, 3) += position[2];
 
    auto linearColor = QSSGUtils::color::sRGBToLinear(color);
 
    return {
        xform.row(0),
        xform.row(1),
        xform.row(2),
        linearColor,
        customData
    };
}
 
QQuick3DInstanceList::QQuick3DInstanceList(QQuick3DObject *parent) : QQuick3DInstancing(parent) {}
 
QQuick3DInstanceList::~QQuick3DInstanceList() {}
 
QByteArray QQuick3DInstanceList::getInstanceBuffer(int *instanceCount)
{
    if (m_dirty)
        generateInstanceData();
    if (instanceCount)
        *instanceCount = m_instances.size();
    return m_instanceData;
}
 
QQmlListProperty<QQuick3DInstanceListEntry> QQuick3DInstanceList::instances()
{
 
    return QQmlListProperty<QQuick3DInstanceListEntry>(this,
                                                          nullptr,
                                                          qmlAppendInstanceListEntry,
                                                          qmlInstanceListEntriesCount,
                                                          qmlInstanceListEntryAt,
                                                          qmlClearInstanceListEntries);
}
 
int QQuick3DInstanceList::instanceCount() const
{
    return m_instances.size();
}
 
void QQuick3DInstanceList::onInstanceDestroyed(QObject *object)
{
    if (m_instances.removeAll(object))
        handleInstanceChange();
}
 
void QQuick3DInstanceList::qmlAppendInstanceListEntry(QQmlListProperty<QQuick3DInstanceListEntry> *list, QQuick3DInstanceListEntry *instance)
{
    if (instance == nullptr)
        return;
    auto *self = static_cast<QQuick3DInstanceList *>(list->object);
    self->m_instances.push_back(instance);
 
    if (instance->parentItem() == nullptr)
        instance->setParentItem(self);
    connect(instance, &QQuick3DInstanceListEntry::changed, self, &QQuick3DInstanceList::handleInstanceChange);
    connect(instance, &QObject::destroyed, self, &QQuick3DInstanceList::onInstanceDestroyed);
    self->handleInstanceChange();
}
 
QQuick3DInstanceListEntry *QQuick3DInstanceList::qmlInstanceListEntryAt(QQmlListProperty<QQuick3DInstanceListEntry> *list, qsizetype index)
{
    auto *self = static_cast<QQuick3DInstanceList *>(list->object);
    return self->m_instances.at(index);
}
 
qsizetype QQuick3DInstanceList::qmlInstanceListEntriesCount(QQmlListProperty<QQuick3DInstanceListEntry> *list)
{
    auto *self = static_cast<QQuick3DInstanceList *>(list->object);
    return self->m_instances.size();
}
 
void QQuick3DInstanceList::qmlClearInstanceListEntries(QQmlListProperty<QQuick3DInstanceListEntry> *list)
{
    auto *self = static_cast<QQuick3DInstanceList *>(list->object);
    for (auto *instance : self->m_instances) {
        disconnect(instance, &QObject::destroyed, self, &QQuick3DInstanceList::onInstanceDestroyed);
        disconnect(instance, &QQuick3DInstanceListEntry::changed, self, &QQuick3DInstanceList::handleInstanceChange);
    }
    self->m_instances.clear();
    self->handleInstanceChange();
}
 
void QQuick3DInstanceList::handleInstanceChange()
{
    m_dirty = true;
    markDirty();
    emit instanceCountChanged();
}
 
void QQuick3DInstanceList::generateInstanceData()
{
    m_dirty = false;
    const int count = m_instances.size();
 
    qsizetype tableSize = count * sizeof(InstanceTableEntry);
    m_instanceData.resize(tableSize);
    auto *array = reinterpret_cast<InstanceTableEntry*>(m_instanceData.data());
    for (int i = 0; i < count; ++i) {
        const auto *inst = m_instances.at(i);
        if (inst->m_useEulerRotation)
            array[i] = calculateTableEntry(inst->position(), inst->scale(), inst->eulerRotation(), inst->color(), inst->customData());
        else
            array[i] = calculateTableEntryFromQuaternion(inst->position(), inst->scale(), inst->rotation(), inst->color(), inst->customData());
    }
}
 
QQuick3DInstanceListEntry::QQuick3DInstanceListEntry(QQuick3DObject *parent)
    : QQuick3DObject(parent)
{
}
 
void QQuick3DInstanceListEntry::setPosition(QVector3D position)
{
    if (m_position == position)
        return;
 
    m_position = position;
    emit positionChanged();
    emit changed();
}
 
void QQuick3DInstanceListEntry::setScale(QVector3D scale)
{
    if (m_scale == scale)
        return;
 
    m_scale = scale;
    emit scaleChanged();
    emit changed();
}
 
void QQuick3DInstanceListEntry::setEulerRotation(QVector3D eulerRotation)
{
    if (m_useEulerRotation && m_eulerRotation == eulerRotation)
        return;
    m_eulerRotation = eulerRotation;
    m_useEulerRotation = true;
    emit eulerRotationChanged();
    emit changed();
}
 
void QQuick3DInstanceListEntry::setRotation(QQuaternion rotation)
{
    if (!m_useEulerRotation && m_rotation == rotation)
        return;
 
    m_rotation = rotation;
    m_useEulerRotation = false;
    emit rotationChanged();
    emit changed();
}
 
void QQuick3DInstanceListEntry::setColor(QColor color)
{
    if (m_color == color)
        return;
 
    m_color = color;
    emit colorChanged();
    emit changed();
}
 
void QQuick3DInstanceListEntry::setCustomData(QVector4D customData)
{
    if (m_customData == customData)
        return;
 
    m_customData = customData;
    emit customDataChanged();
    emit changed();
}
 
static constexpr quint16 currentMajorVersion = 1;
 
struct QQuick3DInstancingBinaryFileHeader
{
    char magic[4] = { 'Q', 't', 'I', 'R' };
    const quint16 majorVersion = currentMajorVersion;
    const quint16 minorVersion = 0;
    const quint32 stride = sizeof(QQuick3DInstancing::InstanceTableEntry);
    quint32 offset;
    quint32 count;
};
 
static bool writeInstanceTable(QIODevice *out, const QByteArray &instanceData, int instanceCount)
{
    QQuick3DInstancingBinaryFileHeader header;
 
    header.offset = sizeof(header);
    header.count = instanceCount;
 
    if (instanceData.size() != qsizetype(header.stride) * instanceCount) {
        qWarning() << "inconsistent data";
        return false;
    }
 
    // Ignoring endianness: Assume we always create on little-endian, and then special-case reading if we need to.
 
    out->write(reinterpret_cast<const char *>(&header), sizeof(header));
    out->write(instanceData.constData(), instanceData.size());
    return true;
}
 
 
bool QQuick3DFileInstancing::loadFromBinaryFile(const QString &filename)
{
    auto binaryFile = std::make_unique<QFile>(filename);
    if (!binaryFile->open(QFile::ReadOnly))
        return false;
 
    constexpr auto headerSize = sizeof(QQuick3DInstancingBinaryFileHeader);
    const quint64 fileSize = binaryFile->size();
    if (fileSize < headerSize) {
        qWarning() << "data file too small";
        return false;
    }
    const char *data = reinterpret_cast<const char *>(binaryFile->map(0, fileSize));
    const auto *header = reinterpret_cast<const QQuick3DInstancingBinaryFileHeader *>(data);
 
    if (header->majorVersion > currentMajorVersion) {
        qWarning() << "Version" << header->majorVersion << "is too new";
        return false;
    }
 
    if (fileSize != headerSize + header->count * header->stride) {
        qWarning() << "wrong data size";
        return false;
    }
 
    delete m_dataFile;
 
    // In order to use fromRawData safely, the file has to stay open so that the mmap stays valid
    m_dataFile = binaryFile.release();
 
    m_instanceData = QByteArray::fromRawData(data + header->offset, header->count * header->stride);
    m_instanceCount = header->count;
 
    return true;
}
 
bool QQuick3DFileInstancing::loadFromXmlFile(const QString &filename)
{
    QFile f(filename);
    if (!f.open(QFile::ReadOnly))
        return false;
 
    bool valid = false;
    QXmlStreamReader reader(&f);
    int instances = 0;
 
    //### Why is there not a QTextStream constructor that takes a QStringView
    const auto toVector3D = [](const QStringView &str) {
        float x, y, z;
        QTextStream(str.toLocal8Bit()) >> x >> y >> z;
        return QVector3D { x, y, z };
    };
    const auto toVector4D = [](const QStringView &str) {
        float x, y, z, w;
        QTextStream(str.toLocal8Bit()) >> x >> y >> z >> w;
        return QVector4D { x, y, z, w };
    };
 
    QByteArray instanceData;
 
    while (reader.readNextStartElement()) {
 
        if (reader.name() == QLatin1String("InstanceTable")) {
            valid = true;
            while (reader.readNextStartElement()) {
                if (reader.name() == QLatin1String("Instance")) {
                    QColor color = Qt::white;
                    QVector3D position;
                    QVector3D eulerRotation;
                    QQuaternion quaternion;
                    bool useQuaternion = false;
                    QVector4D custom;
                    QVector3D scale { 1, 1, 1 };
                    for (auto &attr : reader.attributes()) {
                        if (attr.name() == QLatin1String("color")) {
                            color = QColor::fromString(attr.value());
                        } else if (attr.name() == QLatin1String("position")) {
                            position = toVector3D(attr.value());
                        } else if (attr.name() == QLatin1String("eulerRotation")) {
                            eulerRotation = toVector3D(attr.value());
                        } else if (attr.name() == QLatin1String("scale")) {
                            scale = toVector3D(attr.value());
                        } else if (attr.name() == QLatin1String("quaternion")) {
                            quaternion = QQuaternion(toVector4D(attr.value()));
                            useQuaternion = true;
                        } else if (attr.name() == QLatin1String("custom")) {
                            custom = toVector4D(attr.value());
                        }
                    }
                    auto entry = useQuaternion ? calculateTableEntryFromQuaternion(position, scale, quaternion, color, custom)
                                               : calculateTableEntry(position, scale, eulerRotation, color, custom);
                    instanceData.append(reinterpret_cast<const char *>(&entry), sizeof(entry));
                    instances++;
                }
                reader.skipCurrentElement();
            }
        } else {
            reader.skipCurrentElement();
        }
    }
 
    if (valid) {
        m_instanceCount = instances;
        m_instanceData = instanceData;
    }
 
    f.close();
    return valid;
}
 
int QQuick3DFileInstancing::writeToBinaryFile(QIODevice *out)
{
    bool success = writeInstanceTable(out, m_instanceData, m_instanceCount);
    return success ? m_instanceCount : -1;
}
 
int QQuick3DFileInstancing::instanceCount() const
{
    return m_instanceCount;
}
 
bool QQuick3DFileInstancing::loadFromFile(const QUrl &source)
{
    const QQmlContext *context = qmlContext(this);
 
    const QString filePath = QQmlFile::urlToLocalFileOrQrc(context ? context->resolvedUrl(source) : source);
 
    if (filePath.endsWith(QStringLiteral(".bin")))
        return loadFromBinaryFile(filePath);
 
    const QString binaryFilePath = filePath + QStringLiteral(".bin");
 
    int oldCount = m_instanceCount;
    bool success = loadFromBinaryFile(binaryFilePath) || loadFromXmlFile(filePath);
    if (m_instanceCount != oldCount)
        emit instanceCountChanged();
 
    return success;
}
 
QQuick3DFileInstancing::QQuick3DFileInstancing(QQuick3DObject *parent) : QQuick3DInstancing(parent) { }
 
QQuick3DFileInstancing::~QQuick3DFileInstancing()
{
    delete m_dataFile;
}
 
const QUrl &QQuick3DFileInstancing::source() const
{
    return m_source;
}
 
void QQuick3DFileInstancing::setSource(const QUrl &newSource)
{
    if (m_source == newSource)
        return;
    m_source = newSource;
    m_dirty = true;
    markDirty();
 
    emit sourceChanged();
}
 
QByteArray QQuick3DFileInstancing::getInstanceBuffer(int *instanceCount)
{
    if (m_dirty) {
        if (!loadFromFile(m_source))  {
            qWarning() << Q_FUNC_INFO << "could not load" << m_source;
            m_instanceData = {};
            m_instanceCount = 0;
        }
        m_dirty = false;
    }
 
    if (instanceCount)
        *instanceCount = m_instanceCount;
    return m_instanceData;
}
 
static_assert(sizeof(QQuick3DInstancing::InstanceTableEntry) == sizeof(QSSGRenderInstanceTableEntry)
                && alignof(QQuick3DInstancing::InstanceTableEntry) == alignof(QSSGRenderInstanceTableEntry),
              "QSSGRenderInstanceTableEntry and QQuick3DInstancing::InstanceTableEntry do not match");
 
QT_END_NAMESPACE