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#include "shaderdata_p.h"
#include "qshaderdata.h"
#include "qshaderdata_p.h"
#include <QMetaProperty>
#include <QMetaObject>
#include <Qt3DCore/qscenepropertychange.h>
#include <private/graphicscontext_p.h>
#include <private/qbackendnode_p.h>
#include <private/uniformbuffer_p.h>
#include <private/managers_p.h>

QT_BEGIN_NAMESPACE

using namespace Qt3DCore;

namespace Qt3DRender {
namespace Render {

QList<Qt3DCore::QNodeId> ShaderData::m_updatedShaderData;

ShaderData::ShaderData()
    : QBackendNode()
    , m_manager(Q_NULLPTR)
    , m_mutex(new QMutex())
{
}

ShaderData::~ShaderData()
{
    delete m_mutex;
}

void ShaderData::updateFromPeer(Qt3DCore::QNode *peer)
{
    m_properties.clear();
    const QShaderData *shaderData = static_cast<const QShaderData *>(peer);
    m_propertyReader = shaderData->propertyReader();
    if (!m_propertyReader.isNull())
        readPeerProperties(const_cast<QShaderData *>(shaderData));
}

// Call by cleanup job (single thread)
void ShaderData::clearUpdate()
{
    m_updatedProperties.clear();
    const QHash<QString, QVariant>::const_iterator end = m_nestedShaderDataProperties.end();
    QHash<QString, QVariant>::const_iterator it = m_nestedShaderDataProperties.begin();

    while (it != end) {
        if (it.value().userType() == QMetaType::QVariantList) {
            Q_FOREACH (const QVariant &v, it.value().value<QVariantList>()) {
                ShaderData *nested = m_manager->lookupResource(v.value<QNodeId>());
                if (nested != Q_NULLPTR)
                    nested->clearUpdate();
            }
        } else {
            ShaderData *nested = m_manager->lookupResource(it.value().value<QNodeId>());
            if (nested != Q_NULLPTR)
                nested->clearUpdate();
        }
        ++it;
    }
}

// Called by renderview jobs (several concurrent threads)
/*!
  \internal
  Lookup if the current ShaderData or a nested ShaderData has updated properties.
  UpdateProperties contains either the value of the propertie of a QNodeId if it's another ShaderData.
  Transformed properties are updated for all of ShaderData that have ones at the point.

  \note This needs to be performed for every top level ShaderData every time it is used.
  As we don't know if the transformed properties use the same viewMatrix for all RenderViews.
 */
bool ShaderData::needsUpdate(const QMatrix4x4 &viewMatrix)
{
    // We can't perform this only once as we don't know if we would be call as the root or a
    // nested ShaderData
    QMutexLocker lock(m_mutex);

    // Update transformed properties
    // We check the matrices and decide if the transform has changed since the previous call to needsUpdate
    if (m_viewMatrix != viewMatrix) {
        m_viewMatrix = viewMatrix;
        const QHash<QString, QShaderData::TransformType>::const_iterator transformedEnd = m_transformedProperties.end();
        QHash<QString, QShaderData::TransformType>::const_iterator transformedIt = m_transformedProperties.begin();

        while (transformedIt != transformedEnd) {
            if (transformedIt.value() == QShaderData::ModelToEye) {
                m_updatedProperties.insert(transformedIt.key(), m_viewMatrix * m_worldMatrix * m_originalProperties.value(transformedIt.key()).value<QVector3D>());
                m_properties.insert(transformedIt.key(), m_viewMatrix * m_worldMatrix * m_originalProperties.value(transformedIt.key()).value<QVector3D>());
            }
            ++transformedIt;
        }
    }
    const QHash<QString, QVariant>::const_iterator end = m_nestedShaderDataProperties.end();
    QHash<QString, QVariant>::const_iterator it = m_nestedShaderDataProperties.begin();

    while (it != end) {
        if (it.value().userType() == QMetaType::QVariantList) {
            QVariantList updatedNodes;
            bool nestedNeedsUpdate = false;
            Q_FOREACH (const QVariant &v, it.value().value<QVariantList>()) {
                ShaderData *nested = m_manager->lookupResource(v.value<QNodeId>());
                if (nested != Q_NULLPTR) {
                    // We need to add the nested nodes to the updated property list
                    // as we need to maintain order
                    // if node[0] doesn't need update but node[1] does,
                    // if we only have a single element, the renderer would update element [0]
                    nestedNeedsUpdate |= nested->needsUpdate(viewMatrix);
                    updatedNodes << v;
                }
            }
            // Of course we only add all the nodes if at least one of the nested nodes required and update
            if (nestedNeedsUpdate && !updatedNodes.empty())
                m_updatedProperties.insert(it.key(), updatedNodes);
        } else {
            ShaderData *nested = m_manager->lookupResource(it.value().value<QNodeId>());
            if (nested != Q_NULLPTR && nested->needsUpdate(viewMatrix))
                m_updatedProperties.insert(it.key(), it.value());
        }
        ++it;
    }
    return m_updatedProperties.size() > 0;
}

void ShaderData::updateTransformedProperties(const QMatrix4x4 &nodeWorldMatrix)
{
    if (m_worldMatrix != nodeWorldMatrix) {
        m_worldMatrix = nodeWorldMatrix;

        const QHash<QString, QShaderData::TransformType>::const_iterator transformedEnd = m_transformedProperties.end();
        QHash<QString, QShaderData::TransformType>::const_iterator transformedIt = m_transformedProperties.begin();

        while (transformedIt != transformedEnd) {
            if (transformedIt.value() == QShaderData::ModelToEye) {
                m_updatedProperties.insert(transformedIt.key(), m_viewMatrix * m_worldMatrix * m_originalProperties.value(transformedIt.key()).value<QVector3D>());
                m_properties.insert(transformedIt.key(), m_viewMatrix * m_worldMatrix * m_originalProperties.value(transformedIt.key()).value<QVector3D>());
            } else {
                m_updatedProperties.insert(transformedIt.key(), m_worldMatrix * m_originalProperties.value(transformedIt.key()).value<QVector3D>());
                m_properties.insert(transformedIt.key(), m_worldMatrix * m_originalProperties.value(transformedIt.key()).value<QVector3D>());
            }
            ++transformedIt;
        }
    }
}

// This will add the ShaderData to be cleared from updates at the end of the frame
// by the cleanup job
// Called by renderview jobs (several concurrent threads)
void ShaderData::addToClearUpdateList()
{
    QMutexLocker lock(m_mutex);
    if (!ShaderData::m_updatedShaderData.contains(peerUuid()))
        ShaderData::m_updatedShaderData.append(peerUuid());
}

const int qNodeIdTypeId = qMetaTypeId<Qt3DCore::QNodeId>();

void ShaderData::readPeerProperties(QShaderData *shaderData)
{
    const QMetaObject *metaObject = shaderData->metaObject();
    const int propertyOffset = QShaderData::staticMetaObject.propertyOffset();
    const int propertyCount = metaObject->propertyCount();

    for (int i = propertyOffset; i < propertyCount; ++i) {
        const QMetaProperty property = metaObject->property(i);
        if (strcmp(property.name(), "data") == 0 || strcmp(property.name(), "childNodes") == 0) // We don't handle default Node properties
            continue;
        QVariant propertyValue = m_propertyReader->readProperty(shaderData->property(property.name()));
        QString propertyName = QString::fromLatin1(property.name());

        m_properties.insert(propertyName, propertyValue);
        m_originalProperties.insert(propertyName, propertyValue);

        // We check if the property is a QNodeId or QList<QNodeId> so that we can
        // check nested QShaderData for update
        if (propertyValue.userType() == qNodeIdTypeId) {
            m_nestedShaderDataProperties.insert(propertyName, propertyValue);
        } else if (propertyValue.userType() == QMetaType::QVariantList) {
            QVariantList list = propertyValue.value<QVariantList>();
            if (list.count() > 0 && list.at(0).userType() == qNodeIdTypeId)
                m_nestedShaderDataProperties.insert(propertyName, propertyValue);
        }
    }

    // We look for transformed properties
    QHash<QString, QVariant>::iterator it = m_properties.begin();
    const QHash<QString, QVariant>::iterator end = m_properties.end();

    while (it != end) {
        if (static_cast<QMetaType::Type>(it.value().type()) == QMetaType::QVector3D) {
            // if there is a matching QShaderData::TransformType propertyTransformed
            QVariant value = m_properties.value(it.key() + QStringLiteral("Transformed"));
            // if that's the case, we apply a space transformation to the property
            if (value.isValid() && value.type() == QVariant::Int)
                m_transformedProperties.insert(it.key(), static_cast<QShaderData::TransformType>(value.toInt()));
        }
        ++it;
    }
}

void ShaderData::setManager(ShaderDataManager *manager)
{
    m_manager = manager;
}

void ShaderData::sceneChangeEvent(const Qt3DCore::QSceneChangePtr &e)
{
    if (!m_propertyReader.isNull()) {
        QScenePropertyChangePtr propertyChange = qSharedPointerCast<QScenePropertyChange>(e);
        QString propertyName = QString::fromLatin1(propertyChange->propertyName());
        switch (e->type()) {
        case NodeUpdated: {
            // Note we aren't notified about nested QShaderData in this call
            // only scalar / vec properties
            if (m_properties.contains(propertyName)) {
                QVariant val = m_propertyReader->readProperty(propertyChange->value());
                // If this is a Transformed property, we need to multiply against the correct
                // matrices
                m_originalProperties.insert(propertyName, val);
                if (m_transformedProperties.contains(propertyName)) {
                    if (m_transformedProperties[propertyName] == QShaderData::ModelToEye)
                        val = m_viewMatrix * m_worldMatrix * val.value<QVector3D>();
                    else
                        val = m_worldMatrix * val.value<QVector3D>();
                }
                m_properties.insert(propertyName, val);
                m_updatedProperties.insert(propertyName, val);
            }
            break;
        }
        case NodeAdded: {
            m_properties.insert(propertyName, m_propertyReader->readProperty(propertyChange->value()));
            m_originalProperties.insert(propertyName, m_propertyReader->readProperty(propertyChange->value()));
            m_nestedShaderDataProperties.insert(propertyName, propertyChange->value());
            break;
        }
        case NodeRemoved: {
            if (m_properties.contains(propertyName)) {
                m_originalProperties.remove(propertyName);
                m_properties.remove(propertyName);
                m_nestedShaderDataProperties.remove(propertyName);
            }
            break;
        }
        default:
            break;
        }
    }
}

RenderShaderDataFunctor::RenderShaderDataFunctor(ShaderDataManager *manager)
    : m_manager(manager)
{
}

Qt3DCore::QBackendNode *RenderShaderDataFunctor::create(Qt3DCore::QNode *frontend, const Qt3DCore::QBackendNodeFactory *factory) const
{
    ShaderData *backend = m_manager->getOrCreateResource(frontend->id());
    backend->setFactory(factory);
    backend->setManager(m_manager);
    backend->setPeer(frontend);
    return backend;
}

Qt3DCore::QBackendNode *RenderShaderDataFunctor::get(const Qt3DCore::QNodeId &id) const
{
    return m_manager->lookupResource(id);
}

void RenderShaderDataFunctor::destroy(const Qt3DCore::QNodeId &id) const
{
    m_manager->releaseResource(id);
}

} // namespace Render
} // namespace Qt3DRender

QT_END_NAMESPACE