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#include "qrendertargetselector.h"
#include "qrendertargetselector_p.h"
#include <Qt3DRender/qrendertarget.h>
#include <Qt3DCore/qpropertyupdatedchange.h>
#include <Qt3DRender/private/qrenderpass_p.h>
#include <Qt3DRender/qframegraphnodecreatedchange.h>

QT_BEGIN_NAMESPACE

using namespace Qt3DCore;

namespace Qt3DRender {
/*!
    \class Qt3DRender::QRenderTargetSelector
    \inmodule Qt3DRender
    \since 5.7
    \brief Provides a way of specifying a render target.

    A Qt3DRender::QRenderTargetSelector is used to select active Qt3DRender::QRenderTarget
    for the FrameGraph. When QRenderTargetSelector is present in the FrameGraph,
    the rendering is directed into QTexture objects or draw buffers instead of the surface
    specified in the Qt3DRender::QRenderSurfaceSelector. A render buffer is automatically
    generated for an attachment point if drawBuffers contain attachment point that any
    output in the QRenderTarget do not specify. If the drawBuffers is empty,
    the renderer will default to using all the outputs in QRenderTarget.
 */

/*!
    \qmltype RenderTargetSelector
    \inqmlmodule Qt3D.Render
    \since 5.7
    \instantiates Qt3DRender::QRenderTargetSelector
    \inherits FrameGraphNode
    \brief Provides a way of specifying a render target.

    A RenderTargetSelector is used to select active RenderTarget
    for the FrameGraph. When RenderTargetSelector is present in the FrameGraph,
    the rendering is directed into Texture objects or draw buffers instead of the surface
    specified in the RenderSurfaceSelector.
 */
/*!
    \qmlproperty list<variant> RenderTargetSelector::drawBuffers
    Holds the list of draw buffers enabled for the RenderTarget.

    \sa Qt3DRender::QRenderTargetOutput::AttachmentPoint
 */

QRenderTargetSelectorPrivate::QRenderTargetSelectorPrivate()
    : QFrameGraphNodePrivate()
    , m_target(nullptr)
{
}

/*!
    Constructs QRenderTargetSelector with given \a parent.
 */
QRenderTargetSelector::QRenderTargetSelector(QNode *parent)
    : QFrameGraphNode(*new QRenderTargetSelectorPrivate, parent)
{
}

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

/*!
    \property QRenderTargetSelector::target
    Holds the current render target
 */

/*! \qmlproperty RenderTarget Qt3D.Render::RenderTargetSelector::target

    Holds the current render target
 */
void QRenderTargetSelector::setTarget(QRenderTarget *target)
{
    Q_D(QRenderTargetSelector);
    if (d->m_target != target) {

        if (d->m_target)
            d->unregisterDestructionHelper(d->m_target);

        // For inline declaration cases
        if (target != nullptr && !target->parent())
            target->setParent(this);

        d->m_target = target;

        if (d->m_target)
            d->registerDestructionHelper(d->m_target, &QRenderTargetSelector::setTarget, d->m_target);

        emit targetChanged(target);
    }
}

QRenderTarget *QRenderTargetSelector::target() const
{
    Q_D(const QRenderTargetSelector);
    return d->m_target;
}

/*!
    Sets the draw \a buffers to be used. The draw buffers should be
    matching the Qt3DRender::QRenderTargetOutput::AttachmentPoint
    defined in the attachments of the Qt3DRender::QRenderTarget associated to the
    Qt3DRender::QRenderTargetSelector instance.

    \note At render time, if no draw buffer has been specified, the renderer will
    default to using all the attachments' draw buffers.
 */
void QRenderTargetSelector::setOutputs(const QVector<QRenderTargetOutput::AttachmentPoint> &buffers)
{
    Q_D(QRenderTargetSelector);
    if (buffers != d->m_outputs) {
        d->m_outputs = buffers;

        if (d->m_changeArbiter) {
            auto change = QPropertyUpdatedChangePtr::create(d->m_id);
            change->setPropertyName("outputs");
            change->setValue(QVariant::fromValue(d->m_outputs));
            d->notifyObservers(change);
        }
    }
}

/*!
    \return the list of draw buffers for the current Qt3DRender::QRenderTargetSelector instance.
 */
QVector<QRenderTargetOutput::AttachmentPoint> QRenderTargetSelector::outputs() const
{
    Q_D(const QRenderTargetSelector);
    return d->m_outputs;
}

/*! \internal */
QRenderTargetSelector::QRenderTargetSelector(QRenderTargetSelectorPrivate &dd, QNode *parent)
    : QFrameGraphNode(dd, parent)
{
}

Qt3DCore::QNodeCreatedChangeBasePtr QRenderTargetSelector::createNodeCreationChange() const
{
    auto creationChange = QFrameGraphNodeCreatedChangePtr<QRenderTargetSelectorData>::create(this);
    auto &data = creationChange->data;
    Q_D(const QRenderTargetSelector);
    data.targetId = qIdForNode(d->m_target);
    data.outputs = d->m_outputs;
    return creationChange;
}

} // namespace Qt3DRender

QT_END_NAMESPACE
