Qt Quick 3D - Stencil Outline Extension Example

// Copyright (C) 2023 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#ifndef OUTLINERENDEREXTENSION_H
#define OUTLINERENDEREXTENSION_H
#include <QtQuick3D/qquick3drenderextensions.h>
#include <QtQmlIntegration>
class OutlineRenderExtension : public QQuick3DRenderExtension
{
    Q_OBJECT
    Q_PROPERTY(QQuick3DObject * target READ target WRITE setTarget NOTIFY targetChanged)
    Q_PROPERTY(QQuick3DObject * outlineMaterial READ outlineMaterial WRITE setOutlineMaterial NOTIFY outlineMaterialChanged)
    Q_PROPERTY(float outlineScale READ outlineScale WRITE setOutlineScale NOTIFY outlineScaleChanged)
    QML_ELEMENT
public:
    OutlineRenderExtension() = default;
    ~OutlineRenderExtension() override;
    float outlineScale() const;
    void setOutlineScale(float newOutlineScale);
    QQuick3DObject *target() const;
    void setTarget(QQuick3DObject *newTarget);
    QQuick3DObject *outlineMaterial() const;
    void setOutlineMaterial(QQuick3DObject *newOutlineMaterial);
signals:
    void outlineColorChanged();
    void outlineScaleChanged();
    void targetChanged();
    void outlineMaterialChanged();
protected:
    QSSGRenderGraphObject *updateSpatialNode(QSSGRenderGraphObject *node) override;
private:
    enum Dirty : quint8
    {
        Target = 1 << 0,
        OutlineMaterial = 1 << 1,
        OutlineScale = 1 << 2
    };
    using DirtyT = std::underlying_type_t<Dirty>;
    void markDirty(Dirty v);
    QPointer<QQuick3DObject> m_target;
    QPointer<QQuick3DObject> m_outlineMaterial;
    float m_outlineScale = 1.05f;
    DirtyT m_dirtyFlag {};
};
#endif // OUTLINERENDEREXTENSION_H