QGeometry: add minExtent/maxExtent properties

To allow computing a bounding box for a given QGeometry while waiting
for a proper bounding volume aspect.

Change-Id: If1ecf2f9236beaf569c650e5f8b05a6151ca6381
Reviewed-by: Mike Krus <mike.krus@kdab.com>

5 files changed, 114 insertions, 2 deletions

diff --git a/src/render/geometry/geometry.cpp b/src/render/geometry/geometry.cpp
index d87b4d8eb..4ee02a74d 100644
--- a/src/render/geometry/geometry.cpp
+++ b/src/render/geometry/geometry.cpp
@@ -53,8 +53,10 @@ namespace Qt3DRender {
 namespace Render {
 
 Geometry::Geometry()
-    : BackendNode(ReadOnly)
+    : BackendNode(ReadWrite)
     , m_geometryDirty(false)
+    , m_shouldNotifyMinExtentChanged(false)
+    , m_shouldNotifyMaxExtentChanged(false)
 {
 }
 
@@ -68,6 +70,10 @@ void Geometry::cleanup()
     m_attributes.clear();
     m_geometryDirty = false;
     m_boundingPositionAttribute = Qt3DCore::QNodeId();
+    m_min = QVector3D();
+    m_max = QVector3D();
+    m_shouldNotifyMinExtentChanged = false;
+    m_shouldNotifyMaxExtentChanged = false;
 }
 
 void Geometry::initializeFromPeer(const Qt3DCore::QNodeCreatedChangeBasePtr &change)
@@ -122,6 +128,37 @@ void Geometry::unsetDirty()
     m_geometryDirty = false;
 }
 
+// Called from calcboundingvolumejob (in a QtConcurrent thead (can't send
+// update changes from such a thread))
+void Geometry::updateExtent(const QVector3D &min, const QVector3D &max)
+{
+    // Send notification to frontend
+    if (m_min != min) {
+        m_min = min;
+        m_shouldNotifyMinExtentChanged = true;
+    }
+
+    if (m_max != max) {
+        m_max = max;
+        m_shouldNotifyMaxExtentChanged = true;
+    }
+}
+
+// Called from calcboundingvolumejob after all bounding volumes have been
+// updated (in an aspect thread)
+void Geometry::notifyExtentChanged()
+{
+    if (m_shouldNotifyMinExtentChanged || m_shouldNotifyMaxExtentChanged) {
+        auto change = Qt3DCore::QPropertyUpdatedChangePtr::create(peerId());
+        change->setDeliveryFlags(Qt3DCore::QSceneChange::Nodes);
+        change->setPropertyName("extent");
+        change->setValue(QVariant::fromValue(QPair<QVector3D, QVector3D>(m_min, m_max)));
+        notifyObservers(change);
+        m_shouldNotifyMinExtentChanged = false;
+        m_shouldNotifyMaxExtentChanged = false;
+    }
+}
+
 } // namespace Render
 } // namespace Qt3DRender
 
diff --git a/src/render/geometry/geometry_p.h b/src/render/geometry/geometry_p.h
index b158648ad..e66524787 100644
--- a/src/render/geometry/geometry_p.h
+++ b/src/render/geometry/geometry_p.h
@@ -75,12 +75,22 @@ public:
     inline Qt3DCore::QNodeId boundingPositionAttribute() const { return m_boundingPositionAttribute; }
     void unsetDirty();
 
+    inline QVector3D min() const { return m_min; }
+    inline QVector3D max() const { return m_max; }
+
+    void updateExtent(const QVector3D &min, const QVector3D &max);
+    void notifyExtentChanged();
+
 private:
     void initializeFromPeer(const Qt3DCore::QNodeCreatedChangeBasePtr &change) final;
 
     QVector<Qt3DCore::QNodeId> m_attributes;
     bool m_geometryDirty;
     Qt3DCore::QNodeId m_boundingPositionAttribute;
+    QVector3D m_min;
+    QVector3D m_max;
+    bool m_shouldNotifyMinExtentChanged;
+    bool m_shouldNotifyMaxExtentChanged;
 };
 
 } // namespace Render
diff --git a/src/render/geometry/qgeometry.cpp b/src/render/geometry/qgeometry.cpp
index c49dde822..ec80e2657 100644
--- a/src/render/geometry/qgeometry.cpp
+++ b/src/render/geometry/qgeometry.cpp
@@ -153,6 +153,28 @@ QGeometry::QGeometry(QGeometryPrivate &dd, QNode *parent)
 {
 }
 
+void QGeometry::sceneChangeEvent(const QSceneChangePtr &change)
+{
+    Q_D(QGeometry);
+    QPropertyUpdatedChangePtr e = qSharedPointerCast<QPropertyUpdatedChange>(change);
+    if (e->type() == PropertyUpdated) {
+        const bool blocked = blockNotifications(true);
+        if (e->propertyName() == QByteArrayLiteral("extent")) {
+            const QPair<QVector3D, QVector3D> extent = e->value().value<QPair<QVector3D, QVector3D>>();
+
+            if (extent.first != d->m_minExtent) {
+                d->m_minExtent = extent.first;
+                emit minExtentChanged(extent.first);
+            }
+            if (extent.second != d->m_maxExtent) {
+                d->m_maxExtent = extent.second;
+                emit maxExtentChanged(d->m_maxExtent);
+            }
+        }
+        blockNotifications(blocked);
+    }
+}
+
 /*!
     \fn void Qt3DRender::QGeometry::addAttribute(Qt3DRender::QAttribute *attribute)
     Adds an \a attribute to this geometry.
@@ -216,6 +238,40 @@ QAttribute *QGeometry::boundingVolumePositionAttribute() const
 }
 
 /*!
+    \qmlproperty vector3d Geometry::minExtent
+
+    Holds the vertex with the lowest x, y, z position values.
+ */
+
+/*!
+    \property QGeometry::minExtent
+
+    Holds the vertex with the lowest x, y, z position values.
+ */
+QVector3D QGeometry::minExtent() const
+{
+    Q_D(const QGeometry);
+    return d->m_minExtent;
+}
+
+/*!
+    \qmlproperty vector3d Geometry::maxExtent
+
+    Holds the vertex with the highest x, y, z position values.
+ */
+
+/*!
+    \property QGeometry::maxExtent
+
+    Holds the vertex with the highest x, y, z position values.
+ */
+QVector3D QGeometry::maxExtent() const
+{
+    Q_D(const QGeometry);
+    return d->m_maxExtent;
+}
+
+/*!
     Returns the list of attributes in this geometry.
  */
 QVector<QAttribute *> QGeometry::attributes() const
diff --git a/src/render/geometry/qgeometry.h b/src/render/geometry/qgeometry.h
index 0e6f7d68e..61508c7d2 100644
--- a/src/render/geometry/qgeometry.h
+++ b/src/render/geometry/qgeometry.h
@@ -54,6 +54,8 @@ class QT3DRENDERSHARED_EXPORT QGeometry : public Qt3DCore::QNode
 {
     Q_OBJECT
     Q_PROPERTY(Qt3DRender::QAttribute *boundingVolumePositionAttribute READ boundingVolumePositionAttribute WRITE setBoundingVolumePositionAttribute NOTIFY boundingVolumePositionAttributeChanged)
+    Q_PROPERTY(QVector3D minExtent READ minExtent NOTIFY minExtentChanged REVISION 13)
+    Q_PROPERTY(QVector3D maxExtent READ maxExtent NOTIFY maxExtentChanged REVISION 13)
 public:
     explicit QGeometry(Qt3DCore::QNode *parent = nullptr);
     ~QGeometry();
@@ -63,15 +65,19 @@ public:
     Q_INVOKABLE void removeAttribute(Qt3DRender::QAttribute *attribute);
 
     QAttribute *boundingVolumePositionAttribute() const;
+    QVector3D minExtent() const;
+    QVector3D maxExtent() const;
 
 public Q_SLOTS:
     void setBoundingVolumePositionAttribute(QAttribute *boundingVolumePositionAttribute);
 
 Q_SIGNALS:
     void boundingVolumePositionAttributeChanged(QAttribute *boundingVolumePositionAttribute);
-
+    void minExtentChanged(const QVector3D &minExtent);
+    void maxExtentChanged(const QVector3D &maxExtent);
 protected:
     explicit QGeometry(QGeometryPrivate &dd, Qt3DCore::QNode *parent = nullptr);
+    void sceneChangeEvent(const Qt3DCore::QSceneChangePtr &change) override;
 
 private:
     Q_DECLARE_PRIVATE(QGeometry)
diff --git a/src/render/geometry/qgeometry_p.h b/src/render/geometry/qgeometry_p.h
index e07b9ff0d..f53548e43 100644
--- a/src/render/geometry/qgeometry_p.h
+++ b/src/render/geometry/qgeometry_p.h
@@ -53,6 +53,7 @@
 
 #include <Qt3DRender/private/qt3drender_global_p.h>
 #include <Qt3DCore/private/qnode_p.h>
+#include <QVector3D>
 
 QT_BEGIN_NAMESPACE
 
@@ -68,6 +69,8 @@ public:
 
     QVector<QAttribute *> m_attributes;
     QAttribute *m_boundingVolumePositionAttribute;
+    QVector3D m_minExtent;
+    QVector3D m_maxExtent;
 };
 
 struct QGeometryData