QObjectPicker and QPickingSettings NearestPriorityPick picking mode

Add a new priority property on QObjectPicker and a new QPickingSettings mode.
This will select the result with the highest priority if there are several results
on a given ray. If we have several results with identical properties, the result
with the closest distance is selected.

[ChangeLog][Qt3DRender] QObjectPicker: add a priority based result selection

Change-Id: I7af12db6e163c3c2d9dad696e6d9f9bbbee064ed
Reviewed-by: Mike Krus <mike.krus@kdab.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/src/render/picking/qobjectpicker.cpp b/src/render/picking/qobjectpicker.cpp
index c3671d018..a0b6d8dcd 100644
--- a/src/render/picking/qobjectpicker.cpp
+++ b/src/render/picking/qobjectpicker.cpp
@@ -266,6 +266,23 @@ void QObjectPicker::setDragEnabled(bool dragEnabled)
 }
 
 /*!
+ * Sets the picker's priority to \a priority. This is used when the pick result
+ * mode on QPickingSettings is set to QPickingSettings::NearestPriorityPick.
+ * Picking results are sorted by highest priority and shortest picking
+ * distance.
+ *
+ * \since 5.13
+ */
+void QObjectPicker::setPriority(int priority)
+{
+    Q_D(QObjectPicker);
+    if (priority != d->m_priority) {
+        d->m_priority = priority;
+        emit priorityChanged(priority);
+    }
+}
+
+/*!
     \qmlproperty bool Qt3D.Render::ObjectPicker::dragEnabled
 */
 /*!
@@ -312,6 +329,25 @@ bool QObjectPicker::isPressed() const
     return d->m_pressed;
 }
 
+/*!
+    \qmlproperty int Qt3D.Render::ObjectPicker::priority
+
+    The priority to be used when filtering pick results by priority when
+    PickingSettings.pickResultMode is set to PickingSettings.PriorityPick.
+*/
+/*!
+  \property Qt3DRender::QObjectPicker::priority
+
+    The priority to be used when filtering pick results by priority when
+    QPickingSettings::pickResultMode is set to
+    QPickingSettings::NearestPriorityPick.
+*/
+int QObjectPicker::priority() const
+{
+    Q_D(const QObjectPicker);
+    return d->m_priority;
+}
+
 /*! \internal */
 void QObjectPicker::sceneChangeEvent(const Qt3DCore::QSceneChangePtr &change)
 {
@@ -465,6 +501,7 @@ Qt3DCore::QNodeCreatedChangeBasePtr QObjectPicker::createNodeCreationChange() co
     Q_D(const QObjectPicker);
     data.hoverEnabled = d->m_hoverEnabled;
     data.dragEnabled = d->m_dragEnabled;
+    data.priority = d->m_priority;
     return creationChange;
 }