Add SubtreeEnabler frame graph node

SubtreeEnabler allows easy enabling and disabling of
frame graph subtrees.

[ChangeLog] Added SubtreeEnabler to allow easing enabling
and disabling of frame graph subtrees.

Change-Id: Ibd4dd305c41b2985225311a0cc49675e60a3727f
Reviewed-by: Mike Krus <mike.krus@kdab.com>

7 files changed, 318 insertions, 7 deletions

diff --git a/src/render/framegraph/framegraph.pri b/src/render/framegraph/framegraph.pri
index 1489c2659..e833d4590 100644
--- a/src/render/framegraph/framegraph.pri
+++ b/src/render/framegraph/framegraph.pri
@@ -66,7 +66,9 @@ HEADERS += \
     $$PWD/setfence_p.h \
     $$PWD/waitfence_p.h \
     $$PWD/qnopicking.h \
-    $$PWD/nopicking_p.h
+    $$PWD/nopicking_p.h \
+    $$PWD/qsubtreeenabler.h \
+    $$PWD/subtreeenabler_p.h
 
 SOURCES += \
     $$PWD/cameraselectornode.cpp \
@@ -114,4 +116,6 @@ SOURCES += \
     $$PWD/setfence.cpp \
     $$PWD/waitfence.cpp \
     $$PWD/qnopicking.cpp \
-    $$PWD/nopicking.cpp
+    $$PWD/nopicking.cpp \
+    $$PWD/qsubtreeenabler.cpp \
+    $$PWD/subtreeenabler.cpp
diff --git a/src/render/framegraph/framegraphnode_p.h b/src/render/framegraph/framegraphnode_p.h
index 420abce56..3edd4f57d 100644
--- a/src/render/framegraph/framegraphnode_p.h
+++ b/src/render/framegraph/framegraphnode_p.h
@@ -90,7 +90,7 @@ public:
         Viewport,
         ClearBuffers,
         SortMethod,
-        SubtreeSelector,
+        SubtreeEnabler,
         StateSet,
         NoDraw,
         FrustumCulling,
diff --git a/src/render/framegraph/framegraphvisitor.cpp b/src/render/framegraph/framegraphvisitor.cpp
index cd8b08219..5ccad87e1 100644
--- a/src/render/framegraph/framegraphvisitor.cpp
+++ b/src/render/framegraph/framegraphvisitor.cpp
@@ -74,10 +74,8 @@ QVector<FrameGraphNode *> FrameGraphVisitor::traverse(FrameGraphNode *root)
 
 void FrameGraphVisitor::visit(Render::FrameGraphNode *node)
 {
-    // TO DO: check if node is a subtree selector
-    // in which case, we only visit the subtrees returned
-    // by the selector functor and not all the children
-    // as we would otherwise do
+    if (node->nodeType() == Render::FrameGraphNode::SubtreeEnabler && !node->isEnabled())
+        return;
 
     // Recurse to children (if we have any), otherwise if this is a leaf node,
     // initiate a rendering from the current camera
diff --git a/src/render/framegraph/qsubtreeenabler.cpp b/src/render/framegraph/qsubtreeenabler.cpp
new file mode 100644
index 000000000..5355b6fbd
--- /dev/null
+++ b/src/render/framegraph/qsubtreeenabler.cpp
@@ -0,0 +1,113 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 Ford Motor Company
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <Qt3DRender/qsubtreeenabler.h>
+#include <Qt3DRender/private/qframegraphnode_p.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3DRender
+{
+
+/*!
+    \class Qt3DRender::QSubtreeEnabler
+    \inmodule Qt3DRender
+    \brief Enables or disables entire subtrees of framegraph nodes.
+    \since 5.14
+
+    While QFrameGraphNodes can be individually enabled and disabled via the
+    \c enabled property, this can become tedious when an entire path
+    needs to be turned on or off. QSubtreeEnabler is a convenience node
+    that makes this use case trivial, allowing all of its children to be
+    controlled by a single switch.
+
+    QSubtreeEnabler is enabled by default.
+*/
+
+/*!
+    \qmltype SubtreeEnabler
+    \inqmlmodule Qt3D.Render
+    \since 5.14
+    \instantiates Qt3DRender::QSubtreeEnabler
+    \inherits FrameGraphNode
+    \brief Enables or disables entire subtrees of frame graph nodes.
+
+    While FrameGraphNodes can be individually enabled and disabled via the
+    \c enabled property, this can become tedious when an entire path
+    needs to be turned on or off. SubtreeEnabler is a convenience node
+    that makes this use case trivial, allowing all of its children to be
+    controlled by a single switch.
+
+    For example, the following simplified frame graph includes a subtree for
+    debug rendering that can easily be enabled only when debugging.
+
+    \qml
+    RenderSurfaceSelector {
+        ClearBuffers {
+            Viewport {
+                CameraSelector {}
+            }
+        }
+
+        SubtreeEnabler {
+            enabled: showDebugView
+            Viewport {
+                CameraSelector {
+                    RenderPassFilter {}
+                }
+            }
+        }
+    }
+    \endqml
+
+    SubtreeEnabler is enabled by default.
+ */
+
+QSubtreeEnabler::QSubtreeEnabler(Qt3DCore::QNode *parent)
+    : QFrameGraphNode(*new QFrameGraphNodePrivate, parent)
+{
+}
+
+QSubtreeEnabler::~QSubtreeEnabler()
+{
+}
+
+} //Qt3DRender
+
+QT_END_NAMESPACE
diff --git a/src/render/framegraph/qsubtreeenabler.h b/src/render/framegraph/qsubtreeenabler.h
new file mode 100644
index 000000000..bb62dd170
--- /dev/null
+++ b/src/render/framegraph/qsubtreeenabler.h
@@ -0,0 +1,65 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 Ford Motor Company
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QT3DRENDER_QSUBTREEENABLER_H
+#define QT3DRENDER_QSUBTREEENABLER_H
+
+#include <Qt3DRender/QFrameGraphNode>
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3DRender
+{
+
+class Q_3DRENDERSHARED_EXPORT QSubtreeEnabler : public QFrameGraphNode
+{
+    Q_OBJECT
+public:
+    explicit QSubtreeEnabler(Qt3DCore::QNode *parent = nullptr);
+    ~QSubtreeEnabler();
+
+private:
+    void *m_reserved;
+};
+
+} //Qt3DRender
+
+QT_END_NAMESPACE
+
+#endif // QT3DRENDER_QSUBTREEENABLER_H
diff --git a/src/render/framegraph/subtreeenabler.cpp b/src/render/framegraph/subtreeenabler.cpp
new file mode 100644
index 000000000..e4b4e4ba7
--- /dev/null
+++ b/src/render/framegraph/subtreeenabler.cpp
@@ -0,0 +1,57 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 Ford Motor Company
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "subtreeenabler_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3DRender {
+
+namespace Render {
+
+SubtreeEnabler::SubtreeEnabler()
+    : FrameGraphNode(FrameGraphNode::SubtreeEnabler)
+{
+}
+
+} //Render
+
+} //Qt3DRender
+
+QT_END_NAMESPACE
diff --git a/src/render/framegraph/subtreeenabler_p.h b/src/render/framegraph/subtreeenabler_p.h
new file mode 100644
index 000000000..22782da12
--- /dev/null
+++ b/src/render/framegraph/subtreeenabler_p.h
@@ -0,0 +1,74 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 Ford Motor Company
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef SUBTREEENABLER_P_H
+#define SUBTREEENABLER_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists for the convenience
+// of other Qt classes.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <Qt3DRender/private/framegraphnode_p.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3DRender {
+
+namespace Render {
+
+class Q_AUTOTEST_EXPORT SubtreeEnabler : public FrameGraphNode
+{
+public:
+    SubtreeEnabler();
+};
+
+} //Render
+
+} //Qt3DRender
+
+QT_END_NAMESPACE
+
+#endif // SUBTREEENABLER_P_H