Add new QClipPlane render state

glEnable(GL_CLIP_DISTANCE0 + i);

Change-Id: Ic102b1d369d74052ddec08b5fc6bc8fee05a3718
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

4 files changed, 205 insertions, 3 deletions

diff --git a/src/render/frontend/qclipplane.cpp b/src/render/frontend/qclipplane.cpp
new file mode 100644
index 000000000..61f406187
--- /dev/null
+++ b/src/render/frontend/qclipplane.cpp
@@ -0,0 +1,125 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Klaralvdalens Datakonsult AB (KDAB).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://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.LGPLv3 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.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 later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qclipplane.h"
+#include <Qt3DRenderer/private/qrenderstate_p.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3D {
+
+class QClipPlanePrivate : public QRenderStatePrivate
+{
+public:
+    QClipPlanePrivate()
+        : QRenderStatePrivate(QRenderState::ClipPlane)
+        , m_plane(0)
+    {}
+
+    int m_plane;
+};
+
+/*!
+    \class Qt3D::QClipPlane
+    \inmodule Qt3DRenderer
+    \since 5.5
+    \brief Enables an additional OpenGL clipping plane that can be in shaders
+    using gl_ClipDistance
+
+    By default, OpenGL supports up to 8 additional clipping planes.
+    Qt3D::QClipPlane allows to enable one of these additional planes. These
+    planes can then be manipulated in the shaders using gl_ClipDistance[i]
+    where i varies between 0 and 8.
+ */
+
+/*!
+    \qmltype ClipPlane
+    \instantiates Qt3D::QClipPlane
+    \inherits RenderState
+    \inqmlmodule Qt3D.Renderer
+    \since 5.5
+    \brief Enables an additional OpenGL clipping plane that can be in shaders
+    using gl_ClipDistance
+
+    By default, OpenGL supports up to 8 additional clipping planes. ClipPlane
+    allows to enable one of these additional planes. These planes can then be
+    manipulated in the shaders using gl_ClipDistance[i] where i varies between
+    0 and 8.
+*/
+
+QClipPlane::QClipPlane(QNode *parent)
+    : QRenderState(*new QClipPlanePrivate(), parent)
+{
+}
+
+QClipPlane::~QClipPlane()
+{
+    QNode::cleanup();
+}
+
+/*!
+ * Returns the index of the clip plane.
+ * \note usually between 0-7
+ */
+int QClipPlane::plane() const
+{
+    Q_D(const QClipPlane);
+    return d->m_plane;
+}
+
+/*!
+ * Sets the index of the clip plane to \a plane.
+ * \note above 7, support is not garanteed
+ */
+void QClipPlane::setPlane(int plane)
+{
+    Q_D(QClipPlane);
+    if (plane != d->m_plane) {
+        d->m_plane = plane;
+        Q_EMIT planeChanged();
+    }
+}
+
+void QClipPlane::copy(const QNode *ref)
+{
+    QRenderState::copy(ref);
+    const QClipPlane *refClip = static_cast<const QClipPlane *>(ref);
+    d_func()->m_plane = refClip->plane();
+}
+
+} // Qt3D
+
+QT_END_NAMESPACE
diff --git a/src/render/frontend/qclipplane.h b/src/render/frontend/qclipplane.h
new file mode 100644
index 000000000..a1d6c0db3
--- /dev/null
+++ b/src/render/frontend/qclipplane.h
@@ -0,0 +1,74 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Klaralvdalens Datakonsult AB (KDAB).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://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.LGPLv3 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.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 later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QT3D_QCLIPPLANE_H
+#define QT3D_QCLIPPLANE_H
+
+#include <Qt3DRenderer/qrenderstate.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3D {
+
+class QClipPlanePrivate;
+
+class QT3DRENDERERSHARED_EXPORT QClipPlane : public QRenderState
+{
+    Q_OBJECT
+    Q_PROPERTY(int plane READ plane WRITE setPlane NOTIFY planeChanged)
+public:
+    explicit QClipPlane(QNode *parent = 0);
+    ~QClipPlane();
+
+    int plane() const;
+    void setPlane(int);
+
+protected:
+    void copy(const QNode *ref) Q_DECL_FINAL;
+
+Q_SIGNALS:
+    void planeChanged();
+
+private:
+    Q_DECLARE_PRIVATE(QClipPlane)
+    QT3D_CLONEABLE(QClipPlane)
+};
+
+} // Qt3D
+
+QT_END_NAMESPACE
+
+#endif // QT3D_QCLIPPLANE_H
diff --git a/src/render/frontend/qrenderstate.h b/src/render/frontend/qrenderstate.h
index 90290f8dc..7cf89cb11 100644
--- a/src/render/frontend/qrenderstate.h
+++ b/src/render/frontend/qrenderstate.h
@@ -66,7 +66,8 @@ public:
         FrontFace,
         PolygonOffset,
         ScissorTest,
-        StencilTest
+        StencilTest,
+        ClipPlane
     };
     Q_ENUM(Type)
 
diff --git a/src/render/frontend/render-frontend.pri b/src/render/frontend/render-frontend.pri
index 34e8249bd..e146ffc82 100644
--- a/src/render/frontend/render-frontend.pri
+++ b/src/render/frontend/render-frontend.pri
@@ -74,7 +74,8 @@ HEADERS += \
     $$PWD/qabstracttextureimage.h \
     $$PWD/qabstracttextureimage_p.h \
     $$PWD/qtextureimage.h \
-    $$PWD/qtextureproviders.h
+    $$PWD/qtextureproviders.h \
+    $$PWD/qclipplane.h
 
 SOURCES += \
     $$PWD/qmaterial.cpp \
@@ -123,4 +124,5 @@ SOURCES += \
     $$PWD/qwrapmode.cpp \
     $$PWD/qabstracttextureimage.cpp \
     $$PWD/qtextureimage.cpp \
-    $$PWD/qtextureproviders.cpp
+    $$PWD/qtextureproviders.cpp \
+    $$PWD/qclipplane.cpp