Added QOffscreenSurface class.

Inherits QSurface and allows to use OpenGL from an arbitrary thread.
Platform plugins can implement QPlatformOffscreenSurface, otherwise an
invisible QWindow is used by QOffscreenSurface.
This patch includes an implementation of QOffscreenSurface for XCB
and EglFS platform plugins using pbuffers.

Change-Id: I57b4fc1db417331f34826dcfa754b7698782fde4
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Samuel Rødal <samuel.rodal@digia.com>

1 files changed, 98 insertions, 0 deletions

diff --git a/src/gui/kernel/qoffscreensurface.h b/src/gui/kernel/qoffscreensurface.h
new file mode 100644
index 0000000000..a1b46f9b88
--- /dev/null
+++ b/src/gui/kernel/qoffscreensurface.h
@@ -0,0 +1,98 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtGui 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 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 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QOFFSCREENSURFACE_H
+#define QOFFSCREENSURFACE_H
+
+#include <QtCore/QObject>
+#include <QtGui/qsurface.h>
+
+QT_BEGIN_NAMESPACE
+
+class QOffscreenSurfacePrivate;
+
+class QScreen;
+class QPlatformOffscreenSurface;
+
+class Q_GUI_EXPORT QOffscreenSurface : public QObject, public QSurface
+{
+    Q_OBJECT
+    Q_DECLARE_PRIVATE(QOffscreenSurface)
+
+public:
+
+    explicit QOffscreenSurface(QScreen *screen = 0);
+    virtual ~QOffscreenSurface();
+
+    SurfaceType surfaceType() const;
+
+    void create();
+    void destroy();
+
+    bool isValid() const;
+
+    void setFormat(const QSurfaceFormat &format);
+    QSurfaceFormat format() const;
+    QSurfaceFormat requestedFormat() const;
+
+    QSize size() const;
+
+    QScreen *screen() const;
+    void setScreen(QScreen *screen);
+
+    QPlatformOffscreenSurface *handle() const;
+
+Q_SIGNALS:
+    void screenChanged(QScreen *screen);
+
+private Q_SLOTS:
+    void screenDestroyed(QObject *screen);
+
+private:
+
+    QPlatformSurface *surfaceHandle() const;
+
+    Q_DISABLE_COPY(QOffscreenSurface)
+};
+
+QT_END_NAMESPACE
+
+#endif // QOFFSCREENSURFACE_H