Share depth-stencil buffers between ShaderEffectSources of same size.

Change-Id: If325a38175249c3a3ffe5043d42ba35dbf90ce0c
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>

1 files changed, 142 insertions, 0 deletions

diff --git a/src/quick/scenegraph/util/qsgdepthstencilbuffer_p.h b/src/quick/scenegraph/util/qsgdepthstencilbuffer_p.h
new file mode 100644
index 0000000000..0d8847feb4
--- /dev/null
+++ b/src/quick/scenegraph/util/qsgdepthstencilbuffer_p.h
@@ -0,0 +1,142 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/
+**
+** This file is part of the QtDeclarative module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** 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, Nokia gives you certain additional
+** rights. These rights are described in the Nokia 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.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QSGDEPTHSTENCILBUFFER_P_H
+#define QSGDEPTHSTENCILBUFFER_P_H
+
+#include <QtCore/qsize.h>
+#include <QtGui/private/qopenglcontext_p.h>
+#include <QtGui/private/qopenglextensions_p.h>
+#include <QtCore/qsharedpointer.h>
+#include <QtCore/qhash.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+class QSGDepthStencilBufferManager;
+
+class QSGDepthStencilBuffer
+{
+public:
+    enum Attachment
+    {
+        NoAttachment = 0x00,
+        DepthAttachment = 0x01,
+        StencilAttachment = 0x02
+    };
+    Q_DECLARE_FLAGS(Attachments, Attachment)
+
+    struct Format
+    {
+        QSize size;
+        int samples;
+        QSGDepthStencilBuffer::Attachments attachments;
+        bool operator == (const Format &other) const;
+    };
+
+    QSGDepthStencilBuffer(QOpenGLContext *context, const Format &format);
+    virtual ~QSGDepthStencilBuffer();
+
+    // Attaches this depth stencil buffer to the currently bound FBO.
+    void attach();
+    // Detaches this depth stencil buffer from the currently bound FBO.
+    void detach();
+
+    QSize size() const { return m_format.size; }
+    int samples() const { return m_format.samples; }
+    Attachments attachments() const { return m_format.attachments; }
+
+protected:
+    virtual void free() = 0;
+
+    QOpenGLExtensions m_functions;
+    QSGDepthStencilBufferManager *m_manager;
+    Format m_format;
+    GLuint m_depthBuffer;
+    GLuint m_stencilBuffer;
+
+    friend class QSGDepthStencilBufferManager;
+};
+
+Q_DECLARE_OPERATORS_FOR_FLAGS(QSGDepthStencilBuffer::Attachments)
+
+inline bool QSGDepthStencilBuffer::Format::operator == (const Format &other) const
+{
+    return size == other.size && samples == other.samples && attachments == other.attachments;
+}
+
+
+class QSGDefaultDepthStencilBuffer : public QSGDepthStencilBuffer
+{
+public:
+    QSGDefaultDepthStencilBuffer(QOpenGLContext *context, const Format &format);
+    virtual ~QSGDefaultDepthStencilBuffer();
+
+protected:
+    virtual void free();
+};
+
+
+class QSGDepthStencilBufferManager
+{
+public:
+    QSGDepthStencilBufferManager(QOpenGLContext *ctx) : m_context(ctx) { }
+    ~QSGDepthStencilBufferManager();
+    QOpenGLContext *context() const { return m_context; }
+    QSharedPointer<QSGDepthStencilBuffer> bufferForFormat(const QSGDepthStencilBuffer::Format &fmt);
+    void insertBuffer(const QSharedPointer<QSGDepthStencilBuffer> &buffer);
+
+private:
+    typedef QHash<QSGDepthStencilBuffer::Format, QWeakPointer<QSGDepthStencilBuffer> > Hash;
+    QOpenGLContext *m_context;
+    Hash m_buffers;
+
+    friend class QSGDepthStencilBuffer;
+};
+
+extern uint qHash(const QSGDepthStencilBuffer::Format &format);
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif