Implemented texture cache for GL paint engine in QtGui.

This is simpler than the existing texture cache in QtOpenGL, as it only
serves the GL paint engine. There's one per context group, to simplify
the design and to prevent performance degradations.

Change-Id: I61e3c9a444d8e246a8b38da019a56f2c0a533c0c
Reviewed-on: http://codereview.qt-project.org/4674
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Kim M. Kalland <kim.kalland@nokia.com>

1 files changed, 102 insertions, 0 deletions

diff --git a/src/gui/opengl/qopengltexturecache_p.h b/src/gui/opengl/qopengltexturecache_p.h
new file mode 100644
index 0000000000..bdee9f4e83
--- /dev/null
+++ b/src/gui/opengl/qopengltexturecache_p.h
@@ -0,0 +1,102 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtGui 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.
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#ifndef QOPENGLTEXTURECACHE_P_H
+#define QOPENGLTEXTURECACHE_P_H
+
+#include <QHash>
+#include <QObject>
+#include <QtGui/QtGui>
+#include <private/qopenglcontext_p.h>
+#include <QtCore/qmutex.h>
+
+QT_BEGIN_NAMESPACE
+
+class QOpenGLCachedTexture
+{
+public:
+    QOpenGLCachedTexture(GLuint id, QOpenGLContext *context);
+    ~QOpenGLCachedTexture() { m_resource->free(); }
+
+    GLuint id() const { return m_resource->id(); }
+
+private:
+    QOpenGLSharedResourceGuard *m_resource;
+};
+
+class QOpenGLTextureCache : public QOpenGLSharedResource
+{
+public:
+    static QOpenGLTextureCache *cacheForContext(QOpenGLContext *context);
+
+    QOpenGLTextureCache(QOpenGLContext *);
+    ~QOpenGLTextureCache();
+
+    GLuint bindTexture(QOpenGLContext *context, const QPixmap &pixmap);
+    GLuint bindTexture(QOpenGLContext *context, const QImage &image);
+
+    void invalidate(qint64 key);
+
+    void invalidateResource();
+    void freeResource(QOpenGLContext *ctx);
+
+private:
+    GLuint bindTexture(QOpenGLContext *context, qint64 key, const QImage &image);
+
+    QMutex m_mutex;
+    QCache<quint64, QOpenGLCachedTexture> m_cache;
+};
+
+QT_END_NAMESPACE
+
+#endif
+