Add support for shared glyph cache

Use a shared graphics cache to back the distance fields if
it is available.

Change-Id: Id5e6e7a28e38e349d787e66016b2d0faebc791d7
Reviewed-by: Jiang Jiang <jiang.jiang@nokia.com>

1 files changed, 113 insertions, 0 deletions

diff --git a/src/quick/scenegraph/qsgshareddistancefieldglyphcache_p.h b/src/quick/scenegraph/qsgshareddistancefieldglyphcache_p.h
new file mode 100644
index 0000000000..6f5696eabb
--- /dev/null
+++ b/src/quick/scenegraph/qsgshareddistancefieldglyphcache_p.h
@@ -0,0 +1,113 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** 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 QSGSHAREDDISTANCEFIELDGLYPHCACHE_H
+#define QSGSHAREDDISTANCEFIELDGLYPHCACHE_H
+
+#include <QtCore/qwaitcondition.h>
+#include <private/qsgadaptationlayer_p.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+class QPlatformSharedGraphicsCache;
+class QSGSharedDistanceFieldGlyphCache : public QObject, public QSGDistanceFieldGlyphCache
+{
+    Q_OBJECT
+public:
+    explicit QSGSharedDistanceFieldGlyphCache(const QByteArray &cacheId,
+                                              QPlatformSharedGraphicsCache *sharedGraphicsCache,
+                                              QSGDistanceFieldGlyphCacheManager *man,
+                                              QOpenGLContext *c,
+                                              const QRawFont &font);
+    ~QSGSharedDistanceFieldGlyphCache();
+
+    void registerOwnerElement(QQuickItem *ownerElement);
+    void unregisterOwnerElement(QQuickItem *ownerElement);
+    void processPendingGlyphs();
+
+    void requestGlyphs(const QSet<glyph_t> &glyphs);
+    void referenceGlyphs(const QSet<glyph_t> &glyphs);
+    void storeGlyphs(const QHash<glyph_t, QImage> &glyphs);
+    void releaseGlyphs(const QSet<glyph_t> &glyphs);
+
+Q_SIGNALS:
+    void glyphsPending();
+
+private Q_SLOTS:
+    void reportItemsMissing(const QByteArray &cacheId, const QVector<quint32> &itemIds);
+    void reportItemsAvailable(const QByteArray &cacheId,
+                          void *bufferId, const QSize &bufferSize,
+                          const QVector<quint32> &itemIds, const QVector<QPoint> &positions);
+    void reportItemsInvalidated(const QByteArray &cacheId, const QVector<quint32> &itemIds);
+
+private:
+    void waitForGlyphs();
+    void saveTexture(GLuint textureId, int width, int height);
+
+    QSet<quint32> m_requestedGlyphsThatHaveNotBeenReturned;
+    QWaitCondition m_pendingGlyphsCondition;
+    QByteArray m_cacheId;
+    QPlatformSharedGraphicsCache *m_sharedGraphicsCache;
+    QMutex m_pendingGlyphsMutex;
+
+    QSet<glyph_t> m_pendingInvalidatedGlyphs;
+    QSet<glyph_t> m_pendingMissingGlyphs;
+
+    struct PendingGlyph
+    {
+        PendingGlyph() : buffer(0) {}
+
+        void *buffer;
+        QSize bufferSize;
+        QPoint position;
+    };
+
+    QHash<quint32, PendingGlyph> m_pendingReadyGlyphs;
+    QHash<glyph_t, void *> m_bufferForGlyph;
+};
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QSGSHAREDDISTANCEFIELDGLYPHCACHE_H