Reference count glyphs in QSGDistanceFieldGlyphCache.

This was previously done only in the default cache implementation. It
has been moved to the base class.
releaseGlyphs() is called when a glyph is not referenced anymore by any
node.
Added a virtual function referenceGlyphs() that is called everytime glyphs
are being used in a node. This function is called just before
requestGlyphs().

Change-Id: If90f86c328c18ae2a5977847a6adf50b99ea1241
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@nokia.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/quick/scenegraph/qsgadaptationlayer_p.h b/src/quick/scenegraph/qsgadaptationlayer_p.h
index 0c777ef639..c4851c326b 100644
--- a/src/quick/scenegraph/qsgadaptationlayer_p.h
+++ b/src/quick/scenegraph/qsgadaptationlayer_p.h
@@ -191,9 +191,10 @@ protected:
         QPointF position;
     };
 
-    virtual void requestGlyphs(const QVector<glyph_t> &glyphs) = 0;
+    virtual void requestGlyphs(const QSet<glyph_t> &glyphs) = 0;
     virtual void storeGlyphs(const QHash<glyph_t, QImage> &glyphs) = 0;
-    virtual void releaseGlyphs(const QVector<glyph_t> &glyphs) = 0;
+    virtual void referenceGlyphs(const QSet<glyph_t> &glyphs) = 0;
+    virtual void releaseGlyphs(const QSet<glyph_t> &glyphs) = 0;
 
     void setGlyphsPosition(const QList<GlyphPosition> &glyphs);
     void setGlyphsTexture(const QVector<glyph_t> &glyphs, const Texture &tex);
@@ -215,6 +216,7 @@ private:
         QHash<glyph_t, QPainterPath> glyphPaths;
         bool doubleGlyphResolution;
         QLinkedList<QSGDistanceFieldGlyphNode*> m_registeredNodes;
+        QHash<glyph_t, quint32> glyphRefCount;
 
         GlyphCacheData(QOpenGLContext *ctx)
             : QOpenGLSharedResource(ctx->shareGroup())