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, 12 insertions, 24 deletions

diff --git a/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache.cpp b/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache.cpp
index 4f69ad8c44..57a9a8741c 100644
--- a/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache.cpp
+++ b/src/quick/scenegraph/qsgdefaultdistancefieldglyphcache.cpp
@@ -65,31 +65,19 @@ QSGDefaultDistanceFieldGlyphCache::QSGDefaultDistanceFieldGlyphCache(QSGDistance
     m_textureData = textureData(c);
 }
 
-void QSGDefaultDistanceFieldGlyphCache::requestGlyphs(const QVector<glyph_t> &glyphs)
+void QSGDefaultDistanceFieldGlyphCache::requestGlyphs(const QSet<glyph_t> &glyphs)
 {
-    int count = glyphs.count();
-
-    // Avoid useless and costly glyph re-generation
-    if (cacheIsFull() && !m_textureData->unusedGlyphs.isEmpty()) {
-        for (int i = 0; i < count; ++i) {
-            glyph_t glyphIndex = glyphs.at(i);
-            if (containsGlyph(glyphIndex) && m_textureData->unusedGlyphs.contains(glyphIndex))
-                m_textureData->unusedGlyphs.remove(glyphIndex);
-        }
-    }
-
     QList<GlyphPosition> glyphPositions;
     QVector<glyph_t> glyphsToRender;
 
-    for (int i = 0; i < count; ++i) {
-        glyph_t glyphIndex = glyphs.at(i);
-
-        if (++m_textureData->glyphRefCount[glyphIndex] == 1)
-            m_textureData->unusedGlyphs.remove(glyphIndex);
+    for (QSet<glyph_t>::const_iterator it = glyphs.constBegin(); it != glyphs.constEnd() ; ++it) {
+        glyph_t glyphIndex = *it;
 
         if (cacheIsFull() && m_textureData->unusedGlyphs.isEmpty())
             continue;
 
+        m_textureData->unusedGlyphs.remove(glyphIndex);
+
         GlyphPosition p;
         p.glyph = glyphIndex;
         p.position = QPointF(m_textureData->currX, m_textureData->currY);
@@ -162,14 +150,14 @@ void QSGDefaultDistanceFieldGlyphCache::storeGlyphs(const QHash<glyph_t, QImage>
     setGlyphsTexture(glyphTextures, t);
 }
 
-void QSGDefaultDistanceFieldGlyphCache::releaseGlyphs(const QVector<glyph_t> &glyphs)
+void QSGDefaultDistanceFieldGlyphCache::referenceGlyphs(const QSet<glyph_t> &glyphs)
 {
-    int count = glyphs.count();
-    for (int i = 0; i < count; ++i) {
-        glyph_t glyphIndex = glyphs.at(i);
-        if (--m_textureData->glyphRefCount[glyphIndex] == 0 && !glyphTexCoord(glyphIndex).isNull())
-            m_textureData->unusedGlyphs.insert(glyphIndex);
-    }
+    m_textureData->unusedGlyphs -= glyphs;
+}
+
+void QSGDefaultDistanceFieldGlyphCache::releaseGlyphs(const QSet<glyph_t> &glyphs)
+{
+    m_textureData->unusedGlyphs += glyphs;
 }
 
 void QSGDefaultDistanceFieldGlyphCache::createTexture(int width, int height)