Support for variable glyph width in QSGDefaultDistanceFieldGlyphCache.

The glyphs are not stored in a fixed 64x64px tile anymore.
Glyphs are stored in area equal to <glyph_width> + 10 (margin) x 64px.
Allocation is now done with QSGAreaAllocator.
When glyph recycling is needed, unused glyphs are freed until the new
glyph can fit in the cache.

Change-Id: I179a8f17bfe35468bdb63bca5113ea4d0f06c414
Reviewed-by: Yoann Lopes <yoann.lopes@nokia.com>

1 files changed, 11 insertions, 8 deletions

diff --git a/src/quick/scenegraph/qsgadaptationlayer.cpp b/src/quick/scenegraph/qsgadaptationlayer.cpp
index 5c7aae0b59..083a9fb602 100644
--- a/src/quick/scenegraph/qsgadaptationlayer.cpp
+++ b/src/quick/scenegraph/qsgadaptationlayer.cpp
@@ -117,21 +117,22 @@ void QSGDistanceFieldGlyphCache::populate(const QVector<glyph_t> &glyphs)
         ++gd.ref;
         referencedGlyphs.insert(glyphIndex);
 
-        if (gd.texCoord.isValid() || newGlyphs.contains(glyphIndex))
+        if (gd.texCoord.isValid() || m_populatingGlyphs.contains(glyphIndex))
             continue;
 
-        gd.texCoord.width = 0;
-        gd.texCoord.height = 0;
+        m_populatingGlyphs.insert(glyphIndex);
 
-        if (!gd.boundingRect.isEmpty())
+        if (gd.boundingRect.isEmpty()) {
+            gd.texCoord.width = 0;
+            gd.texCoord.height = 0;
+        } else {
             newGlyphs.insert(glyphIndex);
+        }
     }
 
-    if (newGlyphs.isEmpty())
-        return;
-
     referenceGlyphs(referencedGlyphs);
-    requestGlyphs(newGlyphs);
+    if (!newGlyphs.isEmpty())
+        requestGlyphs(newGlyphs);
 }
 
 void QSGDistanceFieldGlyphCache::release(const QVector<glyph_t> &glyphs)
@@ -149,6 +150,8 @@ void QSGDistanceFieldGlyphCache::release(const QVector<glyph_t> &glyphs)
 
 void QSGDistanceFieldGlyphCache::update()
 {
+    m_populatingGlyphs.clear();
+
     if (m_pendingGlyphs.isEmpty())
         return;