Optimize QStaticText for space

By caching the results of getGlyphPositions() we can make a code path
in the critical paint engines which is optimal both in space and speed.
The engines where speed is of less importance (pdf engine etc.) which
may need more information, we choose the slower code path of drawText()
which lays out the text again. We should have optimal paths in raster,
vg and GL2 paint engines. The others are less important. Memory
consumption of static text is now 14 bytes per glyph, 8 bytes per item
and a static overhead of 40 bytes per QStaticText object.

1 files changed, 8 insertions, 8 deletions

diff --git a/src/gui/painting/qtextureglyphcache.cpp b/src/gui/painting/qtextureglyphcache.cpp
index 7b7f325..46da88e 100644
--- a/src/gui/painting/qtextureglyphcache.cpp
+++ b/src/gui/painting/qtextureglyphcache.cpp
@@ -55,7 +55,7 @@ QT_BEGIN_NAMESPACE
 
 // #define CACHE_DEBUG
 
-void QTextureGlyphCache::populate(const QTextItemInt &ti,
+void QTextureGlyphCache::populate(QFontEngine *fontEngine,
                                   const QVarLengthArray<glyph_t> &glyphs,
                                   const QVarLengthArray<QFixedPoint> &)
 {
@@ -64,7 +64,7 @@ void QTextureGlyphCache::populate(const QTextItemInt &ti,
     qDebug() << " -> current transformation: " << m_transform;
 #endif
 
-    m_current_textitem = &ti;
+    m_current_fontengine = fontEngine;
     const int margin = glyphMargin();
 
     QHash<glyph_t, Coord> listItemCoordinates;
@@ -77,7 +77,7 @@ void QTextureGlyphCache::populate(const QTextItemInt &ti,
             continue;
         if (listItemCoordinates.contains(glyph))
             continue;
-        glyph_metrics_t metrics = ti.fontEngine->boundingBox(glyph, m_transform);
+        glyph_metrics_t metrics = fontEngine->boundingBox(glyph, m_transform);
 
 #ifdef CACHE_DEBUG
         printf("'%c' (%4x): w=%.2f, h=%.2f, xoff=%.2f, yoff=%.2f, x=%.2f, y=%.2f, ti.ascent=%.2f, ti.descent=%.2f\n",
@@ -182,7 +182,7 @@ QImage QTextureGlyphCache::textureMapForGlyph(glyph_t g) const
             break;
         };
 
-        QFontEngineFT *ft = static_cast<QFontEngineFT*> (m_current_textitem->fontEngine);
+        QFontEngineFT *ft = static_cast<QFontEngineFT*> (m_current_fontengine);
         QFontEngineFT::QGlyphSet *gset = ft->loadTransformedGlyphSet(m_transform);
 
         if (gset && ft->loadGlyphs(gset, &g, 1, format)) {
@@ -194,9 +194,9 @@ QImage QTextureGlyphCache::textureMapForGlyph(glyph_t g) const
     } else
 #endif
     if (m_type == QFontEngineGlyphCache::Raster_RGBMask)
-        return m_current_textitem->fontEngine->alphaRGBMapForGlyph(g, glyphMargin(), m_transform);
+        return m_current_fontengine->alphaRGBMapForGlyph(g, glyphMargin(), m_transform);
     else
-        return m_current_textitem->fontEngine->alphaMapForGlyph(g, m_transform);
+        return m_current_fontengine->alphaMapForGlyph(g, m_transform);
 
     return QImage();
 }
@@ -321,13 +321,13 @@ void QImageTextureGlyphCache::fillTexture(const Coord &c, glyph_t g)
 #ifdef CACHE_DEBUG
 //     QPainter p(&m_image);
 //     p.drawLine(
-    QPoint base(c.x + glyphMargin(), c.y + glyphMargin() + c.baseLineY-1);
+    /*QPoint base(c.x + glyphMargin(), c.y + glyphMargin() + c.baseLineY-1);
     if (m_image.rect().contains(base))
         m_image.setPixel(base, 255);
     m_image.save(QString::fromLatin1("cache-%1-%2-%3.png")
                  .arg(m_current_textitem->font().family())
                  .arg(m_current_textitem->font().pointSize())
-                 .arg(m_transform.type()));
+                 .arg(m_transform.type()));*/
 #endif
 }