Force FT font engine to load the right glyph metrics

Change-Id: If027ea4c1a3b2ca8f972592abe3534165f62cf4e
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>
This commit is contained in:
Gunnar Sletta 2013-11-08 12:28:23 +01:00 committed by The Qt Project
parent 8462a6933c
commit f9399d69ad

View File

@ -152,6 +152,18 @@ bool QTextureGlyphCache::populate(QFontEngine *fontEngine, int numGlyphs, const
continue;
if (listItemCoordinates.contains(GlyphAndSubPixelPosition(glyph, subPixelPosition)))
continue;
// This is a rather crude hack, but it works.
// The FreeType font engine is not capable of getting precise metrics for the alphamap
// without first rasterizing the glyph. If we force the glyph to be rasterized before
// we ask for the alphaMapBoundingBox(), the glyph will be loaded, rasterized and its
// proper metrics will be cached and used later.
if (fontEngine->hasInternalCaching()) {
QImage *locked = fontEngine->lockedAlphaMapForGlyph(glyph, subPixelPosition, format);
if (locked)
fontEngine->unlockAlphaMapForGlyph();
}
glyph_metrics_t metrics = fontEngine->alphaMapBoundingBox(glyph, subPixelPosition, m_transform, format);
#ifdef CACHE_DEBUG