Fix text position with OpenGL engine and Freetype

If you use the OpenGL engine, the left bearing of
the glyph was incorrectly retrieved from the system
as the glyph was queried with the wrong format, and
adjustments for antialiasing were not applied. To
make the position identical to painting with, new
API was added to QFontEngine (The bounding box of
a glyph is also not logically necessarily the same
thing as the bounding box of the rasterized glyph.)

Done-with: Trond
Task-number: QTBUG-14410

1 files changed, 8 insertions, 1 deletions

diff --git a/src/gui/painting/qtextureglyphcache.cpp b/src/gui/painting/qtextureglyphcache.cpp
index 9219876..78c1019 100644
--- a/src/gui/painting/qtextureglyphcache.cpp
+++ b/src/gui/painting/qtextureglyphcache.cpp
@@ -143,6 +143,13 @@ void QTextureGlyphCache::populate(QFontEngine *fontEngine, int numGlyphs, const
     QHash<GlyphAndSubPixelPosition, Coord> listItemCoordinates;
     int rowHeight = 0;
 
+    QFontEngine::GlyphFormat format;
+    switch (m_type) {
+    case Raster_A8: format = QFontEngine::Format_A8; break;
+    case Raster_RGBMask: format = QFontEngine::Format_A32; break;
+    default: format = QFontEngine::Format_Mono; break;
+    }
+
     // check each glyph for its metrics and get the required rowHeight.
     for (int i=0; i < numGlyphs; ++i) {
         const glyph_t glyph = glyphs[i];
@@ -157,7 +164,7 @@ void QTextureGlyphCache::populate(QFontEngine *fontEngine, int numGlyphs, const
             continue;
         if (listItemCoordinates.contains(GlyphAndSubPixelPosition(glyph, subPixelPosition)))
             continue;
-        glyph_metrics_t metrics = fontEngine->boundingBox(glyph, m_transform);
+        glyph_metrics_t metrics = fontEngine->alphaMapBoundingBox(glyph, m_transform, format);
 
 #ifdef CACHE_DEBUG
         printf("(%4x): w=%.2f, h=%.2f, xoff=%.2f, yoff=%.2f, x=%.2f, y=%.2f\n",