Fixed an issue with text drawing under Windows.

Some text drawn with OpenType fonts where cut off by a pixel or two
under certain circumstances. This adds an additional 2 pixel pad margin
to the glyph cache entries. The padding behaves slightly different
when ClearType is enabled/disabled, hence the general 2 pixel padding.

Task-number: 246196
Reviewed-by: Samuel

2 files changed, 7 insertions, 10 deletions

diff --git a/src/gui/painting/qtextureglyphcache.cpp b/src/gui/painting/qtextureglyphcache.cpp
index 1ea40ba..3fd1ffb 100644
--- a/src/gui/painting/qtextureglyphcache.cpp
+++ b/src/gui/painting/qtextureglyphcache.cpp
@@ -88,11 +88,12 @@ void QTextureGlyphCache::populate(const QTextItemInt &ti,
                ti.ascent.toReal(),
                ti.descent.toReal());
 #endif
-        int glyph_width = metrics.width.ceil().toInt() + margin * 2;
-        int glyph_height = metrics.height.ceil().toInt() + margin * 2;
+        int glyph_width = metrics.width.ceil().toInt();
+        int glyph_height = metrics.height.ceil().toInt();
         if (glyph_height == 0 || glyph_width == 0)
             continue;
-
+        glyph_width += margin * 2 + 2;
+        glyph_height += margin * 2 + 2;
         // align to 8-bit boundary
         if (m_type == QFontEngineGlyphCache::Raster_Mono)
             glyph_width = (glyph_width+7)&~7;
@@ -188,11 +189,7 @@ void QImageTextureGlyphCache::createTextureData(int width, int height)
 
 int QImageTextureGlyphCache::glyphMargin() const
 {
-#ifdef Q_WS_MAC
     return 2;
-#else
-    return m_type == QFontEngineGlyphCache::Raster_RGBMask ? 2 : 0;
-#endif
 }
 
 void QImageTextureGlyphCache::fillTexture(const Coord &c, glyph_t g)
diff --git a/src/gui/text/qfontengine_win.cpp b/src/gui/text/qfontengine_win.cpp
index 1996d44..bf3a176 100644
--- a/src/gui/text/qfontengine_win.cpp
+++ b/src/gui/text/qfontengine_win.cpp
@@ -1406,8 +1406,8 @@ QNativeImage *QFontEngineWin::drawGDIGlyph(HFONT font, glyph_t glyph, int margin
 #endif
 #endif
 
-    QNativeImage *ni = new QNativeImage(iw + 2 * margin,
-                                        ih + 2 * margin,
+    QNativeImage *ni = new QNativeImage(iw + 2 * margin + 2,
+                                        ih + 2 * margin + 2,
                                         QNativeImage::systemFormat(), true);
     ni->image.fill(0xffffffff);
 
@@ -1449,7 +1449,7 @@ QImage QFontEngineWin::alphaMapForGlyph(glyph_t glyph, const QTransform &xform)
         font = CreateFontIndirectW(&lf);
     }
 
-    QNativeImage *mask = drawGDIGlyph(font, glyph, 0, xform);
+    QNativeImage *mask = drawGDIGlyph(font, glyph, 2, xform);
     if (mask == 0)
         return QImage();