Remove special case for color fonts from Freetype font engine

When adding color font support to the Freetype engine, we added
a special case to some functions based on the assumption that
color fonts do not contain the latin alphabet. The reason for
the assumption is that color fonts are currently most popular
for emojis and the most popular ones on Linux did not contain
the latin alphabet. But there is nothing special about color
fonts making them less likely to contain latin characters
than other fonts especially made for non-latin writing systems.

If we want an additional fallback when the x character is
not available, this should be implemented for all font engines
and font types.

Change-Id: I1c4aa28d49c38ba7a416c1cae50a1d1c09cbda41
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
Reviewed-by: jian liang <jianliang79@gmail.com>

1 files changed, 13 insertions, 21 deletions

diff --git a/src/gui/text/qfontengine_ft.cpp b/src/gui/text/qfontengine_ft.cpp
index db2f88f79a..ca6d33c7aa 100644
--- a/src/gui/text/qfontengine_ft.cpp
+++ b/src/gui/text/qfontengine_ft.cpp
@@ -1328,33 +1328,25 @@ QFixed QFontEngineFT::leading() const
 
 QFixed QFontEngineFT::xHeight() const
 {
-    if (!isScalableBitmap()) {
-        TT_OS2 *os2 = (TT_OS2 *)FT_Get_Sfnt_Table(freetype->face, ft_sfnt_os2);
-        if (os2 && os2->sxHeight) {
-            lockFace();
-            QFixed answer = QFixed(os2->sxHeight * freetype->face->size->metrics.y_ppem) / emSquareSize();
-            unlockFace();
-            return answer;
-        }
-    } else {
-        return QFixed(freetype->face->size->metrics.y_ppem) * scalableBitmapScaleFactor;
+    TT_OS2 *os2 = (TT_OS2 *)FT_Get_Sfnt_Table(freetype->face, ft_sfnt_os2);
+    if (os2 && os2->sxHeight) {
+        lockFace();
+        QFixed answer = QFixed(os2->sxHeight * freetype->face->size->metrics.y_ppem) / emSquareSize();
+        unlockFace();
+        return answer;
     }
+
     return QFontEngine::xHeight();
 }
 
 QFixed QFontEngineFT::averageCharWidth() const
 {
-     if (!isScalableBitmap()) {
-         TT_OS2 *os2 = (TT_OS2 *)FT_Get_Sfnt_Table(freetype->face, ft_sfnt_os2);
-         if (os2 && os2->xAvgCharWidth) {
-             lockFace();
-             QFixed answer = QFixed(os2->xAvgCharWidth * freetype->face->size->metrics.x_ppem) / emSquareSize();
-             unlockFace();
-             return answer;
-         }
-     } else {
-         const qreal aspectRatio = (qreal)xsize / ysize;
-         return QFixed::fromReal(fontDef.pixelSize * aspectRatio);
+     TT_OS2 *os2 = (TT_OS2 *)FT_Get_Sfnt_Table(freetype->face, ft_sfnt_os2);
+     if (os2 && os2->xAvgCharWidth) {
+         lockFace();
+         QFixed answer = QFixed(os2->xAvgCharWidth * freetype->face->size->metrics.x_ppem) / emSquareSize();
+         unlockFace();
+         return answer;
      }
 
      return QFontEngine::averageCharWidth();