Don't claim all fonts are smoothly scalable on Windows

Since 40ebda3efbcf00c3393cb70c9eee203c68a57311, bitmap fonts are detected
as smoothly scalable on Windows. While the fontsAlwaysScalable() does say
whether or not the font engine can rasterize the fonts at any size, it does
not determine whether or not the result is "attractive" as the
documentation for isSmoothlyScalable() says.

Only outline fonts are smoothly scalable, and this fact is used in Qt Quick
to determine whether we can use the distance field renderer for the font or
if we have to fall back to the native renderer. The consequence was that
the fonts were no longer usable in Qt Quick.

We also need to revert the optimization for isBitmapScalable() since there
a font that is smoothly scalable should not be identified as bitmap
scalable (basically this means: Font is not smoothly scalable, but it
can be scaled with bitmap scaling artifacts).

[ChangeLog][QtGui][Text] Fixed a regression where raster fonts on Windows
were detected as smoothly scalable and thus rendering with said fonts
in Qt Quick would break.

Task-number: QTBUG-56659
Change-Id: Ia7db6fee8249aca347233a488388be5c3a00c2df
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 0 insertions, 6 deletions

diff --git a/src/gui/text/qfontdatabase.cpp b/src/gui/text/qfontdatabase.cpp
index f063541249..04081a5ca7 100644
--- a/src/gui/text/qfontdatabase.cpp
+++ b/src/gui/text/qfontdatabase.cpp
@@ -1657,9 +1657,6 @@ bool QFontDatabase::isFixedPitch(const QString &family,
 bool QFontDatabase::isBitmapScalable(const QString &family,
                                       const QString &style) const
 {
-    if (QGuiApplicationPrivate::platformIntegration()->fontDatabase()->fontsAlwaysScalable())
-        return true;
-
     bool bitmapScalable = false;
     QString familyName, foundryName;
     parseFontName(family, foundryName, familyName);
@@ -1700,9 +1697,6 @@ bool QFontDatabase::isBitmapScalable(const QString &family,
 */
 bool QFontDatabase::isSmoothlyScalable(const QString &family, const QString &style) const
 {
-    if (QGuiApplicationPrivate::platformIntegration()->fontDatabase()->fontsAlwaysScalable())
-        return true;
-
     bool smoothScalable = false;
     QString familyName, foundryName;
     parseFontName(family, foundryName, familyName);