Improve text performance with QtWebKit in Qt 4.7

Implemented the straight string-to-glyph conversion in the core text
font engine, that bypasses the shaping. This is used by the fast text
code path in QtWebKit.

Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@nokia.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/src/gui/text/qfontengine_mac.mm b/src/gui/text/qfontengine_mac.mm
index 7ceed61..deaad57 100644
--- a/src/gui/text/qfontengine_mac.mm
+++ b/src/gui/text/qfontengine_mac.mm
@@ -348,7 +348,29 @@ bool QCoreTextFontEngineMulti::stringToCMap(const QChar *str, int len, QGlyphLay
 bool QCoreTextFontEngineMulti::stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs,
                                             int *nglyphs, QTextEngine::ShaperFlags flags) const
 {
-    return stringToCMap(str, len, glyphs, nglyphs, flags, 0, 0);
+    *nglyphs = len;
+    QVarLengthArray<CGGlyph> cgGlyphs(len);
+    CTFontGetGlyphsForCharacters(ctfont, (const UniChar*)str, cgGlyphs.data(), len);
+
+    for (int i = 0; i < len; ++i)
+        glyphs->glyphs[i] = cgGlyphs[i];
+
+    if (flags & QTextEngine::GlyphIndicesOnly)
+        return true;
+
+    QVarLengthArray<CGSize> advances(len);
+    CTFontGetAdvancesForGlyphs(ctfont, kCTFontHorizontalOrientation, cgGlyphs.data(), advances.data(), len);
+
+    for (int i = 0; i < len; ++i) {
+        glyphs->advances_x[i] = QFixed::fromReal(advances[i].width);
+        glyphs->advances_y[i] = QFixed::fromReal(advances[i].height);
+        if (fontDef.styleStrategy & QFont::ForceIntegerMetrics) {
+            glyphs->advances_x[i] = glyphs->advances_x[i].round();
+            glyphs->advances_y[i] = glyphs->advances_y[i].round();
+        }
+    }
+
+    return true;
 }
 
 void QCoreTextFontEngineMulti::recalcAdvances(int , QGlyphLayout *, QTextEngine::ShaperFlags) const