Add the Qt::TextBypassShaping flag.

This allows quick layouting especially with Windows fonts which
contain heavy OpenType logic.
On regular latin text the visual compromize is the loss of kerning,
justification, capitalization, word spacing and letter spacing support.

Reviewed-by: Simon Hausmann
Reviewed-by: Eskil

1 files changed, 17 insertions, 0 deletions

diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 657229a..54e0aa3 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -5937,6 +5937,23 @@ void QPainter::drawText(const QPointF &p, const QString &str, int tf, int justif
     if (!d->engine || str.isEmpty() || pen().style() == Qt::NoPen)
         return;
 
+    if (tf & Qt::TextBypassShaping) {
+        // Skip harfbuzz complex shaping, shape using glyph advances only
+        int len = str.length();
+        int numGlyphs = len;
+        QVarLengthGlyphLayoutArray glyphs(len);
+        QFontEngine *fontEngine = d->state->font.d->engineForScript(QUnicodeTables::Common);
+        if (!fontEngine->stringToCMap(str.data(), len, &glyphs, &numGlyphs, 0)) {
+            glyphs.resize(numGlyphs);
+            if (!fontEngine->stringToCMap(str.data(), len, &glyphs, &numGlyphs, 0))
+                Q_ASSERT_X(false, Q_FUNC_INFO, "stringToCMap shouldn't fail twice");
+        }
+
+        QTextItemInt gf(glyphs, &d->state->font, fontEngine);
+        drawTextItem(p, gf);
+        return;
+    }
+
     QStackTextEngine engine(str, d->state->font);
     engine.option.setTextDirection(d->state->layoutDirection);
     if (tf & (Qt::TextForceLeftToRight|Qt::TextForceRightToLeft)) {