Is there a way to get the horizonal advance of every character in a string?

GeraldBrandt

Hi,

I'm looking for something like GetPartialTextExtents() in wxWidgets or GDI+ MeasureCharacterRanges(). Does QT have something like that? QFontMetrics doesn't seem to.

Gerald

Christian Ehrlicher

What's wrong with QFontMetrics::horizontalAdvance(QChar ch) ?

GeraldBrandt

@Christian-Ehrlicher Nothing, except that I'm calling it over 600,000 times.

When I switched from individual character measuring to string measuring (getting each characters width) in wxWidgets, I got a 10x speed improvement.

Gerald

Christian Ehrlicher

@GeraldBrandt said in Is there a way to get the horizonal advance of every character in a string?:

Nothing, except that I'm calling it over 600,000 times.

If you really need it then add a cache.

mrjj

Hi
Just as a note
There is an overload that takes a QString

int horizontalAdvance(const QString &, int len = -1) const;

However, if that is faster then looping the string your self and call the QChar version i don't know.

GeraldBrandt

Actually, 100% my fault. Things are plenty fast. I had an extra call to size() in my method that I didn't need, and that is a slow call.

Thanks,
Gerald