LyX needs help: Broken font metrics computation

[Ruurd Reitsma]

"Michael Schmitt" <michael.schmitt at teststep.org>
wrote in message news:006201c4f291$7bbc8a70$14b2a8c0 at fachwerkrechner...
> However, we have a serious problem with the computation of font metrics. I
> have generated a small test case that illustrates the problem:
>
> #include <qapplication.h>
>
> int main(int argc, char **argv) {
>   QApplication app(argc, argv);
>   QFont f("times",18,QFont::Bold);
>   QFontMetrics fm(f);
>   QRect r = fm.boundingRect('x');
>   printf( "top: %d   bottom: %d", r.top(), r.bottom());
>   return 0;
> }
>
> If you compile and run this program with GPL'd Qt/Win32, it outputs
>
>    top: 16  bottom:36
>
> However, if you run exactly the same program with Qt/X11 on cygwin (or on
> Linux), you get the following output:
>
>   top: -9  bottom: -1
>

On the Lyx side, this helps:

--- ../../qfont_metrics.C       2003-02-14 12:22:48.000000000 +0100
+++ frontends/qt2/qfont_metrics.C       2005-01-05 14:32:20.677692800 +0100
@@ -77,7 +77,11 @@
        if (!lyxrc.use_gui)
                return 1;
        QRect const & r = metrics(f).boundingRect(c);
+#if defined(Q_WS_WIN)
+       return -r.bottom()-1;
+#else
        return r.bottom()+1;
+#endif
 }

At least, with Non-Commercial 3.2.1. Here, the
lyx_gui::needs_ugly_metrics_hack() is also needed. This ugly_metrics_hack is
not needed for the free 3.3.3.

Anyway, I don´t have a X11 LyX handy to compare with. I suspect the
horizontal metrics are also inverted (accents etc.)

Ruurd