+ double const em_width = (em_width_base > 0)
+ ? em_width_base
+ : 10*(dpi/72.27)*zoom;
+ // A different estimate for em_width is
+ // theFontMetrics(LyXFont(LyXFont::ALL_SANE)).width('M')
+ // but this estimate might not be more accurate as the screen font
+ // is different then the latex font.
+