xglyph
is just intended to check whether t1lib works on
a particular system. It is written straight forward and does not care much on
performance and such. Especially, it is not a typical application for a
rasterizer library. The bitmaps are generated and then the output window is
adapted to the size of the bitmap/pixmap generated by the rastering
function. This contradicts the X11 principle of ``drawing into a drawable''
and requires some overhead if one wants a fitted output window. In that sense,
the performance of the X11 rastering functions is not directly comparable to
the performance of the standard rastering functions. This should always be
kept in mind.