[cairo] cairo_stroke_extents() with transformation matrix

[Bill Spitzak]

>> Unfortunately right now the stroke width is interpreted at the time of
>> (and in
>> the space of) the cairo_stroke() command.  You can replace your
>> cairo_stroke_extents() with cairo_stroke() to see what I mean.
>>
>> There has been a proposal to lock the pen space at the time of
>> set_line_width(), but that has not been accepted/implemented yet.
> 
> Hmm, so is there no way of finding out the exact output dimensions of
> a stroked/filled path before drawing it?

It does seem so. Another very good argument for locking the pen in 
device space at the time it is set.