Re: [Gnuplot-info] pdfcairo: superscript in legend shifts text baseline

[Elias A. <eli...@gm...>]

On 05/22/2015 07:09 PM, Hans-Bernhard Bröker wrote:
> Am 22.05.2015 um 10:31 schrieb Elias Assmann:
>> Note that I would not consider this a bug per se.  It can be useful to
>> automatically change the line spread when there are sub- or
>> superscripts.  (Whether it makes sense to do this for a single line
>> could be debated.)
>
> Well, underscores need space, so something has to make way.  I'd say
> that only can this be useful, it is necessary.  It would be a bug not to
> do it.

Yes, this is basically what I meant as well.  But it is not what 
happens; looking at the plots I just sent in another post, no extra 
space is added.  And the shift is not in proportion to the height added 
by the superscript.

In fact, I changed my mind: I would argue that this is clearly a bug 
(whether in gnuplot or cairo, I have no idea).  I agree with you that 
adding extra space make sense, but I am not sure that a shift does. 
Maybe it would be better to keep the alignment between text baseline and 
line sample constant.  (Consider two legend entries “X” and “x”.  Would 
you expect the baseline of “X” to be lower than that of “x”?)

And of course, if you do shift, it should be in proportion to the extra 
height.  It is not so bad with the default font, but quite noticeable 
with the Carlito font.  Also, the vertical placement of the text in 
Carlito seems wrong.  Maybe that is related?

>  > Just that in my case, it looks awful, and I would
>> like to change it.
>
> You may want to use the "spacing" option.  See "help key samples"

Thanks, but ‘spacing’ changes the spacing between all lines.  If 
anything, I would need a per-line option.


By the way, one of the first things I tried to solve this problem was a 
phantom superscript “X^@”, but that does not change anything.  Is there 
a way to make a phantom with nonzero height?


	Elias