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

[Ethan A M. <eam...@gm...>]

On Saturday, 23 May 2015 10:30:34 PM Elias Assmann wrote:
> On 05/22/2015 01:17 PM, Tatsuro MATSUOKA wrote:
> > I have tested on pdfcairo, pngcairo and wxt terminal on gnuplot 5.1
> > (cvs, 2015-05-19) (windows version) and upload a zip archived file.
> >
> > http://www.geocities.co.jp/tmgpltwin/Files/Files.html#0064
> >
> > 0064 test.zip, 105,699 bytes, 2015-05-22, zip archived test files on
> > cairobased terminals on gnuplot 5.1
> 
> Thank you.  Meanwhile, I have also done some more analysis,
> using three variables: terminal (png/pdf), font (default font /
> Carlito), and gnuplot version (4.6 / 5.0).  Carlito
> <http://www.tug.dk/FontCatalogue/carlito/> is the font I use in the plot
> that originally led me to post.  With wxt, I get the same results as
> with pdfcairo.
> 
> First, in the png terminal I do not see the effect.  All the legend
> entries are identically vertically aligned w.r.t. their lines.  (Compare
> nosuper.png and default-5.0.png.)
> 
> With the pdf terminal, the superscripted legend entry is placed further
> down.  The space between legend lines is not changed.  (Compare
> nosuper.pdf and default-5.0.pdf.)  The shift is larger in 4.6 than in 5.0.
> 
> The effect also seems larger with Carlito than with the default font. 
> What is more, with the default font, the legend text (without 
> superscripts) is approximately centered vertically w.r.t. the line.  But 
> for some reason, when using Carlito, it is considerably off-center.
> 
> In your plots, I see the same behavior in the pdf and wxt versions, but
> curiously enough, the shift also happens in your png version.
> 
> You can find my plots at 
> <ftp://ftp.tugraz.at/outgoing/assmann/baseline.zip>:

I do not know why you are seeing this with the cairo terminals.
It doesn't seem to happen when the same test script is processed
by qt.

Regardless of the reason, I suspect that a work-around is to append
'^ ' (carat+space) at the end of all key titles.
That should trigger the same allowance for superscript space consistently
while not actually printing anything extra.

	Ethan



> 
>   * {carlito,default}*: plots as mentioned above
>   * ruler-*: same, with rulers added for clarity
>   * nosuper.*: without any superscripts
>   * optcond_origu.pdf: this is my “real” plot; I think this is actually 
> a better illustration of the problem than the simple test
> 
> 
> 	Elias