Re: crash bug in pdf terminal

[Daniel J S. <dan...@ie...>]

Hans-Bernhard Broeker wrote:

> Daniel J Sebald wrote:
>
>> things work fine.  And using "set xtics offset 0,graph -0.5" in the 
>> above (which should result in the tic text off the PDF plot area) 
>> causes the same crash with pdf_ftoa.  So the problem may be placing 
>> text partially or fully off the screen...
>
>
> Exactly.  PDFlib refuses to have coordinates outside the output page
> boundaries.  Part of the problem is that gnuplot doesn't always clip to
> the page.  Now, in some terminals, notable PostScript, it actually makes
> sense to do have elements outside the "page", so maybe gnuplot shouldn't
> do that.  But in that case, terminal drivers like pdf.trm and those
> writing bitmap files will have to do their own clipping.


Nice routines do the clipping at the lowest levels.  (Perhaps there is a 
compilation flag in the PDF libraries that control ignore/abort...)

>   Maybe yet
> another terminal driver flag bit for "coordinates must be clipped to 
> page"?


Not a great solution.

> Another possible ingredient to this is the infamous signed vs. unsigned
> confusion that infests practically all of gnuplot. 


That is what first came to mind for me.  I'll take a look this evening 
and see if I can identify just exactly what's going on.  Looking closely 
at that error message:

PDFlib value error: floating point value too large in pdf_ftoa

makes me wonder now.  They wouldn't say "too large" if in fact they 
meant "negative" as the source of the problem.  So I think you are right.

Thanks,

Dan