Re: Plans for gnuplot version 5

[Ethan A M. <sf...@us...>]

On Wednesday, 05 March, 2014 22:56:35 Karl-Friedrich Ratzsch wrote:
> 
> On 05.03.2014 18:52, Ethan A Merritt wrote:
> > On Wednesday, 05 March, 2014 19:18:24 Liu Guibin wrote:
> >> I expect that gnuplot can have the following several functions:
> 
> > [control over dashed lines]
> 
> The dashed lines and the point symbols available are different
> between terminals, with postscript having the largest variety
> available. As this would change the output of existing plots,
> change to a common set should be done at a major release.

[point symbols]

Could you make that proposal more specific?

Back in 2008 during the run-up to release of version 4.4 various
people put in a lot of work to make at least the first 8 point types
common across all terminals.   

Are you saying that 8 is not enough?  
That some terminals introduced since 2008 do not conform?

Either way it would help to have a specific proposal for how
many and which symbols will be in the shared set.
If there is a specific target, then I agree it would be reasonable
to include that as a release criterion. 

> Afterwards the asked feature, to individually define new dash
> patterns, would be easier to implement. With the current code, every
> terminal needed it´s own implementation, i think.

[dashed lines]

Every terminal will need it's own implementation anyhow.
The underlying graphics libraries are different from each other.

Peter Juhasz (see parallel thread) is pushing for a well defined
set of dot-dash properties under user control.   I view that as an
entirely new capability, and therefore something that can be added
at any time without issues of backward compatibility.
So I'm all in favor of setting that as a goal and discussing how it is
best accomplished, but I don't think we need to hold off on version 5
while doing so.

> Another thing that should be haromized between terminals is the font
> selection. As this would likely break some old plots, it´s probably
> also one for 5.0. (feature request 363)

It is definitely not possible to offer the same font handling for all
terminals.  It is not even possible to have a single terminal,
e.g. libgd+png,  provide the same font handling across different
operating systems and library versions. 

As to Feature Request 363, I agree that it would be nice to clean
up support for requesting bold/italic/etc.    Since there is no 
consistency in how to capture this in a font name, I suggest that
a better approach is to extend the exhanced text mode to include
LaTeX-like markup   {\it{italic text}  and \bf{boldface text}}
Once the enhanced text code can handle the new tags,
the underlying matchup to suitable fonts can be added one 
terminal type at a time.   

I'm not sure whether this should hold up version 5, even 
assuming someone is keen to work on it.

	Ethan