Re: wxt terminal - questions

[<tim...@en...>]

> Two questions
>
> (1)
> I've been poking about in the code, and so far as I can
> see the code assumes that character strings passed to Pango
> will be interpreted as UTF-8.  E.g. the following comment:
>
>   /* pango needs a string encoded in utf-8. We use g_convert from glib.
>    * gp_cairo_get_encoding() gives the encoding set via 'set enconding'
>    * memory allocated for enhanced_text_utf8 is freed at the end of
>    * gp_cairo_enhanced_flush */
>   string_utf8 =3D g_convert(string, -1, "UTF-8",
> gp_cairo_get_encoding(plot), NULL, NULL, NULL);
>
> But this doesn't happen. My machines are normally set to a UTF-8 locale=
,
> and all characters I type into gnuplot are UTF-8 encoded.
> But the multibyte characters are mangled when displayed in the wxt plot
> window.
> The same strings are properly displayed in x11 (when set to multibyte
> mode)
> and in gd (which by default uses UTF-8).  So I know they are correctly
> stored inside gnuplot. What's going wrong in wxt?

Thanks for digging on this side.

Let me explain how it works currently :
- if the user has used "set encoding ..." where "..." is something
different from "default", the terminal converts from this encoding to utf=
8
- otherwise, it falls back to iso8859-1. That's why the terminal doesn't
show your multibyte-utf8 characters.

I can implement the following :
- if the user has used "set encoding ..." where "..." is something
different from "default", the terminal converts from this encoding to utf=
8
- otherwise, use the 'locale' to determine the input charset, and assume
this is the input encoding for the conversion to utf8.

However, I am still not clear on one thing :
If you launch the demo 'charset.dem' :
- with the current code, the wxt terminal will show all characters as
iso8859-1 encoded.
- with the new code falling back to the 'locale' charset, and if your
locale charset is UTF-8, you won't see the last four lines, as the utf8
specification doesn't allow 8 bits characters where the upper bit is 1
(see http://en.wikipedia.org/wiki/UTF-8 for details on this specification=
)

At the same time, the X11 terminal will show these lines !!! So my
question is : what is the X11 terminal doing ?? Ethan, can you check on
your box ?


>
> (2)
> I happened across a page of sample plots from another plotting program,
> and was struck by how useful transparency can be in some cases.
> In particular in the case of overlapping histograms
>    http://sourceforge.net/project/screenshots.php?group_id=3D15494
> I think it would be possible to support this in gd.trm and svg.trm,
> but I'm not sure about any other terminals.   Do the Cairo graphics
> primitives support an alpha channel, so that wxt.trm could use this als=
o?
>

Chris has already answered, and I can only confirm. Cairo has definetely
been designed with alpha transparency in mind.


Regards,

Timoth=E9e