Re: A backend("fltk") problem

[Michael D. Godfrey]

On 09/02/2009 02:22 PM, John W. Eaton wrote:
> Off list, I sent Michael a patch to try to avoid the crash he was
> seeing.
>
> Back on the mailing list:
>
> On  1-Sep-2009, Michael D. Godfrey wrote:
>
> | I said:
> |
> |>  For now, I will just try commenting the ::error
> |
> | I said I would try this with almost zero expectation that it
> | would work, but it does !!
> |
> | So far, I only wrote a title at the top of a plot, but it
> | looks right and in a sans serif font that looks about right.
>
> What versions of freetype and fontconfig do you have installed?  I
> seem to have freetype 2.3.9 and fontconfig 2.6.0.
>    
[vzero:plot] rpm -q fontconfig
fontconfig-2.7.1-1.fc11.x86_64
fontconfig-2.7.1-1.fc11.i586
[vzero:plot] rpm -q freetype
freetype-2.3.9-5.fc11.x86_64
freetype-2.3.9-5.fc11.i586

> When I try something like
>
>    set (0, 'defaultaxesfontname', 'foobarfont')
>    set (0, 'defaulttextfontname', 'foobarfont')
>    text (0.5, 0.5, 'foobar')
>
> I don't see a crash.  It still works for me and uses some default
> font (even without the change I sent to you).  Stepping through
> ft_manager::do_get_font, I see that the font name is "foobarfont", but
> even so, FcFontMatch returns a valid font object.  That's apparently
> not happening for you, so maybe there is a difference in the versions
> of freetype and/or fontconfig that we have installed, and my version
> is returning some default font when there is no match on the font
> pattern?  I see there is a call to
>
> This all works for me even if I remove what I think are the
> corresponding font packages that you mentioned.  On my system:
>
>    xfonts-base xfonts-100dpi xfonts-75dpi
>
> So now I'm a bit confused about exactly what dependency we should be
> adding.
>    
I am not clear about this either.  Right now I do not have
a copy of the current system without the patch that removes the
error::  lines.
> jwe
>    
In any case, the fonts that I mentioned,
xorg-x11-fonts-75dpi-7.2-8.fc11.noarch
xorg-x11-fonts-100dpi-7.2-8.fc11.noarc
only fixed the "interpreter", "tex" problem
in the unpatched system.

To add a brief summary of what I know about fltk/OpenGL:

1. With the unofficial patches, all plotting that I have
    tried seems to work well.  This is mainly plots that
    gnuplot could not handle at all.

2. The things that do not work are print, and the
    "interpreter", "tex" mode.  The main reason print
    fails to do anything is that the drawnow call seems
    to do nothing.  It is clear that ghostscript is not being
    set up correctly. I made a few changes in print.m to
    get that far.  "interpreter", "tex"  is just ignored.

There may be more significant problems, but I think
that with the 2 above items resolved it would at least
be at a point where it could be made available as
a "beta" test.

I will try to do some more on this soon.  But, a reaction
from the real experts would be helpful.  I have only
just started on this.

Michael