[Gnuplot-beta] Patch 584968: Enable filled arrow heads

[Harald H. <h.h...@tu...>]

Yesterday I have posted a patch to sourceforge which enables arrow heads
to get filled. I have tested it only for postscript and x11 terminal.

Petr Mikulik has sent me an email where he suggests me to discuss my patch
at gnuplot-beta mailing list.

Here is what he wrote:


Comment By: Petr Mikulik (mikulik)
Date: 2002-07-22 18:21

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Interesting patch, this functionality is really missing. I
have the following comments:

1. It uses PM3D functionality. Please accompany such code
with #ifdef PM3D ... #endif, and test whether it compiles
without PM3D defined.

2. Your patch changes terminal API for arrows. This is a
major change which should be discussed at info-gnuplot-beta
mailing list. Please subscribe.

Thus, in order not to crash gnuplot when output is directed
to terminals not using do_arrow(), but having their own
_arrow() routine (e.g. fig, metapost, et al), I propose:

1. Don't change terminal API but use the same nasty hack
I've done for head length+angle using global variables:

int curr_arrow_headlength;    /* access head length + angle
without changing API */
double curr_arrow_headangle;  /* angle in degrees */

With that, I think the patch could be submitted -- but
please discuss at gnuplot-beta anyway.

2. Propose a change of the _arrow() terminal API so that the
last parameter is a structure with head options. This would
make it consistent over all terminals and would get rid of
those nasty hacks.



Thus, my questions are:

What do you think, should I introduce a hack in order to avoid changing
the API? Or would it be better to change the API as Petr has suggested?
I would prefer a change of the API since this would make future
enhancements easier.

Yours
Harald

--=20
Harald Harders                              Langer Kamp 8
Institut f=FCr Werkstoffe                     D-38106 Braunschweig
Technische Universit=E4t Braunschweig         Germany
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