#631 Add arrow style filledonly

[Christoph Bersch]

Hi,

there are some problem with arrow heads, when

1. The head angle is too small, then e.g. the wxt terminal changes the linejoin
2. The arrow uses a dashed line style.

I propose an arrow style 'filledonly', which only fills the arrow heads, but does not draw the outline. See the attached patch.
To test it:

reset
set terminal wxt dashed
set xrange[0:1]
set yrange[0:1]

set arrow 1 from graph 0.1, graph 0.1 rto 0, graph 0.6 head size graph 0.05,15,70 empty lw 4

set arrow 2 from graph 0.2, graph 0.1 rto 0, graph 0.6 head size graph 0.05,15,70 filled lw 4 lt 2 lc rgb 'black'

set arrow 3 from graph 0.3, graph 0.1 rto 0, graph 0.6 head size graph 0.05,15,70 filledonly lw 4 lt 2 lc rgb 'black'
plot NaN

[Ethan Merritt]

I like it.

Could I suggest changing the keyword from "filledonly" to "nooutline" or "noborder"?

This option may satisfy the problem reported in Bug 1109.
That is, it may have guarantee that the tip of the arrow head lies precisely on the coordinates for the endpoint of the vector. That's worth mentioning in the documentation.

[Christoph Bersch]

Of course you can change the keyword, I am not the native speaker :-) From these two I would prefer "noborder" to be consistent with e.g. the set object syntax (although for objects "noborder" does not imply that the object is filled).

And yes, it does satisfy all problems of Bug 1109 (arrow head being cut off and having the arrow ending at the specified position).