Few more thoughts about arrowheads

[Radek Krahl <ptasz3k o2 pl>]

Hi all,

Today i took a closer look at drawing previews of arrowheads in dia's
main windows after recent addition of calculate_arrow_point to
dia_arrow_preview_expose(). I have 'discovered' few problems.

1. Two arrows look the same now -- 'Hollow triangle' and 'Unfilled
triangle'. There is one difference between them - first of them is drawn
with triangle filled with background colour and second is drawn with
hollow triangle.
2. After changing gtk theme to dark one: few arrowheads still use
blanking with white together with 'line shortening': hollow-: -triangle,
-diamond, -ellipse, -dot, -double triangle, -box, slashed, integral
symbol (last two look the same for me, too). Lars said, that blanking is
not a good way to draw arrows and additionally, i think,  getting rid of
all that fill- and draw-with-background-color functions should speed up
drawing of diagram a little.

So, my question is -- do you also see the sense of cleaning up arrow
routines (removing drawing with background color)? I don't want to do
anything that is unnecessary :).
And second -- what to do with doubled arrows (i know that there can be a
problem with back compatibility here), they look a little strange now.

Best regards,
Radek