Re: Rounded Polyline, and other questions?

[anthonym overture com]

Wow, its been a while since I posted this, but I've been super busy with
other stuff.  Anyway, last night I finished a first pass at adding
rounded corners to zigzaglines and polylines, by adding some code to
the diarenderer.  I was developing against the DIA_0_94_DEV tag, should
I post patches against that, or against the HEAD?  Also, I'd be interested
once I post it in knowing whether some of the added functions should make
their way into the geometry.* files.

Anyway, if someone could let me know which is the current tag to submit
patches against I'll post it.

-Anthony

On Wed, Apr 28, 2004 at 10:44:47AM +0200, Cyrille Chepelov wrote:
> Le Mon, Apr 26, 2004, Ã  02:32:28PM -0700, anthonym overture com a écrit:
>
> >   Now I'm working on the sequence and message flows which are essentially
> > zigzaglines with a certain subset of arrows.  One difference however is
> > that in the BPMN docs, the flows use orthogonal connections with rounded
> > corners, and I would like to mimic this.
> >
> >   I've looked the the current crop of programmed objects and found that
> > the SADT arrow does this, but this object seems to rely on a new orth
> > connection object which is claimed to be a short term object.
> > The SADT arrow also seems to not include some of the code in the
> > zigzagline which pushes the line behind the arrow point (behavior I like
> > because it makes the arrow heads look nicer).
>
> Indeed. SADT was one of my first dips into dia, and it hasn't
> benefited from some subsequent waves of refactoring. In particular, not
> only it does not push the line end behind the arrow point like most
> other objects do, but I think it also lacks autorouting and
> autodirection.
>
> The approach you outlined seems like a good plan (especially with the
> default renderer in place), and I'm looking forwards to seeing it. If
> you have the time to refactor and port SADT arrow over to the new code
> (beware the automatic colouring), my gratitude will be proportional to
> the number of SADT-specific line you delete, at constant feature set ;-)
>
>
>
> >   Now I have a couple of questions.  Is the above a feasible approach?
> > Are there any recommendations on different approaches?  Should I
> > implement a rounded corner dialog into the zigzagline, such that
> > the corner rounding works the way it does with the box (ie, you have
> > an option to set a corner radius, if it's zero don't round and use
> > the old functions if it is greater than zero use the rounded methods)?
>
> It could be a simple extra property (for poly_conn and orth_conn). In
> fact, that was my original approach, which Alex shot down in favour of
> diagram type-specific objects (and with the experience since then, I'd
> say he was totally right with respect to user-visible objects, though
> I'd say the question of whether to make PolyConn and OrthConn aware of
> the concept of corner radii, or to extract RoundedPolyConn and
> RoundedOrthConn out of a blend of Poly/OrthConn and "SADT - Arrow" could
> be a subject to debate. I'd say that the former approach may be better
> today, if it can be done without creating a lot of mess in the code. As
> this seems to affect only the rendering and perhaps the mouse hit code
> in the case corner_radius > 1e-3, it may be a good thing to add a
> (hidden, unsaved) corner_radius field to these base classes, which can
> be declared as the storage place for properties in your new objects if
> they need (and statically reinitialised to SADT's current corner
> radius). Later if users want it in the generic zig-zag and ortho line
> objects, the property can be exposed there.
>
> >   I'm really new to the code so could be completely off on all of the
> > above, please correct me if I am.
>
> I think I agree with Lars' reply to this paragraph: welcome on board!
>
>       -- Cyrille
>
> -- 
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-- 
------------------------------------------------------------------------
Anthony Molinaro                                 <anthonym overture com>