Public Comment

[comment-form@oasis-open.org]

Comment from: dwheeler@dwheeler.com

Should there be 45-degree or polar coordinate glue points?

Section 9.2.18 describes glue points for
connectors, and specifies that there
are 4 standard glue points
(basically North, South, East, West).

But should there also be "standard" glue points
for 45-degree connections (NE, SE, NW, SW)?
These are fairly common in drawings
using connectors.

For circular objects (circles, ellipses), the
Position representation of 45-degree points
is almost always a compromise.
For a unit circle you want
x="cos(45degrees)" y="sin(45degrees)"
which can't be precisely represented
(the "best" representation will work
well enough, but will be confusing to read
later).

A more general (though more complicated)
representation might be to also permit
glue point representations to
use (angle, range) to define a point.
This is basically a polar representation.
Perhaps it would also be useful to be able to
specify just the "angle", to represent
"longest distance in the shape,
where angle is measured in degrees (this is
useful when shapes have many points and are
connected with splines).

E.g.:  direction="45" range="1"

This is definitely more of a "wish list" item,
but I thought you might want to think about it.
If not for version 1, you could at least note
that "future versions may add..." if you
think it might be added in the future.