Proposal to add the attribute "rotation" to <TerminalGraphicalRepresentation>

[TorstenBlochwitz]

There is currently no way to define the rotation of the icon of a Terminal. According to section 2.4.9.1.2 CoordinateSystem we allow flipping only:

Flipping of the FMU icon or a terminal can be realized by setting its attributes x2 < x1 or y2 < y1 without changing the coordinate system.

This makes it hard to have Terminals at the upper or lower side of an FMU icon.

A workaround would be to provide rotated bitmaps, but this makes it hard for an importer with a GUI to define a direction into a connection line should go first. And it disables the re-usage of icon-bitmaps.

For that reason we propose the introduction of the new attribute "rotation". We propose a similar semantics as it is used in Modelica language: The rotation attribute specifies the rotation of the graphical item counter-clockwise in degrees around the center of the rectangle spanned by x1, y1 and x2, y2.

[chrbertsch]

FMI Design Webmeeiting:

Christian: Can we add attributes in a bugfix release?
Pierre: Some of the implementations out could have a problem, as we do not have a different namespace.
Torsten S: tools would not know what to do with this attribute
Christian: Can/must this be fixed in a 3.1?
Pierre: no, we have not designed the schema in that way ... . For a feature like this, this does not make sense as a new attribute, should be realized in another way.
Torsten B: in patch versions it is not allowed, only in major releases
Torsten B: I will make a proposal for a standardized annotation for a maintenance release.

[CSchulzeTLK]

I remember that the rotation attribute was rejected, because a tool can export the rotated terminals in separate svg/png files. I don't think we discussed the direction a connection line leaving the fmu icon.
I think the attributes rotation and also origin would fit in there and address this issue. However, a major release might be necessary to change that.