model: markers on lines

[mtbc]

The OME-XML schema at http://www.openmicroscopy.org/Schemas/Documentation/Generated/OME-2015-01/ROI_xsd.html has markerStart and markerEnd properties on lines. These are absent among OMERO's model objects but are clearly anticipated by https://github.com/openmicroscopy/openmicroscopy/blob/037f0caf/components/model/resources/mappings/roi.ome.xml#L70.

Should String-based markerStart and markerEnd properties be added to OMERO's Line and Polyline? Perhaps some other change would be better to bring the two schemas into line?

[joshmoore]

Not having an alternative proposal, I would think we unify by adding the markers to OMERO.

[will-moore]

Enumerations for MarkerStart and MarkerEnd are

• Arrow
• Circle
• Square

Any idea's how a Circle and Square are displayed on the end of a line? E.g are they centred at the x,y coordinate, or fit inside it (like the Arrow does in OMERO.figure)?

Do they have a fixed size?
In OMERO.figure, I try to make a suitable-sized Arrow based on the line width, so maybe the same approach would apply to Circle and Square?
Do we even have any need for Circle and Square? Maybe we should only support Arrow?

[joshmoore]

The current list of Graffle supported arrow heads:

[mtbc]

The current plan is to add markerStart and markerEnd to OMERO but to restrict OME-XML Marker to simply Arrow for the meantime.

[mtbc]

Fixed by ome/bioformats#2286 in ome/bioformats@a84850b and by ome/openmicroscopy#4533 in ome/openmicroscopy@f107310.