TrackScheme branch edge painting problem.

[tinevez]

In TrackScheme, edges are not painted correctly if the source or target vertex is "away" from the painted area. For instance, this is what is correctly painted with an edge for which source and target are in the rendered area:

If we zoom in a little bit so as to put some target vertices out of the rendered area, they loose their edge (in a literal way):

[tinevez]

Maybe we could add as ScreenEdge all the edges of a painted vertex? In: https://github.com/fiji/TrackMate3/blob/model-edit-actions/src/main/java/org/mastodon/revised/trackscheme/LineageTreeLayout.java#L362

? But you say the problem is much more complex so there might be more than this.

[tpietzsch]

This would solve it partially. But we still wouldn't get edges with both start and end vertex out of the field of view (but with the edge still passing through field of view). We could check all edges whether they pass the field of view, but that would be quite expensive.

[tinevez]

Shooting random ideas about heuristics.

• only edges with ∆t > 5, or with ∆X > 5 are affected, because of the max zoom level we allow.
• treat them specially.

[tinevez]

There is a solution to this in the PR related to having a branch graph: #159