[GraphEdit] Convert to minimap line after getting connection line.

[Daylily-Zeleen]

Users can change the start and end position of connection line by overriding _get_connection_line().
We should pass the positions in graph to _get_connection_line() consistently, then conver the line for minimap.

Before:

After:

[Geometror]

The one problem I have with this solution is that we now need to convert every line point to graph space, not just the start and end point. The minimap is already quite costly.
I'm also unable to reproduce your bug. Could you provide a MRP?

[Daylily-Zeleen]

@Geometror ,here is MRP:
FixGrapEdit.zip

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Without this pr:

With this pr:

[Geometror]

Well, just to be clear, this specifically is not the intended usage.

Users can change the start and end position of connection line by overriding _get_connection_line()

The system was designed so that you can provide a custom line "shape", not offsetting the start and end positions of connections.

That said, you're right, there are a few valid cases that come to my mind where it currently breaks. E.g.:

(Unity Shadergraph) Where you would want a straight line segment before/after each port with an absolute length.
To avoid recalculating this transform, we could add another method to the API (something along _get_minimap_connection_line), but I'm not really a fan of that. So this solution seems fine to me :)

[Geometror]

Nice work :)

[akien-mga]

Thanks!