[ENHANCEMENT] - Option to merge graph lanes

[Shimoon]

Problem

When dealing with large Git repositories that contains a lot of branches, it is very commun to get visual bottle necks when a lot of branches share the same parent commit and start to accumulate at one particular place in the graph.

Proposal

An option to merge the graph lanes that share the same parent.
It have two benefices :

1. avoid lanes stacking
2. greatly reduce the horizontal graph size

Such option would make a new branch to only appear when its first commit is created instead of going on without any useful information to give to the user.
Like so, the graph complexity is diluted and informations appears only where they are relevant.

Mockup

The only example of this feature I can think of is in GitExtensions :

On the left :

• The graph behave just like the one in SourceGit and the lanes are stacked at one place, where branches share a common parent.
• This produce a lot of visually empty branches that goes up until their first commit happen. But like so, they simply pollute the space without much information to give.
• Moreover, branches that starts earlier in the graph are trying to avoid this stack and therefore add more complexity to this area by agraving this behavior.
  This is becoming hard to know at first glance which branch start on the previous commit or if it start at a lower level in the graph.

On the right :

• The setting is activated and produce a gradual split of branches along the original one. They only appear when their first commit is created.
• Notice how much the horizontal graph size is reduced, and so, without losing any information.

SourceGit for reference :

As always, thanks a lot for your hard work !!

[love-linger]

Currently, if there's no other commits between the commit and its 2nd/3rd parent, we use short link curve, just like the line pointed by RED arrow. Otherwise we use a standalone curve for it, see the line pointed by GREEN arrow.

In anther word, we only use short link curve for merge nodes, and only used it for the parent that is not the first one.

This design is also used by Fork.

[Shimoon]

If I understand correctly, there is currently nothing that could potentially be used to create a branch from elsewhere than a commit ?
Is there any chance that this design could be improved to include this behavior ?
If this proposal cannot be implemented, could it be possible to address this issue through another solution ?

I think this is really important to improve the graph readability ! Right now, I have to filter branches out to see clearly but it prevent me to understand the repository organization as a whole which is kinda lame..

[love-linger]

Before:

After enable merge lines:

I don't think it's any clearer with merge branch lines enabled...

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Edit: Testing repo AvaloniaUI/Avalonia. Commit: 6705d3836634fdb73c92e0e55cdd25e548a024b1 . There are 13 branches that based on the same revision.

[love-linger]

• Each branch line has its own color. Tracking this branch is not difficult. If it is merged with other branches in advance, users also need to determine whether there is a merged commit or we have just merged the two lines and then need to remember the changed branch color. This is not to simplify the problem, but to complicate the problem

• Visually, too many horizontal lines interfere with the understanding of the commit graph. It is not easy to tell where the current commit occurs (on which branch). Same problem as above, it is necessary to determine whether it is due to a merged commit or just two lines being merged.